Now that the submodule-config subsystem can lazily read the gitmodules
file we no longer need to explicitly pre-read the gitmodules by calling
'gitmodules_config()' so let's remove it.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Migrate the functions used to initialize the submodule-config to
submodule-config.c so that the callback routine used in the
initialization process can be static and prevent it from being used
outside of initializing the submodule-config through the main API.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the last remaining caller of 'submodule_config()' as well as the
function itself.
With 'submodule_config()' being removed the submodule-config API can be
a little simpler as callers don't need to worry about whether or not
they need to overlay the repository's config on top of the
submodule-config. This also makes it more difficult to accidentally
add non-submodule specific configuration to the .gitmodules file.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Don't rely on overlaying the repository's config on top of the
submodule-config, instead query the repository's config directly for the
url and the update strategy configuration.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add 'is_gitmodules_unmerged()' function which can be used to determine
in the '.gitmodules' file is unmerged based on the passed in index
instead of relying on a global variable which is set during the
submodule-config parsing.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach 'is_staging_gitmodules_ok()' to be able to determine in the
'.gitmodules' file has unstaged changes based on the passed in index
instead of relying on a global variable which is set during the
submodule-config parsing.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the 'fetch.recursesubmodules' configuration option from the
general submodule-config parsing and instead rely on using
'config_from_gitmodules()' in order to maintain backwards compatibility
with this config being placed in the '.gitmodules' file.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The '.gitmodules' file should only contain information pertinent to
configuring individual submodules (name to path mapping, URL where to
obtain the submodule, etc.) while other configuration like the number of
jobs to use when fetching submodules should be a part of the
repository's config.
Remove the 'submodule.fetchjobs' configuration option from the general
submodule-config parsing and instead rely on using the
'config_from_gitmodules()' in order to maintain backwards compatibility
with this config being placed in the '.gitmodules' file.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As the submodule process is no longer attached to the same file pointer
'o->file' as the superprojects process, there is a different result in
color.c::check_auto_color. That is why we need to pass coloring explicitly,
such that the submodule coloring decision will be made by the child process
processing the submodule. Only DIFF_SYMBOL_SUBMODULE_PIPETHROUGH contains
color, the other symbols are for embedding the submodule output into the
superprojects output.
Remove the colors from the function signatures, as all the coloring
decisions will be made either inside the child process or the final
emit_diff_symbol, but not in the functions driving the submodule diff.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert 'is_submodule_initialized()' to take a repository object and
while we're at it, lets rename the function to 'is_submodule_active()'
and remove the NEEDSWORK comment.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the repo object to be able to populate the submodule_cache by
reading the repository's gitmodules file.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach pull to optionally update submodules when '--recurse-submodules'
is provided. This will teach pull to run 'submodule update --rebase'
when the '--recurse-submodules' and '--rebase' flags are given under
specific circumstances.
On a rebase workflow:
=====================
1. Both sides change the submodule
------------------------------
Let's assume the following history in a submodule:
H---I---J---K---L local branch
\
M---N---O---P remote branch
and the following in the superproject (recorded submodule in parens):
A(H)---B(I)---F(K)---G(L) local branch
\
C(N)---D(N)---E(P) remote branch
In an ideal world this would rebase the submodule and rewrite
the submodule pointers that the superproject points at such that
the superproject looks like
A(H)---B(I) F(K')---G(L') rebased branch
\ /
C(N)---D(N)---E(P) remote branch
and the submodule as:
J---K---L (old dangeling tip)
/
H---I J'---K'---L' rebased branch
\ /
M---N---O---P remote branch
And if a conflict arises in the submodule the superproject rebase
would stop at that commit at which the submodule conflict occurs.
Currently a "pull --rebase" in the superproject produces
a merge conflict as the submodule pointer changes are
conflicting and cannot be resolved.
2. Local submodule changes only
-----------------------
Assuming histories as above, except that the remote branch
would not contain submodule changes, then a result as
A(H)---B(I) F(K)---G(L) rebased branch
\ /
C(I)---D(I)---E(I) remote branch
is desire-able. This is what currently happens in rebase.
