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Author SHA1 Message Date
Junio C Hamano
d243a323a5 Merge branch 'ph/pack-objects-mutex-fix'
"git pack-objects" incorrectly used uninitialized mutex, which has
been corrected.

* ph/pack-objects-mutex-fix:
  pack-objects: merge read_lock and lock in packing_data struct
  pack-objects: move read mutex to packing_data struct
2019-02-05 14:26:16 -08:00
Junio C Hamano
371820d5f1 Merge branch 'bc/tree-walk-oid'
The code to walk tree objects has been taught that we may be
working with object names that are not computed with SHA-1.

* bc/tree-walk-oid:
  cache: make oidcpy always copy GIT_MAX_RAWSZ bytes
  tree-walk: store object_id in a separate member
  match-trees: use hashcpy to splice trees
  match-trees: compute buffer offset correctly when splicing
  tree-walk: copy object ID before use
2019-01-29 12:47:56 -08:00
Patrick Hogg
edb673cf10 pack-objects: merge read_lock and lock in packing_data struct
Rename the packing_data lock to obd_lock and upgrade it to a recursive
mutex to make it suitable for current read_lock usages. Additionally
remove the superfluous #ifndef NO_PTHREADS guard around mutex
initialization in prepare_packing_data as the mutex functions
themselves are already protected.

Signed-off-by: Patrick Hogg <phogg@novamoon.net>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-28 11:22:12 -08:00
Patrick Hogg
459307b139 pack-objects: move read mutex to packing_data struct
ac77d0c37 ("pack-objects: shrink size field in struct object_entry",
2018-04-14) added an extra usage of read_lock/read_unlock in the newly
introduced oe_get_size_slow for thread safety in parallel calls to
try_delta(). Unfortunately oe_get_size_slow is also used in serial
code, some of which is called before the first invocation of
ll_find_deltas. As such the read mutex is not guaranteed to be
initialized.

Resolve this by moving the read mutex to packing_data and initializing
it in prepare_packing_data which is initialized in cmd_pack_objects.

Signed-off-by: Patrick Hogg <phogg@novamoon.net>
Reviewed-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-28 11:22:06 -08:00
brian m. carlson
ea82b2a085 tree-walk: store object_id in a separate member
When parsing a tree, we read the object ID directly out of the tree
buffer. This is normally fine, but such an object ID cannot be used with
oidcpy, which copies GIT_MAX_RAWSZ bytes, because if we are using SHA-1,
there may not be that many bytes to copy.

Instead, store the object ID in a separate struct member. Since we can
no longer efficiently compute the path length, store that information as
well in struct name_entry. Ensure we only copy the object ID into the
new buffer if the path length is nonzero, as some callers will pass us
an empty path with no object ID following it, and we will not want to
read past the end of the buffer.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-15 09:57:41 -08:00
Junio C Hamano
6e5be1f2d5 Merge branch 'md/exclude-promisor-objects-fix-cleanup'
Code clean-up.

* md/exclude-promisor-objects-fix-cleanup:
  revision.c: put promisor option in specialized struct
2019-01-14 15:29:31 -08:00
Junio C Hamano
cde555480b Merge branch 'nd/the-index'
More codepaths become aware of working with in-core repository
instance other than the default "the_repository".

* nd/the-index: (22 commits)
  rebase-interactive.c: remove the_repository references
  rerere.c: remove the_repository references
  pack-*.c: remove the_repository references
  pack-check.c: remove the_repository references
  notes-cache.c: remove the_repository references
  line-log.c: remove the_repository reference
  diff-lib.c: remove the_repository references
  delta-islands.c: remove the_repository references
  cache-tree.c: remove the_repository references
  bundle.c: remove the_repository references
  branch.c: remove the_repository reference
  bisect.c: remove the_repository reference
  blame.c: remove implicit dependency the_repository
  sequencer.c: remove implicit dependency on the_repository
  sequencer.c: remove implicit dependency on the_index
  transport.c: remove implicit dependency on the_index
  notes-merge.c: remove implicit dependency the_repository
  notes-merge.c: remove implicit dependency on the_index
  list-objects.c: reduce the_repository references
  list-objects-filter.c: remove implicit dependency on the_index
  ...
2019-01-04 13:33:33 -08:00
Matthew DeVore
bbcde41a70 revision.c: put promisor option in specialized struct
Put the allow_exclude_promisor_objects flag in setup_revision_opt. When
it was in rev_info, it was unclear when it was used, since rev_info is
passed to functions that don't use the flag. This resulted in
unnecessary setting of the flag in prune.c, so fix that as well.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-06 14:52:56 +09:00
Junio C Hamano
7fab474656 Merge branch 'cc/delta-islands'
A few issues in the implementation of "delta-islands" feature has
been corrected.

