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Author SHA1 Message Date
Jeff King
ee1c6c34ac sha1_file: only freshen packs once per run
Since 33d4221 (write_sha1_file: freshen existing objects,
2014-10-15), we update the mtime of existing objects that we
would have written out (had they not existed). For the
common case in which many objects are packed, we may update
the mtime on a single packfile repeatedly. This can result
in a noticeable performance problem if calling utime() is
expensive (e.g., because your storage is on NFS).

We can fix this by keeping a per-pack flag that lets us
freshen only once per program invocation.

An alternative would be to keep the packed_git.mtime flag up
to date as we freshen, and freshen only once every N
seconds. In practice, it's not worth the complexity. We are
racing against prune expiration times here, which inherently
must be set to accomodate reasonable program running times
(because they really care about the time between an object
being written and it becoming referenced, and the latter is
typically the last step a program takes).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-20 13:09:40 -07:00
Jeff King
b5f52f372e sha1_file: freshen pack objects before loose
When writing out an object file, we first check whether it
already exists and if so optimize out the write. Prior to
33d4221, we did this by calling has_sha1_file(), which will
check for packed objects followed by loose. Since that
commit, we check loose objects first.

For the common case of a repository whose objects are mostly
packed, this means we will make a lot of extra access()
system calls checking for loose objects. We should follow
the same packed-then-loose order that all of our other
lookups use.

Reported-by: Stefan Saasen <ssaasen@atlassian.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-20 13:09:38 -07:00
Jeff King
1385bb7ba3 reachable: only mark local objects as recent
When pruning and repacking a repository that has an
alternate object store configured, we may traverse a large
number of objects in the alternate. This serves no purpose,
and may be expensive to do. A longer explanation is below.

Commits d3038d2 and abcb865 taught prune and pack-objects
(respectively) to treat "recent" objects as tips for
reachability, so that we keep whole chunks of history. They
built on the object traversal in 660c889 (sha1_file: add
for_each iterators for loose and packed objects,
2014-10-15), which covers both local and alternate objects.

In both cases, covering alternate objects is unnecessary, as
both commands can only drop objects from the local
repository. In the case of prune, we traverse only the local
object directory. And in the case of repacking, while we may
or may not include local objects in our pack, we will never
reach into the alternate with "repack -d". The "-l" option
is only a question of whether we are migrating objects from
the alternate into our repository, or leaving them
untouched.

It is possible that we may drop an object that is depended
upon by another object in the alternate. For example,
imagine two repositories, A and B, with A pointing to B as
an alternate. Now imagine a commit that is in B which
references a tree that is only in A. Traversing from recent
objects in B might prevent A from dropping that tree. But
this case isn't worth covering. Repo B should take
responsibility for its own objects. It would never have had
the commit in the first place if it did not also have the
tree, and assuming it is using the same "keep recent chunks
of history" scheme, then it would itself keep the tree, as
well.

So checking the alternate objects is not worth doing, and
come with a significant performance impact. In both cases,
we skip any recent objects that have already been marked
SEEN (i.e., that we know are already reachable for prune, or
included in the pack for a repack). So there is a slight
waste of time in opening the alternate packs at all, only to
notice that we have already considered each object. But much
worse, the alternate repository may have a large number of
objects that are not reachable from the local repository at
all, and we end up adding them to the traversal.

We can fix this by considering only local unseen objects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-20 13:09:27 -07:00
Jonathon Mah
b0a4264277 sha1_file: fix iterating loose alternate objects
The string in 'base' contains a path suffix to a specific object;
when its value is used, the suffix must either be filled (as in
stat_sha1_file, open_sha1_file, check_and_freshen_nonlocal) or
cleared (as in prepare_packed_git) to avoid junk at the end.

660c889e (sha1_file: add for_each iterators for loose and packed
objects, 2014-10-15) introduced loose_from_alt_odb(), but this did
neither and treated 'base' as a complete path to the "base" object
directory, instead of a pointer to the "base" of the full path
string.

The trailing path after 'base' is still initialized to NUL, hiding
the bug in some common cases.  Additionally the descendent
for_each_file_in_obj_subdir() function swallows ENOENT, so an error
only shows if the alternate's path was last filled with a valid
object (where statting /path/to/existing/00/0bjectfile/00 fails).

