kernel
/
git
mirror of https://git.kernel.org/pub/scm/git/git.git
1
0
Fork 0
Code Releases Activity

Merge branch 'hw/doc-in-header' 

* hw/doc-in-header:
  trace2: move doc to trace2.h
  submodule-config: move doc to submodule-config.h
  tree-walk: move doc to tree-walk.h
  trace: move doc to trace.h
  run-command: move doc to run-command.h
  parse-options: add link to doc file in parse-options.h
  credential: move doc to credential.h
  argv-array: move doc to argv-array.h
  cache: move doc to cache.h
  sigchain: move doc to sigchain.h
  pathspec: move doc to pathspec.h
  revision: move doc to revision.h
  attr: move doc to attr.h
  refs: move doc to refs.h
  remote: move doc to remote.h and refspec.h
  sha1-array: move doc to sha1-array.h
  merge: move doc to ll-merge.h
  graph: move doc to graph.h and graph.c
  dir: move doc to dir.h
  diff: move doc to diff.h and diffcore.h
maint
Junio C Hamano 2019-12-16 13:08:39 -08:00
parent f0070a7df9 6c51cb525d
commit 26c816a67d
48 changed files with 1931 additions and 2452 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Documentation/MyFirstObjectWalk.txt
View File

@ -17,7 +17,7 @@ revision walk is used for operations like `git log`.

- `Documentation/user-manual.txt` under "Hacking Git" contains some coverage of
the revision walker in its various incarnations.
- `Documentation/technical/api-revision-walking.txt`
- `revision.h`
- https://eagain.net/articles/git-for-computer-scientists/[Git for Computer Scientists]
gives a good overview of the types of objects in Git and what your object
walk is really describing.
@ -119,9 +119,8 @@ parameters provided by the user over the CLI.

`nr` represents the number of `rev_cmdline_entry` present in the array.

`alloc` is used by the `ALLOC_GROW` macro. Check
`Documentation/technical/api-allocation-growing.txt` - this variable is used to
track the allocated size of the list.
`alloc` is used by the `ALLOC_GROW` macro. Check `cache.h` - this variable is
used to track the allocated size of the list.

Per entry, we find:


3
Documentation/git-credential.txt
View File

@ -19,8 +19,7 @@ from system-specific helpers, as well as prompting the user for
usernames and passwords. The git-credential command exposes this
interface to scripts which may want to retrieve, store, or prompt for
credentials in the same manner as Git. The design of this scriptable
interface models the internal C API; see
link:technical/api-credentials.html[the Git credential API] for more
interface models the internal C API; see credential.h for more
background on the concepts.

git-credential takes an "action" option on the command-line (one of

3
Documentation/gitcredentials.txt
View File

@ -186,8 +186,7 @@ CUSTOM HELPERS
--------------

You can write your own custom helpers to interface with any system in
which you keep credentials. See the documentation for Git's
link:technical/api-credentials.html[credentials API] for details.
which you keep credentials. See credential.h for details.

GIT
---

39
Documentation/technical/api-allocation-growing.txt
View File

@ -1,39 +0,0 @@
allocation growing API
======================

Dynamically growing an array using realloc() is error prone and boring.

Define your array with:

* a pointer (`item`) that points at the array, initialized to `NULL`
(although please name the variable based on its contents, not on its
type);

* an integer variable (`alloc`) that keeps track of how big the current
allocation is, initialized to `0`;

* another integer variable (`nr`) to keep track of how many elements the
array currently has, initialized to `0`.

Then before adding `n`th element to the item, call `ALLOC_GROW(item, n,
alloc)`. This ensures that the array can hold at least `n` elements by
calling `realloc(3)` and adjusting `alloc` variable.

------------
sometype *item;
size_t nr;
size_t alloc

for (i = 0; i < nr; i++)
if (we like item[i] already)
return;

/* we did not like any existing one, so add one */
ALLOC_GROW(item, nr + 1, alloc);
item[nr++] = value you like;
------------

You are responsible for updating the `nr` variable.

If you need to specify the number of elements to allocate explicitly
then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`.

65
Documentation/technical/api-argv-array.txt
View File

@ -1,65 +0,0 @@
argv-array API
==============

The argv-array API allows one to dynamically build and store
NULL-terminated lists. An argv-array maintains the invariant that the
`argv` member always points to a non-NULL array, and that the array is
always NULL-terminated at the element pointed to by `argv[argc]`. This
makes the result suitable for passing to functions expecting to receive
argv from main(), or the link:api-run-command.html[run-command API].

The string-list API (documented in string-list.h) is similar, but cannot be
used for these purposes; instead of storing a straight string pointer,
it contains an item structure with a `util` field that is not compatible
with the traditional argv interface.

Each `argv_array` manages its own memory. Any strings pushed into the
array are duplicated, and all memory is freed by argv_array_clear().

Data Structures
---------------

`struct argv_array`::

A single array. This should be initialized by assignment from
`ARGV_ARRAY_INIT`, or by calling `argv_array_init`. The `argv`
member contains the actual array; the `argc` member contains the
number of elements in the array, not including the terminating
NULL.

Functions
---------

`argv_array_init`::
Initialize an array. This is no different than assigning from
`ARGV_ARRAY_INIT`.

`argv_array_push`::
Push a copy of a string onto the end of the array.

`argv_array_pushl`::
Push a list of strings onto the end of the array. The arguments
should be a list of `const char *` strings, terminated by a NULL
argument.

`argv_array_pushf`::
Format a string and push it onto the end of the array. This is a
convenience wrapper combining `strbuf_addf` and `argv_array_push`.

`argv_array_pushv`::
Push a null-terminated array of strings onto the end of the array.

`argv_array_pop`::
Remove the final element from the array. If there are no
elements in the array, do nothing.

`argv_array_clear`::
Free all memory associated with the array and return it to the
initial, empty state.

`argv_array_detach`::
Disconnect the `argv` member from the `argv_array` struct and
return it. The caller is responsible for freeing the memory used
by the array, and by the strings it references. After detaching,
the `argv_array` is in a reinitialized state and can be pushed
into again.

271
Documentation/technical/api-credentials.txt
View File

@ -1,271 +0,0 @@
credentials API
===============

The credentials API provides an abstracted way of gathering username and
password credentials from the user (even though credentials in the wider
world can take many forms, in this document the word "credential" always
refers to a username and password pair).

This document describes two interfaces: the C API that the credential
subsystem provides to the rest of Git, and the protocol that Git uses to
communicate with system-specific "credential helpers". If you are
writing Git code that wants to look up or prompt for credentials, see
the section "C API" below. If you want to write your own helper, see
the section on "Credential Helpers" below.

Typical setup
-------------

------------
+-----------------------+
| Git code (C) |--- to server requiring --->
| | authentication
|.......................|
| C credential API |--- prompt ---> User
+-----------------------+
^ |
| pipe |
| v
+-----------------------+
| Git credential helper |
+-----------------------+
------------

The Git code (typically a remote-helper) will call the C API to obtain
credential data like a login/password pair (credential_fill). The
API will itself call a remote helper (e.g. "git credential-cache" or
"git credential-store") that may retrieve credential data from a
store. If the credential helper cannot find the information, the C API
will prompt the user. Then, the caller of the API takes care of
contacting the server, and does the actual authentication.

C API
-----

The credential C API is meant to be called by Git code which needs to
acquire or store a credential. It is centered around an object
representing a single credential and provides three basic operations:
fill (acquire credentials by calling helpers and/or prompting the user),
approve (mark a credential as successfully used so that it can be stored
for later use), and reject (mark a credential as unsuccessful so that it
can be erased from any persistent storage).

Data Structures
~~~~~~~~~~~~~~~

`struct credential`::

This struct represents a single username/password combination
along with any associated context. All string fields should be
heap-allocated (or NULL if they are not known or not applicable).
The meaning of the individual context fields is the same as
their counterparts in the helper protocol; see the section below
for a description of each field.
+
The `helpers` member of the struct is a `string_list` of helpers. Each
string specifies an external helper which will be run, in order, to
either acquire or store credentials. See the section on credential
helpers below. This list is filled-in by the API functions
according to the corresponding configuration variables before
consulting helpers, so there usually is no need for a caller to
modify the helpers field at all.
+
This struct should always be initialized with `CREDENTIAL_INIT` or
`credential_init`.


Functions
~~~~~~~~~

`credential_init`::

Initialize a credential structure, setting all fields to empty.

`credential_clear`::

Free any resources associated with the credential structure,
returning it to a pristine initialized state.

`credential_fill`::

Instruct the credential subsystem to fill the username and
password fields of the passed credential struct by first
consulting helpers, then asking the user. After this function
returns, the username and password fields of the credential are
guaranteed to be non-NULL. If an error occurs, the function will
die().

`credential_reject`::

Inform the credential subsystem that the provided credentials
have been rejected. This will cause the credential subsystem to
notify any helpers of the rejection (which allows them, for
example, to purge the invalid credentials from storage). It
will also free() the username and password fields of the
credential and set them to NULL (readying the credential for
another call to `credential_fill`). Any errors from helpers are
ignored.

`credential_approve`::

Inform the credential subsystem that the provided credentials
were successfully used for authentication. This will cause the
credential subsystem to notify any helpers of the approval, so
that they may store the result to be used again. Any errors
from helpers are ignored.

`credential_from_url`::

Parse a URL into broken-down credential fields.

