git/shallow.c, branch v2.2.0

Merge branch 'eb/no-pthreads'

2014-10-24T21:59:10Z

Allow us build with NO_PTHREADS=NoThanks compilation option. * eb/no-pthreads: Handle atexit list internaly for unthreaded builds pack-objects: set number of threads before checking and warning index-pack: fix compilation with NO_PTHREADS

Handle atexit list internaly for unthreaded builds

2014-10-19T22:38:30Z

Wrap atexit()s calls on unthreaded builds to handle callback list internally. This is needed because on unthreaded builds, asyncs inherits parent's atexit() list, that gets run as soon as the async exit()s (and again at the end of async's parent process). That led to remove temporary files too early. Also remove a by-atexit-callback guard against this kind of issue in clone.c, as this patch makes it redundant. Fixes test 5537 (temporary shallow file vanished before unpack-objects could open it) BTW remove an unused variable in shallow.c. Helped-by: Duy Nguyen Helped-by: Andreas Schwab Helped-by: Junio C Hamano Signed-off-by: Etienne Buira Signed-off-by: Junio C Hamano

lockfile.h: extract new header file for the functions in lockfile.c

2014-10-01T20:56:14Z

Move the interface declaration for the functions in lockfile.c from cache.h to a new file, lockfile.h. Add #includes where necessary (and remove some redundant includes of cache.h by files that already include builtin.h). Move the documentation of the lock_file state diagram from lockfile.c to the new header file. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

lockfile: change lock_file::filename into a strbuf

2014-10-01T20:50:01Z

For now, we still make sure to allocate at least PATH_MAX characters for the strbuf because resolve_symlink() doesn't know how to expand the space for its return value. (That will be fixed in a moment.) Another alternative would be to just use a strbuf as scratch space in lock_file() but then store a pointer to the naked string in struct lock_file. But lock_file objects are often reused. By reusing the same strbuf, we can avoid having to reallocate the string most times when a lock_file object is reused. Helped-by: Torsten Bögershausen Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano

use REALLOC_ARRAY for changing the allocation size of arrays

2014-09-18T16:13:42Z

Signed-off-by: Rene Scharfe Signed-off-by: Junio C Hamano

trace: improve trace performance

2014-07-14T04:24:23Z

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 Signed-off-by: Junio C Hamano

shallow: verify shallow file after taking lock

2014-03-17T22:03:32Z

Before writing the shallow file, we stat() the existing file to make sure it has not been updated since our operation began. However, we do not do so under a lock, so there is a possible race: 1. Process A takes the lock. 2. Process B calls check_shallow_file_for_update and finds no update. 3. Process A commits the lockfile. 4. Process B takes the lock, then overwrite's process A's changes. We can fix this by doing our check while we hold the lock. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

shallow: automatically clean up shallow tempfiles

2014-02-27T20:07:13Z

We sometimes write tempfiles of the form "shallow_XXXXXX" during fetch/push operations with shallow repositories. Under normal circumstances, we clean up the result when we are done. However, we do no take steps to clean up after ourselves when we exit due to die() or signal death. This patch teaches the tempfile creation code to register handlers to clean up after ourselves. To handle this, we change the ownership semantics of the filename returned by setup_temporary_shallow. It now keeps a copy of the filename itself, and returns only a const pointer to it. We can also do away with explicit tempfile removal in the callers. They all exit not long after finishing with the file, so they can rely on the auto-cleanup, simplifying the code. Note that we keep things simple and maintain only a single filename to be cleaned. This is sufficient for the current caller, but we future-proof it with a die("BUG"). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

shallow: use stat_validity to check for up-to-date file

2014-02-27T20:04:23Z

When we are about to write the shallow file, we check that it has not changed since we last read it. Instead of hand-rolling this, we can use stat_validity. This is built around the index stat-check, so it is more robust than just checking the mtime, as we do now (it uses the same check as we do for index files). The new code also handles the case of a shallow file appearing unexpectedly. With the current code, two simultaneous processes making us shallow (e.g., two "git fetch --depth=1" running at the same time in a non-shallow repository) can race to overwrite each other. As a bonus, we also remove a race in determining the stat information of what we read (we stat and then open, leaving a race window; instead we should open and then fstat the descriptor). Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'nd/shallow-clone'

2014-01-17T20:21:20Z

Fetching from a shallow-cloned repository used to be forbidden, primarily because the codepaths involved were not carefully vetted and we did not bother supporting such usage. This attempts to allow object transfer out of a shallow-cloned repository in a controlled way (i.e. the receiver become a shallow repository with truncated history). * nd/shallow-clone: (31 commits) t5537: fix incorrect expectation in test case 10 shallow: remove unused code send-pack.c: mark a file-local function static git-clone.txt: remove shallow clone limitations prune: clean .git/shallow after pruning objects clone: use git protocol for cloning shallow repo locally send-pack: support pushing from a shallow clone via http receive-pack: support pushing to a shallow clone via http smart-http: support shallow fetch/clone remote-curl: pass ref SHA-1 to fetch-pack as well send-pack: support pushing to a shallow clone receive-pack: allow pushes that update .git/shallow connected.c: add new variant that runs with --shallow-file add GIT_SHALLOW_FILE to propagate --shallow-file to subprocesses receive/send-pack: support pushing from a shallow clone receive-pack: reorder some code in unpack() fetch: add --update-shallow to accept refs that update .git/shallow upload-pack: make sure deepening preserves shallow roots fetch: support fetching from a shallow repository clone: support remote shallow repository ...