Signed-off-by: Jonathon Mah <me@JonathonMah.com>
Helped-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-09 14:14:56 -08:00
Jeff King
e6f875e052 for_each_loose_file_in_objdir: take an optional strbuf path
We feed a root "objdir" path to this iterator function,
which then copies the result into a strbuf, so that it can
repeatedly append the object sub-directories to it. Let's
make it easy for callers to just pass us a strbuf in the
first place.

We leave the original interface as a convenience for callers
who want to just pass a const string like the result of
get_object_directory().

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-09 14:14:53 -08:00
Jeff King
33d4221c79 write_sha1_file: freshen existing objects
When we try to write a loose object file, we first check
whether that object already exists. If so, we skip the
write as an optimization. However, this can interfere with
prune's strategy of using mtimes to mark files in progress.

For example, if a branch contains a particular tree object
and is deleted, that tree object may become unreachable, and
have an old mtime. If a new operation then tries to write
the same tree, this ends up as a noop; we notice we
already have the object and do nothing. A prune running
simultaneously with this operation will see the object as
old, and may delete it.

We can solve this by "freshening" objects that we avoid
writing by updating their mtime. The algorithm for doing so
is essentially the same as that of has_sha1_file. Therefore
we provide a new (static) interface "check_and_freshen",
which finds and optionally freshens the object. It's trivial
to implement freshening and simple checking by tweaking a
single parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-16 10:10:43 -07:00
Jeff King
660c889e46 sha1_file: add for_each iterators for loose and packed objects
We typically iterate over the reachable objects in a
repository by starting at the tips and walking the graph.
There's no easy way to iterate over all of the objects,
including unreachable ones. Let's provide a way of doing so.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-16 10:10:41 -07:00
Jeff King
27e1e22d5e prune: factor out loose-object directory traversal
Prune has to walk $GIT_DIR/objects/?? in order to find the
set of loose objects to prune. Other parts of the code
(e.g., count-objects) want to do the same. Let's factor it
out into a reusable for_each-style function.

Note that this is not quite a straight code movement. The
original code had strange behavior when it found a file of
the form "[0-9a-f]{2}/.{38}" that did _not_ contain all hex
digits. It executed a "break" from the loop, meaning that we
stopped pruning in that directory (but still pruned other
directories!). This was probably a bug; we do not want to
process the file as an object, but we should keep going
otherwise (and that is how the new code handles it).

We are also a little more careful with loose object
directories which fail to open. The original code silently
ignored any failures, but the new code will complain about
any problems besides ENOENT.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-16 10:10:39 -07:00
Jeff King
fe1b22686f foreach_alt_odb: propagate return value from callback
We check the return value of the callback and stop iterating
if it is non-zero. However, we do not make the non-zero
return value available to the caller, so they have no way of
knowing whether the operation succeeded or not (technically
they can keep their own error flag in the callback data, but
that is unlike our other for_each functions).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-16 10:10:35 -07:00
Junio C Hamano
f0d8900175 Merge branch 'sp/stream-clean-filter'
When running a required clean filter, we do not have to mmap the
original before feeding the filter.  Instead, stream the file
contents directly to the filter and process its output.

* sp/stream-clean-filter:
  sha1_file: don't convert off_t to size_t too early to avoid potential die()
  convert: stream from fd to required clean filter to reduce used address space
  copy_fd(): do not close the input file descriptor
  mmap_limit: introduce GIT_MMAP_LIMIT to allow testing expected mmap size
  memory_limit: use git_env_ulong() to parse GIT_ALLOC_LIMIT
  config.c: add git_env_ulong() to parse environment variable
  convert: drop arguments other than 'path' from would_convert_to_git()
2014-10-08 13:05:32 -07:00
Steffen Prohaska
9079ab7cb6 sha1_file: don't convert off_t to size_t too early to avoid potential die()
xsize_t() checks if an off_t argument can be safely converted to
a size_t return value.  If the check is executed too early, it could
fail for large files on 32-bit architectures even if the size_t code
path is not taken.  Other paths might be able to handle the large file.
Specifically, index_stream_convert_blob() is able to handle a large file
if a filter is configured that returns a small result.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-22 12:40:55 -07:00
Junio C Hamano
bedd3b4b7b Merge branch 'nd/large-blobs'
Teach a few codepaths to punt (instead of dying) when large blobs
that would not fit in core are involved in the operation.