Example
~~~~~~~

The example below shows how the functions of the credential API could be
used to login to a fictitious "foo" service on a remote host:

-----------------------------------------------------------------------
int foo_login(struct foo_connection *f)
{
int status;
/*
* Create a credential with some context; we don't yet know the
* username or password.
*/

struct credential c = CREDENTIAL_INIT;
c.protocol = xstrdup("foo");
c.host = xstrdup(f->hostname);

/*
* Fill in the username and password fields by contacting
* helpers and/or asking the user. The function will die if it
* fails.
*/
credential_fill(&c);

/*
* Otherwise, we have a username and password. Try to use it.
*/
status = send_foo_login(f, c.username, c.password);
switch (status) {
case FOO_OK:
/* It worked. Store the credential for later use. */
credential_accept(&c);
break;
case FOO_BAD_LOGIN:
/* Erase the credential from storage so we don't try it
* again. */
credential_reject(&c);
break;
default:
/*
* Some other error occurred. We don't know if the
* credential is good or bad, so report nothing to the
* credential subsystem.
*/
}

/* Free any associated resources. */
credential_clear(&c);

return status;
}
-----------------------------------------------------------------------


Credential Helpers
------------------

Credential helpers are programs executed by Git to fetch or save
credentials from and to long-term storage (where "long-term" is simply
longer than a single Git process; e.g., credentials may be stored
in-memory for a few minutes, or indefinitely on disk).

Each helper is specified by a single string in the configuration
variable `credential.helper` (and others, see linkgit:git-config[1]).
The string is transformed by Git into a command to be executed using
these rules:

1. If the helper string begins with "!", it is considered a shell
snippet, and everything after the "!" becomes the command.

2. Otherwise, if the helper string begins with an absolute path, the
verbatim helper string becomes the command.

3. Otherwise, the string "git credential-" is prepended to the helper
string, and the result becomes the command.

The resulting command then has an "operation" argument appended to it
(see below for details), and the result is executed by the shell.

Here are some example specifications:

----------------------------------------------------
# run "git credential-foo"
foo

# same as above, but pass an argument to the helper
foo --bar=baz

# the arguments are parsed by the shell, so use shell
# quoting if necessary
foo --bar="whitespace arg"

# you can also use an absolute path, which will not use the git wrapper
/path/to/my/helper --with-arguments

# or you can specify your own shell snippet
!f() { echo "password=`cat $HOME/.secret`"; }; f
----------------------------------------------------

Generally speaking, rule (3) above is the simplest for users to specify.
Authors of credential helpers should make an effort to assist their
users by naming their program "git-credential-$NAME", and putting it in
the $PATH or $GIT_EXEC_PATH during installation, which will allow a user
to enable it with `git config credential.helper $NAME`.

When a helper is executed, it will have one "operation" argument
appended to its command line, which is one of:

`get`::

Return a matching credential, if any exists.

`store`::

Store the credential, if applicable to the helper.

`erase`::

Remove a matching credential, if any, from the helper's storage.

The details of the credential will be provided on the helper's stdin
stream. The exact format is the same as the input/output format of the
`git credential` plumbing command (see the section `INPUT/OUTPUT
FORMAT` in linkgit:git-credential[1] for a detailed specification).

For a `get` operation, the helper should produce a list of attributes
on stdout in the same format. A helper is free to produce a subset, or
even no values at all if it has nothing useful to provide. Any provided
attributes will overwrite those already known about by Git. If a helper
outputs a `quit` attribute with a value of `true` or `1`, no further
helpers will be consulted, nor will the user be prompted (if no
credential has been provided, the operation will then fail).

For a `store` or `erase` operation, the helper's output is ignored.
If it fails to perform the requested operation, it may complain to
stderr to inform the user. If it does not support the requested
operation (e.g., a read-only store), it should silently ignore the
request.

If a helper receives any other operation, it should silently ignore the
request. This leaves room for future operations to be added (older
helpers will just ignore the new requests).

See also
--------

linkgit:gitcredentials[7]

linkgit:git-config[1] (See configuration variables `credential.*`)

174
Documentation/technical/api-diff.txt
View File

@ -1,174 +0,0 @@
diff API
========

The diff API is for programs that compare two sets of files (e.g. two
trees, one tree and the index) and present the found difference in
various ways. The calling program is responsible for feeding the API
pairs of files, one from the "old" set and the corresponding one from
"new" set, that are different. The library called through this API is
called diffcore, and is responsible for two things.

* finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and
changes that touch a string (`-S`), as specified by the caller.

* outputting the differences in various formats, as specified by the
caller.

Calling sequence
----------------

* Prepare `struct diff_options` to record the set of diff options, and
then call `repo_diff_setup()` to initialize this structure. This
sets up the vanilla default.

* Fill in the options structure to specify desired output format, rename
detection, etc. `diff_opt_parse()` can be used to parse options given
from the command line in a way consistent with existing git-diff
family of programs.

* Call `diff_setup_done()`; this inspects the options set up so far for
internal consistency and make necessary tweaking to it (e.g. if
textual patch output was asked, recursive behaviour is turned on);
the callback set_default in diff_options can be used to tweak this more.

* As you find different pairs of files, call `diff_change()` to feed
modified files, `diff_addremove()` to feed created or deleted files,
or `diff_unmerge()` to feed a file whose state is 'unmerged' to the
API. These are thin wrappers to a lower-level `diff_queue()` function
that is flexible enough to record any of these kinds of changes.

* Once you finish feeding the pairs of files, call `diffcore_std()`.
This will tell the diffcore library to go ahead and do its work.

* Calling `diff_flush()` will produce the output.


Data structures
---------------

* `struct diff_filespec`

This is the internal representation for a single file (blob). It
records the blob object name (if known -- for a work tree file it
typically is a NUL SHA-1), filemode and pathname. This is what the
`diff_addremove()`, `diff_change()` and `diff_unmerge()` synthesize and
feed `diff_queue()` function with.

* `struct diff_filepair`

This records a pair of `struct diff_filespec`; the filespec for a file
in the "old" set (i.e. preimage) is called `one`, and the filespec for a
file in the "new" set (i.e. postimage) is called `two`. A change that
represents file creation has NULL in `one`, and file deletion has NULL
in `two`.

A `filepair` starts pointing at `one` and `two` that are from the same
filename, but `diffcore_std()` can break pairs and match component
filespecs with other filespecs from a different filepair to form new
filepair. This is called 'rename detection'.

* `struct diff_queue`

This is a collection of filepairs. Notable members are:

`queue`::

An array of pointers to `struct diff_filepair`. This
dynamically grows as you add filepairs;

`alloc`::

The allocated size of the `queue` array;

`nr`::

The number of elements in the `queue` array.


* `struct diff_options`

This describes the set of options the calling program wants to affect
the operation of diffcore library with.

Notable members are:

`output_format`::
The output format used when `diff_flush()` is run.

`context`::
Number of context lines to generate in patch output.

`break_opt`, `detect_rename`, `rename-score`, `rename_limit`::
Affects the way detection logic for complete rewrites, renames
and copies.

`abbrev`::
Number of hexdigits to abbreviate raw format output to.

`pickaxe`::
A constant string (can and typically does contain newlines to
look for a block of text, not just a single line) to filter out
the filepairs that do not change the number of strings contained
in its preimage and postimage of the diff_queue.

`flags`::
This is mostly a collection of boolean options that affects the
operation, but some do not have anything to do with the diffcore
library.

`touched_flags`::
Records whether a flag has been changed due to user request
(rather than just set/unset by default).

`set_default`::
Callback which allows tweaking the options in diff_setup_done().

BINARY, TEXT;;
Affects the way how a file that is seemingly binary is treated.

FULL_INDEX;;
Tells the patch output format not to use abbreviated object
names on the "index" lines.

FIND_COPIES_HARDER;;
Tells the diffcore library that the caller is feeding unchanged
filepairs to allow copies from unmodified files be detected.

COLOR_DIFF;;
Output should be colored.

COLOR_DIFF_WORDS;;
Output is a colored word-diff.

NO_INDEX;;
Tells diff-files that the input is not tracked files but files
in random locations on the filesystem.

ALLOW_EXTERNAL;;
Tells output routine that it is Ok to call user specified patch
output routine. Plumbing disables this to ensure stable output.

QUIET;;
Do not show any output.

REVERSE_DIFF;;
Tells the library that the calling program is feeding the
filepairs reversed; `one` is two, and `two` is one.

EXIT_WITH_STATUS;;
For communication between the calling program and the options
parser; tell the calling program to signal the presence of
difference using program exit code.

HAS_CHANGES;;
Internal; used for optimization to see if there is any change.

SILENT_ON_REMOVE;;
Affects if diff-files shows removed files.

RECURSIVE, TREE_IN_RECURSIVE;;
Tells if tree traversal done by tree-diff should recursively
descend into a tree object pair that are different in preimage
and postimage set.

(JC)

130
Documentation/technical/api-directory-listing.txt
View File

@ -1,130 +0,0 @@
directory listing API
=====================

The directory listing API is used to enumerate paths in the work tree,
optionally taking `.git/info/exclude` and `.gitignore` files per
directory into account.

Data structure
--------------

`struct dir_struct` structure is used to pass directory traversal
options to the library and to record the paths discovered. A single
`struct dir_struct` is used regardless of whether or not the traversal
recursively descends into subdirectories.

The notable options are:

`exclude_per_dir`::

The name of the file to be read in each directory for excluded
files (typically `.gitignore`).

`flags`::

A bit-field of options:

`DIR_SHOW_IGNORED`:::

Return just ignored files in `entries[]`, not untracked
files. This flag is mutually exclusive with
`DIR_SHOW_IGNORED_TOO`.

`DIR_SHOW_IGNORED_TOO`:::

Similar to `DIR_SHOW_IGNORED`, but return ignored files in
`ignored[]` in addition to untracked files in
`entries[]`. This flag is mutually exclusive with
`DIR_SHOW_IGNORED`.

`DIR_KEEP_UNTRACKED_CONTENTS`:::

Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is set, the
untracked contents of untracked directories are also returned in
`entries[]`.

`DIR_SHOW_IGNORED_TOO_MODE_MATCHING`:::

Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if
this is set, returns ignored files and directories that match
an exclude pattern. If a directory matches an exclude pattern,
then the directory is returned and the contained paths are
not. A directory that does not match an exclude pattern will
not be returned even if all of its contents are ignored. In
this case, the contents are returned as individual entries.
+
If this is set, files and directories that explicitly match an ignore
pattern are reported. Implicitly ignored directories (directories that
do not match an ignore pattern, but whose contents are all ignored)
are not reported, instead all of the contents are reported.

`DIR_COLLECT_IGNORED`:::

Special mode for git-add. Return ignored files in `ignored[]` and
untracked files in `entries[]`. Only returns ignored files that match
pathspec exactly (no wildcards). Does not recurse into ignored
directories.

`DIR_SHOW_OTHER_DIRECTORIES`:::

Include a directory that is not tracked.

`DIR_HIDE_EMPTY_DIRECTORIES`:::

Do not include a directory that is not tracked and is empty.

`DIR_NO_GITLINKS`:::

If set, recurse into a directory that looks like a Git
directory. Otherwise it is shown as a directory.

The result of the enumeration is left in these fields:

`entries[]`::

An array of `struct dir_entry`, each element of which describes
a path.

`nr`::

The number of members in `entries[]` array.

`alloc`::

Internal use; keeps track of allocation of `entries[]` array.

`ignored[]`::

An array of `struct dir_entry`, used for ignored paths with the
`DIR_SHOW_IGNORED_TOO` and `DIR_COLLECT_IGNORED` flags.

`ignored_nr`::

The number of members in `ignored[]` array.

Calling sequence
----------------

Note: index may be looked at for .gitignore files that are CE_SKIP_WORKTREE
marked. If you to exclude files, make sure you have loaded index first.

* Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0,
sizeof(dir))`.

* To add single exclude pattern, call `add_pattern_list()` and then
`add_pattern()`.

* To add patterns from a file (e.g. `.git/info/exclude`), call
`add_patterns_from_file()` , and/or set `dir.exclude_per_dir`. A
short-hand function `setup_standard_excludes()` can be used to set
up the standard set of exclude settings.

* Set options described in the Data Structure section above.

* Call `read_directory()`.

* Use `dir.entries[]`.

* Call `clear_directory()` when none of the contained elements are no longer in use.

(JC)

154
Documentation/technical/api-gitattributes.txt
View File

@ -1,154 +0,0 @@
gitattributes API
=================

gitattributes mechanism gives a uniform way to associate various
attributes to set of paths.


Data Structure
--------------

`struct git_attr`::

An attribute is an opaque object that is identified by its name.
Pass the name to `git_attr()` function to obtain the object of
this type. The internal representation of this structure is
of no interest to the calling programs. The name of the
attribute can be retrieved by calling `git_attr_name()`.

`struct attr_check_item`::

This structure represents one attribute and its value.

`struct attr_check`::

This structure represents a collection of `attr_check_item`.
It is passed to `git_check_attr()` function, specifying the
attributes to check, and receives their values.


Attribute Values
----------------

An attribute for a path can be in one of four states: Set, Unset,
Unspecified or set to a string, and `.value` member of `struct
attr_check_item` records it. There are three macros to check these:

`ATTR_TRUE()`::

Returns true if the attribute is Set for the path.

`ATTR_FALSE()`::

Returns true if the attribute is Unset for the path.

`ATTR_UNSET()`::

Returns true if the attribute is Unspecified for the path.

If none of the above returns true, `.value` member points at a string
value of the attribute for the path.


Querying Specific Attributes
----------------------------

* Prepare `struct attr_check` using attr_check_initl()
function, enumerating the names of attributes whose values you are
interested in, terminated with a NULL pointer. Alternatively, an
empty `struct attr_check` can be prepared by calling
`attr_check_alloc()` function and then attributes you want to
ask about can be added to it with `attr_check_append()`
function.

* Call `git_check_attr()` to check the attributes for the path.

* Inspect `attr_check` structure to see how each of the
attribute in the array is defined for the path.


Example
-------

To see how attributes "crlf" and "ident" are set for different paths.

. Prepare a `struct attr_check` with two elements (because
we are checking two attributes):

------------
static struct attr_check *check;
static void setup_check(void)
{
if (check)
return; /* already done */
check = attr_check_initl("crlf", "ident", NULL);
}
------------

. Call `git_check_attr()` with the prepared `struct attr_check`:

------------
const char *path;

setup_check();
git_check_attr(path, check);
------------

. Act on `.value` member of the result, left in `check->items[]`:

------------
const char *value = check->items[0].value;

if (ATTR_TRUE(value)) {
The attribute is Set, by listing only the name of the
attribute in the gitattributes file for the path.
} else if (ATTR_FALSE(value)) {
The attribute is Unset, by listing the name of the
attribute prefixed with a dash - for the path.
} else if (ATTR_UNSET(value)) {
The attribute is neither set nor unset for the path.
} else if (!strcmp(value, "input")) {
If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
true, the value is a string set in the gitattributes
file for the path by saying "attr=value".
} else if (... other check using value as string ...) {
...
}
------------

To see how attributes in argv[] are set for different paths, only
the first step in the above would be different.

------------
static struct attr_check *check;
static void setup_check(const char **argv)
{
check = attr_check_alloc();
while (*argv) {
struct git_attr *attr = git_attr(*argv);
attr_check_append(check, attr);
argv++;
}
}
------------


Querying All Attributes
-----------------------

To get the values of all attributes associated with a file:

* Prepare an empty `attr_check` structure by calling
`attr_check_alloc()`.

* Call `git_all_attrs()`, which populates the `attr_check`
with the attributes attached to the path.

* Iterate over the `attr_check.items[]` array to examine
the attribute names and values. The name of the attribute
described by an `attr_check.items[]` object can be retrieved via
`git_attr_name(check->items[i].attr)`. (Please note that no items
will be returned for unset attributes, so `ATTR_UNSET()` will return
false for all returned `attr_check.items[]` objects.)

* Free the `attr_check` struct by calling `attr_check_free()`.

173
Documentation/technical/api-history-graph.txt
View File

@ -1,173 +0,0 @@
history graph API
=================

The graph API is used to draw a text-based representation of the commit
history. The API generates the graph in a line-by-line fashion.

Functions
---------

Core functions:

* `graph_init()` creates a new `struct git_graph`

* `graph_update()` moves the graph to a new commit.

* `graph_next_line()` outputs the next line of the graph into a strbuf. It
does not add a terminating newline.

* `graph_padding_line()` outputs a line of vertical padding in the graph. It
is similar to `graph_next_line()`, but is guaranteed to never print the line
containing the current commit. Where `graph_next_line()` would print the
commit line next, `graph_padding_line()` prints a line that simply extends
all branch lines downwards one row, leaving their positions unchanged.

* `graph_is_commit_finished()` determines if the graph has output all lines
necessary for the current commit. If `graph_update()` is called before all
lines for the current commit have been printed, the next call to
`graph_next_line()` will output an ellipsis, to indicate that a portion of
the graph was omitted.

The following utility functions are wrappers around `graph_next_line()` and
`graph_is_commit_finished()`. They always print the output to stdout.
They can all be called with a NULL graph argument, in which case no graph
output will be printed.

* `graph_show_commit()` calls `graph_next_line()` and
`graph_is_commit_finished()` until one of them return non-zero. This prints
all graph lines up to, and including, the line containing this commit.
Output is printed to stdout. The last line printed does not contain a
terminating newline.

* `graph_show_oneline()` calls `graph_next_line()` and prints the result to
stdout. The line printed does not contain a terminating newline.

* `graph_show_padding()` calls `graph_padding_line()` and prints the result to
stdout. The line printed does not contain a terminating newline.

* `graph_show_remainder()` calls `graph_next_line()` until
`graph_is_commit_finished()` returns non-zero. Output is printed to stdout.
The last line printed does not contain a terminating newline. Returns 1 if
output was printed, and 0 if no output was necessary.

* `graph_show_strbuf()` prints the specified strbuf to stdout, prefixing all
lines but the first with a graph line. The caller is responsible for
ensuring graph output for the first line has already been printed to stdout.
(This can be done with `graph_show_commit()` or `graph_show_oneline()`.) If
a NULL graph is supplied, the strbuf is printed as-is.

* `graph_show_commit_msg()` is similar to `graph_show_strbuf()`, but it also
prints the remainder of the graph, if more lines are needed after the strbuf
ends. It is better than directly calling `graph_show_strbuf()` followed by
`graph_show_remainder()` since it properly handles buffers that do not end in
a terminating newline. The output printed by `graph_show_commit_msg()` will
end in a newline if and only if the strbuf ends in a newline.

Data structure
--------------
`struct git_graph` is an opaque data type used to store the current graph
state.

Calling sequence
----------------

* Create a `struct git_graph` by calling `graph_init()`. When using the
revision walking API, this is done automatically by `setup_revisions()` if
the '--graph' option is supplied.

* Use the revision walking API to walk through a group of contiguous commits.
The `get_revision()` function automatically calls `graph_update()` each time
it is invoked.

* For each commit, call `graph_next_line()` repeatedly, until
`graph_is_commit_finished()` returns non-zero. Each call to
`graph_next_line()` will output a single line of the graph. The resulting
lines will not contain any newlines. `graph_next_line()` returns 1 if the
resulting line contains the current commit, or 0 if this is merely a line
needed to adjust the graph before or after the current commit. This return
value can be used to determine where to print the commit summary information
alongside the graph output.

Limitations
-----------

* `graph_update()` must be called with commits in topological order. It should
not be called on a commit if it has already been invoked with an ancestor of
that commit, or the graph output will be incorrect.

* `graph_update()` must be called on a contiguous group of commits. If
`graph_update()` is called on a particular commit, it should later be called
on all parents of that commit. Parents must not be skipped, or the graph
output will appear incorrect.
+
`graph_update()` may be used on a pruned set of commits only if the parent list
has been rewritten so as to include only ancestors from the pruned set.

* The graph API does not currently support reverse commit ordering. In
order to implement reverse ordering, the graphing API needs an
(efficient) mechanism to find the children of a commit.

Sample usage
------------

------------
struct commit *commit;
struct git_graph *graph = graph_init(opts);

while ((commit = get_revision(opts)) != NULL) {
while (!graph_is_commit_finished(graph))
{
struct strbuf sb;
int is_commit_line;

strbuf_init(&sb, 0);
is_commit_line = graph_next_line(graph, &sb);
fputs(sb.buf, stdout);

if (is_commit_line)
log_tree_commit(opts, commit);
else
putchar(opts->diffopt.line_termination);
}
}
------------

Sample output
-------------

The following is an example of the output from the graph API. This output does
not include any commit summary information--callers are responsible for
outputting that information, if desired.

------------
*
*
*
|\
* |
| | *
| \ \
| \ \
*-. \ \
|\ \ \ \
| | * | |
| | | | | *
| | | | | *
| | | | | *
| | | | | |\
| | | | | | *
| * | | | | |
| | | | | * \
| | | | | |\ |
| | | | * | | |
| | | | * | | |
* | | | | | | |
| |/ / / / / /
|/| / / / / /
* | | | | | |
|/ / / / / /
* | | | | |
| | | | | *
| | | | |/
| | | | *
------------

72
Documentation/technical/api-merge.txt
View File

@ -28,77 +28,9 @@ and `diff.c` for examples.

* `struct ll_merge_options`

This describes the set of options the calling program wants to affect
the operation of a low-level (single file) merge. Some options:

`virtual_ancestor`::
Behave as though this were part of a merge between common
ancestors in a recursive merge.
If a helper program is specified by the
`[merge "<driver>"] recursive` configuration, it will
be used (see linkgit:gitattributes[5]).

`variant`::
Resolve local conflicts automatically in favor
of one side or the other (as in 'git merge-file'
`--ours`/`--theirs`/`--union`). Can be `0`,
`XDL_MERGE_FAVOR_OURS`, `XDL_MERGE_FAVOR_THEIRS`, or
`XDL_MERGE_FAVOR_UNION`.

`renormalize`::
Resmudge and clean the "base", "theirs" and "ours" files
before merging. Use this when the merge is likely to have
overlapped with a change in smudge/clean or end-of-line
normalization rules.
Check ll-merge.h for details.

Low-level (single file) merge
-----------------------------

`ll_merge`::

Perform a three-way single-file merge in core. This is
a thin wrapper around `xdl_merge` that takes the path and
any merge backend specified in `.gitattributes` or
`.git/info/attributes` into account. Returns 0 for a
clean merge.

Calling sequence:

* Prepare a `struct ll_merge_options` to record options.
If you have no special requests, skip this and pass `NULL`
as the `opts` parameter to use the default options.

* Allocate an mmbuffer_t variable for the result.

* Allocate and fill variables with the file's original content
and two modified versions (using `read_mmfile`, for example).

* Call `ll_merge()`.

* Read the merged content from `result_buf.ptr` and `result_buf.size`.

* Release buffers when finished. A simple
`free(ancestor.ptr); free(ours.ptr); free(theirs.ptr);
free(result_buf.ptr);` will do.

If the modifications do not merge cleanly, `ll_merge` will return a
nonzero value and `result_buf` will generally include a description of
the conflict bracketed by markers such as the traditional `<<<<<<<`
and `>>>>>>>`.

The `ancestor_label`, `our_label`, and `their_label` parameters are
used to label the different sides of a conflict if the merge driver
supports this.

Everything else
---------------

Talk about <merge-recursive.h> and merge_file():

- merge_trees() to merge with rename detection
- merge_recursive() for ancestor consolidation
- try_merge_command() for other strategies
- conflict format
- merge options

(Daniel, Miklos, Stephan, JC)
Check ll-merge.h for details.

90
Documentation/technical/api-oid-array.txt
View File

@ -1,90 +0,0 @@
oid-array API
==============

The oid-array API provides storage and manipulation of sets of object
identifiers. The emphasis is on storage and processing efficiency,
making them suitable for large lists. Note that the ordering of items is
not preserved over some operations.

Data Structures
---------------

`struct oid_array`::

A single array of object IDs. This should be initialized by
assignment from `OID_ARRAY_INIT`. The `oid` member contains
the actual data. The `nr` member contains the number of items in
the set. The `alloc` and `sorted` members are used internally,
and should not be needed by API callers.

Functions
---------

`oid_array_append`::
Add an item to the set. The object ID will be placed at the end of
the array (but note that some operations below may lose this
ordering).

`oid_array_lookup`::
Perform a binary search of the array for a specific object ID.
If found, returns the offset (in number of elements) of the
object ID. If not found, returns a negative integer. If the array
is not sorted, this function has the side effect of sorting it.

`oid_array_clear`::
Free all memory associated with the array and return it to the
initial, empty state.

`oid_array_for_each`::
Iterate over each element of the list, executing the callback
function for each one. Does not sort the list, so any custom
hash order is retained. If the callback returns a non-zero
value, the iteration ends immediately and the callback's
return is propagated; otherwise, 0 is returned.

`oid_array_for_each_unique`::
Iterate over each unique element of the list in sorted order,
but otherwise behave like `oid_array_for_each`. If the array
is not sorted, this function has the side effect of sorting
it.

`oid_array_filter`::
Apply the callback function `want` to each entry in the array,
retaining only the entries for which the function returns true.
Preserve the order of the entries that are retained.

Examples
--------

-----------------------------------------
int print_callback(const struct object_id *oid,
void *data)
{
printf("%s\n", oid_to_hex(oid));
return 0; /* always continue */
}

void some_func(void)
{