* cc/delta-islands:
  pack-objects: fix off-by-one in delta-island tree-depth computation
  pack-objects: zero-initialize tree_depth/layer arrays
  pack-objects: fix tree_depth and layer invariants
2018-11-21 20:39:02 +09:00
Jeff King
3949053617 pack-objects: fix off-by-one in delta-island tree-depth computation
When delta-islands are in use, we need to record the deepest path at
which we find each tree and blob. Our loop to do so counts slashes, so
"foo" is depth 0, "foo/bar" is depth 1, and so on.

However, this neglects root trees, which are represented by the empty
string. Those also have depth 0, but are at a layer above "foo". Thus,
"foo" should be 1, "foo/bar" at 2, and so on. We use this depth to
topo-sort the trees in resolve_tree_islands(). As a result, we may fail
to visit a root tree before the sub-trees it contains, and therefore not
correctly pass down the island marks.

That in turn could lead to missing some delta opportunities (objects are
in the same island, but we didn't realize it) or creating unwanted
cross-island deltas (one object is in an island another isn't, but we
don't realize). In practice, it seems to have only a small effect.  Some
experiments on the real-world git/git fork network at GitHub showed an
improvement of only 0.14% in the resulting clone size.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-21 13:50:28 +09:00
Junio C Hamano
f5f0f68d61 Merge branch 'tb/print-size-t-with-uintmax-format'
Code preparation to replace ulong vars with size_t vars where
appropriate.

* tb/print-size-t-with-uintmax-format:
  Upcast size_t variables to uintmax_t when printing
2018-11-19 16:24:41 +09:00
Junio C Hamano
137399934d Merge branch 'ds/push-squelch-ambig-warning'
"git push" used to check ambiguities between object-names and
refnames while processing the list of refs' old and new values,
which was unnecessary (as it knew that it is feeding raw object
names).  This has been optimized out.

* ds/push-squelch-ambig-warning:
  pack-objects: ignore ambiguous object warnings
2018-11-19 16:24:40 +09:00
Junio C Hamano
ab96f28ba4 Merge branch 'jk/unused-parameter-fixes'
Various functions have been audited for "-Wunused-parameter" warnings
and bugs in them got fixed.

* jk/unused-parameter-fixes:
  midx: double-check large object write loop
  assert NOARG/NONEG behavior of parse-options callbacks
  parse-options: drop OPT_DATE()
  apply: return -1 from option callback instead of calling exit(1)
  cat-file: report an error on multiple --batch options
  tag: mark "--message" option with NONEG
  show-branch: mark --reflog option as NONEG
  format-patch: mark "--no-numbered" option with NONEG
  status: mark --find-renames option with NONEG
  cat-file: mark batch options with NONEG
  pack-objects: mark index-version option as NONEG
  ls-files: mark exclude options as NONEG
  am: handle --no-patch-format option
  apply: mark include/exclude options as NONEG
2018-11-18 18:23:53 +09:00
Junio C Hamano
26b80a841a Merge branch 'nd/pthreads'
The codebase has been cleaned up to reduce "#ifndef NO_PTHREADS".

* nd/pthreads:
  Clean up pthread_create() error handling
  read-cache.c: initialize copy_len to shut up gcc 8
  read-cache.c: reduce branching based on HAVE_THREADS
  read-cache.c: remove #ifdef NO_PTHREADS
  pack-objects: remove #ifdef NO_PTHREADS
  preload-index.c: remove #ifdef NO_PTHREADS
  grep: clean up num_threads handling
  grep: remove #ifdef NO_PTHREADS
  attr.c: remove #ifdef NO_PTHREADS
  name-hash.c: remove #ifdef NO_PTHREADS
  index-pack: remove #ifdef NO_PTHREADS
  send-pack.c: move async's #ifdef NO_PTHREADS back to run-command.c
  run-command.h: include thread-utils.h instead of pthread.h
  thread-utils: macros to unconditionally compile pthreads API
2018-11-18 18:23:52 +09:00
Torsten Bögershausen
ca473cef91 Upcast size_t variables to uintmax_t when printing
When printing variables which contain a size, today "unsigned long"
is used at many places.
In order to be able to change the type from "unsigned long" into size_t
some day in the future, we need to have a way to print 64 bit variables
on a system that has "unsigned long" defined to be 32 bit, like Win64.