* nd/large-blobs:
  diff: shortcut for diff'ing two binary SHA-1 objects
  diff --stat: mark any file larger than core.bigfilethreshold binary
  diff.c: allow to pass more flags to diff_populate_filespec
  sha1_file.c: do not die failing to malloc in unpack_compressed_entry
  wrapper.c: introduce gentle xmallocz that does not die()
2014-09-11 10:33:33 -07:00
Junio C Hamano
f655651e09 Merge branch 'rs/strbuf-getcwd'
Reduce the use of fixed sized buffer passed to getcwd() calls
by introducing xgetcwd() helper.

* rs/strbuf-getcwd:
  use strbuf_add_absolute_path() to add absolute paths
  abspath: convert absolute_path() to strbuf
  use xgetcwd() to set $GIT_DIR
  use xgetcwd() to get the current directory or die
  wrapper: add xgetcwd()
  abspath: convert real_path_internal() to strbuf
  abspath: use strbuf_getcwd() to remember original working directory
  setup: convert setup_git_directory_gently_1 et al. to strbuf
  unix-sockets: use strbuf_getcwd()
  strbuf: add strbuf_getcwd()
2014-09-02 13:28:44 -07:00
Steffen Prohaska
9035d75a2b convert: stream from fd to required clean filter to reduce used address space
The data is streamed to the filter process anyway.  Better avoid mapping
the file if possible.  This is especially useful if a clean filter
reduces the size, for example if it computes a sha1 for binary data,
like git media.  The file size that the previous implementation could
handle was limited by the available address space; large files for
example could not be handled with (32-bit) msysgit.  The new
implementation can filter files of any size as long as the filter output
is small enough.

The new code path is only taken if the filter is required.  The filter
consumes data directly from the fd.  If it fails, the original data is
not immediately available.  The condition can easily be handled as
a fatal error, which is expected for a required filter anyway.

If the filter was not required, the condition would need to be handled
in a different way, like seeking to 0 and reading the data.  But this
would require more restructuring of the code and is probably not worth
it.  The obvious approach of falling back to reading all data would not
help achieving the main purpose of this patch, which is to handle large
files with limited address space.  If reading all data is an option, we
can simply take the old code path right away and mmap the entire file.

The environment variable GIT_MMAP_LIMIT, which has been introduced in
a previous commit is used to test that the expected code path is taken.
A related test that exercises required filters is modified to verify
that the data actually has been modified on its way from the file system
to the object store.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-28 10:25:15 -07:00
Steffen Prohaska
02710228dd mmap_limit: introduce GIT_MMAP_LIMIT to allow testing expected mmap size
In order to test expectations about mmap in a way similar to testing
expectations about malloc with GIT_ALLOC_LIMIT introduced by
d41489a6 (Add more large blob test cases, 2012-03-07), introduce a
new environment variable GIT_MMAP_LIMIT to limit the largest allowed
mmap length.

xmmap() is modified to check the size of the requested region and
fail it if it is beyond the limit.  Together with GIT_ALLOC_LIMIT
tests can now confirm expectations about memory consumption.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-28 10:25:14 -07:00
Steffen Prohaska
7ce7c7607b convert: drop arguments other than 'path' from would_convert_to_git()
It is only the path that matters in the decision whether to filter
or not.  Clarify this by making path the only argument of
would_convert_to_git().

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-21 15:27:20 -07:00
Nguyễn Thái Ngọc Duy
735efde838 sha1_file.c: do not die failing to malloc in unpack_compressed_entry
Fewer die() gives better control to the caller, provided that the
caller _can_ handle it. And in unpack_compressed_entry() case, it can,
because unpack_compressed_entry() already returns NULL if it fails to
inflate data.

A side effect from this is fsck continues to run when very large blobs
are present (and do not fit in memory).