struct sha1_array hashes = OID_ARRAY_INIT;
struct object_id oid;

/* Read objects into our set */
while (read_object_from_stdin(oid.hash))
oid_array_append(&hashes, &oid);

/* Check if some objects are in our set */
while (read_object_from_stdin(oid.hash)) {
if (oid_array_lookup(&hashes, &oid) >= 0)
printf("it's in there!\n");

/*
* Print the unique set of objects. We could also have
* avoided adding duplicate objects in the first place,
* but we would end up re-sorting the array repeatedly.
* Instead, this will sort once and then skip duplicates
* in linear time.
*/
oid_array_for_each_unique(&hashes, print_callback, NULL);
}
-----------------------------------------

78
Documentation/technical/api-ref-iteration.txt
View File

@ -1,78 +0,0 @@
ref iteration API
=================


Iteration of refs is done by using an iterate function which will call a
callback function for every ref. The callback function has this
signature:

int handle_one_ref(const char *refname, const struct object_id *oid,
int flags, void *cb_data);

There are different kinds of iterate functions which all take a
callback of this type. The callback is then called for each found ref
until the callback returns nonzero. The returned value is then also
returned by the iterate function.

Iteration functions
-------------------

* `head_ref()` just iterates the head ref.

* `for_each_ref()` iterates all refs.

* `for_each_ref_in()` iterates all refs which have a defined prefix and
strips that prefix from the passed variable refname.

* `for_each_tag_ref()`, `for_each_branch_ref()`, `for_each_remote_ref()`,
`for_each_replace_ref()` iterate refs from the respective area.

* `for_each_glob_ref()` iterates all refs that match the specified glob
pattern.

* `for_each_glob_ref_in()` the previous and `for_each_ref_in()` combined.

* Use `refs_` API for accessing submodules. The submodule ref store could
be obtained with `get_submodule_ref_store()`.

* `for_each_rawref()` can be used to learn about broken ref and symref.

* `for_each_reflog()` iterates each reflog file.

Submodules
----------

If you want to iterate the refs of a submodule you first need to add the
submodules object database. You can do this by a code-snippet like
this:

const char *path = "path/to/submodule"
if (add_submodule_odb(path))
die("Error submodule '%s' not populated.", path);

`add_submodule_odb()` will return zero on success. If you
do not do this you will get an error for each ref that it does not point
to a valid object.

Note: As a side-effect of this you cannot safely assume that all
objects you lookup are available in superproject. All submodule objects
will be available the same way as the superprojects objects.

Example:
--------

----
static int handle_remote_ref(const char *refname,
const unsigned char *sha1, int flags, void *cb_data)
{
struct strbuf *output = cb_data;
strbuf_addf(output, "%s\n", refname);
return 0;
}

...

struct strbuf output = STRBUF_INIT;
for_each_remote_ref(handle_remote_ref, &output);
printf("%s", output.buf);
----

127
Documentation/technical/api-remote.txt
View File

@ -1,127 +0,0 @@
Remotes configuration API
=========================

The API in remote.h gives access to the configuration related to
remotes. It handles all three configuration mechanisms historically
and currently used by Git, and presents the information in a uniform
fashion. Note that the code also handles plain URLs without any
configuration, giving them just the default information.

struct remote
-------------

`name`::

The user's nickname for the remote

`url`::

An array of all of the url_nr URLs configured for the remote

`pushurl`::

An array of all of the pushurl_nr push URLs configured for the remote

`push`::

An array of refspecs configured for pushing, with
push_refspec being the literal strings, and push_refspec_nr
being the quantity.

`fetch`::

An array of refspecs configured for fetching, with
fetch_refspec being the literal strings, and fetch_refspec_nr
being the quantity.

`fetch_tags`::

The setting for whether to fetch tags (as a separate rule from
the configured refspecs); -1 means never to fetch tags, 0
means to auto-follow tags based on the default heuristic, 1
means to always auto-follow tags, and 2 means to fetch all
tags.

`receivepack`, `uploadpack`::

The configured helper programs to run on the remote side, for
Git-native protocols.

`http_proxy`::

The proxy to use for curl (http, https, ftp, etc.) URLs.

`http_proxy_authmethod`::

The method used for authenticating against `http_proxy`.

struct remotes can be found by name with remote_get(), and iterated
through with for_each_remote(). remote_get(NULL) will return the
default remote, given the current branch and configuration.

struct refspec
--------------

A struct refspec holds the parsed interpretation of a refspec. If it
will force updates (starts with a '+'), force is true. If it is a
pattern (sides end with '*') pattern is true. src and dest are the
two sides (including '*' characters if present); if there is only one
side, it is src, and dst is NULL; if sides exist but are empty (i.e.,
the refspec either starts or ends with ':'), the corresponding side is
"".

An array of strings can be parsed into an array of struct refspecs
using parse_fetch_refspec() or parse_push_refspec().

remote_find_tracking(), given a remote and a struct refspec with
either src or dst filled out, will fill out the other such that the
result is in the "fetch" specification for the remote (note that this
evaluates patterns and returns a single result).

struct branch
-------------

Note that this may end up moving to branch.h

struct branch holds the configuration for a branch. It can be looked
up with branch_get(name) for "refs/heads/{name}", or with
branch_get(NULL) for HEAD.

It contains:

`name`::

The short name of the branch.

`refname`::

The full path for the branch ref.

`remote_name`::

The name of the remote listed in the configuration.

`merge_name`::

An array of the "merge" lines in the configuration.

`merge`::

An array of the struct refspecs used for the merge lines. That
is, merge[i]->dst is a local tracking ref which should be
merged into this branch by default.

`merge_nr`::

The number of merge configurations

branch_has_merge_config() returns true if the given branch has merge
configuration given.

Other stuff
-----------

There is other stuff in remote.h that is related, in general, to the
process of interacting with remotes.

(Daniel Barkalow)

72
Documentation/technical/api-revision-walking.txt
View File

@ -1,72 +0,0 @@
revision walking API
====================

The revision walking API offers functions to build a list of revisions
and then iterate over that list.

Calling sequence
----------------

The walking API has a given calling sequence: first you need to
initialize a rev_info structure, then add revisions to control what kind
of revision list do you want to get, finally you can iterate over the
revision list.

Functions
---------

`repo_init_revisions`::

Initialize a rev_info structure with default values. The third
parameter may be NULL or can be prefix path, and then the `.prefix`
variable will be set to it. This is typically the first function you
want to call when you want to deal with a revision list. After calling
this function, you are free to customize options, like set
`.ignore_merges` to 0 if you don't want to ignore merges, and so on. See
`revision.h` for a complete list of available options.

`add_pending_object`::

This function can be used if you want to add commit objects as revision
information. You can use the `UNINTERESTING` object flag to indicate if
you want to include or exclude the given commit (and commits reachable
from the given commit) from the revision list.
+
NOTE: If you have the commits as a string list then you probably want to
use setup_revisions(), instead of parsing each string and using this
function.

`setup_revisions`::

Parse revision information, filling in the `rev_info` structure, and
removing the used arguments from the argument list. Returns the number
of arguments left that weren't recognized, which are also moved to the
head of the argument list. The last parameter is used in case no
parameter given by the first two arguments.

`prepare_revision_walk`::

Prepares the rev_info structure for a walk. You should check if it
returns any error (non-zero return code) and if it does not, you can
start using get_revision() to do the iteration.

`get_revision`::

Takes a pointer to a `rev_info` structure and iterates over it,
returning a `struct commit *` each time you call it. The end of the
revision list is indicated by returning a NULL pointer.

`reset_revision_walk`::

Reset the flags used by the revision walking api. You can use
this to do multiple sequential revision walks.

Data structures
---------------

Talk about <revision.h>, things like:

* two diff_options, one for path limiting, another for output;
* remaining functions;

(Linus, JC, Dscho)

264
Documentation/technical/api-run-command.txt
View File

@ -1,264 +0,0 @@
run-command API
===============

The run-command API offers a versatile tool to run sub-processes with
redirected input and output as well as with a modified environment
and an alternate current directory.

A similar API offers the capability to run a function asynchronously,
which is primarily used to capture the output that the function
produces in the caller in order to process it.


Functions
---------

`child_process_init`::

Initialize a struct child_process variable.

`start_command`::

Start a sub-process. Takes a pointer to a `struct child_process`
that specifies the details and returns pipe FDs (if requested).
See below for details.

`finish_command`::

Wait for the completion of a sub-process that was started with
start_command().

`run_command`::

A convenience function that encapsulates a sequence of
start_command() followed by finish_command(). Takes a pointer
to a `struct child_process` that specifies the details.

`run_command_v_opt`, `run_command_v_opt_cd_env`::

Convenience functions that encapsulate a sequence of
start_command() followed by finish_command(). The argument argv
specifies the program and its arguments. The argument opt is zero
or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`,
`RUN_COMMAND_STDOUT_TO_STDERR`, or `RUN_SILENT_EXEC_FAILURE`
that correspond to the members .no_stdin, .git_cmd,
.stdout_to_stderr, .silent_exec_failure of `struct child_process`.
The argument dir corresponds the member .dir. The argument env
corresponds to the member .env.

`child_process_clear`::

Release the memory associated with the struct child_process.
Most users of the run-command API don't need to call this
function explicitly because `start_command` invokes it on
failure and `finish_command` calls it automatically already.

The functions above do the following:

. If a system call failed, errno is set and -1 is returned. A diagnostic
is printed.

. If the program was not found, then -1 is returned and errno is set to
ENOENT; a diagnostic is printed only if .silent_exec_failure is 0.

. Otherwise, the program is run. If it terminates regularly, its exit
code is returned. No diagnostic is printed, even if the exit code is
non-zero.

. If the program terminated due to a signal, then the return value is the
signal number + 128, ie. the same value that a POSIX shell's $? would
report. A diagnostic is printed.


`start_async`::

Run a function asynchronously. Takes a pointer to a `struct
async` that specifies the details and returns a set of pipe FDs
for communication with the function. See below for details.

`finish_async`::

Wait for the completion of an asynchronous function that was
started with start_async().

`run_hook`::

Run a hook.
The first argument is a pathname to an index file, or NULL
if the hook uses the default index file or no index is needed.
The second argument is the name of the hook.
The further arguments correspond to the hook arguments.
The last argument has to be NULL to terminate the arguments list.
If the hook does not exist or is not executable, the return
value will be zero.
If it is executable, the hook will be executed and the exit
status of the hook is returned.
On execution, .stdout_to_stderr and .no_stdin will be set.
(See below.)


Data structures
---------------

* `struct child_process`

This describes the arguments, redirections, and environment of a
command to run in a sub-process.

The caller:

1. allocates and clears (using child_process_init() or
CHILD_PROCESS_INIT) a struct child_process variable;
2. initializes the members;
3. calls start_command();
4. processes the data;
5. closes file descriptors (if necessary; see below);
6. calls finish_command().

The .argv member is set up as an array of string pointers (NULL
terminated), of which .argv[0] is the program name to run (usually
without a path). If the command to run is a git command, set argv[0] to
the command name without the 'git-' prefix and set .git_cmd = 1.

Note that the ownership of the memory pointed to by .argv stays with the
caller, but it should survive until `finish_command` completes. If the
.argv member is NULL, `start_command` will point it at the .args
`argv_array` (so you may use one or the other, but you must use exactly
one). The memory in .args will be cleaned up automatically during
`finish_command` (or during `start_command` when it is unsuccessful).

The members .in, .out, .err are used to redirect stdin, stdout,
stderr as follows:

. Specify 0 to request no special redirection. No new file descriptor
is allocated. The child process simply inherits the channel from the
parent.

. Specify -1 to have a pipe allocated; start_command() replaces -1
by the pipe FD in the following way:

.in: Returns the writable pipe end into which the caller writes;
the readable end of the pipe becomes the child's stdin.

.out, .err: Returns the readable pipe end from which the caller
reads; the writable end of the pipe end becomes child's
stdout/stderr.

The caller of start_command() must close the so returned FDs
after it has completed reading from/writing to it!

. Specify a file descriptor > 0 to be used by the child:

.in: The FD must be readable; it becomes child's stdin.
.out: The FD must be writable; it becomes child's stdout.
.err: The FD must be writable; it becomes child's stderr.

The specified FD is closed by start_command(), even if it fails to
run the sub-process!

. Special forms of redirection are available by setting these members
to 1:

.no_stdin, .no_stdout, .no_stderr: The respective channel is
redirected to /dev/null.

.stdout_to_stderr: stdout of the child is redirected to its
stderr. This happens after stderr is itself redirected.
So stdout will follow stderr to wherever it is
redirected.

To modify the environment of the sub-process, specify an array of
string pointers (NULL terminated) in .env:

. If the string is of the form "VAR=value", i.e. it contains '='
the variable is added to the child process's environment.

. If the string does not contain '=', it names an environment
variable that will be removed from the child process's environment.

If the .env member is NULL, `start_command` will point it at the
.env_array `argv_array` (so you may use one or the other, but not both).
The memory in .env_array will be cleaned up automatically during
`finish_command` (or during `start_command` when it is unsuccessful).

To specify a new initial working directory for the sub-process,
specify it in the .dir member.

If the program cannot be found, the functions return -1 and set
errno to ENOENT. Normally, an error message is printed, but if
.silent_exec_failure is set to 1, no message is printed for this
special error condition.


* `struct async`

This describes a function to run asynchronously, whose purpose is
to produce output that the caller reads.

The caller:

1. allocates and clears (memset(&asy, 0, sizeof(asy));) a
struct async variable;
2. initializes .proc and .data;
3. calls start_async();
4. processes communicates with proc through .in and .out;
5. closes .in and .out;
6. calls finish_async().

The members .in, .out are used to provide a set of fd's for
communication between the caller and the callee as follows:

. Specify 0 to have no file descriptor passed. The callee will
receive -1 in the corresponding argument.

. Specify < 0 to have a pipe allocated; start_async() replaces
with the pipe FD in the following way:

.in: Returns the writable pipe end into which the caller
writes; the readable end of the pipe becomes the function's
in argument.

.out: Returns the readable pipe end from which the caller
reads; the writable end of the pipe becomes the function's
out argument.

The caller of start_async() must close the returned FDs after it
has completed reading from/writing from them.

. Specify a file descriptor > 0 to be used by the function:

.in: The FD must be readable; it becomes the function's in.
.out: The FD must be writable; it becomes the function's out.

The specified FD is closed by start_async(), even if it fails to
run the function.

The function pointer in .proc has the following signature:

int proc(int in, int out, void *data);

. in, out specifies a set of file descriptors to which the function
must read/write the data that it needs/produces. The function
*must* close these descriptors before it returns. A descriptor
may be -1 if the caller did not configure a descriptor for that
direction.

. data is the value that the caller has specified in the .data member
of struct async.

. The return value of the function is 0 on success and non-zero
on failure. If the function indicates failure, finish_async() will
report failure as well.


There are serious restrictions on what the asynchronous function can do
because this facility is implemented by a thread in the same address
space on most platforms (when pthreads is available), but by a pipe to
a forked process otherwise:

. It cannot change the program's state (global variables, environment,
etc.) in a way that the caller notices; in other words, .in and .out
are the only communication channels to the caller.

. It must not change the program's state that the caller of the
facility also uses.

47
Documentation/technical/api-setup.txt
View File

@ -1,47 +0,0 @@
setup API
=========

Talk about

* setup_git_directory()
* setup_git_directory_gently()
* is_inside_git_dir()
* is_inside_work_tree()
* setup_work_tree()

(Dscho)

Pathspec
--------

See glossary-context.txt for the syntax of pathspec. In memory, a
pathspec set is represented by "struct pathspec" and is prepared by
parse_pathspec(). This function takes several arguments:

- magic_mask specifies what features that are NOT supported by the
following code. If a user attempts to use such a feature,
parse_pathspec() can reject it early.

- flags specifies other things that the caller wants parse_pathspec to
perform.

- prefix and args come from cmd_* functions

parse_pathspec() helps catch unsupported features and reject them
politely. At a lower level, different pathspec-related functions may
not support the same set of features. Such pathspec-sensitive
functions are guarded with GUARD_PATHSPEC(), which will die in an
unfriendly way when an unsupported feature is requested.

The command designers are supposed to make sure that GUARD_PATHSPEC()
never dies. They have to make sure all unsupported features are caught
by parse_pathspec(), not by GUARD_PATHSPEC. grepping GUARD_PATHSPEC()
should give the designers all pathspec-sensitive codepaths and what
features they support.

A similar process is applied when a new pathspec magic is added. The
designer lifts the GUARD_PATHSPEC restriction in the functions that
support the new magic. At the same time (s)he has to make sure this
new feature will be caught at parse_pathspec() in commands that cannot
handle the new magic in some cases. grepping parse_pathspec() should
help.

41
Documentation/technical/api-sigchain.txt
View File

@ -1,41 +0,0 @@
sigchain API
============

Code often wants to set a signal handler to clean up temporary files or
other work-in-progress when we die unexpectedly. For multiple pieces of
code to do this without conflicting, each piece of code must remember
the old value of the handler and restore it either when:

1. The work-in-progress is finished, and the handler is no longer
necessary. The handler should revert to the original behavior
(either another handler, SIG_DFL, or SIG_IGN).

2. The signal is received. We should then do our cleanup, then chain
to the next handler (or die if it is SIG_DFL).

Sigchain is a tiny library for keeping a stack of handlers. Your handler
and installation code should look something like:

------------------------------------------
void clean_foo_on_signal(int sig)
{
clean_foo();
sigchain_pop(sig);
raise(sig);
}

void other_func()
{
sigchain_push_common(clean_foo_on_signal);
mess_up_foo();
clean_foo();
}
------------------------------------------

Handlers are given the typedef of sigchain_fun. This is the same type
that is given to signal() or sigaction(). It is perfectly reasonable to
push SIG_DFL or SIG_IGN onto the stack.

You can sigchain_push and sigchain_pop individual signals. For
convenience, sigchain_push_common will push the handler onto the stack
for many common signals.

66
Documentation/technical/api-submodule-config.txt
View File

@ -1,66 +0,0 @@
submodule config cache API
==========================

The submodule config cache API allows to read submodule
configurations/information from specified revisions. Internally
information is lazily read into a cache that is used to avoid
unnecessary parsing of the same .gitmodules files. Lookups can be done by
submodule path or name.

Usage
-----

To initialize the cache with configurations from the worktree the caller
typically first calls `gitmodules_config()` to read values from the
worktree .gitmodules and then to overlay the local git config values
`parse_submodule_config_option()` from the config parsing
infrastructure.

The caller can look up information about submodules by using the
`submodule_from_path()` or `submodule_from_name()` functions. They return
a `struct submodule` which contains the values. The API automatically
initializes and allocates the needed infrastructure on-demand. If the
caller does only want to lookup values from revisions the initialization
can be skipped.

If the internal cache might grow too big or when the caller is done with
the API, all internally cached values can be freed with submodule_free().

Data Structures
---------------

`struct submodule`::

This structure is used to return the information about one
submodule for a certain revision. It is returned by the lookup
functions.

Functions
---------

`void submodule_free(struct repository *r)`::

Use these to free the internally cached values.

`int parse_submodule_config_option(const char *var, const char *value)`::

Can be passed to the config parsing infrastructure to parse
local (worktree) submodule configurations.

`const struct submodule *submodule_from_path(const unsigned char *treeish_name, const char *path)`::

Given a tree-ish in the superproject and a path, return the
submodule that is bound at the path in the named tree.

`const struct submodule *submodule_from_name(const unsigned char *treeish_name, const char *name)`::

The same as above but lookup by name.

Whenever a submodule configuration is parsed in `parse_submodule_config_option`
via e.g. `gitmodules_config()`, it will overwrite the null_sha1 entry.
So in the normal case, when HEAD:.gitmodules is parsed first and then overlaid
with the repository configuration, the null_sha1 entry contains the local
configuration of a submodule (e.g. consolidated values from local git
configuration and the .gitmodules file in the worktree).

For an example usage see test-submodule-config.c.

140
Documentation/technical/api-trace.txt
View File

@ -1,140 +0,0 @@
trace API
=========

The trace API can be used to print debug messages to stderr or a file. Trace
code is inactive unless explicitly enabled by setting `GIT_TRACE*` environment
variables.

The trace implementation automatically adds `timestamp file:line ... \n` to
all trace messages. E.g.:

------------
23:59:59.123456 git.c:312 trace: built-in: git 'foo'
00:00:00.000001 builtin/foo.c:99 foo: some message
------------

Data Structures
---------------

`struct trace_key`::

Defines a trace key (or category). The default (for API functions that
don't take a key) is `GIT_TRACE`.
+
E.g. to define a trace key controlled by environment variable `GIT_TRACE_FOO`:
+
------------
static struct trace_key trace_foo = TRACE_KEY_INIT(FOO);

static void trace_print_foo(const char *message)
{
trace_printf_key(&trace_foo, "%s", message);
}
------------
+
Note: don't use `const` as the trace implementation stores internal state in
the `trace_key` structure.

Functions
---------

`int trace_want(struct trace_key *key)`::

Checks whether the trace key is enabled. Used to prevent expensive
string formatting before calling one of the printing APIs.

`void trace_disable(struct trace_key *key)`::

Disables tracing for the specified key, even if the environment
variable was set.

`void trace_printf(const char *format, ...)`::
`void trace_printf_key(struct trace_key *key, const char *format, ...)`::

Prints a formatted message, similar to printf.

`void trace_argv_printf(const char **argv, const char *format, ...)``::

Prints a formatted message, followed by a quoted list of arguments.

`void trace_strbuf(struct trace_key *key, const struct strbuf *data)`::

Prints the strbuf, without additional formatting (i.e. doesn't
choke on `%` or even `\0`).

`uint64_t getnanotime(void)`::

Returns nanoseconds since the epoch (01/01/1970), typically used
for performance measurements.
+
Currently there are high precision timer implementations for Linux (using
`clock_gettime(CLOCK_MONOTONIC)`) and Windows (`QueryPerformanceCounter`).
Other platforms use `gettimeofday` as time source.

`void trace_performance(uint64_t nanos, const char *format, ...)`::
`void trace_performance_since(uint64_t start, const char *format, ...)`::

Prints the elapsed time (in nanoseconds), or elapsed time since
`start`, followed by a formatted message. Enabled via environment
variable `GIT_TRACE_PERFORMANCE`. Used for manual profiling, e.g.:
+
------------
uint64_t start = getnanotime();
/* code section to measure */
trace_performance_since(start, "foobar");
------------
+
------------
uint64_t t = 0;
for (;;) {
/* ignore */
t -= getnanotime();
/* code section to measure */
t += getnanotime();
/* ignore */
}
trace_performance(t, "frotz");
------------

Bugs & Caveats
--------------

GIT_TRACE_* environment variables can be used to tell Git to show
trace output to its standard error stream. Git can often spawn a pager
internally to run its subcommand and send its standard output and
standard error to it.

Because GIT_TRACE_PERFORMANCE trace is generated only at the very end
of the program with atexit(), which happens after the pager exits, it
would not work well if you send its log to the standard error output
and let Git spawn the pager at the same time.

As a work around, you can for example use '--no-pager', or set
GIT_TRACE_PERFORMANCE to another file descriptor which is redirected
to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its
absolute path.

For example instead of the following command which by default may not
print any performance information:

------------
GIT_TRACE_PERFORMANCE=2 git log -1
------------

you may want to use:

------------
GIT_TRACE_PERFORMANCE=2 git --no-pager log -1
------------

or:

------------
GIT_TRACE_PERFORMANCE=3 3>&2 git log -1
------------

or:

------------
GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1
------------

243
Documentation/technical/api-trace2.txt
View File

@ -188,261 +188,36 @@ purposes.
=== Basic Command Messages

These are concerned with the lifetime of the overall git process.

`void trace2_initialize_clock()`::

Initialize the Trace2 start clock and nothing else. This should
be called at the very top of main() to capture the process start
time and reduce startup order dependencies.

`void trace2_initialize()`::

Determines if any Trace2 Targets should be enabled and
initializes the Trace2 facility. This includes setting up the
Trace2 thread local storage (TLS).
+
This function emits a "version" message containing the version of git
and the Trace2 protocol.
+
This function should be called from `main()` as early as possible in
the life of the process after essential process initialization.

`int trace2_is_enabled()`::

Returns 1 if Trace2 is enabled (at least one target is
active).

`void trace2_cmd_start(int argc, const char **argv)`::

Emits a "start" message containing the process command line
arguments.

`int trace2_cmd_exit(int exit_code)`::

Emits an "exit" message containing the process exit-code and
elapsed time.
+
Returns the exit-code.

`void trace2_cmd_error(const char *fmt, va_list ap)`::

Emits an "error" message containing a formatted error message.

`void trace2_cmd_path(const char *pathname)`::

Emits a "cmd_path" message with the full pathname of the
current process.
