In some code paths (e.g. giving "add -i" to prepare the contents to
be committed interactively inside "commit -p") where a caller takes
a lock, writes the new content, give chance for others to use it
while still holding the lock, and then releases the lock when all is
done. As an extension, allow the caller to re-update an already
closed file while still holding the lock (i.e. not yet committed) by
re-opening the file, to be followed by updating the contents and
then by the usual close_lock_file() or commit_lock_file().
This is necessary if we want to add code to rebuild the cache-tree
and write the resulting index out after "add -i" returns the control
to "commit -p", for example.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the revert command updates the work tree as expected (for
submodule changes which don't result in conflicts). Add a helper function
to first revert the checked out target commit to make the last revert
produce the to-be-tested work tree.
Set the KNOWN_FAILURE_CHERRY_PICK_SEES_EMPTY_COMMIT and
KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR switches to
document that revert has the similar failures.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the stash apply command updates the work tree as expected for
changes which don't result in conflicts. To make that work add a helper
function that uses read-tree to apply the changes of the target commit
to the work tree, then stashes these changes and at last applies that
stash.
Implement the KNOWN_FAILURE_STASH_DOES_IGNORE_SUBMODULE_CHANGES switch
and reuse two other already present switches to expect the known
failure that stash does ignore submodule changes.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the am command updates the work tree as expected (for submodule
changes which don't result in conflicts). To make that work add two
helper functions that use format-patch to create the input for am.
Add the KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES
switch to expect the known failure that --no-ff merges attempt to merge
the new files in the former submodule directory with those of the removed
submodule.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the cherry-pick command updates the work tree as expected (for
submodule changes which don't result in conflicts).
Set KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES
and KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR to
document that cherry-pick has the same --no-ff known failures merge has.
Implement the KNOWN_FAILURE_CHERRY_PICK_SEES_EMPTY_COMMIT switch to expect
the known failure that while cherry picking just a SHA-1 update for an
ignored submodule the commit incorrectly fails with "The previous
cherry-pick is now empty, possibly due to conflict resolution.".
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the pull command updates the work tree as expected (for
submodule changes which don't result in conflicts) when used without
arguments or with the '--ff', '--ff-only' and '--no-ff' flag each. Add
helper functions to reset the branch to be updated to to the current
HEAD so that pull is doing the transition from HEAD to the given branch.
Set KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES
and KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR to
document that pull has the same --no-ff known failures merge has.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the rebase command updates the work tree as expected for
changes which don't result in conflicts. To make that work add two
helper functions that add a commit only touching files and then
revert it. This allows to rebase the target commit over these two
and to compare the result.
Set KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR to
document that "replace directory with submodule" fails for an
interactive rebase because a directory "sub1" already exists.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the merge command updates the work tree as expected (for
submodule changes which don't result in conflicts) when used without
arguments or with the '--ff', '--ff-only' and '--no-ff' flag.
Implement the KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR
switch to expect the known failure that --no-ff merges do not create the
empty submodule directory.
The KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES
switch is also implemented to expect the known failure that --no-ff
merges attempt to merge the new files in the former submodule directory
with those of the removed submodule.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the bisect command updates the work tree as expected. To make
that work with the new submodule test framework a git_bisect helper
function is added. This adds a commit after the one given to be switched
to and makes that one the bad commit. The starting point is then given to
bisect as the good commit which makes bisect change the work tree to the
commit in between, which is the commit given.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the reset command updates the work tree as expected for changes
with '--keep', '--merge' (for changes which don't result in conflicts) and
'--hard'.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the read-tree command updates the work tree as expected for
changes which don't result in conflicts with the '-m' and '--reset' flag.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the apply command updates the work tree as expected for the
'--index' and the '--3way' options (for submodule changes which don't
result in conflicts).
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test that the checkout command updates the work tree as expected with
and without the '-f' flag.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add this test library to simplify covering all combinations of submodule
update scenarios without having to add those to a test of each work tree
manipulating command over and over again.
The functions test_submodule_switch() and test_submodule_forced_switch()
are intended to be called from a test script with a single argument. This
argument is either a work tree manipulating command (including any command
line options) or a function (when more than a single git command is needed
to switch work trees from the current HEAD to another commit). This
command (or function) is passed a target branch as argument. The two new
functions check that each submodule transition is handled as expected,
which currently means that submodule work trees are not affected until
"git submodule update" is called. The "forced" variant is for commands
using their '-f' or '--hard' option and expects them to overwrite local
modifications as a result. Each of these two functions contains 14
tests_expect_* calls.
Calling one of these test functions the first time creates a repository
named "submodule_update_repo". At first it contains two files, then a
single submodule is added in another commit followed by commits covering
all relevant submodule modifications. This repository is newly cloned into
the "submodule_update" for each test_expect_* to avoid interference
between different parts of the test functions (some to-be-tested commands
also manipulate refs along with the work tree, e.g. "git reset").