Upcast all those variables into uintmax_t before they are printed.
This is to prepare for a bigger change, when "unsigned long"
will be converted into size_t for variables which may be > 4Gib.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 16:43:52 +09:00
Nguyễn Thái Ngọc Duy
7c14112741 pack-*.c: remove the_repository references
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:50:06 +09:00
Nguyễn Thái Ngọc Duy
385cb64ff3 delta-islands.c: remove the_repository references
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:50:06 +09:00
Derrick Stolee
a4544b311e pack-objects: ignore ambiguous object warnings
A git push process runs several processes during its run, but one
includes git send-pack which calls git pack-objects and passes
the known have/wants into stdin using object ids. However, the
default setting for core.warnAmbiguousRefs requires git pack-objects
to check for ref names matching the ref_rev_parse_rules array in
refs.c. This means that every object is triggering at least six
"file exists?" queries.  When there are a lot of refs, this can
add up significantly! I observed a simple push spending three
seconds checking these paths.

The fix here is similar to 4c30d50 "rev-list: disable object/refname
ambiguity check with --stdin".  While the get_object_list() method
reads the objects from stdin, turn warn_on_object_refname_ambiguity
flag (which is usually true) to false.  Just for code hygiene, save
away the original at the beginning and restore it once we are done.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-07 10:49:58 +09:00
Junio C Hamano
a29b8bcf62 Merge branch 'md/exclude-promisor-objects-fix'
Operations on promisor objects make sense in the context of only a
small subset of the commands that internally use the revisions
machinery, but the "--exclude-promisor-objects" option were taken
and led to nonsense results by commands like "log", to which it
didn't make much sense.  This has been corrected.

* md/exclude-promisor-objects-fix:
  exclude-promisor-objects: declare when option is allowed
  Documentation/git-log.txt: do not show --exclude-promisor-objects
2018-11-06 15:50:21 +09:00
Jeff King
517fe807d6 assert NOARG/NONEG behavior of parse-options callbacks
When we define a parse-options callback, the flags we put in the option
struct must match what the callback expects. For example, a callback
which does not handle the "unset" parameter should only be used with
PARSE_OPT_NONEG. But since the callback and the option struct are not
defined next to each other, it's easy to get this wrong (as earlier
patches in this series show).

Fortunately, the compiler can help us here: compiling with
-Wunused-parameters can show us which callbacks ignore their "unset"
parameters (and likewise, ones that ignore "arg" expect to be triggered
with PARSE_OPT_NOARG).

But after we've inspected a callback and determined that all of its
callers use the right flags, what do we do next? We'd like to silence
the compiler warning, but do so in a way that will catch any wrong calls
in the future.

We can do that by actually checking those variables and asserting that
they match our expectations. Because this is such a common pattern,
we'll introduce some helper macros. The resulting messages aren't
as descriptive as we could make them, but the file/line information from
BUG() is enough to identify the problem (and anyway, the point is that
these should never be seen).

Each of the annotated callbacks in this patch triggers
-Wunused-parameters, and was manually inspected to make sure all callers
use the correct options (so none of these BUGs should be triggerable).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-06 12:56:29 +09:00
Jeff King
f53c163bcd pack-objects: mark index-version option as NONEG
Running "git pack-objects --no-index-version" will segfault, since the
callback is not prepared to handle the "unset" flag.

In theory this might be used to counteract an earlier "--index-version",
or override a pack.indexversion config setting. But the semantics aren't
immediately obvious, and it's unlikely anybody wants this. Let's just
disable the broken option for now.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-06 12:55:35 +09:00
Nguyễn Thái Ngọc Duy
9c897c5c2a pack-objects: remove #ifdef NO_PTHREADS
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-05 13:42:11 +09:00
Junio C Hamano
620b00e167 Merge branch 'js/pack-objects-mutex-init-fix'
A mutex used in "git pack-objects" were not correctly initialized
and this caused "git repack" to dump core on Windows.

* js/pack-objects-mutex-init-fix:
  pack-objects (mingw): initialize `packing_data` mutex in the correct spot
  pack-objects (mingw): demonstrate a segmentation fault with large deltas
  pack-objects: fix typo 'detla' -> 'delta'
2018-10-30 15:43:43 +09:00
Matthew DeVore
669b1d2aae exclude-promisor-objects: declare when option is allowed
The --exclude-promisor-objects option causes some funny behavior in at
least two commands: log and blame. It causes a BUG crash:

	$ git log --exclude-promisor-objects
	BUG: revision.c:2143: exclude_promisor_objects can only be used
	when fetch_if_missing is 0
	Aborted
	[134]