e.g: `void trace2_initialize_clock()`, `void trace2_initialize()`,
`int trace2_is_enabled()`, `void trace2_cmd_start(int argc, const char **argv)`.

=== Command Detail Messages

These are concerned with describing the specific Git command
after the command line, config, and environment are inspected.

`void trace2_cmd_name(const char *name)`::

Emits a "cmd_name" message with the canonical name of the
command, for example "status" or "checkout".

`void trace2_cmd_mode(const char *mode)`::

Emits a "cmd_mode" message with a qualifier name to further
describe the current git command.
+
This message is intended to be used with git commands having multiple
major modes. For example, a "checkout" command can checkout a new
branch or it can checkout a single file, so the checkout code could
emit a cmd_mode message of "branch" or "file".

`void trace2_cmd_alias(const char *alias, const char **argv_expansion)`::

Emits an "alias" message containing the alias used and the
argument expansion.

`void trace2_def_param(const char *parameter, const char *value)`::

Emits a "def_param" message containing a key/value pair.
+
This message is intended to report some global aspect of the current
command, such as a configuration setting or command line switch that
significantly affects program performance or behavior, such as
`core.abbrev`, `status.showUntrackedFiles`, or `--no-ahead-behind`.

`void trace2_cmd_list_config()`::

Emits a "def_param" messages for "important" configuration
settings.
+
The environment variable `GIT_TRACE2_CONFIG_PARAMS` or the `trace2.configParams`
config value can be set to a
list of patterns of important configuration settings, for example:
`core.*,remote.*.url`. This function will iterate over all config
settings and emit a "def_param" message for each match.

`void trace2_cmd_set_config(const char *key, const char *value)`::

Emits a "def_param" message for a new or updated key/value
pair IF `key` is considered important.
+
This is used to hook into `git_config_set()` and catch any
configuration changes and update a value previously reported by
`trace2_cmd_list_config()`.

`void trace2_def_repo(struct repository *repo)`::

Registers a repository with the Trace2 layer. Assigns a
unique "repo-id" to `repo->trace2_repo_id`.
+
Emits a "worktree" messages containing the repo-id and the worktree
pathname.
+
Region and data messages (described later) may refer to this repo-id.
+
The main/top-level repository will have repo-id value 1 (aka "r1").
+
The repo-id field is in anticipation of future in-proc submodule
repositories.
e.g: `void trace2_cmd_name(const char *name)`,
`void trace2_cmd_mode(const char *mode)`.

=== Child Process Messages

These are concerned with the various spawned child processes,
including shell scripts, git commands, editors, pagers, and hooks.

`void trace2_child_start(struct child_process *cmd)`::

Emits a "child_start" message containing the "child-id",
"child-argv", and "child-classification".
+
Before calling this, set `cmd->trace2_child_class` to a name
describing the type of child process, for example "editor".
+
This function assigns a unique "child-id" to `cmd->trace2_child_id`.
This field is used later during the "child_exit" message to associate
it with the "child_start" message.
+
This function should be called before spawning the child process.

`void trace2_child_exit(struct child_proess *cmd, int child_exit_code)`::

Emits a "child_exit" message containing the "child-id",
the child's elapsed time and exit-code.
+
The reported elapsed time includes the process creation overhead and
time spend waiting for it to exit, so it may be slightly longer than
the time reported by the child itself.
+
This function should be called after reaping the child process.

`int trace2_exec(const char *exe, const char **argv)`::

Emits a "exec" message containing the "exec-id" and the
argv of the new process.
+
This function should be called before calling one of the `exec()`
variants, such as `execvp()`.
+
This function returns a unique "exec-id". This value is used later
if the exec() fails and a "exec-result" message is necessary.

`void trace2_exec_result(int exec_id, int error_code)`::

Emits a "exec_result" message containing the "exec-id"
and the error code.
+
On Unix-based systems, `exec()` does not return if successful.
This message is used to indicate that the `exec()` failed and
that the current program is continuing.
e.g: `void trace2_child_start(struct child_process *cmd)`.

=== Git Thread Messages

These messages are concerned with Git thread usage.

`void trace2_thread_start(const char *thread_name)`::

Emits a "thread_start" message.
+
The `thread_name` field should be a descriptive name, such as the
unique name of the thread-proc. A unique "thread-id" will be added
to the name to uniquely identify thread instances.
+
Region and data messages (described later) may refer to this thread
name.
+
This function must be called by the thread-proc of the new thread
(so that TLS data is properly initialized) and not by the caller
of `pthread_create()`.

`void trace2_thread_exit()`::

Emits a "thread_exit" message containing the thread name
and the thread elapsed time.
+
This function must be called by the thread-proc before it returns
(so that the correct TLS data is used and cleaned up). It should
not be called by the caller of `pthread_join()`.
e.g: `void trace2_thread_start(const char *thread_name)`.

=== Region and Data Messages

These are concerned with recording performance data
over regions or spans of code.
over regions or spans of code. e.g:
`void trace2_region_enter(const char *category, const char *label, const struct repository *repo)`.

`void trace2_region_enter(const char *category, const char *label, const struct repository *repo)`::

`void trace2_region_enter_printf(const char *category, const char *label, const struct repository *repo, const char *fmt, ...)`::

`void trace2_region_enter_printf_va(const char *category, const char *label, const struct repository *repo, const char *fmt, va_list ap)`::

Emits a thread-relative "region_enter" message with optional
printf string.
+
This function pushes a new region nesting stack level on the current
thread and starts a clock for the new stack frame.
+
The `category` field is an arbitrary category name used to classify
regions by feature area, such as "status" or "index". At this time
it is only just printed along with the rest of the message. It may
be used in the future to filter messages.
+
The `label` field is an arbitrary label used to describe the activity
being started, such as "read_recursive" or "do_read_index".
+
The `repo` field, if set, will be used to get the "repo-id", so that
recursive operations can be attributed to the correct repository.

`void trace2_region_leave(const char *category, const char *label, const struct repository *repo)`::

`void trace2_region_leave_printf(const char *category, const char *label, const struct repository *repo, const char *fmt, ...)`::

`void trace2_region_leave_printf_va(const char *category, const char *label, const struct repository *repo, const char *fmt, va_list ap)`::

Emits a thread-relative "region_leave" message with optional
printf string.
+
This function pops the region nesting stack on the current thread
and reports the elapsed time of the stack frame.
+
The `category`, `label`, and `repo` fields are the same as above.
The `category` and `label` do not need to match the corresponding
"region_enter" message, but it makes the data stream easier to
understand.

`void trace2_data_string(const char *category, const struct repository *repo, const char *key, const char * value)`::

`void trace2_data_intmax(const char *category, const struct repository *repo, const char *key, intmax value)`::

`void trace2_data_json(const char *category, const struct repository *repo, const char *key, const struct json_writer *jw)`::

Emits a region- and thread-relative "data" or "data_json" message.
+
This is a key/value pair message containing information about the
current thread, region stack, and repository. This could be used
to print the number of files in a directory during a multi-threaded
recursive tree walk.

`void trace2_printf(const char *fmt, ...)`::

`void trace2_printf_va(const char *fmt, va_list ap)`::

Emits a region- and thread-relative "printf" message.
Refer to trace2.h for details about all trace2 functions.

== Trace2 Target Formats


149
Documentation/technical/api-tree-walking.txt
View File

@ -1,149 +0,0 @@
tree walking API
================

The tree walking API is used to traverse and inspect trees.

Data Structures
---------------

`struct name_entry`::

An entry in a tree. Each entry has a sha1 identifier, pathname, and
mode.

`struct tree_desc`::

A semi-opaque data structure used to maintain the current state of the
walk.
+
* `buffer` is a pointer into the memory representation of the tree. It always
points at the current entry being visited.

* `size` counts the number of bytes left in the `buffer`.

* `entry` points to the current entry being visited.

`struct traverse_info`::

A structure used to maintain the state of a traversal.
+
* `prev` points to the traverse_info which was used to descend into the
current tree. If this is the top-level tree `prev` will point to
a dummy traverse_info.

* `name` is the entry for the current tree (if the tree is a subtree).

* `pathlen` is the length of the full path for the current tree.

* `conflicts` can be used by callbacks to maintain directory-file conflicts.

* `fn` is a callback called for each entry in the tree. See Traversing for more
information.

* `data` can be anything the `fn` callback would want to use.

* `show_all_errors` tells whether to stop at the first error or not.

Initializing
------------

`init_tree_desc`::

Initialize a `tree_desc` and decode its first entry. The buffer and
size parameters are assumed to be the same as the buffer and size
members of `struct tree`.

`fill_tree_descriptor`::

Initialize a `tree_desc` and decode its first entry given the
object ID of a tree. Returns the `buffer` member if the latter
is a valid tree identifier and NULL otherwise.

`setup_traverse_info`::

Initialize a `traverse_info` given the pathname of the tree to start
traversing from.

Walking
-------

`tree_entry`::

Visit the next entry in a tree. Returns 1 when there are more entries
left to visit and 0 when all entries have been visited. This is
commonly used in the test of a while loop.

`tree_entry_len`::

Calculate the length of a tree entry's pathname. This utilizes the
memory structure of a tree entry to avoid the overhead of using a
generic strlen().

`update_tree_entry`::

Walk to the next entry in a tree. This is commonly used in conjunction
with `tree_entry_extract` to inspect the current entry.

`tree_entry_extract`::

Decode the entry currently being visited (the one pointed to by
`tree_desc's` `entry` member) and return the sha1 of the entry. The
`pathp` and `modep` arguments are set to the entry's pathname and mode
respectively.

`get_tree_entry`::

Find an entry in a tree given a pathname and the sha1 of a tree to
search. Returns 0 if the entry is found and -1 otherwise. The third
and fourth parameters are set to the entry's sha1 and mode
respectively.

Traversing
----------

`traverse_trees`::

Traverse `n` number of trees in parallel. The `fn` callback member of
`traverse_info` is called once for each tree entry.

`traverse_callback_t`::
The arguments passed to the traverse callback are as follows:
+
* `n` counts the number of trees being traversed.

* `mask` has its nth bit set if something exists in the nth entry.

* `dirmask` has its nth bit set if the nth tree's entry is a directory.

* `entry` is an array of size `n` where the nth entry is from the nth tree.

* `info` maintains the state of the traversal.

+
Returning a negative value will terminate the traversal. Otherwise the
return value is treated as an update mask. If the nth bit is set the nth tree
will be updated and if the bit is not set the nth tree entry will be the
same in the next callback invocation.

`make_traverse_path`::

Generate the full pathname of a tree entry based from the root of the
traversal. For example, if the traversal has recursed into another
tree named "bar" the pathname of an entry "baz" in the "bar"
tree would be "bar/baz".

`traverse_path_len`::

Calculate the length of a pathname returned by `make_traverse_path`.
This utilizes the memory structure of a tree entry to avoid the
overhead of using a generic strlen().

`strbuf_make_traverse_path`::

Convenience wrapper to `make_traverse_path` into a strbuf.

Authors
-------

Written by Junio C Hamano <gitster@pobox.com> and Linus Torvalds
<torvalds@linux-foundation.org>

62
argv-array.h
View File

@ -1,8 +1,32 @@
#ifndef ARGV_ARRAY_H
#define ARGV_ARRAY_H

/**
* The argv-array API allows one to dynamically build and store
* NULL-terminated lists. An argv-array maintains the invariant that the
* `argv` member always points to a non-NULL array, and that the array is
* always NULL-terminated at the element pointed to by `argv[argc]`. This
* makes the result suitable for passing to functions expecting to receive
* argv from main().
*
* The string-list API (documented in string-list.h) is similar, but cannot be
* used for these purposes; instead of storing a straight string pointer,
* it contains an item structure with a `util` field that is not compatible
* with the traditional argv interface.
*
* Each `argv_array` manages its own memory. Any strings pushed into the
* array are duplicated, and all memory is freed by argv_array_clear().
*/

extern const char *empty_argv[];

/**
* A single array. This should be initialized by assignment from
* `ARGV_ARRAY_INIT`, or by calling `argv_array_init`. The `argv`
* member contains the actual array; the `argc` member contains the
* number of elements in the array, not including the terminating
* NULL.
*/
struct argv_array {
const char **argv;
int argc;
@ -11,17 +35,55 @@ struct argv_array {

#define ARGV_ARRAY_INIT { empty_argv, 0, 0 }

/**
* Initialize an array. This is no different than assigning from
* `ARGV_ARRAY_INIT`.
*/
void argv_array_init(struct argv_array *);

/* Push a copy of a string onto the end of the array. */
const char *argv_array_push(struct argv_array *, const char *);

/**
* Format a string and push it onto the end of the array. This is a
* convenience wrapper combining `strbuf_addf` and `argv_array_push`.
*/
__attribute__((format (printf,2,3)))
const char *argv_array_pushf(struct argv_array *, const char *fmt, ...);

/**
* Push a list of strings onto the end of the array. The arguments
* should be a list of `const char *` strings, terminated by a NULL
* argument.
*/
LAST_ARG_MUST_BE_NULL
void argv_array_pushl(struct argv_array *, ...);

/* Push a null-terminated array of strings onto the end of the array. */
void argv_array_pushv(struct argv_array *, const char **);

/**
* Remove the final element from the array. If there are no
* elements in the array, do nothing.
*/
void argv_array_pop(struct argv_array *);

/* Splits by whitespace; does not handle quoted arguments! */
void argv_array_split(struct argv_array *, const char *);

/**
* Free all memory associated with the array and return it to the
* initial, empty state.
*/
void argv_array_clear(struct argv_array *);

/**
* Disconnect the `argv` member from the `argv_array` struct and
* return it. The caller is responsible for freeing the memory used
* by the array, and by the strings it references. After detaching,
* the `argv_array` is in a reinitialized state and can be pushed
* into again.
*/
const char **argv_array_detach(struct argv_array *);

#endif /* ARGV_ARRAY_H */

3
attr.c
View File

@ -1,7 +1,6 @@
/*
* Handle git attributes. See gitattributes(5) for a description of
* the file syntax, and Documentation/technical/api-gitattributes.txt
* for a description of the API.
* the file syntax, and attr.h for a description of the API.
*
* One basic design decision here is that we are not going to support
* an insanely large number of attributes.

141
attr.h
View File

@ -1,9 +1,121 @@
#ifndef ATTR_H
#define ATTR_H

/**
* gitattributes mechanism gives a uniform way to associate various attributes
* to set of paths.
*
*
* Querying Specific Attributes
* ----------------------------
*
* - Prepare `struct attr_check` using attr_check_initl() function, enumerating
* the names of attributes whose values you are interested in, terminated with
* a NULL pointer. Alternatively, an empty `struct attr_check` can be
* prepared by calling `attr_check_alloc()` function and then attributes you
* want to ask about can be added to it with `attr_check_append()` function.
*
* - Call `git_check_attr()` to check the attributes for the path.
*
* - Inspect `attr_check` structure to see how each of the attribute in the
* array is defined for the path.
*
*
* Example
* -------
*
* To see how attributes "crlf" and "ident" are set for different paths.
*
* - Prepare a `struct attr_check` with two elements (because we are checking
* two attributes):
*
* ------------
* static struct attr_check *check;
* static void setup_check(void)
* {
* if (check)
* return; // already done
* check = attr_check_initl("crlf", "ident", NULL);
* }
* ------------
*
* - Call `git_check_attr()` with the prepared `struct attr_check`:
*
* ------------
* const char *path;
*
* setup_check();
* git_check_attr(path, check);
* ------------
*
* - Act on `.value` member of the result, left in `check->items[]`:
*
* ------------
* const char *value = check->items[0].value;
*
* if (ATTR_TRUE(value)) {
* The attribute is Set, by listing only the name of the
* attribute in the gitattributes file for the path.
* } else if (ATTR_FALSE(value)) {
* The attribute is Unset, by listing the name of the
* attribute prefixed with a dash - for the path.
* } else if (ATTR_UNSET(value)) {
* The attribute is neither set nor unset for the path.
* } else if (!strcmp(value, "input")) {
* If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
* true, the value is a string set in the gitattributes
* file for the path by saying "attr=value".
* } else if (... other check using value as string ...) {
* ...
* }
* ------------
*
* To see how attributes in argv[] are set for different paths, only
* the first step in the above would be different.
*
* ------------
* static struct attr_check *check;
* static void setup_check(const char **argv)
* {
* check = attr_check_alloc();
* while (*argv) {
* struct git_attr *attr = git_attr(*argv);
* attr_check_append(check, attr);
* argv++;
* }
* }
* ------------
*
*
* Querying All Attributes
* -----------------------
*
* To get the values of all attributes associated with a file:
*
* - Prepare an empty `attr_check` structure by calling `attr_check_alloc()`.
*
* - Call `git_all_attrs()`, which populates the `attr_check` with the
* attributes attached to the path.
*
* - Iterate over the `attr_check.items[]` array to examine the attribute
* names and values. The name of the attribute described by an
* `attr_check.items[]` object can be retrieved via
* `git_attr_name(check->items[i].attr)`. (Please note that no items will be
* returned for unset attributes, so `ATTR_UNSET()` will return false for all
* returned `attr_check.items[]` objects.)
*
* - Free the `attr_check` struct by calling `attr_check_free()`.
*/

struct index_state;

/* An attribute is a pointer to this opaque structure */
/**
* An attribute is an opaque object that is identified by its name. Pass the
* name to `git_attr()` function to obtain the object of this type.
* The internal representation of this structure is of no interest to the
* calling programs. The name of the attribute can be retrieved by calling
* `git_attr_name()`.
*/
struct git_attr;

/* opaque structures used internally for attribute collection */
@ -21,21 +133,36 @@ const struct git_attr *git_attr(const char *);
extern const char git_attr__true[];
extern const char git_attr__false[];

/* For public to check git_attr_check results */
/**
* Attribute Values
* ----------------
*
* An attribute for a path can be in one of four states: Set, Unset, Unspecified
* or set to a string, and `.value` member of `struct attr_check_item` records
* it. The three macros check these, if none of them returns true, `.value`
* member points at a string value of the attribute for the path.
*/

/* Returns true if the attribute is Set for the path. */
#define ATTR_TRUE(v) ((v) == git_attr__true)

/* Returns true if the attribute is Unset for the path. */
#define ATTR_FALSE(v) ((v) == git_attr__false)

/* Returns true if the attribute is Unspecified for the path. */
#define ATTR_UNSET(v) ((v) == NULL)

/*
* Send one or more git_attr_check to git_check_attrs(), and
* each 'value' member tells what its value is.
* Unset one is returned as NULL.
*/
/* This structure represents one attribute and its value. */
struct attr_check_item {
const struct git_attr *attr;
const char *value;
};

/**
* This structure represents a collection of `attr_check_item`. It is passed to
* `git_check_attr()` function, specifying the attributes to check, and
* receives their values.
*/
struct attr_check {
int nr;
int alloc;

41
cache.h
View File

@ -632,10 +632,43 @@ int daemonize(void);

#define alloc_nr(x) (((x)+16)*3/2)

/*
* Realloc the buffer pointed at by variable 'x' so that it can hold
* at least 'nr' entries; the number of entries currently allocated
* is 'alloc', using the standard growing factor alloc_nr() macro.
/**
* Dynamically growing an array using realloc() is error prone and boring.
*
* Define your array with:
*
* - a pointer (`item`) that points at the array, initialized to `NULL`
* (although please name the variable based on its contents, not on its
* type);
*
* - an integer variable (`alloc`) that keeps track of how big the current
* allocation is, initialized to `0`;
*
* - another integer variable (`nr`) to keep track of how many elements the
* array currently has, initialized to `0`.
*
* Then before adding `n`th element to the item, call `ALLOC_GROW(item, n,
* alloc)`. This ensures that the array can hold at least `n` elements by
* calling `realloc(3)` and adjusting `alloc` variable.
*
* ------------
* sometype *item;
* size_t nr;
* size_t alloc
*
* for (i = 0; i < nr; i++)
* if (we like item[i] already)
* return;
*
* // we did not like any existing one, so add one
* ALLOC_GROW(item, nr + 1, alloc);
* item[nr++] = value you like;
* ------------
*
* You are responsible for updating the `nr` variable.
*
* If you need to specify the number of elements to allocate explicitly
* then use the macro `REALLOC_ARRAY(item, alloc)` instead of `ALLOC_GROW`.
*
* Consider using ALLOC_GROW_BY instead of ALLOC_GROW as it has some
* added niceties.

236
credential.h
View File

@ -3,8 +3,208 @@

#include "string-list.h"

/**
* The credentials API provides an abstracted way of gathering username and
* password credentials from the user.
*
* Typical setup
* -------------
*
* ------------
* +-----------------------+
* | Git code (C) |--- to server requiring --->
* | | authentication
* |.......................|
* | C credential API |--- prompt ---> User
* +-----------------------+
* ^ |
* | pipe |
* | v
* +-----------------------+
* | Git credential helper |
* +-----------------------+
* ------------
*
* The Git code (typically a remote-helper) will call the C API to obtain
* credential data like a login/password pair (credential_fill). The
* API will itself call a remote helper (e.g. "git credential-cache" or
* "git credential-store") that may retrieve credential data from a
* store. If the credential helper cannot find the information, the C API
* will prompt the user. Then, the caller of the API takes care of
* contacting the server, and does the actual authentication.
*
* C API
* -----
*
* The credential C API is meant to be called by Git code which needs to
* acquire or store a credential. It is centered around an object
* representing a single credential and provides three basic operations:
* fill (acquire credentials by calling helpers and/or prompting the user),
* approve (mark a credential as successfully used so that it can be stored
* for later use), and reject (mark a credential as unsuccessful so that it
* can be erased from any persistent storage).
*
* Example
* ~~~~~~~
*
* The example below shows how the functions of the credential API could be
* used to login to a fictitious "foo" service on a remote host:
*
* -----------------------------------------------------------------------
* int foo_login(struct foo_connection *f)
* {
* int status;
* // Create a credential with some context; we don't yet know the
* // username or password.
*
* struct credential c = CREDENTIAL_INIT;
* c.protocol = xstrdup("foo");
* c.host = xstrdup(f->hostname);
*
* // Fill in the username and password fields by contacting
* // helpers and/or asking the user. The function will die if it
* // fails.
* credential_fill(&c);
*
* // Otherwise, we have a username and password. Try to use it.
*
* status = send_foo_login(f, c.username, c.password);
* switch (status) {
* case FOO_OK:
* // It worked. Store the credential for later use.
* credential_accept(&c);
* break;
* case FOO_BAD_LOGIN:
* // Erase the credential from storage so we don't try it again.
* credential_reject(&c);
* break;
* default:
* // Some other error occurred. We don't know if the
* // credential is good or bad, so report nothing to the
* // credential subsystem.
* }
*
* // Free any associated resources.
* credential_clear(&c);
*
* return status;
* }
* -----------------------------------------------------------------------
*
* Credential Helpers
* ------------------
*
* Credential helpers are programs executed by Git to fetch or save
* credentials from and to long-term storage (where "long-term" is simply
* longer than a single Git process; e.g., credentials may be stored
* in-memory for a few minutes, or indefinitely on disk).
*
* Each helper is specified by a single string in the configuration
* variable `credential.helper` (and others, see Documentation/git-config.txt).
* The string is transformed by Git into a command to be executed using
* these rules:
*
* 1. If the helper string begins with "!", it is considered a shell
* snippet, and everything after the "!" becomes the command.
*
* 2. Otherwise, if the helper string begins with an absolute path, the
* verbatim helper string becomes the command.
*
* 3. Otherwise, the string "git credential-" is prepended to the helper
* string, and the result becomes the command.
*
* The resulting command then has an "operation" argument appended to it
* (see below for details), and the result is executed by the shell.
*
* Here are some example specifications:
*
* ----------------------------------------------------
* # run "git credential-foo"
* foo
*
* # same as above, but pass an argument to the helper
* foo --bar=baz
*
* # the arguments are parsed by the shell, so use shell
* # quoting if necessary
* foo --bar="whitespace arg"
*
* # you can also use an absolute path, which will not use the git wrapper
* /path/to/my/helper --with-arguments
*
* # or you can specify your own shell snippet
* !f() { echo "password=`cat $HOME/.secret`"; }; f
* ----------------------------------------------------
*
* Generally speaking, rule (3) above is the simplest for users to specify.
* Authors of credential helpers should make an effort to assist their
* users by naming their program "git-credential-$NAME", and putting it in
* the $PATH or $GIT_EXEC_PATH during installation, which will allow a user
* to enable it with `git config credential.helper $NAME`.
*
* When a helper is executed, it will have one "operation" argument
* appended to its command line, which is one of:
*
* `get`::
*
* Return a matching credential, if any exists.
*
* `store`::
*
* Store the credential, if applicable to the helper.
*
* `erase`::
*
* Remove a matching credential, if any, from the helper's storage.
*
* The details of the credential will be provided on the helper's stdin
* stream. The exact format is the same as the input/output format of the
* `git credential` plumbing command (see the section `INPUT/OUTPUT
* FORMAT` in Documentation/git-credential.txt for a detailed specification).
*
* For a `get` operation, the helper should produce a list of attributes
* on stdout in the same format. A helper is free to produce a subset, or
* even no values at all if it has nothing useful to provide. Any provided
* attributes will overwrite those already known about by Git. If a helper
* outputs a `quit` attribute with a value of `true` or `1`, no further
* helpers will be consulted, nor will the user be prompted (if no
* credential has been provided, the operation will then fail).
*
* For a `store` or `erase` operation, the helper's output is ignored.
* If it fails to perform the requested operation, it may complain to
* stderr to inform the user. If it does not support the requested
* operation (e.g., a read-only store), it should silently ignore the
* request.
*
* If a helper receives any other operation, it should silently ignore the
* request. This leaves room for future operations to be added (older
* helpers will just ignore the new requests).
*
*/