If the recursive flag is given, the ideal git would
produce a superproject as:
A(H)---B(I) F(K')---G(L') rebased branch (incl. sub rebase!)
\ /
C(I)---D(I)---E(I) remote branch
and the submodule as:
J---K---L (old dangeling tip)
/
H---I J'---K'---L' locally rebased branch
\ /
M---N---O---P advanced branch
This patch doesn't address this issue, however
a test is added that this fails up front.
3. Remote submodule changes only
----------------------
Assuming histories as in (1) except that the local superproject branch
would not have touched the submodule the rebase already works out in the
superproject with no conflicts:
A(H)---B(I) F(P)---G(P) rebased branch (no sub changes)
\ /
C(N)---D(N)---E(P) remote branch
The recurse flag as presented in this patch would additionally
update the submodule as:
H---I J'---K'---L' rebased branch
\ /
M---N---O---P remote branch
As neither J, K, L nor J', K', L' are referred to from the superproject,
no rewriting of the superproject commits is required.
Conclusion for 'pull --rebase --recursive'
-----------------------------------------
If there are no local superproject changes it is sufficient to call
"submodule update --rebase" as this produces the desired results. In case
of conflicts, the behavior is the same as in 'submodule update --recursive'
which is assumed to be sane.
This patch implements (3) only.
On a merge workflow:
====================
We'll start off with the same underlying DAG as in (1) in the rebase
workflow. So in an ideal world a 'pull --merge --recursive' would
produce this:
H---I---J---K---L----X
\ /
M---N---O---P
with X as the new merge-commit in the submodule and the superproject
as:
A(H)---B(I)---F(K)---G(L)---Y(X)
\ /
C(N)---D(N)---E(P)
However modifying the submodules on the fly is not supported in git-merge
such that Y(X) is not easy to produce in a single patch. In fact git-merge
doesn't know about submodules at all.
However when at least one side does not contain commits touching the
submodule at all, then we do not need to perform the merge for the
submodule but a fast-forward can be done via checking out either L or P
in the submodule. This strategy is implemented in 68d03e4a6e (Implement
automatic fast-forward merge for submodules, 2010-07-07) already, so
to align with the rebase behavior we need to also update the worktree
of the submodule.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Any command that understands '--recurse-submodules' can have its
default changed to true, by setting the new 'submodule.recurse'
option.
This patch includes read-tree/checkout/reset for working tree
manipulating commands. Later patches will cover other commands.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The callback function is essentially duplicated 3 times. Remove all
of them and offer a new callback function, that lives in submodule.c
By putting the callback function there, we no longer need the function
'set_config_update_recurse_submodules', nor duplicate the global variable
in each builtin as well as submodule.c
In the three builtins we have different 2 ways how to load the .gitmodules
and config file, which are slightly different. git-checkout has to load
the submodule config all the time due to 23b4c7bcc5 (checkout: Use
submodule.*.ignore settings from .git/config and .gitmodules, 2010-08-28)
git-reset and git-read-tree do not respect these diff settings, so loading
the submodule configuration is optional. Also put that into submodule.c
for code deduplication.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since (ae8d08242 pathspec: pass directory indicator to
match_pathspec_item()) the path matching logic has been able to cope
with submodules without needing to strip off a trailing slash if a path
refers to a submodule.
Since the stripping the trailing slash is no longer necessary, remove
the PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE flag. In addition, factor
out the logic which dies if a path decends into a submodule so that it
can still be used as a check after a pathspec struct has been
initialized.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently 'git add' is the only command which dies when launched from an
unpopulated submodule (the place-holder directory for a submodule which
hasn't been checked out). This is triggered implicitly by passing the
PATHSPEC_STRIP_SUBMODULE_SLASH_EXPENSIVE flag to 'parse_pathspec()'.