Noticed-by: Dale R. Worley <worley@alum.mit.edu>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-18 10:15:19 -07:00
Junio C Hamano
9f2de9c121 Merge branch 'kb/perf-trace'
* kb/perf-trace:
  api-trace.txt: add trace API documentation
  progress: simplify performance measurement by using getnanotime()
  wt-status: simplify performance measurement by using getnanotime()
  git: add performance tracing for git's main() function to debug scripts
  trace: add trace_performance facility to debug performance issues
  trace: add high resolution timer function to debug performance issues
  trace: add 'file:line' to all trace output
  trace: move code around, in preparation to file:line output
  trace: add current timestamp to all trace output
  trace: disable additional trace output for unit tests
  trace: add infrastructure to augment trace output with additional info
  sha1_file: change GIT_TRACE_PACK_ACCESS logging to use trace API
  Documentation/git.txt: improve documentation of 'GIT_TRACE*' variables
  trace: improve trace performance
  trace: remove redundant printf format attribute
  trace: consistently name the format parameter
  trace: move trace declarations from cache.h to new trace.h
2014-07-22 10:59:19 -07:00
Junio C Hamano
a8c565b227 Merge branch 'ek/alt-odb-entry-fix'
* ek/alt-odb-entry-fix:
  sha1_file: do not add own object directory as alternate
2014-07-21 11:18:46 -07:00
Junio C Hamano
6e4094731a Merge branch 'jk/strip-suffix'
* jk/strip-suffix:
  prepare_packed_git_one: refactor duplicate-pack check
  verify-pack: use strbuf_strip_suffix
  strbuf: implement strbuf_strip_suffix
  index-pack: use strip_suffix to avoid magic numbers
  use strip_suffix instead of ends_with in simple cases
  replace has_extension with ends_with
  implement ends_with via strip_suffix
  add strip_suffix function
  sha1_file: replace PATH_MAX buffer with strbuf in prepare_packed_git_one()
2014-07-16 11:26:00 -07:00
Junio C Hamano
5a3db94539 Merge branch 'rs/fix-alt-odb-path-comparison' into maint
Code to avoid adding the same alternate object store twice was
subtly broken for a long time, but nobody seems to have noticed.

* rs/fix-alt-odb-path-comparison:
  sha1_file: avoid overrunning alternate object base string
2014-07-16 11:17:08 -07:00
Ephrim Khong
539e75069f sha1_file: do not add own object directory as alternate
When adding alternate object directories, we try not to add the
directory of the current repository to avoid cycles.  Unfortunately,
that test was broken, since it compared an absolute with a relative
path.

Signed-off-by: Ephrim Khong <dr.khong@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-15 11:50:15 -07:00
Karsten Blees
67dc598ec4 sha1_file: change GIT_TRACE_PACK_ACCESS logging to use trace API
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>
2014-07-13 21:25:18 -07:00
Junio C Hamano
b41a4636ee Merge branch 'rs/fix-alt-odb-path-comparison'
* rs/fix-alt-odb-path-comparison:
  sha1_file: avoid overrunning alternate object base string
2014-07-10 11:27:52 -07:00
René Scharfe
80b47854ca sha1_file: avoid overrunning alternate object base string
While checking if a new alternate object database is a duplicate make
sure that old and new base paths have the same length before comparing
them with memcmp.  This avoids overrunning the buffer of the existing
entry if the new one is longer and it stops rejecting foobar/ after
foo/ was already added.

Signed-off-by: Rene Scharfe <ls.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-01 13:30:50 -07:00
Jeff King
47bf4b0fc5 prepare_packed_git_one: refactor duplicate-pack check
When we are reloading the list of packs, we check whether a
particular pack has been loaded. This is slightly tricky,
because we load packs based on the presence of their ".idx"
files, but record the name of the matching ".pack" file.
Therefore we want to compare their bases.

The existing code stripped off ".idx" from a file we found,
then compared that whole base length to strings containing
the ".pack" version. This meant we could end up comparing
bytes past what the ".pack" string contained, if the ".idx"
file name was much longer.

In practice, it worked OK because memcmp would end up seeing
a difference in the two strings and would return early
before hitting the full length. However, memcmp may
sometimes read extra bytes past a difference (e.g., because
it is comparing 64-bit words), or is even free to compare in
reverse order.

Furthermore, our memcmp made no guarantees that we matched
the whole pack name, up to ".pack". So "foo.idx" would match
"foo-bar.pack", which is wrong (but does not typically
happen, because our pack names have a fixed size).

We can fix both issues, avoid magic numbers, and document
that we expect to compare against a string with ".pack" by
using strip_suffix.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-30 13:43:32 -07:00
Jeff King
2975c770ca replace has_extension with ends_with
These two are almost the same function, with the exception
that has_extension only matches if there is content before
the suffix. So ends_with(".exe", ".exe") is true, but
has_extension would not be.

This distinction does not matter to any of the callers,
though, and we can just replace uses of has_extension with
ends_with. We prefer the "ends_with" name because it is more
generic, and there is nothing about the function that
requires it to be used for file extensions.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-30 13:43:16 -07:00
René Scharfe
880fb8de67 sha1_file: replace PATH_MAX buffer with strbuf in prepare_packed_git_one()
Instead of using strbuf to create a message string in case a path is
too long for our fixed-size buffer, replace that buffer with a strbuf
and thus get rid of the limitation.