/**
* This struct represents a single username/password combination
* along with any associated context. All string fields should be
* heap-allocated (or NULL if they are not known or not applicable).
* The meaning of the individual context fields is the same as
* their counterparts in the helper protocol.
*
* This struct should always be initialized with `CREDENTIAL_INIT` or
* `credential_init`.
*/
struct credential {

/**
* A `string_list` of helpers. Each string specifies an external
* helper which will be run, in order, to either acquire or store
* credentials. This list is filled-in by the API functions
* according to the corresponding configuration variables before
* consulting helpers, so there usually is no need for a caller to
* modify the helpers field at all.
*/
struct string_list helpers;

unsigned approved:1,
configured:1,
quit:1,
@ -19,16 +219,52 @@ struct credential {

#define CREDENTIAL_INIT { STRING_LIST_INIT_DUP }

/* Initialize a credential structure, setting all fields to empty. */
void credential_init(struct credential *);

/**
* Free any resources associated with the credential structure, returning
* it to a pristine initialized state.
*/
void credential_clear(struct credential *);

/**
* Instruct the credential subsystem to fill the username and
* password fields of the passed credential struct by first
* consulting helpers, then asking the user. After this function
* returns, the username and password fields of the credential are
* guaranteed to be non-NULL. If an error occurs, the function will
* die().
*/
void credential_fill(struct credential *);

/**
* Inform the credential subsystem that the provided credentials
* were successfully used for authentication. This will cause the
* credential subsystem to notify any helpers of the approval, so
* that they may store the result to be used again. Any errors
* from helpers are ignored.
*/
void credential_approve(struct credential *);

/**
* Inform the credential subsystem that the provided credentials
* have been rejected. This will cause the credential subsystem to
* notify any helpers of the rejection (which allows them, for
* example, to purge the invalid credentials from storage). It
* will also free() the username and password fields of the
* credential and set them to NULL (readying the credential for
* another call to `credential_fill`). Any errors from helpers are
* ignored.
*/
void credential_reject(struct credential *);

int credential_read(struct credential *, FILE *);
void credential_write(const struct credential *, FILE *);

/* Parse a URL into broken-down credential fields. */
void credential_from_url(struct credential *, const char *url);

int credential_match(const struct credential *have,
const struct credential *want);


126
diff.h
View File

@ -9,6 +9,49 @@
#include "object.h"
#include "oidset.h"

/**
* The diff API is for programs that compare two sets of files (e.g. two trees,
* one tree and the index) and present the found difference in various ways.
* The calling program is responsible for feeding the API pairs of files, one
* from the "old" set and the corresponding one from "new" set, that are
* different.
* The library called through this API is called diffcore, and is responsible
* for two things.
*
* - finding total rewrites (`-B`), renames (`-M`) and copies (`-C`), and
* changes that touch a string (`-S`), as specified by the caller.
*
* - outputting the differences in various formats, as specified by the caller.
*
* Calling sequence
* ----------------
*
* - Prepare `struct diff_options` to record the set of diff options, and then
* call `repo_diff_setup()` to initialize this structure. This sets up the
* vanilla default.
*
* - Fill in the options structure to specify desired output format, rename
* detection, etc. `diff_opt_parse()` can be used to parse options given
* from the command line in a way consistent with existing git-diff family
* of programs.
*
* - Call `diff_setup_done()`; this inspects the options set up so far for
* internal consistency and make necessary tweaking to it (e.g. if textual
* patch output was asked, recursive behaviour is turned on); the callback
* set_default in diff_options can be used to tweak this more.
*
* - As you find different pairs of files, call `diff_change()` to feed
* modified files, `diff_addremove()` to feed created or deleted files, or
* `diff_unmerge()` to feed a file whose state is 'unmerged' to the API.
* These are thin wrappers to a lower-level `diff_queue()` function that is
* flexible enough to record any of these kinds of changes.
*
* - Once you finish feeding the pairs of files, call `diffcore_std()`.
* This will tell the diffcore library to go ahead and do its work.
*
* - Calling `diff_flush()` will produce the output.
*/

struct combine_diff_path;
struct commit;
struct diff_filespec;
@ -65,21 +108,66 @@ typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data)

#define DIFF_FLAGS_INIT { 0 }
struct diff_flags {

/**
* Tells if tree traversal done by tree-diff should recursively descend
* into a tree object pair that are different in preimage and postimage set.
*/
unsigned recursive;
unsigned tree_in_recursive;

/* Affects the way how a file that is seemingly binary is treated. */
unsigned binary;
unsigned text;

/**
* Tells the patch output format not to use abbreviated object names on the
* "index" lines.
*/
unsigned full_index;

/* Affects if diff-files shows removed files. */
unsigned silent_on_remove;

/**
* Tells the diffcore library that the caller is feeding unchanged
* filepairs to allow copies from unmodified files be detected.
*/
unsigned find_copies_harder;

unsigned follow_renames;
unsigned rename_empty;

/* Internal; used for optimization to see if there is any change. */
unsigned has_changes;

unsigned quick;

/**
* Tells diff-files that the input is not tracked files but files in random
* locations on the filesystem.
*/
unsigned no_index;

/**
* Tells output routine that it is Ok to call user specified patch output
* routine. Plumbing disables this to ensure stable output.
*/
unsigned allow_external;

/**
* For communication between the calling program and the options parser;
* tell the calling program to signal the presence of difference using
* program exit code.
*/
unsigned exit_with_status;

/**
* Tells the library that the calling program is feeding the filepairs
* reversed; `one` is two, and `two` is one.
*/
unsigned reverse_diff;

unsigned check_failed;
unsigned relative_name;
unsigned ignore_submodules;
@ -131,36 +219,72 @@ enum diff_submodule_format {
DIFF_SUBMODULE_INLINE_DIFF
};

/**
* the set of options the calling program wants to affect the operation of
* diffcore library with.
*/
struct diff_options {
const char *orderfile;

/**
* A constant string (can and typically does contain newlines to look for
* a block of text, not just a single line) to filter out the filepairs
* that do not change the number of strings contained in its preimage and
* postimage of the diff_queue.
*/
const char *pickaxe;

const char *single_follow;
const char *a_prefix, *b_prefix;
const char *line_prefix;
size_t line_prefix_length;

/**
* collection of boolean options that affects the operation, but some do
* not have anything to do with the diffcore library.
*/
struct diff_flags flags;

/* diff-filter bits */
unsigned int filter;

int use_color;

/* Number of context lines to generate in patch output. */
int context;

int interhunkcontext;

/* Affects the way detection logic for complete rewrites, renames and
* copies.
*/
int break_opt;
int detect_rename;

int irreversible_delete;
int skip_stat_unmatch;
int line_termination;

/* The output format used when `diff_flush()` is run. */
int output_format;

unsigned pickaxe_opts;

/* Affects the way detection logic for complete rewrites, renames and
* copies.
*/
int rename_score;
int rename_limit;

int needed_rename_limit;
int degraded_cc_to_c;
int show_rename_progress;
int dirstat_permille;
int setup;

/* Number of hexdigits to abbreviate raw format output to. */
int abbrev;

int ita_invisible_in_index;
/* white-space error highlighting */
#define WSEH_NEW (1<<12)
@ -192,6 +316,7 @@ struct diff_options {
/* to support internal diff recursion by --follow hack*/
int found_follow;

/* Callback which allows tweaking the options in diff_setup_done(). */
void (*set_default)(struct diff_options *);

FILE *file;
@ -286,6 +411,7 @@ enum color_diff {
DIFF_FILE_OLD_BOLD = 21,
DIFF_FILE_NEW_BOLD = 22,
};

const char *diff_get_color(int diff_use_color, enum color_diff ix);
#define diff_get_color_opt(o, ix) \
diff_get_color((o)->use_color, ix)

32
diffcore.h
View File

@ -28,6 +28,12 @@ struct userdiff_driver;

#define MINIMUM_BREAK_SIZE 400 /* do not break a file smaller than this */

/**
* the internal representation for a single file (blob). It records the blob
* object name (if known -- for a work tree file it typically is a NUL SHA-1),
* filemode and pathname. This is what the `diff_addremove()`, `diff_change()`
* and `diff_unmerge()` synthesize and feed `diff_queue()` function with.
*/
struct diff_filespec {
struct object_id oid;
char *path;
@ -66,6 +72,17 @@ void diff_free_filespec_data(struct diff_filespec *);
void diff_free_filespec_blob(struct diff_filespec *);
int diff_filespec_is_binary(struct repository *, struct diff_filespec *);

/**
* This records a pair of `struct diff_filespec`; the filespec for a file in
* the "old" set (i.e. preimage) is called `one`, and the filespec for a file
* in the "new" set (i.e. postimage) is called `two`. A change that represents
* file creation has NULL in `one`, and file deletion has NULL in `two`.
*
* A `filepair` starts pointing at `one` and `two` that are from the same
* filename, but `diffcore_std()` can break pairs and match component filespecs
* with other filespecs from a different filepair to form new filepair. This is
* called 'rename detection'.
*/
struct diff_filepair {
struct diff_filespec *one;
struct diff_filespec *two;
@ -77,6 +94,7 @@ struct diff_filepair {
unsigned done_skip_stat_unmatch : 1;
unsigned skip_stat_unmatch_result : 1;
};

#define DIFF_PAIR_UNMERGED(p) ((p)->is_unmerged)

#define DIFF_PAIR_RENAME(p) ((p)->renamed_pair)
@ -94,11 +112,25 @@ void diff_free_filepair(struct diff_filepair *);

int diff_unmodified_pair(struct diff_filepair *);

/**
* This is a collection of filepairs. Notable members are:
*
* - `queue`:
* An array of pointers to `struct diff_filepair`. This dynamically grows as
* you add filepairs;
*
* - `alloc`:
* The allocated size of the `queue` array;
*
* - `nr`:
* The number of elements in the `queue` array.
*/
struct diff_queue_struct {
struct diff_filepair **queue;
int alloc;
int nr;
};

#define DIFF_QUEUE_CLEAR(q) \
do { \
(q)->queue = NULL; \

2
dir.c
View File

@ -2,8 +2,6 @@
* This handles recursive filename detection with exclude
* files, index knowledge etc..
*
* See Documentation/technical/api-directory-listing.txt
*
* Copyright (C) Linus Torvalds, 2005-2006
* Junio Hamano, 2005-2006
*/

119
dir.h
View File

@ -1,11 +1,44 @@
#ifndef DIR_H
#define DIR_H

/* See Documentation/technical/api-directory-listing.txt */

#include "cache.h"
#include "strbuf.h"

/**
* The directory listing API is used to enumerate paths in the work tree,
* optionally taking `.git/info/exclude` and `.gitignore` files per directory
* into account.
*/

/**
* Calling sequence
* ----------------
*
* Note: The index may be checked for .gitignore files that are
* CE_SKIP_WORKTREE marked. If you want to exclude files, make sure you have
* loaded the index first.
*
* - Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0,
* sizeof(dir))`.
*
* - To add single exclude pattern, call `add_pattern_list()` and then
* `add_pattern()`.
*
* - To add patterns from a file (e.g. `.git/info/exclude`), call
* `add_patterns_from_file()` , and/or set `dir.exclude_per_dir`. A
* short-hand function `setup_standard_excludes()` can be used to set
* up the standard set of exclude settings.
*
* - Set options described in the Data Structure section above.
*
* - Call `read_directory()`.
*
* - Use `dir.entries[]`.
*
* - Call `clear_directory()` when none of the contained elements are no longer in use.
*
*/

struct dir_entry {
unsigned int len;
char name[FLEX_ARRAY]; /* more */
@ -144,25 +177,101 @@ struct untracked_cache {
unsigned int use_fsmonitor : 1;
};

/**
* structure is used to pass directory traversal options to the library and to
* record the paths discovered. A single `struct dir_struct` is used regardless
* of whether or not the traversal recursively descends into subdirectories.
*/
struct dir_struct {
int nr, alloc;
int ignored_nr, ignored_alloc;

/* The number of members in `entries[]` array. */
int nr;

/* Internal use; keeps track of allocation of `entries[]` array.*/
int alloc;

/* The number of members in `ignored[]` array. */
int ignored_nr;

int ignored_alloc;

/* bit-field of options */
enum {

/**
* Return just ignored files in `entries[]`, not untracked files.
* This flag is mutually exclusive with `DIR_SHOW_IGNORED_TOO`.
*/
DIR_SHOW_IGNORED = 1<<0,

/* Include a directory that is not tracked. */
DIR_SHOW_OTHER_DIRECTORIES = 1<<1,

/* Do not include a directory that is not tracked and is empty. */
DIR_HIDE_EMPTY_DIRECTORIES = 1<<2,

/**
* If set, recurse into a directory that looks like a Git directory.
* Otherwise it is shown as a directory.
*/
DIR_NO_GITLINKS = 1<<3,

/**
* Special mode for git-add. Return ignored files in `ignored[]` and
* untracked files in `entries[]`. Only returns ignored files that match
* pathspec exactly (no wildcards). Does not recurse into ignored
* directories.
*/
DIR_COLLECT_IGNORED = 1<<4,

/**
* Similar to `DIR_SHOW_IGNORED`, but return ignored files in
* `ignored[]` in addition to untracked files in `entries[]`.
* This flag is mutually exclusive with `DIR_SHOW_IGNORED`.
*/
DIR_SHOW_IGNORED_TOO = 1<<5,