Fix this such that the option is treated like any other unknown option.
The commands that must support it are limited, so declare in those
commands that the flag is supported. In particular:

	pack-objects
	prune
	rev-list

The commands were found by searching for logic which parses
--exclude-promisor-objects outside of revision.c. Extra logic outside of
revision.c is needed because fetch_if_missing must be turned on before
revision.c sees the option or it will BUG-crash. The above list is
supported by the fact that no other command is introspectively invoked
by another command passing --exclude-promisor-object.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-23 13:52:57 +09:00
Johannes Schindelin
34204c8166 pack-objects (mingw): initialize packing_data mutex in the correct spot
In 9ac3f0e5b3 (pack-objects: fix performance issues on packing large
deltas, 2018-07-22), a mutex was introduced that is used to guard the
call to set the delta size. This commit even added code to initialize
it, but at an incorrect spot: in `init_threaded_search()`, while the
call to `oe_set_delta_size()` (and hence to `packing_data_lock()`) can
happen in the call chain `check_object()` <- `get_object_details()` <-
`prepare_pack()` <- `cmd_pack_objects()`, which is long before the
`prepare_pack()` function calls `ll_find_deltas()` (which initializes
the threaded search).

Another tell-tale that the mutex was initialized in an incorrect spot is
that the function to initialize it lives in builtin/, while the code
that uses the mutex is defined in a libgit.a header file.

Let's use a more appropriate function: `prepare_packing_data()`, which
not only lives in libgit.a, but *has* to be called before the
`packing_data` struct is used that contains that mutex.

This fixes https://github.com/git-for-windows/git/issues/1839.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-19 14:28:44 +09:00
Junio C Hamano
11877b9ebe Merge branch 'nd/the-index'
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".

* nd/the-index: (23 commits)
  revision.c: reduce implicit dependency the_repository
  revision.c: remove implicit dependency on the_index
  ws.c: remove implicit dependency on the_index
  tree-diff.c: remove implicit dependency on the_index
  submodule.c: remove implicit dependency on the_index
  line-range.c: remove implicit dependency on the_index
  userdiff.c: remove implicit dependency on the_index
  rerere.c: remove implicit dependency on the_index
  sha1-file.c: remove implicit dependency on the_index
  patch-ids.c: remove implicit dependency on the_index
  merge.c: remove implicit dependency on the_index
  merge-blobs.c: remove implicit dependency on the_index
  ll-merge.c: remove implicit dependency on the_index
  diff-lib.c: remove implicit dependency on the_index
  read-cache.c: remove implicit dependency on the_index
  diff.c: remove implicit dependency on the_index
  grep.c: remove implicit dependency on the_index
  diff.c: remove the_index dependency in textconv() functions
  blame.c: rename "repo" argument to "r"
  combine-diff.c: remove implicit dependency on the_index
  ...
2018-10-19 13:34:02 +09:00
Junio C Hamano
73b9c6f583 Merge branch 'jk/delta-islands-with-bitmap-reuse-delta-fix'
Fix interactions between two recent topics.

* jk/delta-islands-with-bitmap-reuse-delta-fix:
  pack-objects: handle island check for "external" delta base
2018-10-16 16:16:00 +09:00
Junio C Hamano
10de0f802d Merge branch 'tb/void-check-attr'
Code clean-up.

* tb/void-check-attr:
  Make git_check_attr() a void function
2018-09-24 10:30:45 -07:00
Nguyễn Thái Ngọc Duy
2abf350385 revision.c: remove implicit dependency on the_index
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:51:19 -07:00
Jeff King
2fa233a554 pack-objects: handle island check for "external" delta base
Two recent topics, jk/pack-delta-reuse-with-bitmap and
cc/delta-islands, can have a funny interaction. When
checking if we can reuse an on-disk delta, the first topic
allows base_entry to be NULL when we find an object that's
not in the packing list. But the latter topic introduces a
call to in_same_island(), which needs to look at
base_entry->idx.oid. When these two features are used
together, we might try to dereference a NULL base_entry.

In practice, this doesn't really happen. We'd generally only
use delta islands when packing to disk, since the whole
point is to optimize the pack for serving fetches later. And
the new delta-reuse code relies on having used reachability
bitmaps to determine the set of objects, which we would
typically only do when serving an actual fetch.

However, it is technically possible to combine these
features. And even without doing so, building with
"SANITIZE=address,undefined" will cause t5310.46 to
complain.  Even though that test does not have delta islands
enabled, we still take the address of the NULL entry to pass
to in_same_island(). That function then promptly returns
without dereferencing the value when it sees that islands
are not enabled, but it's enough to trigger a sanitizer
error.

The solution is straight-forward: when both features are
used together, we should pass the oid of the found base to
in_same_island().