Instead make this desire more explicit by creating a function
'die_in_unpopulated_submodule()' which dies if the provided 'prefix' has
a leading path component which matches a submodule in the the index.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a caller of lookup_commit_reference, which we will convert
later.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach "push --recurse-submodules" to propagate, if given a name as remote, the
provided remote and refspec recursively to the pushes performed in the
submodules. The push will therefore only succeed if all submodules have a
remote with such a name configured.
Note that "push --recurse-submodules" with a path or URL as remote will not
propagate the remote or refspec and instead use the default remote and refspec
configured in the submodule, preserving the current behavior.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach push --recurse-submodules to propagate push-options recursively to
the pushes performed in the submodules.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since this structure handles an array of object IDs, rename it to struct
oid_array. Also rename the accessor functions and the initialization
constant.
This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:
perl -pi -E 's/struct sha1_array/struct oid_array/g'
perl -pi -E 's/\bsha1_array_/oid_array_/g'
perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All of the callers of this function have been converted, so convert this
function and update the callers. This function also calls
sha1_array_append, which we'll convert shortly.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
refs is learning to avoid path rewriting that is done by
strbuf_git_path_submodule(). Factor out this code so it could be reused
by refs_* functions.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In later patches we introduce the options and flag for commands
that modify the working directory, e.g. git-checkout.
This piece of code will be used universally for
all these working tree modifications as it
* supports dry run to answer the question:
"Is it safe to change the submodule to this new state?"
e.g. is it overwriting untracked files or are there local
changes that would be overwritten?
* supports a force flag that can be used for resetting
the tree.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In later patches we introduce the --recurse-submodule flag for commands
that modify the working directory, e.g. git-checkout.
It is potentially expensive to check if a submodule needs an update,
because a common theme to interact with submodules is to spawn a child
process for each interaction.
So let's introduce a function that checks if a submodule needs
to be checked for an update before attempting the update.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In later patches we introduce the options and flag for commands
that modify the working directory, e.g. git-checkout.
Have a central place to store such settings whether we want to update
a submodule.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We need the gentle version in a later patch. As we have just one caller,
migrate the caller.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In some situations it is useful to know if the given repository
is a submodule of another repository.
Add the flag --show-superproject-working-tree to git-rev-parse
to make it easy to find out if there is a superproject. When no
superproject exists, the output will be empty.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In different contexts the question "Is it ok to delete a submodule?"
may be answered differently.
In 293ab15eea (submodule: teach rm to remove submodules unless they
contain a git directory, 2012-09-26) a case was made that we can safely
ignore ignored untracked files for removal as we explicitely ask for the
removal of the submodule.
In a later patch we want to remove submodules even when the user doesn't
explicitly ask for it (e.g. checking out a tree-ish in which the submodule
doesn't exist). In that case we want to be more careful when it comes
to deletion of untracked files. As of this patch it is unclear how this
will be implemented exactly, so we'll offer flags in which the caller
can specify how the different untracked files ought to be handled.
As the flags allow the function to not die on an error when spawning
a child process, we need to find an appropriate return code for the
case when the child process could not be started. As in that case we
cannot tell if the submodule is ok to remove, we'd want to return 'false'.
As only 0 is understood as false, rename the function to invert the
meaning, i.e. the return code of 0 signals the removal of the submodule
is fine, and other values can be used to return a more precise answer
what went wrong.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As the upcoming series will add a lot of functions to the submodule
header, let's first make the header consistent to the rest of the project
by adding the extern keyword to functions.
As per the CodingGuidelines we try to stay below 80 characters per line,
so adapt all those functions to stay below 80 characters that are already
using more than one line. Those function using just one line are better
kept in one line than breaking them up into multiple lines just for the
goal of staying below the character limit as it makes grepping
for functions easier if they are one liners.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
teach submodules to load a '.gitmodules' file from a commit sha1. This
enables the population of the submodule_cache to be based on the state
of the '.gitmodules' file from a particular commit.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the `is_submodule_initialized()` helper function to submodules.c.
`is_submodule_initialized()` performs a check to determine if the
submodule at the given path has been initialized.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the `is_submodule_populated()` helper function to submodules.c.
`is_submodule_populated()` performes a check to see if a submodule has
been checkout out (and has a valid .git directory/file) at the given path.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the `RECURSE_SUBMODULES_ONLY` enum value to submodule.h. This enum
value will be used in a later patch to push to indicate that only
submodules should be pushed, while the superproject should remain
unpushed.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a submodule has its git dir inside the working dir, the submodule
support for checkout that we plan to add in a later patch will fail.
Add functionality to migrate the git directory to be absorbed
into the superprojects git directory.
The newly added code in this patch is structured such that other areas of
Git can also make use of it. The code in the submodule--helper is a mere
wrapper and option parser for the function
`absorb_git_dir_into_superproject`, that takes care of embedding the
submodules git directory into the superprojects git dir. That function
makes use of the more abstract function for this use case
`relocate_gitdir`, which can be used by e.g. the worktree code eventually
to move around a git directory.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
That function was primarily used by submodule code, but the function
itself is not inherently about submodules. In the next patch we'll
introduce relocate_git_dir, which can be used by worktrees as well,
so find a neutral middle ground in dir.h.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach push to respect the --dry-run option when configured to
recursively push submodules 'on-demand'. This is done by passing the
--dry-run flag to the child process which performs a push for a
submodules when performing a dry-run.
In order to preserve good user experience, the additional check for
unpushed submodules is skipped during a dry-run when
--recurse-submodules=on-demand. The check is skipped because the submodule
pushes were performed as dry-runs and this check would always fail as the
submodules would still need to be pushed.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We are iterating over each pushed ref and want to check whether it
contains changes to submodules. Instead of immediately checking each ref
lets first collect them and then do the check for all of them in one
revision walk.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach git-diff and friends a new format for displaying the difference
of a submodule. The new format is an inline diff of the contents of the
submodule between the commit range of the update. This allows the user
to see the actual code change caused by a submodule update.
Add tests for the new format and option.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we're going to be changing this function in a future patch, lets
go ahead and convert this to use object_id now.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of having a whitelist of command-line config
options to pass to submodules was two-fold:
1. It prevented obvious nonsense like using core.worktree
for multiple repos.
2. It could prevent surprise when the user did not mean
for the options to leak to the submodules (e.g.,
http.sslverify=false).
For case 1, the answer is mostly "if it hurts, don't do
that". For case 2, we can note that any such example has a
matching inverted surprise (e.g., a user who meant
http.sslverify=true to apply everywhere, but it didn't).
So this whitelist is probably not giving us any benefit, and
is already creating a hassle as people propose things to put
on it. Let's just drop it entirely.
Note that we still need to keep a special code path for
"prepare the submodule environment", because we still have
to take care to pass through $GIT_CONFIG_PARAMETERS (and
block the rest of the repo-specific environment variables).
We can do this easily from within the submodule shell
script, which lets us drop the submodule--helper option
entirely (and it's OK to do so because as a "--" program, it
is entirely a private implementation detail).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These functions should be used by any code which spawns a
submodule process, which may happen in submodule.c (e.g.,
for spawning fetch). Let's move them there and make them
public so that submodule--helper can continue to use them.
Since they're now public, let's also provide a basic overview
of their intended use.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By having the `submodule init` functionality in C, we can reference it
easier from other parts in the code in later patches. The code is split
up to have one function to initialize one submodule and a calling function
that takes care of the rest, such as argument handling and translating the
arguments to the paths of the submodules.
This is the first submodule subcommand that is fully converted to C
except for the usage string, so this is actually removing a call to
the `submodule--helper list` function, which is supposed to be used in
this transition. Instead we'll make a direct call to `module_list_compute`.
An explanation why we need to edit the prefixes in cmd_update in
git-submodule.sh in this patch:
By having no processing in the shell part, we need to convey the notion
of wt_prefix and prefix to the C parts, which former patches punted on
and did the processing of displaying path in the shell.