DIR_COLLECT_KILLED_ONLY = 1<<6,

/**
* Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is
* set, the untracked contents of untracked directories are also
* returned in `entries[]`.
*/
DIR_KEEP_UNTRACKED_CONTENTS = 1<<7,

/**
* Only has meaning if `DIR_SHOW_IGNORED_TOO` is also set; if this is
* set, returns ignored files and directories that match an exclude
* pattern. If a directory matches an exclude pattern, then the
* directory is returned and the contained paths are not. A directory
* that does not match an exclude pattern will not be returned even if
* all of its contents are ignored. In this case, the contents are
* returned as individual entries.
*
* If this is set, files and directories that explicitly match an ignore
* pattern are reported. Implicitly ignored directories (directories that
* do not match an ignore pattern, but whose contents are all ignored)
* are not reported, instead all of the contents are reported.
*/
DIR_SHOW_IGNORED_TOO_MODE_MATCHING = 1<<8,

DIR_SKIP_NESTED_GIT = 1<<9
} flags;

/* An array of `struct dir_entry`, each element of which describes a path. */
struct dir_entry **entries;

/**
* used for ignored paths with the `DIR_SHOW_IGNORED_TOO` and
* `DIR_COLLECT_IGNORED` flags.
*/
struct dir_entry **ignored;

/* Exclude info */
/**
* The name of the file to be read in each directory for excluded files
* (typically `.gitignore`).
*/
const char *exclude_per_dir;

/*

1
graph.c
View File

@ -34,6 +34,7 @@ static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
* handle directly. It is assumed that this is the same file handle as the
* file specified by the graph diff options. This is necessary so that
* graph_show_strbuf can be called even with a NULL graph.
* If a NULL graph is supplied, the strbuf is printed as-is.
*/
static void graph_show_strbuf(struct git_graph *graph,
FILE *file,

121
graph.h
View File

@ -2,6 +2,103 @@
#define GRAPH_H
#include "diff.h"

/**
* The graph API is used to draw a text-based representation of the commit
* history. The API generates the graph in a line-by-line fashion.
*
* Calling sequence
* ----------------
*
* - Create a `struct git_graph` by calling `graph_init()`. When using the
* revision walking API, this is done automatically by `setup_revisions()` if
* the '--graph' option is supplied.
*
* - Use the revision walking API to walk through a group of contiguous commits.
* The `get_revision()` function automatically calls `graph_update()` each time
* it is invoked.
*
* - For each commit, call `graph_next_line()` repeatedly, until
* `graph_is_commit_finished()` returns non-zero. Each call to
* `graph_next_line()` will output a single line of the graph. The resulting
* lines will not contain any newlines. `graph_next_line()` returns 1 if the
* resulting line contains the current commit, or 0 if this is merely a line
* needed to adjust the graph before or after the current commit. This return
* value can be used to determine where to print the commit summary information
* alongside the graph output.
*
* Limitations
* -----------
* - Check the graph_update() function for its limitations.
*
* - The graph API does not currently support reverse commit ordering. In
* order to implement reverse ordering, the graphing API needs an
* (efficient) mechanism to find the children of a commit.
*
* Sample usage
* ------------
*
* ------------
* struct commit *commit;
* struct git_graph *graph = graph_init(opts);
*
* while ((commit = get_revision(opts)) != NULL) {
* while (!graph_is_commit_finished(graph))
* {
* struct strbuf sb;
* int is_commit_line;
*
* strbuf_init(&sb, 0);
* is_commit_line = graph_next_line(graph, &sb);
* fputs(sb.buf, stdout);
*
* if (is_commit_line)
* log_tree_commit(opts, commit);
* else
* putchar(opts->diffopt.line_termination);
* }
* }
* ------------
* Sample output
* -------------
*
* The following is an example of the output from the graph API. This output does
* not include any commit summary information--callers are responsible for
* outputting that information, if desired.
* ------------
* *
* *
* *
* |\
* * |
* | | *
* | \ \
* | \ \
* *-. \ \
* |\ \ \ \
* | | * | |
* | | | | | *
* | | | | | *
* | | | | | *
* | | | | | |\
* | | | | | | *
* | * | | | | |
* | | | | | * \
* | | | | | |\ |
* | | | | * | | |
* | | | | * | | |
* * | | | | | | |
* | |/ / / / / /
* |/| / / / / /
* * | | | | | |
* |/ / / / / /
* * | | | | |
* | | | | | *
* | | | | |/
* | | | | *
* ------------
*
*/

/* A graph is a pointer to this opaque structure */
struct git_graph;

@ -50,6 +147,21 @@ struct git_graph *graph_init(struct rev_info *opt);
* If graph_update() is called before graph_is_commit_finished() returns 1,
* the next call to graph_next_line() will output an ellipsis ("...")
* to indicate that a portion of the graph is missing.
*
* Limitations:
* -----------
*
* - `graph_update()` must be called with commits in topological order. It should
* not be called on a commit if it has already been invoked with an ancestor of
* that commit, or the graph output will be incorrect.
*
* - `graph_update()` must be called on a contiguous group of commits. If
* `graph_update()` is called on a particular commit, it should later be called
* on all parents of that commit. Parents must not be skipped, or the graph
* output will appear incorrect.
*
* - `graph_update()` may be used on a pruned set of commits only if the parent list
* has been rewritten so as to include only ancestors from the pruned set.
*/
void graph_update(struct git_graph *graph, struct commit *commit);

@ -62,6 +174,10 @@ void graph_update(struct git_graph *graph, struct commit *commit);
* for this commit. If 0 is returned, graph_next_line() may still be
* called without calling graph_update(), and it will merely output
* appropriate "vertical padding" in the graph.
*
* If `graph_update()` is called before all lines for the current commit have
* been printed, the next call to `graph_next_line()` will output an ellipsis,
* to indicate that a portion of the graph was omitted.
*/
int graph_is_commit_finished(struct git_graph const *graph);

@ -112,6 +228,7 @@ void graph_show_padding(struct git_graph *graph);
/*
* If the graph is non-NULL, print the rest of the history graph for this
* commit to stdout. Does not print a terminating newline on the last line.
* Returns 1 if output was printed, and 0 if no output was necessary.
*/
int graph_show_remainder(struct git_graph *graph);

@ -121,6 +238,10 @@ int graph_show_remainder(struct git_graph *graph);
* This is similar to graph_show_strbuf(), but it always prints the
* remainder of the graph.
*
* It is better than directly calling `graph_show_strbuf()` followed by
* `graph_show_remainder()` since it properly handles buffers that do not end in
* a terminating newline.
*
* If the strbuf ends with a newline, the output printed by
* graph_show_commit_msg() will end with a newline. If the strbuf is
* missing a terminating newline (including if it is empty), the output

73
ll-merge.h
View File

@ -7,16 +7,87 @@

#include "xdiff/xdiff.h"

/**
*
* Calling sequence:
* ----------------
*
* - Prepare a `struct ll_merge_options` to record options.
* If you have no special requests, skip this and pass `NULL`
* as the `opts` parameter to use the default options.
*
* - Allocate an mmbuffer_t variable for the result.
*
* - Allocate and fill variables with the file's original content
* and two modified versions (using `read_mmfile`, for example).
*
* - Call `ll_merge()`.
*
* - Read the merged content from `result_buf.ptr` and `result_buf.size`.
*
* - Release buffers when finished. A simple
* `free(ancestor.ptr); free(ours.ptr); free(theirs.ptr);
* free(result_buf.ptr);` will do.
*
* If the modifications do not merge cleanly, `ll_merge` will return a
* nonzero value and `result_buf` will generally include a description of
* the conflict bracketed by markers such as the traditional `<<<<<<<`
* and `>>>>>>>`.
*
* The `ancestor_label`, `our_label`, and `their_label` parameters are
* used to label the different sides of a conflict if the merge driver
* supports this.
*/


struct index_state;

/**
* This describes the set of options the calling program wants to affect
* the operation of a low-level (single file) merge.
*/
struct ll_merge_options {

/**
* Behave as though this were part of a merge between common ancestors in
* a recursive merge (merges of binary files may need to be handled
* differently in such cases, for example). If a helper program is
* specified by the `[merge "<driver>"] recursive` configuration, it will
* be used.
*/
unsigned virtual_ancestor : 1;
unsigned variant : 2; /* favor ours, favor theirs, or union merge */

/**
* Resolve local conflicts automatically in favor of one side or the other
* (as in 'git merge-file' `--ours`/`--theirs`/`--union`). Can be `0`,
* `XDL_MERGE_FAVOR_OURS`, `XDL_MERGE_FAVOR_THEIRS`,
* or `XDL_MERGE_FAVOR_UNION`.
*/
unsigned variant : 2;

/**
* Resmudge and clean the "base", "theirs" and "ours" files before merging.
* Use this when the merge is likely to have overlapped with a change in
* smudge/clean or end-of-line normalization rules.
*/
unsigned renormalize : 1;

/**
* Increase the length of conflict markers so that nested conflicts
 * can be differentiated.
*/
unsigned extra_marker_size;

/* Extra xpparam_t flags as defined in xdiff/xdiff.h. */
long xdl_opts;
};

/**
* Perform a three-way single-file merge in core. This is a thin wrapper
* around `xdl_merge` that takes the path and any merge backend specified in
* `.gitattributes` or `.git/info/attributes` into account.
* Returns 0 for a clean merge.
*/
int ll_merge(mmbuffer_t *result_buf,
const char *path,
mmfile_t *ancestor, const char *ancestor_label,

4
parse-options.h
View File

@ -1,6 +1,10 @@
#ifndef PARSE_OPTIONS_H
#define PARSE_OPTIONS_H

/**
* Refer to Documentation/technical/api-parse-options.txt for the API doc.
*/

enum parse_opt_type {
/* special types */
OPTION_END,

35
pathspec.h
View File

@ -22,6 +22,11 @@ struct index_state;

#define PATHSPEC_ONESTAR 1 /* the pathspec pattern satisfies GFNM_ONESTAR */

/**
* See glossary-context.txt for the syntax of pathspec.
* In memory, a pathspec set is represented by "struct pathspec" and is
* prepared by parse_pathspec().
*/
struct pathspec {
int nr;
unsigned int has_wildcard:1;
@ -73,12 +78,39 @@ struct pathspec {
*/
#define PATHSPEC_LITERAL_PATH (1<<6)

/*
/**
* Given command line arguments and a prefix, convert the input to
* pathspec. die() if any magic in magic_mask is used.
*
* Any arguments used are copied. It is safe for the caller to modify
* or free 'prefix' and 'args' after calling this function.
*
* - magic_mask specifies what features that are NOT supported by the following
* code. If a user attempts to use such a feature, parse_pathspec() can reject
* it early.
*
* - flags specifies other things that the caller wants parse_pathspec to
* perform.
*
* - prefix and args come from cmd_* functions
*
* parse_pathspec() helps catch unsupported features and reject them politely.
* At a lower level, different pathspec-related functions may not support the
* same set of features. Such pathspec-sensitive functions are guarded with
* GUARD_PATHSPEC(), which will die in an unfriendly way when an unsupported
* feature is requested.
*
* The command designers are supposed to make sure that GUARD_PATHSPEC() never
* dies. They have to make sure all unsupported features are caught by
* parse_pathspec(), not by GUARD_PATHSPEC. grepping GUARD_PATHSPEC() should
* give the designers all pathspec-sensitive codepaths and what features they
* support.
*
* A similar process is applied when a new pathspec magic is added. The designer
* lifts the GUARD_PATHSPEC restriction in the functions that support the new
* magic. At the same time (s)he has to make sure this new feature will be
* caught at parse_pathspec() in commands that cannot handle the new magic in
* some cases. grepping parse_pathspec() should help.
*/
void parse_pathspec(struct pathspec *pathspec,
unsigned magic_mask,
@ -95,6 +127,7 @@ void parse_pathspec_file(struct pathspec *pathspec,
const char *prefix,
const char *file,
int nul_term_line);

void copy_pathspec(struct pathspec *dst, const struct pathspec *src);
void clear_pathspec(struct pathspec *);


51
refs.h
View File

@ -310,19 +310,35 @@ int refs_for_each_branch_ref(struct ref_store *refs,
int refs_for_each_remote_ref(struct ref_store *refs,
each_ref_fn fn, void *cb_data);

/* just iterates the head ref. */
int head_ref(each_ref_fn fn, void *cb_data);

/* iterates all refs. */
int for_each_ref(each_ref_fn fn, void *cb_data);

/**
* iterates all refs which have a defined prefix and strips that prefix from
* the passed variable refname.
*/
int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);

int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
each_ref_fn fn, void *cb_data,
unsigned int broken);
int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
unsigned int broken);

/**
* iterate refs from the respective area.
*/
int for_each_tag_ref(each_ref_fn fn, void *cb_data);
int for_each_branch_ref(each_ref_fn fn, void *cb_data);
int for_each_remote_ref(each_ref_fn fn, void *cb_data);
int for_each_replace_ref(struct repository *r, each_repo_ref_fn fn, void *cb_data);

/* iterates all refs that match the specified glob pattern. */
int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);

int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
const char *prefix, void *cb_data);

@ -791,6 +807,41 @@ int reflog_expire(const char *refname, const struct object_id *oid,
int ref_storage_backend_exists(const char *name);

struct ref_store *get_main_ref_store(struct repository *r);

/**
* Submodules
* ----------
*
* If you want to iterate the refs of a submodule you first need to add the
* submodules object database. You can do this by a code-snippet like
* this:
*
* const char *path = "path/to/submodule"
* if (add_submodule_odb(path))
* die("Error submodule '%s' not populated.", path);
*
* `add_submodule_odb()` will return zero on success. If you
* do not do this you will get an error for each ref that it does not point
* to a valid object.
*
* Note: As a side-effect of this you cannot safely assume that all
* objects you lookup are available in superproject. All submodule objects
* will be available the same way as the superprojects objects.
*
* Example:
* --------
*
* ----
* static int handle_remote_ref(const char *refname,
* const unsigned char *sha1, int flags, void *cb_data)
* {
* struct strbuf *output = cb_data;
* strbuf_addf(output, "%s\n", refname);
* return 0;
* }
*
*/

/*
* Return the ref_store instance for the specified submodule. For the
* main repository, use submodule==NULL; such a call cannot fail. For

16
refspec.h
View File

@ -20,6 +20,22 @@ struct refspec_item {
#define REFSPEC_INIT_FETCH { .fetch = REFSPEC_FETCH }
#define REFSPEC_INIT_PUSH { .fetch = REFSPEC_PUSH }

/**
* A struct refspec holds the parsed interpretation of a refspec. If it will
* force updates (starts with a '+'), force is true. If it is a pattern
* (sides end with '*') pattern is true. src and dest are the two sides
* (including '*' characters if present); if there is only one side, it is src,
* and dst is NULL; if sides exist but are empty (i.e., the refspec either
* starts or ends with ':'), the corresponding side is "".
*
* An array of strings can be parsed into an array of struct refspecs using
* parse_fetch_refspec() or parse_push_refspec().
*
* remote_find_tracking(), given a remote and a struct refspec with either src
* or dst filled out, will fill out the other such that the result is in the
* "fetch" specification for the remote (note that this evaluates patterns and
* returns a single result).
*/
struct refspec {
struct refspec_item *items;
int alloc;

57
remote.h
View File

@ -6,6 +6,14 @@
#include "hashmap.h"
#include "refspec.h"

/**
* The API gives access to the configuration related to remotes. It handles
* all three configuration mechanisms historically and currently used by Git,
* and presents the information in a uniform fashion. Note that the code also
* handles plain URLs without any configuration, giving them just the default
* information.
*/

enum {
REMOTE_UNCONFIGURED = 0,
REMOTE_CONFIG,
@ -16,16 +24,22 @@ enum {
struct remote {
struct hashmap_entry ent;

/* The user's nickname for the remote */
const char *name;

int origin, configured_in_repo;

const char *foreign_vcs;

/* An array of all of the url_nr URLs configured for the remote */
const char **url;

int url_nr;
int url_alloc;

/* An array of all of the pushurl_nr push URLs configured for the remote */
const char **pushurl;

int pushurl_nr;
int pushurl_alloc;

@ -34,32 +48,47 @@ struct remote {
struct refspec fetch;

/*
* The setting for whether to fetch tags (as a separate rule from the
* configured refspecs);
* -1 to never fetch tags
* 0 to auto-follow tags on heuristic (default)
* 1 to always auto-follow tags
* 2 to always fetch tags
*/
int fetch_tags;

int skip_default_update;
int mirror;
int prune;
int prune_tags;

/**
* The configured helper programs to run on the remote side, for
* Git-native protocols.
*/
const char *receivepack;
const char *uploadpack;

/*
* for curl remotes only
*/
/* The proxy to use for curl (http, https, ftp, etc.) URLs. */
char *http_proxy;

/* The method used for authenticating against `http_proxy`. */
char *http_proxy_authmethod;
};

/**
* struct remotes can be found by name with remote_get().
* remote_get(NULL) will return the default remote, given the current branch
* and configuration.
*/
struct remote *remote_get(const char *name);

struct remote *pushremote_get(const char *name);
int remote_is_configured(struct remote *remote, int in_repo);

typedef int each_remote_fn(struct remote *remote, void *priv);

/* iterate through struct remotes */
int for_each_remote(each_remote_fn fn, void *priv);

int remote_has_url(struct remote *remote, const char *url);
@ -194,16 +223,36 @@ struct ref *get_remote_ref(const struct ref *remote_refs, const char *name);
*/
int remote_find_tracking(struct remote *remote, struct refspec_item *refspec);

/**
* struct branch holds the configuration for a branch. It can be looked up with
* branch_get(name) for "refs/heads/{name}", or with branch_get(NULL) for HEAD.
*/
struct branch {

/* The short name of the branch. */
const char *name;

/* The full path for the branch ref. */
const char *refname;

/* The name of the remote listed in the configuration. */
const char *remote_name;

const char *pushremote_name;

/* An array of the "merge" lines in the configuration. */
const char **merge_name;

/**
* An array of the struct refspecs used for the merge lines. That is,
* merge[i]->dst is a local tracking ref which should be merged into this
* branch by default.
*/
struct refspec_item **merge;

/* The number of merge configurations */
int merge_nr;

int merge_alloc;

const char *push_tracking_ref;
@ -215,7 +264,9 @@ const char *pushremote_for_branch(struct branch *branch, int *explicit);
const char *remote_ref_for_branch(struct branch *branch, int for_push,
int *explicit);

/* returns true if the given branch has merge configuration given. */
int branch_has_merge_config(struct branch *branch);

int branch_merge_matches(struct branch *, int n, const char *);

/**

59
revision.h
View File

@ -9,6 +9,19 @@
#include "diff.h"
#include "commit-slab-decl.h"

/**
* The revision walking API offers functions to build a list of revisions
* and then iterate over that list.
*
* Calling sequence
* ----------------
*
* The walking API has a given calling sequence: first you need to initialize
* a rev_info structure, then add revisions to control what kind of revision
* list do you want to get, finally you can iterate over the revision list.
*
*/

/* Remember to update object flag allocation in object.h */
#define SEEN (1u<<0)
#define UNINTERESTING (1u<<1)
@ -306,11 +319,29 @@ struct setup_revision_opt {
#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
#define init_revisions(revs, prefix) repo_init_revisions(the_repository, revs, prefix)
#endif

/**
* Initialize a rev_info structure with default values. The third parameter may
* be NULL or can be prefix path, and then the `.prefix` variable will be set
* to it. This is typically the first function you want to call when you want
* to deal with a revision list. After calling this function, you are free to
* customize options, like set `.ignore_merges` to 0 if you don't want to
* ignore merges, and so on.
*/
void repo_init_revisions(struct repository *r,
struct rev_info *revs,
const char *prefix);