Helped-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-30 13:43:16 -07:00
Junio C Hamano
81bd9b1000 Merge branch 'jk/report-fail-to-read-objects-better' into maint
Reworded the error message given upon a failure to open an existing
loose object file due to e.g. permission issues; it was reported as
the object being corrupt, but that is not quite true.

* jk/report-fail-to-read-objects-better:
  open_sha1_file: report "most interesting" errno
2014-06-25 11:43:58 -07:00
Junio C Hamano
9d1d882e9c Merge branch 'jk/report-fail-to-read-objects-better'
* jk/report-fail-to-read-objects-better:
  open_sha1_file: report "most interesting" errno
2014-06-16 10:06:15 -07:00
Jeff King
d6c8a05bd5 open_sha1_file: report "most interesting" errno
When we try to open a loose object file, we first attempt to
open in the local object database, and then try any
alternates. This means that the errno value when we return
will be from the last place we looked (and due to the way
the code is structured, simply ENOENT if we do not have have
any alternates).

This can cause confusing error messages, as read_sha1_file
checks for ENOENT when reporting a missing object. If errno
is something else, we report that. If it is ENOENT, but
has_loose_object reports that we have it, then we claim the
object is corrupted. For example:

    $ chmod 0 .git/objects/??/*
    $ git rev-list --all
    fatal: loose object b2d6fab18b92d49eac46dc3c5a0bcafabda20131 (stored in .git/objects/b2/d6fab18b92d49eac46dc3c5a0bcafabda20131) is corrupt

This patch instead keeps track of the "most interesting"
errno we receive during our search. We consider ENOENT to be
the least interesting of all, and otherwise report the first
error found (so problems in the object database take
precedence over ones in alternates). Here it is with this
patch:

    $ git rev-list --all
    fatal: failed to read object b2d6fab18b92d49eac46dc3c5a0bcafabda20131: Permission denied

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-05-15 10:03:06 -07:00
Junio C Hamano
d59c12d7ad Merge branch 'jl/nor-or-nand-and'
Eradicate mistaken use of "nor" (that is, essentially "nor" used
not in "neither A nor B" ;-)) from in-code comments, command output
strings, and documentations.

* jl/nor-or-nand-and:
  code and test: fix misuses of "nor"
  comments: fix misuses of "nor"
  contrib: fix misuses of "nor"
  Documentation: fix misuses of "nor"
2014-04-08 12:00:28 -07:00
Justin Lebar
235e8d5914 code and test: fix misuses of "nor"
Signed-off-by: Justin Lebar <jlebar@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-31 15:29:33 -07:00
Justin Lebar
01689909eb comments: fix misuses of "nor"
Signed-off-by: Justin Lebar <jlebar@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-31 15:29:27 -07:00
Junio C Hamano
fe9122a352 Merge branch 'dd/use-alloc-grow'
Replace open-coded reallocation with ALLOC_GROW() macro.

* dd/use-alloc-grow:
  sha1_file.c: use ALLOC_GROW() in pretend_sha1_file()
  read-cache.c: use ALLOC_GROW() in add_index_entry()
  builtin/mktree.c: use ALLOC_GROW() in append_to_tree()
  attr.c: use ALLOC_GROW() in handle_attr_line()
  dir.c: use ALLOC_GROW() in create_simplify()
  reflog-walk.c: use ALLOC_GROW()
  replace_object.c: use ALLOC_GROW() in register_replace_object()
  patch-ids.c: use ALLOC_GROW() in add_commit()
  diffcore-rename.c: use ALLOC_GROW()
  diff.c: use ALLOC_GROW()
  commit.c: use ALLOC_GROW() in register_commit_graft()
  cache-tree.c: use ALLOC_GROW() in find_subtree()
  bundle.c: use ALLOC_GROW() in add_to_ref_list()
  builtin/pack-objects.c: use ALLOC_GROW() in check_pbase_path()
2014-03-18 13:50:21 -07:00
Junio C Hamano
decba94d2c Merge branch 'nd/sha1-file-delta-stack-leakage-fix'
Fix a small leak in the delta stack used when resolving a long
delta chain at runtime.