This is tricky to do inside a single "if" statement. And
after the merge in f3504ea3dd (Merge branch
'cc/delta-islands', 2018-09-17), that "if" condition is
already getting pretty unwieldy. So this patch moves the
logic into a helper function, where we can easily use
multiple return paths. The result is a bit longer, but the
logic should be much easier to follow.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-19 12:03:35 -07:00
Junio C Hamano
769af0fd9e Merge branch 'jk/cocci'
spatch transformation to replace boolean uses of !hashcmp() to
newly introduced oideq() is added, and applied, to regain
performance lost due to support of multiple hash algorithms.

* jk/cocci:
  show_dirstat: simplify same-content check
  read-cache: use oideq() in ce_compare functions
  convert hashmap comparison functions to oideq()
  convert "hashcmp() != 0" to "!hasheq()"
  convert "oidcmp() != 0" to "!oideq()"
  convert "hashcmp() == 0" to hasheq()
  convert "oidcmp() == 0" to oideq()
  introduce hasheq() and oideq()
  coccinelle: use <...> for function exclusion
2018-09-17 13:53:57 -07:00
Junio C Hamano
f3504ea3dd Merge branch 'cc/delta-islands'
Lift code from GitHub to restrict delta computation so that an
object that exists in one fork is not made into a delta against
another object that does not appear in the same forked repository.

* cc/delta-islands:
  pack-objects: move 'layer' into 'struct packing_data'
  pack-objects: move tree_depth into 'struct packing_data'
  t5320: tests for delta islands
  repack: add delta-islands support
  pack-objects: add delta-islands support
  pack-objects: refactor code into compute_layer_order()
  Add delta-islands.{c,h}
2018-09-17 13:53:55 -07:00
Junio C Hamano
3ebdef2e1b Merge branch 'jk/pack-delta-reuse-with-bitmap'
When creating a thin pack, which allows objects to be made into a
delta against another object that is not in the resulting pack but
is known to be present on the receiving end, the code learned to
take advantage of the reachability bitmap; this allows the server
to send a delta against a base beyond the "boundary" commit.

* jk/pack-delta-reuse-with-bitmap:
  pack-objects: reuse on-disk deltas for thin "have" objects
  pack-bitmap: save "have" bitmap from walk
  t/perf: add perf tests for fetches from a bitmapped server
  t/perf: add infrastructure for measuring sizes
  t/perf: factor out percent calculations
  t/perf: factor boilerplate out of test_perf
2018-09-17 13:53:53 -07:00
Junio C Hamano
49f210fd52 Merge branch 'ds/multi-pack-index'
When there are too many packfiles in a repository (which is not
recommended), looking up an object in these would require
consulting many pack .idx files; a new mechanism to have a single
file that consolidates all of these .idx files is introduced.

* ds/multi-pack-index: (32 commits)
  pack-objects: consider packs in multi-pack-index
  midx: test a few commands that use get_all_packs
  treewide: use get_all_packs
  packfile: add all_packs list
  midx: fix bug that skips midx with alternates
  midx: stop reporting garbage
  midx: mark bad packed objects
  multi-pack-index: store local property
  multi-pack-index: provide more helpful usage info
  midx: clear midx on repack
  packfile: skip loading index if in multi-pack-index
  midx: prevent duplicate packfile loads
  midx: use midx in approximate_object_count
  midx: use existing midx when writing new one
  midx: use midx in abbreviation calculations
  midx: read objects from multi-pack-index
  config: create core.multiPackIndex setting
  midx: write object offsets
  midx: write object id fanout chunk
  midx: write object ids in a chunk
  ...
2018-09-17 13:53:50 -07:00
Torsten Bögershausen
d64324cb60 Make git_check_attr() a void function
git_check_attr() returns always 0.
Remove all the error handling code of the callers, which is never executed.
Change git_check_attr() to be a void function.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-12 15:15:34 -07:00
Jeff King
4a7e27e957 convert "oidcmp() == 0" to oideq()
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.

The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).

This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.

I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Junio C Hamano
29d9e3e2c4 Merge branch 'nd/pack-deltify-regression-fix'
In a recent update in 2.18 era, "git pack-objects" started
producing a larger than necessary packfiles by missing
opportunities to use large deltas.

* nd/pack-deltify-regression-fix:
  pack-objects: fix performance issues on packing large deltas
2018-08-22 11:17:05 -07:00
Jeff King
6a1e32d532 pack-objects: reuse on-disk deltas for thin "have" objects
When we serve a fetch, we pass the "wants" and "haves" from
the fetch negotiation to pack-objects. That tells us not
only which objects we need to send, but we also use the
boundary commits as "preferred bases": their trees and blobs
are candidates for delta bases, both for reusing on-disk
deltas and for finding new ones.