Follow-up commits will then call these two test functions for all work
tree manipulating commands (with a combination of all their options
relevant to what they do with the work tree) making sure they work as
expected. Later this test library will be extended to cover merges
resulting in conflicts too. Also it is intended to be easily extendable
for the recursive update functionality, where even more combinations of
submodule modifications have to be tested for.
This version documents two bugs in current Git with expected failures:
*) When a submodule is replaced with a tracked file of the same name the
submodule work tree including any local modifications (and even the
whole history if it uses a .git directory instead of a gitfile!) is
silently removed.
*) Forced work tree updates happily manipulate files in the directory of a
submodule that has just been removed in the superproject (but is of
course still present in the work tree due to the way submodules are
currently handled). This becomes dangerous when files in the submodule
directory are overwritten by files from the new superproject commit, as
any modifications to the submodule files will be lost) and is expected
to also destroy history in the - admittedly unlikely case - the new
commit adds a file named ".git" to the submodule directory.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update ref_transaction_update() do some basic error checking and return
non-zero on error. Update all callers to check ref_transaction_update() for
error. There are currently no conditions in _update that will return error but
there will be in the future. Add an err argument that will be updated on
failure. In future patches we will start doing both locking and checking
for name conflicts in _update instead of _commit at which time this function
will start returning errors for these conditions.
Also check for BUGs during update and die(BUG:...) if we are calling
_update with have_old but the old_sha1 pointer is NULL.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Since all callers now use QUIET_ON_ERR we no longer need to provide an onerr
argument any more. Remove the onerr argument from the ref_transaction_commit
signature.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Call ref_transaction_commit with QUIET_ON_ERR and use the strbuf that is
returned to print a log message if/after the transaction fails.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Change update_ref_write to also update an error strbuf on failure.
This makes the error available to ref_transaction_commit callers if the
transaction failed due to update_ref_sha1/write_ref_sha1 failures.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Make ref_update_reject_duplicates return any error that occurs through a
new strbuf argument. This means that when a transaction commit fails in
this function we will now be able to pass a helpful error message back to the
caller.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno from write_ref_sha1() meaningful, which should fix
* a bug in "git checkout -b" where it prints strerror(errno)
despite errno possibly being zero or clobbered
* a bug in "git fetch"'s s_update_ref, which trusts the result of an
errno == ENOTDIR check to detect D/F conflicts
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno when returning from resolve_ref_unsafe() meaningful,
which should fix
* a bug in lock_ref_sha1_basic, where it assumes EISDIR
means it failed due to a directory being in the way
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno when returning from commit_packed_refs() meaningful,
which should fix
* a bug in "git clone" where it prints strerror(errno) based on
errno, despite errno possibly being zero and potentially having
been clobbered by that point
* the same kind of bug in "git pack-refs"
and prepares for repack_without_refs() to get a meaningful
error message when commit_packed_refs() fails without falling into
the same bug.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno when returning from remove_empty_directories() more
obviously meaningful, which should provide some peace of mind for
people auditing lock_ref_sha1_basic.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno when returning from verify_lock() meaningful, which
should almost but not completely fix
* a bug in "git fetch"'s s_update_ref, which trusts the result of an
errno == ENOTDIR check to detect D/F conflicts
ENOTDIR makes sense as a sign that a file was in the way of a
directory we wanted to create. Should "git fetch" also look for
ENOTEMPTY or EEXIST to catch cases where a directory was in the way
of a file to be created?
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno when returning from log_ref_setup() meaningful,
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Update repack_without_refs to take an err argument and update it if there
is a failure. Pass the err variable from ref_transaction_commit to this
function so that callers can print a meaningful error message if _commit
fails due to this function.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Making errno when returning from lock_file() meaningful, which should
fix
* an existing almost-bug in lock_ref_sha1_basic where it assumes
errno==ENOENT is meaningful and could waste some work on retries
* an existing bug in repack_without_refs where it prints
strerror(errno) and picks advice based on errno, despite errno
potentially being zero and potentially having been clobbered by
that point
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Introducing a new unable_to_lock_message helper, which has nicer
semantics than unable_to_lock_error and cleans up lockfile.c a little.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Add a strbuf argument to _commit so that we can pass an error string back to
the caller. So that we can do error logging from the caller instead of from
_commit.
Longer term plan is to first convert all callers to use onerr==QUIET_ON_ERR
and craft any log messages from the callers themselves and finally remove the
onerr argument completely.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Allow ref_transaction_free(NULL) as a no-op. This makes ref_transaction_free
easier to use and more similar to plain 'free'.