/**
* Parse revision information, filling in the `rev_info` structure, and
* removing the used arguments from the argument list. Returns the number
* of arguments left that weren't recognized, which are also moved to the
* head of the argument list. The last parameter is used in case no
* parameter given by the first two arguments.
*/
int setup_revisions(int argc, const char **argv, struct rev_info *revs,
struct setup_revision_opt *);

void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
const struct option *options,
const char * const usagestr[]);
@ -319,9 +350,26 @@ void parse_revision_opt(struct rev_info *revs, struct parse_opt_ctx_t *ctx,
int handle_revision_arg(const char *arg, struct rev_info *revs,
int flags, unsigned revarg_opt);

/**
* Reset the flags used by the revision walking api. You can use this to do
* multiple sequential revision walks.
*/
void reset_revision_walk(void);

/**
* Prepares the rev_info structure for a walk. You should check if it returns
* any error (non-zero return code) and if it does not, you can start using
* get_revision() to do the iteration.
*/
int prepare_revision_walk(struct rev_info *revs);

/**
* Takes a pointer to a `rev_info` structure and iterates over it, returning a
* `struct commit *` each time you call it. The end of the revision list is
* indicated by returning a NULL pointer.
*/
struct commit *get_revision(struct rev_info *revs);

const char *get_revision_mark(const struct rev_info *revs,
const struct commit *commit);
void put_revision_mark(const struct rev_info *revs,
@ -333,8 +381,19 @@ void mark_trees_uninteresting_sparse(struct repository *r, struct oidset *trees)

void show_object_with_name(FILE *, struct object *, const char *);

/**
* This function can be used if you want to add commit objects as revision
* information. You can use the `UNINTERESTING` object flag to indicate if
* you want to include or exclude the given commit (and commits reachable
* from the given commit) from the revision list.
*
* NOTE: If you have the commits as a string list then you probably want to
* use setup_revisions(), instead of parsing each string and using this
* function.
*/
void add_pending_object(struct rev_info *revs,
struct object *obj, const char *name);

void add_pending_oid(struct rev_info *revs,
const char *name, const struct object_id *oid,
unsigned int flags);

252
run-command.h
View File

@ -5,8 +5,60 @@

#include "argv-array.h"

/**
* The run-command API offers a versatile tool to run sub-processes with
* redirected input and output as well as with a modified environment
* and an alternate current directory.
*
* A similar API offers the capability to run a function asynchronously,
* which is primarily used to capture the output that the function
* produces in the caller in order to process it.
*/


/**
* This describes the arguments, redirections, and environment of a
* command to run in a sub-process.
*
* The caller:
*
* 1. allocates and clears (using child_process_init() or
* CHILD_PROCESS_INIT) a struct child_process variable;
* 2. initializes the members;
* 3. calls start_command();
* 4. processes the data;
* 5. closes file descriptors (if necessary; see below);
* 6. calls finish_command().
*
* Special forms of redirection are available by setting these members
* to 1:
*
* .no_stdin, .no_stdout, .no_stderr: The respective channel is
* redirected to /dev/null.
*
* .stdout_to_stderr: stdout of the child is redirected to its
* stderr. This happens after stderr is itself redirected.
* So stdout will follow stderr to wherever it is
* redirected.
*/
struct child_process {

/**
* The .argv member is set up as an array of string pointers (NULL
* terminated), of which .argv[0] is the program name to run (usually
* without a path). If the command to run is a git command, set argv[0] to
* the command name without the 'git-' prefix and set .git_cmd = 1.
*
* Note that the ownership of the memory pointed to by .argv stays with the
* caller, but it should survive until `finish_command` completes. If the
* .argv member is NULL, `start_command` will point it at the .args
* `argv_array` (so you may use one or the other, but you must use exactly
* one). The memory in .args will be cleaned up automatically during
* `finish_command` (or during `start_command` when it is unsuccessful).
*
*/
const char **argv;

struct argv_array args;
struct argv_array env_array;
pid_t pid;
@ -18,8 +70,8 @@ struct child_process {

/*
* Using .in, .out, .err:
* - Specify 0 for no redirections (child inherits stdin, stdout,
* stderr from parent).
* - Specify 0 for no redirections. No new file descriptor is allocated.
* (child inherits stdin, stdout, stderr from parent).
* - Specify -1 to have a pipe allocated as follows:
* .in: returns the writable pipe end; parent writes to it,
* the readable pipe end becomes child's stdin
@ -37,13 +89,43 @@ struct child_process {
int in;
int out;
int err;

/**
* To specify a new initial working directory for the sub-process,
* specify it in the .dir member.
*/
const char *dir;

/**
* To modify the environment of the sub-process, specify an array of
* string pointers (NULL terminated) in .env:
*
* - If the string is of the form "VAR=value", i.e. it contains '='
* the variable is added to the child process's environment.
*
* - If the string does not contain '=', it names an environment
* variable that will be removed from the child process's environment.
*
* If the .env member is NULL, `start_command` will point it at the
* .env_array `argv_array` (so you may use one or the other, but not both).
* The memory in .env_array will be cleaned up automatically during
* `finish_command` (or during `start_command` when it is unsuccessful).
*/
const char *const *env;

unsigned no_stdin:1;
unsigned no_stdout:1;
unsigned no_stderr:1;
unsigned git_cmd:1; /* if this is to be git sub-command */
unsigned git_cmd:1; /* if this is to be git sub-command */

/**
* If the program cannot be found, the functions return -1 and set
* errno to ENOENT. Normally, an error message is printed, but if
* .silent_exec_failure is set to 1, no message is printed for this
* special error condition.
*/
unsigned silent_exec_failure:1;

unsigned stdout_to_stderr:1;
unsigned use_shell:1;
unsigned clean_on_exit:1;
@ -53,13 +135,63 @@ struct child_process {
};

#define CHILD_PROCESS_INIT { NULL, ARGV_ARRAY_INIT, ARGV_ARRAY_INIT }

/**
* The functions: child_process_init, start_command, finish_command,
* run_command, run_command_v_opt, run_command_v_opt_cd_env, child_process_clear
* do the following:
*
* - If a system call failed, errno is set and -1 is returned. A diagnostic
* is printed.
*
* - If the program was not found, then -1 is returned and errno is set to
* ENOENT; a diagnostic is printed only if .silent_exec_failure is 0.
*
* - Otherwise, the program is run. If it terminates regularly, its exit
* code is returned. No diagnostic is printed, even if the exit code is
* non-zero.
*
* - If the program terminated due to a signal, then the return value is the
* signal number + 128, ie. the same value that a POSIX shell's $? would
* report. A diagnostic is printed.
*
*/

/**
* Initialize a struct child_process variable.
*/
void child_process_init(struct child_process *);

/**
* Release the memory associated with the struct child_process.
* Most users of the run-command API don't need to call this
* function explicitly because `start_command` invokes it on
* failure and `finish_command` calls it automatically already.
*/
void child_process_clear(struct child_process *);

int is_executable(const char *name);

/**
* Start a sub-process. Takes a pointer to a `struct child_process`
* that specifies the details and returns pipe FDs (if requested).
* See below for details.
*/
int start_command(struct child_process *);

/**
* Wait for the completion of a sub-process that was started with
* start_command().
*/
int finish_command(struct child_process *);

int finish_command_in_signal(struct child_process *);

/**
* A convenience function that encapsulates a sequence of
* start_command() followed by finish_command(). Takes a pointer
* to a `struct child_process` that specifies the details.
*/
int run_command(struct child_process *);

/*
@ -68,6 +200,20 @@ int run_command(struct child_process *);
* overwritten by further calls to find_hook and run_hook_*.
*/
const char *find_hook(const char *name);

/**
* Run a hook.
* The first argument is a pathname to an index file, or NULL
* if the hook uses the default index file or no index is needed.
* The second argument is the name of the hook.
* The further arguments correspond to the hook arguments.
* The last argument has to be NULL to terminate the arguments list.
* If the hook does not exist or is not executable, the return
* value will be zero.
* If it is executable, the hook will be executed and the exit
* status of the hook is returned.
* On execution, .stdout_to_stderr and .no_stdin will be set.
*/
LAST_ARG_MUST_BE_NULL
int run_hook_le(const char *const *env, const char *name, ...);
int run_hook_ve(const char *const *env, const char *name, va_list args);
@ -78,6 +224,18 @@ int run_hook_ve(const char *const *env, const char *name, va_list args);
#define RUN_SILENT_EXEC_FAILURE 8
#define RUN_USING_SHELL 16
#define RUN_CLEAN_ON_EXIT 32

/**
* Convenience functions that encapsulate a sequence of
* start_command() followed by finish_command(). The argument argv
* specifies the program and its arguments. The argument opt is zero
* or more of the flags `RUN_COMMAND_NO_STDIN`, `RUN_GIT_CMD`,
* `RUN_COMMAND_STDOUT_TO_STDERR`, or `RUN_SILENT_EXEC_FAILURE`
* that correspond to the members .no_stdin, .git_cmd,
* .stdout_to_stderr, .silent_exec_failure of `struct child_process`.
* The argument dir corresponds the member .dir. The argument env
* corresponds to the member .env.
*/
int run_command_v_opt(const char **argv, int opt);
int run_command_v_opt_tr2(const char **argv, int opt, const char *tr2_class);
/*
@ -125,15 +283,84 @@ static inline int capture_command(struct child_process *cmd,
* It is expected that no synchronization and mutual exclusion between
* the caller and the feed function is necessary so that the function
* can run in a thread without interfering with the caller.
*
* The caller:
*
* 1. allocates and clears (memset(&asy, 0, sizeof(asy));) a
* struct async variable;
* 2. initializes .proc and .data;
* 3. calls start_async();
* 4. processes communicates with proc through .in and .out;
* 5. closes .in and .out;
* 6. calls finish_async().
*
* There are serious restrictions on what the asynchronous function can do
* because this facility is implemented by a thread in the same address
* space on most platforms (when pthreads is available), but by a pipe to
* a forked process otherwise:
*
* - It cannot change the program's state (global variables, environment,
* etc.) in a way that the caller notices; in other words, .in and .out
* are the only communication channels to the caller.
*
* - It must not change the program's state that the caller of the
* facility also uses.
*
*/
struct async {
/*
* proc reads from in; closes it before return
* proc writes to out; closes it before return
* returns 0 on success, non-zero on failure

/**
* The function pointer in .proc has the following signature:
*
* int proc(int in, int out, void *data);
*
* - in, out specifies a set of file descriptors to which the function
* must read/write the data that it needs/produces. The function
* *must* close these descriptors before it returns. A descriptor
* may be -1 if the caller did not configure a descriptor for that
* direction.
*
* - data is the value that the caller has specified in the .data member
* of struct async.
*
* - The return value of the function is 0 on success and non-zero
* on failure. If the function indicates failure, finish_async() will
* report failure as well.
*
*/
int (*proc)(int in, int out, void *data);

void *data;

/**
* The members .in, .out are used to provide a set of fd's for
* communication between the caller and the callee as follows:
*
* - Specify 0 to have no file descriptor passed. The callee will
* receive -1 in the corresponding argument.
*
* - Specify < 0 to have a pipe allocated; start_async() replaces
* with the pipe FD in the following way:
*
* .in: Returns the writable pipe end into which the caller
* writes; the readable end of the pipe becomes the function's
* in argument.
*
* .out: Returns the readable pipe end from which the caller
* reads; the writable end of the pipe becomes the function's
* out argument.
*
* The caller of start_async() must close the returned FDs after it
* has completed reading from/writing from them.
*
* - Specify a file descriptor > 0 to be used by the function:
*
* .in: The FD must be readable; it becomes the function's in.
* .out: The FD must be writable; it becomes the function's out.
*
* The specified FD is closed by start_async(), even if it fails to
* run the function.
*/
int in; /* caller writes here and closes it */
int out; /* caller reads from here and closes it */
#ifdef NO_PTHREADS
@ -146,8 +373,19 @@ struct async {
int isolate_sigpipe;
};

/**
* Run a function asynchronously. Takes a pointer to a `struct
* async` that specifies the details and returns a set of pipe FDs
* for communication with the function. See below for details.
*/
int start_async(struct async *async);

/**
* Wait for the completion of an asynchronous function that was
* started with start_async().
*/
int finish_async(struct async *async);

int in_async(void);
int async_with_fork(void);
void check_pipe(int err);

2
sha1-array.c
View File

@ -48,7 +48,7 @@ int oid_array_for_each(struct oid_array *array,
{
int i;

/* No oid_array_sort() here! See the api-oid-array.txt docs! */
/* No oid_array_sort() here! See sha1-array.h */

for (i = 0; i < array->nr; i++) {
int ret = fn(array->oid + i, data);

80
sha1-array.h
View File

@ -1,6 +1,52 @@
#ifndef SHA1_ARRAY_H
#define SHA1_ARRAY_H

/**
* The API provides storage and manipulation of sets of object identifiers.
* The emphasis is on storage and processing efficiency, making them suitable
* for large lists. Note that the ordering of items is not preserved over some
* operations.
*
* Examples
* --------
* -----------------------------------------
* int print_callback(const struct object_id *oid,
* void *data)
* {
* printf("%s\n", oid_to_hex(oid));
* return 0; // always continue
* }
*
* void some_func(void)
* {
* struct sha1_array hashes = OID_ARRAY_INIT;
* struct object_id oid;
*
* // Read objects into our set
* while (read_object_from_stdin(oid.hash))
* oid_array_append(&hashes, &oid);
*
* // Check if some objects are in our set
* while (read_object_from_stdin(oid.hash)) {
* if (oid_array_lookup(&hashes, &oid) >= 0)
* printf("it's in there!\n");
*
* // Print the unique set of objects. We could also have
* // avoided adding duplicate objects in the first place,
* // but we would end up re-sorting the array repeatedly.
* // Instead, this will sort once and then skip duplicates
* // in linear time.
*
* oid_array_for_each_unique(&hashes, print_callback, NULL);
* }
*/

/**
* A single array of object IDs. This should be initialized by assignment from
* `OID_ARRAY_INIT`. The `oid` member contains the actual data. The `nr` member
* contains the number of items in the set. The `alloc` and `sorted` members
* are used internally, and should not be needed by API callers.
*/
struct oid_array {
struct object_id *oid;
int nr;
@ -10,18 +56,52 @@ struct oid_array {

#define OID_ARRAY_INIT { NULL, 0, 0, 0 }

/**
* Add an item to the set. The object ID will be placed at the end of the array
* (but note that some operations below may lose this ordering).
*/
void oid_array_append(struct oid_array *array, const struct object_id *oid);

/**
* Perform a binary search of the array for a specific object ID. If found,
* returns the offset (in number of elements) of the object ID. If not found,
* returns a negative integer. If the array is not sorted, this function has
* the side effect of sorting it.
*/
int oid_array_lookup(struct oid_array *array, const struct object_id *oid);

/**
* Free all memory associated with the array and return it to the initial,
* empty state.
*/
void oid_array_clear(struct oid_array *array);

typedef int (*for_each_oid_fn)(const struct object_id *oid,
void *data);
/**
* Iterate over each element of the list, executing the callback function for
* each one. Does not sort the list, so any custom hash order is retained.
* If the callback returns a non-zero value, the iteration ends immediately
* and the callback's return is propagated; otherwise, 0 is returned.
*/
int oid_array_for_each(struct oid_array *array,
for_each_oid_fn fn,
void *data);

/**
* Iterate over each unique element of the list in sorted order, but otherwise
* behave like `oid_array_for_each`. If the array is not sorted, this function
* has the side effect of sorting it.
*/
int oid_array_for_each_unique(struct oid_array *array,
for_each_oid_fn fn,
void *data);

/**
* Apply the callback function `want` to each entry in the array, retaining
* only the entries for which the function returns true. Preserve the order
* of the entries that are retained.
*/
void oid_array_filter(struct oid_array *array,
for_each_oid_fn want,
void *cbdata);

45
sigchain.h
View File

@ -1,12 +1,57 @@
#ifndef SIGCHAIN_H
#define SIGCHAIN_H

/**
* Code often wants to set a signal handler to clean up temporary files or
* other work-in-progress when we die unexpectedly. For multiple pieces of
* code to do this without conflicting, each piece of code must remember
* the old value of the handler and restore it either when:
*
* 1. The work-in-progress is finished, and the handler is no longer
* necessary. The handler should revert to the original behavior
* (either another handler, SIG_DFL, or SIG_IGN).
*
* 2. The signal is received. We should then do our cleanup, then chain
* to the next handler (or die if it is SIG_DFL).
*
* Sigchain is a tiny library for keeping a stack of handlers. Your handler
* and installation code should look something like:
*
* ------------------------------------------
* void clean_foo_on_signal(int sig)
* {
* clean_foo();
* sigchain_pop(sig);
* raise(sig);
* }
*
* void other_func()
* {
* sigchain_push_common(clean_foo_on_signal);
* mess_up_foo();
* clean_foo();
* }
* ------------------------------------------
*
*/

/**
* Handlers are given the typedef of sigchain_fun. This is the same type
* that is given to signal() or sigaction(). It is perfectly reasonable to
* push SIG_DFL or SIG_IGN onto the stack.
*/
typedef void (*sigchain_fun)(int);

/* You can sigchain_push and sigchain_pop individual signals. */
int sigchain_push(int sig, sigchain_fun f);
int sigchain_pop(int sig);

/**
* push the handler onto the stack for the common signals:
* SIGINT, SIGHUP, SIGTERM, SIGQUIT and SIGPIPE.
*/
void sigchain_push_common(sigchain_fun f);

void sigchain_pop_common(void);

#endif /* SIGCHAIN_H */

38
submodule-config.h
View File

@ -7,9 +7,31 @@
#include "submodule.h"
#include "strbuf.h"

/**
* The submodule config cache API allows to read submodule
* configurations/information from specified revisions. Internally
* information is lazily read into a cache that is used to avoid
* unnecessary parsing of the same .gitmodules files. Lookups can be done by
* submodule path or name.
*
* Usage
* -----
*
* The caller can look up information about submodules by using the
* `submodule_from_path()` or `submodule_from_name()` functions. They return
* a `struct submodule` which contains the values. The API automatically
* initializes and allocates the needed infrastructure on-demand. If the
* caller does only want to lookup values from revisions the initialization
* can be skipped.
*
* If the internal cache might grow too big or when the caller is done with
* the API, all internally cached values can be freed with submodule_free().
*
*/

/*
* Submodule entry containing the information about a certain submodule
* in a certain revision.
* in a certain revision. It is returned by the lookup functions.
*/
struct submodule {
const char *path;
@ -41,13 +63,27 @@ int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
void repo_read_gitmodules(struct repository *repo);
void gitmodules_config_oid(const struct object_id *commit_oid);

/**
* Same as submodule_from_path but lookup by name.
*/
const struct submodule *submodule_from_name(struct repository *r,
const struct object_id *commit_or_tree,
const char *name);

/**
* Given a tree-ish in the superproject and a path, return the submodule that
* is bound at the path in the named tree.
*/
const struct submodule *submodule_from_path(struct repository *r,
const struct object_id *commit_or_tree,
const char *path);

/**
* Use these to free the internally cached values.
*/
void submodule_free(struct repository *r);

int print_config_from_gitmodules(struct repository *repo, const char *key);
int config_set_in_gitmodules_file_gently(const char *key, const char *value);


133
trace.h
View File

@ -4,6 +4,82 @@
#include "git-compat-util.h"
#include "strbuf.h"