However, this misses some opportunities. Modulo some special
cases like shallow or partial clones, we know that every
object reachable from the "haves" could be a preferred base.
We don't use all of them for two reasons:

  1. It's expensive to traverse the whole history and
     enumerate all of the objects the other side has.

  2. The delta search is expensive, so we want to keep the
     number of candidate bases sane. The boundary commits
     are the most likely to work.

When we have reachability bitmaps, though, reason 1 no
longer applies. We can efficiently compute the set of
reachable objects on the other side (and in fact already did
so as part of the bitmap set-difference to get the list of
interesting objects). And using this set conveniently
covers the shallow and partial cases, since we have to
disable the use of bitmaps for those anyway.

The second reason argues against using these bases in the
search for new deltas. But there's one case where we can use
this information for free: when we have an existing on-disk
delta that we're considering reusing, we can do so if we
know the other side has the base object. This in fact saves
time during the delta search, because it's one less delta we
have to compute.

And that's exactly what this patch does: when we're
considering whether to reuse an on-disk delta, if bitmaps
tell us the other side has the object (and we're making a
thin-pack), then we reuse it.

Here are the results on p5311 using linux.git, which
simulates a client fetching after `N` days since their last
fetch:

 Test                         origin              HEAD
 --------------------------------------------------------------------------
 5311.3: server   (1 days)    0.27(0.27+0.04)     0.12(0.09+0.03) -55.6%
 5311.4: size     (1 days)               0.9M              237.0K -73.7%
 5311.5: client   (1 days)    0.04(0.05+0.00)     0.10(0.10+0.00) +150.0%
 5311.7: server   (2 days)    0.34(0.42+0.04)     0.13(0.10+0.03) -61.8%
 5311.8: size     (2 days)               1.5M              347.7K -76.5%
 5311.9: client   (2 days)    0.07(0.08+0.00)     0.16(0.15+0.01) +128.6%
 5311.11: server   (4 days)   0.56(0.77+0.08)     0.13(0.10+0.02) -76.8%
 5311.12: size     (4 days)              2.8M              566.6K -79.8%
 5311.13: client   (4 days)   0.13(0.15+0.00)     0.34(0.31+0.02) +161.5%
 5311.15: server   (8 days)   0.97(1.39+0.11)     0.30(0.25+0.05) -69.1%
 5311.16: size     (8 days)              4.3M                1.0M -76.0%
 5311.17: client   (8 days)   0.20(0.22+0.01)     0.53(0.52+0.01) +165.0%
 5311.19: server  (16 days)   1.52(2.51+0.12)     0.30(0.26+0.03) -80.3%
 5311.20: size    (16 days)              8.0M                2.0M -74.5%
 5311.21: client  (16 days)   0.40(0.47+0.03)     1.01(0.98+0.04) +152.5%
 5311.23: server  (32 days)   2.40(4.44+0.20)     0.31(0.26+0.04) -87.1%
 5311.24: size    (32 days)             14.1M                4.1M -70.9%
 5311.25: client  (32 days)   0.70(0.90+0.03)     1.81(1.75+0.06) +158.6%
 5311.27: server  (64 days)   11.76(26.57+0.29)   0.55(0.50+0.08) -95.3%
 5311.28: size    (64 days)             89.4M               47.4M -47.0%
 5311.29: client  (64 days)   5.71(9.31+0.27)     15.20(15.20+0.32) +166.2%
 5311.31: server (128 days)   16.15(36.87+0.40)   0.91(0.82+0.14) -94.4%
 5311.32: size   (128 days)            134.8M              100.4M -25.5%
 5311.33: client (128 days)   9.42(16.86+0.49)    25.34(25.80+0.46) +169.0%

In all cases we save CPU time on the server (sometimes
significant) and the resulting pack is smaller. We do spend
more CPU time on the client side, because it has to
reconstruct more deltas. But that's the right tradeoff to
make, since clients tend to outnumber servers. It just means
the thin pack mechanism is doing its job.

From the user's perspective, the end-to-end time of the
operation will generally be faster. E.g., in the 128-day
case, we saved 15s on the server at a cost of 16s on the
client. Since the resulting pack is 34MB smaller, this is a
net win if the network speed is less than 270Mbit/s. And
that's actually the worst case. The 64-day case saves just
over 11s at a cost of just under 11s. So it's a slight win
at any network speed, and the 40MB saved is pure bonus. That
trend continues for the smaller fetches.

The implementation itself is mostly straightforward, with
the new logic going into check_object(). But there are two
tricky bits.