`wt_prefix` used to hold the path from the repository root to the current
directory, e.g. wt_prefix would be t/ if the user invoked the
`git submodule` command in ~/repo/t and ~repo is the GIT_DIR.
`prefix` used to hold the relative path from the repository root to the
operation, e.g. if you have recursive submodules, the shell script would
modify the `prefix` in each recursive step by adding the submodule path.
We will pass `wt_prefix` into the C helper via `git -C <dir>` as that
will setup git in the directory the user actually called git-submodule.sh
from. The `prefix` will be passed in via the `--prefix` option.
Having `prefix` and `wt_prefix` relative to the GIT_DIR of the
calling superproject is unfortunate with this patch as the C code doesn't
know about a possible recursion from a superproject via `submodule update
--init --recursive`.
To fix this, we change the meaning of `wt_prefix` to point to the current
project instead of the superproject and `prefix` to include any relative
paths issues in the superproject. That way `prefix` will become the leading
part for displaying paths and `wt_prefix` will be empty in recursive
calls for now.
The new notion of `wt_prefix` and `prefix` still allows us to reconstruct
the calling directory in the superproject by just traveling reverse of
`prefix`.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows to configure fetching and updating in parallel
without having the command line option.
This moved the responsibility to determine how many parallel processes
to start from builtin/fetch to submodule.c as we need a way to communicate
"The user did not specify the number of parallel processes in the command
line options" in the builtin fetch. The submodule code takes care of
the precedence (CLI > config > default).
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently submodule.<name>.update is only handled by git-submodule.sh.
C code will start to need to make use of that value as more of the
functionality of git-submodule.sh moves into library code in C.
Add the update field to 'struct submodule' and populate it so it can
be read as sm->update or from sm->update_command.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The --recurse-submodules command line parameter has existed for some
time but it has no config file equivalent.
Following the style of the corresponding parameter for git fetch, let's
invent push.recurseSubmodules to provide a default for this
parameter. This also requires the addition of --recurse-submodules=no to
allow the configuration to be overridden on the command line when
required.
The most straightforward way to implement this appears to be to make
push use code in submodule-config in a similar way to fetch.
Signed-off-by: Mike Crowe <mac@mcrowe.com>
Signed-off-by: Jeff King <peff@peff.net>
We should not die when reading the submodule config cache since the
user might not be able to get out of that situation when the
configuration is part of the history.
We should handle this condition later when the value is about to be
used.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We remove the extracted functions and directly parse into and read out
of the cache. This allows us to have one unified way of accessing
submodule configuration values specific to single submodules. Regardless
whether we need to access a configuration from history or from the
worktree.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a superproject some commands need to interact with submodules. They
need to query values from the .gitmodules file either from the worktree
of from certain revisions. At the moment this is quite hard since a
caller would need to read the .gitmodules file from the history and then
parse the values. We want to provide an API for this so we have one
place to get values from .gitmodules from any revision (including the
worktree).
The API is realized as a cache which allows us to lazily read
.gitmodules configurations by commit into a runtime cache which can then
be used to easily lookup values from it. Currently only the values for
path or name are stored but it can be extended for any value needed.
It is expected that .gitmodules files do not change often between
commits. Thats why we lookup the .gitmodules sha1 from a commit and then
either lookup an already parsed configuration or parse and cache an
unknown one for each sha1. The cache is lazily build on demand for each
requested commit.
This cache can be used for all purposes which need knowledge about
submodule configurations. Example use cases are:
* Recursive submodule checkout needs to lookup a submodule name from
its path when a submodule first appears. This needs be done before
this configuration exists in the worktree.
* The implementation of submodule support for 'git archive' needs to
lookup the submodule name to generate the archive when given a
revision that is not checked out.
* 'git fetch' when given the --recurse-submodules=on-demand option (or
configuration) needs to lookup submodule names by path from the
database rather than reading from the worktree. For new submodule it
needs to lookup the name from its path to allow cloning new
submodules into the .git folder so they can be checked out without
any network interaction when the user does a checkout of that
revision.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Brandon Williams