* nd/sha1-file-delta-stack-leakage-fix:
  sha1_file: fix delta_stack memory leak in unpack_entry
2014-03-18 13:49:23 -07:00
Junio C Hamano
060be00621 Merge branch 'mh/object-code-cleanup'
* mh/object-code-cleanup:
  sha1_file.c: document a bunch of functions defined in the file
  sha1_file_name(): declare to return a const string
  find_pack_entry(): document last_found_pack
  replace_object: use struct members instead of an array
2014-03-14 14:26:29 -07:00
Dmitry S. Dolzhenko
c7353967ca sha1_file.c: use ALLOC_GROW() in pretend_sha1_file()
Helped-by: He Sun <sunheehnus@gmail.com>
Signed-off-by: Dmitry S. Dolzhenko <dmitrys.dolzhenko@yandex.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-03 14:54:58 -08:00
Junio C Hamano
0f9e62e084 Merge branch 'jk/pack-bitmap'
Borrow the bitmap index into packfiles from JGit to speed up
enumeration of objects involved in a commit range without having to
fully traverse the history.

* jk/pack-bitmap: (26 commits)
  ewah: unconditionally ntohll ewah data
  ewah: support platforms that require aligned reads
  read-cache: use get_be32 instead of hand-rolled ntoh_l
  block-sha1: factor out get_be and put_be wrappers
  do not discard revindex when re-preparing packfiles
  pack-bitmap: implement optional name_hash cache
  t/perf: add tests for pack bitmaps
  t: add basic bitmap functionality tests
  count-objects: recognize .bitmap in garbage-checking
  repack: consider bitmaps when performing repacks
  repack: handle optional files created by pack-objects
  repack: turn exts array into array-of-struct
  repack: stop using magic number for ARRAY_SIZE(exts)
  pack-objects: implement bitmap writing
  rev-list: add bitmap mode to speed up object lists
  pack-objects: use bitmaps when packing objects
  pack-objects: split add_object_entry
  pack-bitmap: add support for bitmap indexes
  documentation: add documentation for the bitmap format
  ewah: compressed bitmap implementation
  ...
2014-02-27 14:01:48 -08:00
Michael Haggerty
d40d535b89 sha1_file.c: document a bunch of functions defined in the file
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 16:01:11 -08:00
Michael Haggerty
30d6c6eabf sha1_file_name(): declare to return a const string
Change the return value of sha1_file_name() to (const char *).
(Callers have no business mucking about here.)  Change callers
accordingly, deleting a few superfluous temporary variables along the
way.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 09:10:22 -08:00
Michael Haggerty
1b1005d1b5 find_pack_entry(): document last_found_pack
Add a comment at the declaration of last_found_pack and where it is
used in find_pack_entry().  In the latter, separate the cases (1) to
make a place for the new comment and (2) to turn the success case into
affirmative logic.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 09:09:56 -08:00
Nguyễn Thái Ngọc Duy
019d1e65f5 sha1_file: fix delta_stack memory leak in unpack_entry
This delta_stack array can grow to any length depending on the actual
delta chain, but we forget to free it. Normally it does not matter
because we use small_delta_stack[] from stack and small_delta_stack
can hold 64-delta chains, more than standard --depth=50 in pack-objects.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-24 09:07:12 -08:00
Junio C Hamano
33d4669aaa Merge branch 'ss/safe-create-leading-dir-with-slash'
"git clone $origin foo\bar\baz" on Windows failed to create the
leading directories (i.e. a moral-equivalent of "mkdir -p").

* ss/safe-create-leading-dir-with-slash:
  safe_create_leading_directories(): on Windows, \ can separate path components
2014-01-27 10:45:37 -08:00
Junio C Hamano
d0956cfa8e Merge branch 'mh/safe-create-leading-directories'
Code clean-up and protection against concurrent write access to the
ref namespace.