The first is that check_object() needs access to the
relevant information (the thin flag and bitmap result). We
can do this by pushing these into program-lifetime globals.

The second is that the rest of the code assumes that any
reused delta will point to another "struct object_entry" as
its base. But of course the case we are interested in here
is the one where don't have such an entry!

I looked at a number of options that didn't quite work:

 - we could use a flag to signal a reused delta, but it's
   not a single bit. We have to actually store the oid of
   the base, which is normally done by pointing to the
   existing object_entry. And we'd have to modify all the
   code which looks at deltas.

 - we could add the reused bases to the end of the existing
   object_entry array. While this does create some extra
   work as later stages consider the extra entries, it's
   actually not too bad (we're not sending them, so they
   don't cost much in the delta search, and at most we'd
   have 2*N of them).

   But there's a more subtle problem. Adding to the existing
   array means we might need to grow it with realloc, which
   could move the earlier entries around. While many of the
   references to other entries are done by integer index,
   some (including ones on the stack) use pointers, which
   would become invalidated.

   This isn't insurmountable, but it would require quite a
   bit of refactoring (and it's hard to know that you've got
   it all, since it may work _most_ of the time and then
   fail subtly based on memory allocation patterns).

 - we could allocate a new one-off entry for the base. In
   fact, this is what an earlier version of this patch did.
   However, since the refactoring brought in by ad635e82d6
   (Merge branch 'nd/pack-objects-pack-struct', 2018-05-23),
   the delta_idx code requires that both entries be in the
   main packing list.

So taking all of those options into account, what I ended up
with is a separate list of "external bases" that are not
part of the main packing list. Each delta entry that points
to an external base has a single-bit flag to do so; we have a
little breathing room in the bitfield section of
object_entry.

This lets us limit the change primarily to the oe_delta()
and oe_set_delta_ext() functions. And as a bonus, most of
the rest of the code does not consider these dummy entries
at all, saving both runtime CPU and code complexity.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-21 12:45:49 -07:00
Derrick Stolee
6a22d52126 pack-objects: consider packs in multi-pack-index
When running 'git pack-objects --local', we want to avoid packing
objects that are in an alternate. Currently, we check for these
objects using the packed_git_mru list, which excludes the pack-files
covered by a multi-pack-index.

Add a new iteration over the multi-pack-indexes to find these
copies and mark them as unwanted.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20 15:31:40 -07:00
Derrick Stolee
454ea2e4d7 treewide: use get_all_packs
There are many places in the codebase that want to iterate over
all packfiles known to Git. The purposes are wide-ranging, and
those that can take advantage of the multi-pack-index already
do. So, use get_all_packs() instead of get_packed_git() to be
sure we are iterating over all packfiles.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20 15:31:40 -07:00
Junio C Hamano
dc0f6f9e1d Merge branch 'nd/no-the-index'
The more library-ish parts of the codebase learned to work on the
in-core index-state instance that is passed in by their callers,
instead of always working on the singleton "the_index" instance.

* nd/no-the-index: (24 commits)
  blame.c: remove implicit dependency on the_index
  apply.c: remove implicit dependency on the_index
  apply.c: make init_apply_state() take a struct repository
  apply.c: pass struct apply_state to more functions
  resolve-undo.c: use the right index instead of the_index
  archive-*.c: use the right repository
  archive.c: avoid access to the_index
  grep: use the right index instead of the_index
  attr: remove index from git_attr_set_direction()
  entry.c: use the right index instead of the_index
  submodule.c: use the right index instead of the_index
  pathspec.c: use the right index instead of the_index
  unpack-trees: avoid the_index in verify_absent()
  unpack-trees: convert clear_ce_flags* to avoid the_index
  unpack-trees: don't shadow global var the_index
  unpack-trees: add a note about path invalidation
  unpack-trees: remove 'extern' on function declaration
  ls-files: correct index argument to get_convert_attr_ascii()
  preload-index.c: use the right index instead of the_index
  dir.c: remove an implicit dependency on the_index in pathspec code
  ...
2018-08-20 11:33:53 -07:00
Junio C Hamano
8963bb0c2d Merge branch 'rs/parse-opt-lithelp'
The parse-options machinery learned to refrain from enclosing
placeholder string inside a "<bra" and "ket>" pair automatically
without PARSE_OPT_LITERAL_ARGHELP.  Existing help text for option
arguments that are not formatted correctly have been identified and
fixed.