/**
* The trace API can be used to print debug messages to stderr or a file. Trace
* code is inactive unless explicitly enabled by setting `GIT_TRACE*` environment
* variables.
*
* The trace implementation automatically adds `timestamp file:line ... \n` to
* all trace messages. E.g.:
*
* ------------
* 23:59:59.123456 git.c:312 trace: built-in: git 'foo'
* 00:00:00.000001 builtin/foo.c:99 foo: some message
* ------------
*
* Bugs & Caveats
* --------------
*
* GIT_TRACE_* environment variables can be used to tell Git to show
* trace output to its standard error stream. Git can often spawn a pager
* internally to run its subcommand and send its standard output and
* standard error to it.
*
* Because GIT_TRACE_PERFORMANCE trace is generated only at the very end
* of the program with atexit(), which happens after the pager exits, it
* would not work well if you send its log to the standard error output
* and let Git spawn the pager at the same time.
*
* As a work around, you can for example use '--no-pager', or set
* GIT_TRACE_PERFORMANCE to another file descriptor which is redirected
* to stderr, or set GIT_TRACE_PERFORMANCE to a file specified by its
* absolute path.
*
* For example instead of the following command which by default may not
* print any performance information:
*
* ------------
* GIT_TRACE_PERFORMANCE=2 git log -1
* ------------
*
* you may want to use:
*
* ------------
* GIT_TRACE_PERFORMANCE=2 git --no-pager log -1
* ------------
*
* or:
*
* ------------
* GIT_TRACE_PERFORMANCE=3 3>&2 git log -1
* ------------
*
* or:
*
* ------------
* GIT_TRACE_PERFORMANCE=/path/to/log/file git log -1
* ------------
*
*/

/**
* Defines a trace key (or category). The default (for API functions that
* don't take a key) is `GIT_TRACE`.
*
* E.g. to define a trace key controlled by environment variable `GIT_TRACE_FOO`:
*
* ------------
* static struct trace_key trace_foo = TRACE_KEY_INIT(FOO);
*
* static void trace_print_foo(const char *message)
* {
* trace_printf_key(&trace_foo, "%s", message);
* }
* ------------
*
* Note: don't use `const` as the trace implementation stores internal state in
* the `trace_key` structure.
*/
struct trace_key {
const char * const key;
int fd;
@ -18,31 +94,84 @@ extern struct trace_key trace_perf_key;
extern struct trace_key trace_setup_key;

void trace_repo_setup(const char *prefix);

/**
* Checks whether the trace key is enabled. Used to prevent expensive
* string formatting before calling one of the printing APIs.
*/
int trace_want(struct trace_key *key);

/**
* Disables tracing for the specified key, even if the environment variable
* was set.
*/
void trace_disable(struct trace_key *key);

/**
* Returns nanoseconds since the epoch (01/01/1970), typically used
* for performance measurements.
* Currently there are high precision timer implementations for Linux (using
* `clock_gettime(CLOCK_MONOTONIC)`) and Windows (`QueryPerformanceCounter`).
* Other platforms use `gettimeofday` as time source.
*/
uint64_t getnanotime(void);

void trace_command_performance(const char **argv);
void trace_verbatim(struct trace_key *key, const void *buf, unsigned len);
uint64_t trace_performance_enter(void);

#ifndef HAVE_VARIADIC_MACROS

/**
* Prints a formatted message, similar to printf.
*/
__attribute__((format (printf, 1, 2)))
void trace_printf(const char *format, ...);

__attribute__((format (printf, 2, 3)))
void trace_printf_key(struct trace_key *key, const char *format, ...);

/**
* Prints a formatted message, followed by a quoted list of arguments.
*/
__attribute__((format (printf, 2, 3)))
void trace_argv_printf(const char **argv, const char *format, ...);

/**
* Prints the strbuf, without additional formatting (i.e. doesn't
* choke on `%` or even `\0`).
*/
void trace_strbuf(struct trace_key *key, const struct strbuf *data);

/* Prints elapsed time (in nanoseconds) if GIT_TRACE_PERFORMANCE is enabled. */
/**
* Prints elapsed time (in nanoseconds) if GIT_TRACE_PERFORMANCE is enabled.
*
* Example:
* ------------
* uint64_t t = 0;
* for (;;) {
* // ignore
* t -= getnanotime();
* // code section to measure
* t += getnanotime();
* // ignore
* }
* trace_performance(t, "frotz");
* ------------
*/
__attribute__((format (printf, 2, 3)))
void trace_performance(uint64_t nanos, const char *format, ...);

/* Prints elapsed time since 'start' if GIT_TRACE_PERFORMANCE is enabled. */
/**
* Prints elapsed time since 'start' if GIT_TRACE_PERFORMANCE is enabled.
*
* Example:
* ------------
* uint64_t start = getnanotime();
* // code section to measure
* trace_performance_since(start, "foobar");
* ------------
*/
__attribute__((format (printf, 2, 3)))
void trace_performance_since(uint64_t start, const char *format, ...);


124
trace2.h
View File

@ -1,6 +1,40 @@
#ifndef TRACE2_H
#define TRACE2_H

/**
* The Trace2 API can be used to print debug, performance, and telemetry
* information to stderr or a file. The Trace2 feature is inactive unless
* explicitly enabled by enabling one or more Trace2 Targets.
*
* The Trace2 API is intended to replace the existing (Trace1)
* printf-style tracing provided by the existing `GIT_TRACE` and
* `GIT_TRACE_PERFORMANCE` facilities. During initial implementation,
* Trace2 and Trace1 may operate in parallel.
*
* The Trace2 API defines a set of high-level messages with known fields,
* such as (`start`: `argv`) and (`exit`: {`exit-code`, `elapsed-time`}).
*
* Trace2 instrumentation throughout the Git code base sends Trace2
* messages to the enabled Trace2 Targets. Targets transform these
* messages content into purpose-specific formats and write events to
* their data streams. In this manner, the Trace2 API can drive
* many different types of analysis.
*
* Targets are defined using a VTable allowing easy extension to other
* formats in the future. This might be used to define a binary format,
* for example.
*
* Trace2 is controlled using `trace2.*` config values in the system and
* global config files and `GIT_TRACE2*` environment variables. Trace2 does
* not read from repo local or worktree config files or respect `-c`
* command line config settings.
*
* For more info about: trace2 targets, conventions for public functions and
* macros, trace2 target formats and examples on trace2 API usage refer to
* Documentation/technical/api-trace2.txt
*
*/

struct child_process;
struct repository;
struct json_writer;
@ -39,7 +73,12 @@ void trace2_initialize_clock(void);
/*
* Initialize TRACE2 tracing facility if any of the builtin TRACE2
* targets are enabled in the system config or the environment.
* Emits a 'version' event.
* This includes setting up the Trace2 thread local storage (TLS).
* Emits a 'version' message containing the version of git
* and the Trace2 protocol.
*
* This function should be called from `main()` as early as possible in
* the life of the process after essential process initialization.
*
* Cleanup/Termination is handled automatically by a registered
* atexit() routine.
@ -49,7 +88,7 @@ void trace2_initialize_fl(const char *file, int line);
#define trace2_initialize() trace2_initialize_fl(__FILE__, __LINE__)

/*
* Return true if trace2 is enabled.
* Return 1 if trace2 is enabled (at least one target is active).
*/
int trace2_is_enabled(void);

@ -114,7 +153,8 @@ void trace2_cmd_mode_fl(const char *file, int line, const char *mode);
#define trace2_cmd_mode(sv) trace2_cmd_mode_fl(__FILE__, __LINE__, (sv))

/*
* Emit an 'alias' expansion event.
* Emits an "alias" message containing the alias used and the argument
* expansion.
*/
void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
const char **argv);
@ -123,7 +163,7 @@ void trace2_cmd_alias_fl(const char *file, int line, const char *alias,
trace2_cmd_alias_fl(__FILE__, __LINE__, (alias), (argv))

/*
* Emit one or more 'def_param' events for "interesting" configuration
* Emit one or more 'def_param' events for "important" configuration
* settings.
*
* Use the TR2_SYSENV_CFG_PARAM setting to register a comma-separated
@ -144,7 +184,7 @@ void trace2_cmd_list_config_fl(const char *file, int line);

/*
* Emit a "def_param" event for the given config key/value pair IF
* we consider the key to be "interesting".
* we consider the key to be "important".
*
* Use this for new/updated config settings created/updated after
* trace2_cmd_list_config() is called.
@ -155,20 +195,34 @@ void trace2_cmd_set_config_fl(const char *file, int line, const char *key,
#define trace2_cmd_set_config(k, v) \
trace2_cmd_set_config_fl(__FILE__, __LINE__, (k), (v))

/*
* Emit a 'child_start' event prior to spawning a child process.
/**
* Emits a "child_start" message containing the "child-id",
* "child-argv", and "child-classification".
*
* Before calling optionally set "cmd->trace2_child_class" to a string
* describing the type of the child process. For example, "editor" or
* "pager".
*
* This function assigns a unique "child-id" to `cmd->trace2_child_id`.
* This field is used later during the "child_exit" message to associate
* it with the "child_start" message.
*
* This function should be called before spawning the child process.
*/
void trace2_child_start_fl(const char *file, int line,
struct child_process *cmd);

#define trace2_child_start(cmd) trace2_child_start_fl(__FILE__, __LINE__, (cmd))

/*
* Emit a 'child_exit' event after the child process completes.
/**
* Emits a "child_exit" message containing the "child-id",
* the child's elapsed time and exit-code.
*
* The reported elapsed time includes the process creation overhead and
* time spend waiting for it to exit, so it may be slightly longer than
* the time reported by the child itself.
*
* This function should be called after reaping the child process.
*/
void trace2_child_exit_fl(const char *file, int line, struct child_process *cmd,
int child_exit_code);
@ -176,21 +230,22 @@ void trace2_child_exit_fl(const char *file, int line, struct child_process *cmd,
#define trace2_child_exit(cmd, code) \
trace2_child_exit_fl(__FILE__, __LINE__, (cmd), (code))

/*
/**
* Emit an 'exec' event prior to calling one of exec(), execv(),
* execvp(), and etc. On Unix-derived systems, this will be the
* last event emitted for the current process, unless the exec
* fails. On Windows, exec() behaves like 'child_start' and a
* waitpid(), so additional events may be emitted.
*
* Returns the "exec_id".
* Returns a unique "exec-id". This value is used later
* if the exec() fails and a "exec-result" message is necessary.
*/
int trace2_exec_fl(const char *file, int line, const char *exe,
const char **argv);

#define trace2_exec(exe, argv) trace2_exec_fl(__FILE__, __LINE__, (exe), (argv))

/*
/**
* Emit an 'exec_result' when possible. On Unix-derived systems,
* this should be called after exec() returns (which only happens
* when there is an error starting the new process). On Windows,
@ -226,11 +281,12 @@ void trace2_thread_exit_fl(const char *file, int line);
#define trace2_thread_exit() trace2_thread_exit_fl(__FILE__, __LINE__)

/*
* Emit a 'param' event.
* Emits a "def_param" message containing a key/value pair.
*
* Write a "<param> = <value>" pair describing some aspect of the
* run such as an important configuration setting or command line
* option that significantly changes command behavior.
* This message is intended to report some global aspect of the current
* command, such as a configuration setting or command line switch that
* significantly affects program performance or behavior, such as
* `core.abbrev`, `status.showUntrackedFiles`, or `--no-ahead-behind`.
*/
void trace2_def_param_fl(const char *file, int line, const char *param,
const char *value);
@ -243,18 +299,35 @@ void trace2_def_param_fl(const char *file, int line, const char *param,
* a trace2-repo-id to be used in subsequent activity events.
*
* Emits a 'worktree' event for this repo instance.
*
* Region and data messages may refer to this repo-id.
*
* The main/top-level repository will have repo-id value 1 (aka "r1").
*
* The repo-id field is in anticipation of future in-proc submodule
* repositories.
*/
void trace2_def_repo_fl(const char *file, int line, struct repository *repo);

#define trace2_def_repo(repo) trace2_def_repo_fl(__FILE__, __LINE__, repo)

/*
/**
* Emit a 'region_enter' event for <category>.<label> with optional
* repo-id and printf message.
*
* Enter a new nesting level on the current thread and remember the
* current time. This controls the indenting of all subsequent events
* on this thread.
* This function pushes a new region nesting stack level on the current
* thread and starts a clock for the new stack frame.
*
* The `category` field is an arbitrary category name used to classify
* regions by feature area, such as "status" or "index". At this time
* it is only just printed along with the rest of the message. It may
* be used in the future to filter messages.
*
* The `label` field is an arbitrary label used to describe the activity
* being started, such as "read_recursive" or "do_read_index".
*
* The `repo` field, if set, will be used to get the "repo-id", so that
* recursive oerations can be attributed to the correct repository.
*/
void trace2_region_enter_fl(const char *file, int line, const char *category,
const char *label, const struct repository *repo, ...);
@ -289,12 +362,17 @@ void trace2_region_enter_printf(const char *category, const char *label,
/* clang-format on */
#endif

/*
/**
* Emit a 'region_leave' event for <category>.<label> with optional
* repo-id and printf message.
*
* Leave current nesting level and report the elapsed time spent
* in this nesting level.
*
* The `category`, `label`, and `repo` fields are the same as
* trace2_region_enter_fl. The `category` and `label` do not
* need to match the corresponding "region_enter" message,
* but it makes the data stream easier to understand.
*/
void trace2_region_leave_fl(const char *file, int line, const char *category,
const char *label, const struct repository *repo, ...);
@ -329,10 +407,12 @@ void trace2_region_leave_printf(const char *category, const char *label,
/* clang-format on */
#endif

/*
/**
* Emit a key-value pair 'data' event of the form <category>.<key> = <value>.
* This event implicitly contains information about thread, nesting region,
* and optional repo-id.
* This could be used to print the number of files in a directory during
* a multi-threaded recursive tree walk.
*
* On event-based TRACE2 targets, this generates a 'data' event suitable
* for post-processing. On printf-based TRACE2 targets, this is converted

122
tree-walk.h
View File

@ -3,6 +3,13 @@

#include "cache.h"

/**
* The tree walking API is used to traverse and inspect trees.
*/

/**
* An entry in a tree. Each entry has a sha1 identifier, pathname, and mode.
*/
struct name_entry {
struct object_id oid;
const char *path;
@ -10,12 +17,29 @@ struct name_entry {
unsigned int mode;
};

/**
* A semi-opaque data structure used to maintain the current state of the walk.
*/
struct tree_desc {
/*
* pointer into the memory representation of the tree. It always
* points at the current entry being visited.
*/
const void *buffer;

/* points to the current entry being visited. */
struct name_entry entry;

/* counts the number of bytes left in the `buffer`. */
unsigned int size;
};

/**
* Decode the entry currently being visited (the one pointed to by
* `tree_desc's` `entry` member) and return the sha1 of the entry. The
* `pathp` and `modep` arguments are set to the entry's pathname and mode
* respectively.
*/
static inline const struct object_id *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned short *modep)
{
*pathp = desc->entry.path;
@ -23,6 +47,11 @@ static inline const struct object_id *tree_entry_extract(struct tree_desc *desc,
return &desc->entry.oid;
}

/**
* Calculate the length of a tree entry's pathname. This utilizes the
* memory structure of a tree entry to avoid the overhead of using a
* generic strlen().
*/
static inline int tree_entry_len(const struct name_entry *ne)
{
return ne->pathlen;
@ -33,52 +62,141 @@ static inline int tree_entry_len(const struct name_entry *ne)
* corrupt tree entry rather than dying,
*/

/**
* Walk to the next entry in a tree. This is commonly used in conjunction
* with `tree_entry_extract` to inspect the current entry.
*/
void update_tree_entry(struct tree_desc *);

int update_tree_entry_gently(struct tree_desc *);

/**
* Initialize a `tree_desc` and decode its first entry. The buffer and
* size parameters are assumed to be the same as the buffer and size
* members of `struct tree`.
*/
void init_tree_desc(struct tree_desc *desc, const void *buf, unsigned long size);

int init_tree_desc_gently(struct tree_desc *desc, const void *buf, unsigned long size);

/*
* Helper function that does both tree_entry_extract() and update_tree_entry()
* and returns true for success
* Visit the next entry in a tree. Returns 1 when there are more entries
* left to visit and 0 when all entries have been visited. This is
* commonly used in the test of a while loop.
*/
int tree_entry(struct tree_desc *, struct name_entry *);

int tree_entry_gently(struct tree_desc *, struct name_entry *);

/**
* Initialize a `tree_desc` and decode its first entry given the
* object ID of a tree. Returns the `buffer` member if the latter
* is a valid tree identifier and NULL otherwise.
*/
void *fill_tree_descriptor(struct repository *r,
struct tree_desc *desc,
const struct object_id *oid);

struct traverse_info;
typedef int (*traverse_callback_t)(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *);

/**
* Traverse `n` number of trees in parallel. The `fn` callback member of
* `traverse_info` is called once for each tree entry.
*/
int traverse_trees(struct index_state *istate, int n, struct tree_desc *t, struct traverse_info *info);

enum get_oid_result get_tree_entry_follow_symlinks(struct repository *r, struct object_id *tree_oid, const char *name, struct object_id *result, struct strbuf *result_path, unsigned short *mode);

/**
* A structure used to maintain the state of a traversal.
*/
struct traverse_info {
const char *traverse_path;

/*
* points to the traverse_info which was used to descend into the
* current tree. If this is the top-level tree `prev` will point to
* a dummy traverse_info.
*/
struct traverse_info *prev;

/* is the entry for the current tree (if the tree is a subtree). */
const char *name;

size_t namelen;
unsigned mode;

/* is the length of the full path for the current tree. */
size_t pathlen;

struct pathspec *pathspec;

/* can be used by callbacks to maintain directory-file conflicts. */
unsigned long df_conflicts;

/* a callback called for each entry in the tree.
*
* The arguments passed to the traverse callback are as follows:
*
* - `n` counts the number of trees being traversed.
*
* - `mask` has its nth bit set if something exists in the nth entry.
*
* - `dirmask` has its nth bit set if the nth tree's entry is a directory.
*
* - `entry` is an array of size `n` where the nth entry is from the nth tree.
*
* - `info` maintains the state of the traversal.
*
* Returning a negative value will terminate the traversal. Otherwise the
* return value is treated as an update mask. If the nth bit is set the nth tree
* will be updated and if the bit is not set the nth tree entry will be the
* same in the next callback invocation.
*/
traverse_callback_t fn;

/* can be anything the `fn` callback would want to use. */
void *data;

/* tells whether to stop at the first error or not. */
int show_all_errors;
};

/**
* Find an entry in a tree given a pathname and the sha1 of a tree to
* search. Returns 0 if the entry is found and -1 otherwise. The third
* and fourth parameters are set to the entry's sha1 and mode respectively.
*/
int get_tree_entry(struct repository *, const struct object_id *, const char *, struct object_id *, unsigned short *);

/**
* Generate the full pathname of a tree entry based from the root of the
* traversal. For example, if the traversal has recursed into another
* tree named "bar" the pathname of an entry "baz" in the "bar"
* tree would be "bar/baz".
*/
char *make_traverse_path(char *path, size_t pathlen, const struct traverse_info *info,
const char *name, size_t namelen);

/**
* Convenience wrapper to `make_traverse_path` into a strbuf.
*/
void strbuf_make_traverse_path(struct strbuf *out,
const struct traverse_info *info,
const char *name, size_t namelen);

/**
* Initialize a `traverse_info` given the pathname of the tree to start
* traversing from.
*/
void setup_traverse_info(struct traverse_info *info, const char *base);

/**
* Calculate the length of a pathname returned by `make_traverse_path`.
* This utilizes the memory structure of a tree entry to avoid the
* overhead of using a generic strlen().
*/
static inline size_t traverse_path_len(const struct traverse_info *info,
size_t namelen)
{