In particular, it lets us rollback unconditionally as part of cleanup code
after setting 'transaction = NULL' if a transaction has been committed or
rolled back already.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
ref_transaction_create|delete|update has no need to modify the sha1
arguments passed to it so it should use const unsigned char* instead
of unsigned char*.
Some functions, such as fast_forward_to(), already have its old/new
sha1 arguments as consts. This function will at some point need to
use ref_transaction_update() in which case this change is required.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
We do not yet need both a rollback and a free function for transactions.
Remove ref_transaction_rollback and use ref_transaction_free instead.
At a later stage we may reintroduce a rollback function if we want to start
adding reusable transactions and similar.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Calculating duration from a single uint64_t is simpler than from a struct
timeval. Change throughput measurement from gettimeofday() to
getnanotime().
Also calculate misec only if needed, and change integer division to integer
multiplication + shift, which should be slightly faster.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Calculating duration from a single uint64_t is simpler than from a struct
timeval. Change performance measurement for 'advice.statusuoption' from
gettimeofday() to getnanotime().
Also initialize t_begin to prevent uninitialized variable warning.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use trace_performance to measure and print execution time and command line
arguments of the entire main() function. In constrast to the shell's 'time'
utility, which measures total time of the parent process, this logs all
involved git commands recursively. This is particularly useful to debug
performance issues of scripted commands (i.e. which git commands were
called with which parameters, and how long did they execute).
Due to git's deliberate use of exit(), the implementation uses an atexit
routine rather than just adding trace_performance_since() at the end of
main().
Usage example: > GIT_TRACE_PERFORMANCE=~/git-trace.log git stash list
Creates a log file like this:
23:57:38.638765 trace.c:405 performance: 0.000310107 s: git command: 'git' 'rev-parse' '--git-dir'
23:57:38.644387 trace.c:405 performance: 0.000261759 s: git command: 'git' 'rev-parse' '--show-toplevel'
23:57:38.646207 trace.c:405 performance: 0.000304468 s: git command: 'git' 'config' '--get-colorbool' 'color.interactive'
23:57:38.648491 trace.c:405 performance: 0.000241667 s: git command: 'git' 'config' '--get-color' 'color.interactive.help' 'red bold'
23:57:38.650465 trace.c:405 performance: 0.000243063 s: git command: 'git' 'config' '--get-color' '' 'reset'
23:57:38.654850 trace.c:405 performance: 0.025126313 s: git command: 'git' 'stash' 'list'
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add trace_performance and trace_performance_since macros that print a
duration and an optional printf-formatted text to the file specified in
environment variable GIT_TRACE_PERFORMANCE.
These macros, in conjunction with getnanotime(), are intended to simplify
performance measurements from within the application (i.e. profiling via
manual instrumentation, rather than using an external profiling tool).
Unless enabled via GIT_TRACE_PERFORMANCE, these macros have no noticeable
impact on performance, so that test code for well known time killers may
be shipped in release builds. Alternatively, a developer could provide an
additional performance patch (not meant for master) that allows reviewers
to reproduce performance tests more easily, e.g. on other platforms or
using their own repositories.
Usage examples:
Simple use case (measure one code section):
uint64_t start = getnanotime();
/* code section to measure */
trace_performance_since(start, "foobar");
Complex use case (measure repetitive code sections):
uint64_t t = 0;
for (;;) {
/* ignore */
t -= getnanotime();
/* code section to measure */
t += getnanotime();
/* ignore */
}
trace_performance(t, "frotz");
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a getnanotime() function that returns nanoseconds since 01/01/1970 as
unsigned 64-bit integer (i.e. overflows in july 2554). This is easier to
work with than e.g. struct timeval or struct timespec. Basing the timer on
the epoch allows using the results with other time-related APIs.
To simplify adaption to different platforms, split the implementation into
a common getnanotime() and a platform-specific highres_nanos() function.
The common getnanotime() function handles errors, falling back to
gettimeofday() if highres_nanos() isn't implemented or doesn't work.
getnanotime() is also responsible for normalizing to the epoch. The offset
to the system clock is calculated only once on initialization, i.e.
manually setting the system clock has no impact on the timer (except if
the fallback gettimeofday() is in use). Git processes are typically short
lived, so we don't need to handle clock drift.
The highres_nanos() function returns monotonically increasing nanoseconds
relative to some arbitrary point in time (e.g. system boot), or 0 on
failure. Providing platform-specific implementations should be relatively
easy, e.g. adapting to clock_gettime() as defined by the POSIX realtime
extensions is seven lines of code.
This version includes highres_nanos() implementations for:
* Linux: using clock_gettime(CLOCK_MONOTONIC)
* Windows: using QueryPerformanceCounter()
Todo:
* enable clock_gettime() on more platforms
* add Mac OSX version, e.g. using mach_absolute_time + mach_timebase_info
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is useful to see where trace output came from.
Add 'const char *file, int line' parameters to the printing functions and
rename them to *_fl.