* rs/parse-opt-lithelp:
  parse-options: automatically infer PARSE_OPT_LITERAL_ARGHELP
  shortlog: correct option help for -w
  send-pack: specify --force-with-lease argument help explicitly
  pack-objects: specify --index-version argument help explicitly
  difftool: remove angular brackets from argument help
  add, update-index: fix --chmod argument help
  push: use PARSE_OPT_LITERAL_ARGHELP instead of unbalanced brackets
2018-08-17 13:09:56 -07:00
Christian Couder
fe0ac2fb7f pack-objects: move 'layer' into 'struct packing_data'
This reduces the size of 'struct object_entry' from 88 bytes
to 80 and therefore makes packing objects more efficient.

For example on a Linux repo with 12M objects,
`git pack-objects --all` needs extra 96MB memory even if the
layer feature is not used.

Helped-by: Jeff King <peff@peff.net>
Helped-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-16 10:56:44 -07:00
Christian Couder
108f530385 pack-objects: move tree_depth into 'struct packing_data'
This reduces the size of 'struct object_entry' and therefore
makes packing objects more efficient.

This also renames cmp_tree_depth() into tree_depth_compare(),
as it is more modern to have the name of the compare functions
end with "compare".

Helped-by: Jeff King <peff@peff.net>
Helped-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-16 10:56:44 -07:00
Jeff King
28b8a73080 pack-objects: add delta-islands support
Implement support for delta islands in git pack-objects
and document how delta islands work in
"Documentation/git-pack-objects.txt" and Documentation/config.txt.

This allows users to setup delta islands in their config and
get the benefit of less disk usage while cloning and fetching
is still quite fast and not much more CPU intensive.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-16 10:51:17 -07:00
Christian Couder
f64ba53ee7 pack-objects: refactor code into compute_layer_order()
In a following commit, as we will use delta islands, we will
have to compute the write order for different layers, not just
for one.

Let's prepare for that by refactoring the code that will be
used to compute the write order for a given layer into a new
compute_layer_order() function.

This will make it easier to see and understand what the
following changes are doing.

Helped-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-16 10:51:17 -07:00
Junio C Hamano
2e2c24f82a Merge branch 'nd/pack-objects-threading-doc'
Doc fix.

* nd/pack-objects-threading-doc:
  pack-objects: document about thread synchronization
2018-08-15 15:08:27 -07:00
Junio C Hamano
4bea8485e3 Merge branch 'nd/i18n'
Many more strings are prepared for l10n.

* nd/i18n: (23 commits)
  transport-helper.c: mark more strings for translation
  transport.c: mark more strings for translation
  sha1-file.c: mark more strings for translation
  sequencer.c: mark more strings for translation
  replace-object.c: mark more strings for translation
  refspec.c: mark more strings for translation
  refs.c: mark more strings for translation
  pkt-line.c: mark more strings for translation
  object.c: mark more strings for translation
  exec-cmd.c: mark more strings for translation
  environment.c: mark more strings for translation
  dir.c: mark more strings for translation
  convert.c: mark more strings for translation
  connect.c: mark more strings for translation
  config.c: mark more strings for translation
  commit-graph.c: mark more strings for translation
  builtin/replace.c: mark more strings for translation
  builtin/pack-objects.c: mark more strings for translation
  builtin/grep.c: mark strings for translation
  builtin/config.c: mark more strings for translation
  ...
2018-08-15 15:08:23 -07:00
Junio C Hamano
1689c22c1c Merge branch 'jk/core-use-replace-refs'
A new configuration variable core.usereplacerefs has been added,
primarily to help server installations that want to ignore the
replace mechanism altogether.

* jk/core-use-replace-refs:
  add core.usereplacerefs config option
  check_replace_refs: rename to read_replace_refs
  check_replace_refs: fix outdated comment
2018-08-15 15:08:23 -07:00
Nguyễn Thái Ngọc Duy
7a400a2c02 attr: remove an implicit dependency on the_index
Make the attr API take an index_state instead of assuming the_index in
attr code. All call sites are converted blindly to keep the patch
simple and retain current behavior. Individual call sites may receive
further updates to use the right index instead of the_index.

There is one ugly temporary workaround added in attr.c that needs some
more explanation.

Commit c24f3abace (apply: file commited with CRLF should roundtrip
diff and apply - 2017-08-19) forces one convert_to_git() call to NOT
read the index at all. But what do you know, we read it anyway by
falling back to the_index. When "istate" from convert_to_git is now
propagated down to read_attr_from_array() we will hit segfault
somewhere inside read_blob_data_from_index.

The right way of dealing with this is to kill "use_index" variable and
only follow "istate" but at this stage we are not ready for that:
while most git_attr_set_direction() calls just passes the_index to be
assigned to use_index, unpack-trees passes a different one which is
used by entry.c code, which has no way to know what index to use if we
delete use_index. So this has to be done later.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 14:14:42 -07:00