* mh/safe-create-leading-directories:
  rename_tmp_log(): on SCLD_VANISHED, retry
  rename_tmp_log(): limit the number of remote_empty_directories() attempts
  rename_tmp_log(): handle a possible mkdir/rmdir race
  rename_ref(): extract function rename_tmp_log()
  remove_dir_recurse(): handle disappearing files and directories
  remove_dir_recurse(): tighten condition for removing unreadable dir
  lock_ref_sha1_basic(): if locking fails with ENOENT, retry
  lock_ref_sha1_basic(): on SCLD_VANISHED, retry
  safe_create_leading_directories(): add new error value SCLD_VANISHED
  cmd_init_db(): when creating directories, handle errors conservatively
  safe_create_leading_directories(): introduce enum for return values
  safe_create_leading_directories(): always restore slash at end of loop
  safe_create_leading_directories(): split on first of multiple slashes
  safe_create_leading_directories(): rename local variable
  safe_create_leading_directories(): add explicit "slash" pointer
  safe_create_leading_directories(): reduce scope of local variable
  safe_create_leading_directories(): fix format of "if" chaining
2014-01-27 10:45:33 -08:00
Michael Haggerty
0f5274033e safe_create_leading_directories(): on Windows, \ can separate path components
When cloning to a directory "C:\foo\bar" from Windows' cmd.exe where
"foo" does not exist yet, Git would throw an error like

    fatal: could not create work tree dir 'c:\foo\bar'.: No such file or directory

Fix this by not hard-coding a platform specific directory separator
into safe_create_leading_directories().

This patch, including its entire commit message, is derived from a
patch by Sebastian Schuberth.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-22 11:00:07 -08:00
Jeff King
1a6d8b9148 do not discard revindex when re-preparing packfiles
When an object lookup fails, we re-read the objects/pack
directory to pick up any new packfiles that may have been
created since our last read. We also discard any pack
revindex structs we've allocated.

The discarding is a problem for the pack-bitmap code, which keeps
a pointer to the revindex for the bitmapped pack. After the
discard, the pointer is invalid, and we may read free()d
memory.

Other revindex users do not keep a bare pointer to the
revindex; instead, they always access it through
revindex_for_pack(), which lazily builds the revindex. So
one solution is to teach the pack-bitmap code a similar
trick. It would be slightly less efficient, but probably not
all that noticeable.

However, it turns out this discarding is not actually
necessary. When we call reprepare_packed_git, we do not
throw away our old pack list. We keep the existing entries,
and only add in new ones. So there is no safety problem; we
will still have the pack struct that matches each revindex.
The packfile itself may go away, of course, but we are
already prepared to handle that, and it may happen outside
of reprepare_packed_git anyway.

Throwing away the revindex may save some RAM if the pack
never gets reused (about 12 bytes per object). But it also
wastes some CPU time (to regenerate the index) if the pack
does get reused. It's hard to say which is more valuable,
but in either case, it happens very rarely (only when we
race with a simultaneous repack). Just leaving the revindex
in place is simple and safe both for current and future
code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-16 14:33:46 -08:00
Junio C Hamano
b2132068c6 Merge branch 'jk/oi-delta-base'
Teach "cat-file --batch" to show delta-base object name for a
packed object that is represented as a delta.

* jk/oi-delta-base:
  cat-file: provide %(deltabase) batch format
  sha1_object_info_extended: provide delta base sha1s
2014-01-10 10:33:11 -08:00
Junio C Hamano
c4bccea2d5 Merge branch 'jh/rlimit-nofile-fallback'
When we figure out how many file descriptors to allocate for
keeping packfiles open, a system with non-working getrlimit() could
cause us to die(), but because we make this call only to get a
rough estimate of how many is available and we do not even attempt
to use up all file descriptors available ourselves, it is nicer to
fall back to a reasonable low value rather than dying.

* jh/rlimit-nofile-fallback:
  get_max_fd_limit(): fall back to OPEN_MAX upon getrlimit/sysconf failure
2014-01-10 10:32:28 -08:00
Junio C Hamano
b0504a9519 Merge branch 'cc/replace-object-info'
read_sha1_file() that is the workhorse to read the contents given
an object name honoured object replacements, but there is no
corresponding mechanism to sha1_object_info() that is used to
obtain the metainfo (e.g. type & size) about the object, leading
callers to weird inconsistencies.

* cc/replace-object-info:
  replace info: rename 'full' to 'long' and clarify in-code symbols
  Documentation/git-replace: describe --format option
  builtin/replace: unset read_replace_refs
  t6050: add tests for listing with --format
  builtin/replace: teach listing using short, medium or full formats
  sha1_file: perform object replacement in sha1_object_info_extended()
  t6050: show that git cat-file --batch fails with replace objects
  sha1_object_info_extended(): add an "unsigned flags" parameter
  sha1_file.c: add lookup_replace_object_extended() to pass flags
  replace_object: don't check read_replace_refs twice
  rename READ_SHA1_FILE_REPLACE flag to LOOKUP_REPLACE_OBJECT
2014-01-10 10:32:10 -08:00