Add trace_printf* and trace_strbuf macros resolving to the *_fl functions
and let the preprocessor fill in __FILE__ and __LINE__.
As the trace_printf* functions take a variable number of arguments, this
requires variadic macros (i.e. '#define foo(...) foo_impl(__VA_ARGS__)'.
Though part of C99, it is unclear whether older compilers support this.
Thus keep the old functions and only enable variadic macros for GNUC and
MSVC 2005+ (_MSC_VER 1400). This has the nice side effect that the old
C-style declarations serve as documentation how the macros are to be used.
Print 'file:line ' as prefix to each trace line. Align the remaining trace
output at column 40 to accommodate 18 char file names + 4 digit line
number (currently there are 30 *.c files of length 18 and just 11 of 19).
Trace output from longer source files (e.g. builtin/receive-pack.c) will
not be aligned.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No functional changes, just move stuff around so that the next patch isn't
that ugly...
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is useful to tell apart trace output of separate test runs.
It can also be used for basic, coarse-grained performance analysis. Note
that the accuracy is tainted by writing to the trace file, and you have to
calculate the deltas yourself (which is next to impossible if multiple
threads or processes are involved).
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some unit-tests use trace output to verify internal state, and unstable
output such as timestamps and line numbers are not useful there.
Disable additional trace output if GIT_TRACE_BARE is set.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To be able to add a common prefix or suffix to all trace output (e.g.
a timestamp or file:line of the caller), factor out common setup and
cleanup tasks of the trace* functions.
When adding a common prefix, it makes sense that the output of each trace
call starts on a new line. Add '\n' in case the caller forgot.
Note that this explicitly limits trace output to line-by-line, it is no
longer possible to trace-print just part of a line. Until now, this was
just an implicit assumption (trace-printing part of a line worked, but
messed up the trace file if multiple threads or processes were involved).
Thread-safety / inter-process-safety is also the reason why we need to do
the prefixing and suffixing in memory rather than issuing multiple write()
calls. Write_or_whine_pipe() / xwrite() is atomic unless the size exceeds
MAX_IO_SIZE (8MB, see wrapper.c). In case of trace_strbuf, this costs an
additional string copy (which should be irrelevant for performance in light
of actual file IO).
While we're at it, rename trace_strbuf's 'buf' argument, which suggests
that the function is modifying the buffer. Trace_strbuf() currently is the
only trace API that can print arbitrary binary data (without barfing on
'%' or stopping at '\0'), so 'data' seems more appropriate.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This changes GIT_TRACE_PACK_ACCESS functionality as follows:
* supports the same options as GIT_TRACE (e.g. printing to stderr)
* no longer supports relative paths
* appends to the trace file rather than overwriting
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Separate GIT_TRACE description into what it prints and how to configure
where trace output is printed to. Change other GIT_TRACE_* descriptions to
refer to GIT_TRACE.
Add descriptions for GIT_TRACE_SETUP and GIT_TRACE_SHALLOW.
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The trace API currently rechecks the environment variable and reopens the
trace file on every API call. This has the ugly side effect that errors
(e.g. file cannot be opened, or the user specified a relative path) are
also reported on every call. Performance can be improved by about factor
three by remembering the environment state and keeping the file open.
Replace the 'const char *key' parameter in the API with a pointer to a
'struct trace_key' that bundles the environment variable name with
additional, trace-internal state. Change the call sites of these APIs to
use a static 'struct trace_key' instead of a string constant.
In trace.c::get_trace_fd(), save and reuse the file descriptor in 'struct
trace_key'.
Add a 'trace_disable()' API, so that packet_trace() can cleanly disable
tracing when it encounters packed data (instead of using unsetenv()).
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We generally want to avoid lookup_unknown_object, because it
results in allocating more memory for the object than may be
strictly necessary.
In this case, it is used to check whether we have an
already-parsed object before calling parse_object, to save
us from reading the object from disk. Using lookup_object
would be fine for that purpose, but we can take it a step
further. Since this code was written, parse_object already
learned the "check lookup_object" optimization, so we can
simply call parse_object directly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of the "index" field of struct commit is that
every allocated commit would have one. It is supposed to be
an invariant that whenever object->type is set to
OBJ_COMMIT, we have a unique index.
Commit 969eba6 (commit: push commit_index update into
alloc_commit_node, 2014-06-10) covered this case for
newly-allocated commits. However, we may also allocate an
"unknown" object via lookup_unknown_object, and only later
convert it to a commit. We must make sure that we set the
commit index when we switch the type field.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We keep a static counter to set the commit index on newly
allocated objects. However, since we also need to set the
index on any_objects which are converted to commits, let's
make the counter available as a public function.
While we're moving it, let's make sure the counter is
allocated as an unsigned integer to match the index field in
"struct commit".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano