Commit graph

768 commits

Author SHA1 Message Date
Junio C Hamano
5efabc7ed9 Merge branch 'ew/hashmap'
Code clean-up of the hashmap API, both users and implementation.

* ew/hashmap:
  hashmap_entry: remove first member requirement from docs
  hashmap: remove type arg from hashmap_{get,put,remove}_entry
  OFFSETOF_VAR macro to simplify hashmap iterators
  hashmap: introduce hashmap_free_entries
  hashmap: hashmap_{put,remove} return hashmap_entry *
  hashmap: use *_entry APIs for iteration
  hashmap_cmp_fn takes hashmap_entry params
  hashmap_get{,_from_hash} return "struct hashmap_entry *"
  hashmap: use *_entry APIs to wrap container_of
  hashmap_get_next returns "struct hashmap_entry *"
  introduce container_of macro
  hashmap_put takes "struct hashmap_entry *"
  hashmap_remove takes "const struct hashmap_entry *"
  hashmap_get takes "const struct hashmap_entry *"
  hashmap_add takes "struct hashmap_entry *"
  hashmap_get_next takes "const struct hashmap_entry *"
  hashmap_entry_init takes "struct hashmap_entry *"
  packfile: use hashmap_entry in delta_base_cache_entry
  coccicheck: detect hashmap_entry.hash assignment
  diff: use hashmap_entry_init on moved_entry.ent
2019-10-15 13:48:02 +09:00
Junio C Hamano
a73f91774c Merge branch 'ab/pcre-jit-fixes'
A few simplification and bugfixes to PCRE interface.

* ab/pcre-jit-fixes:
  grep: under --debug, show whether PCRE JIT is enabled
  grep: do not enter PCRE2_UTF mode on fixed matching
  grep: stess test PCRE v2 on invalid UTF-8 data
  grep: create a "is_fixed" member in "grep_pat"
  grep: consistently use "p->fixed" in compile_regexp()
  grep: stop using a custom JIT stack with PCRE v1
  grep: stop "using" a custom JIT stack with PCRE v2
  grep: remove overly paranoid BUG(...) code
  grep: use PCRE v2 for optimized fixed-string search
  grep: remove the kwset optimization
  grep: drop support for \0 in --fixed-strings <pattern>
  grep: make the behavior for NUL-byte in patterns sane
  grep tests: move binary pattern tests into their own file
  grep tests: move "grep binary" alongside the rest
  grep: inline the return value of a function call used only once
  t4210: skip more command-line encoding tests on MinGW
  grep: don't use PCRE2?_UTF8 with "log --encoding=<non-utf8>"
  log tests: test regex backends in "--encode=<enc>" tests
2019-10-11 14:24:47 +09:00
Junio C Hamano
ed6822896b Merge branch 'rs/simplify-by-deco-with-deco-refs-exclude'
"git log --decorate-refs-exclude=<pattern>" was incorrectly
overruled when the "--simplify-by-decoration" option is used, which
has been corrected.

* rs/simplify-by-deco-with-deco-refs-exclude:
  log-tree: call load_ref_decorations() in get_name_decoration()
  log: test --decorate-refs-exclude with --simplify-by-decoration
2019-10-07 11:32:54 +09:00
Eric Wong
404ab78e39 hashmap: remove type arg from hashmap_{get,put,remove}_entry
Since these macros already take a `keyvar' pointer of a known type,
we can rely on OFFSETOF_VAR to get the correct offset without
relying on non-portable `__typeof__' and `offsetof'.

Argument order is also rearranged, so `keyvar' and `member' are
sequential as they are used as: `keyvar->member'

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:12 +09:00
Eric Wong
23dee69f53 OFFSETOF_VAR macro to simplify hashmap iterators
While we cannot rely on a `__typeof__' operator being portable
to use with `offsetof'; we can calculate the pointer offset
using an existing pointer and the address of a member using
pointer arithmetic for compilers without `__typeof__'.

This allows us to simplify usage of hashmap iterator macros
by not having to specify a type when a pointer of that type
is already given.

In the future, list iterator macros (e.g. list_for_each_entry)
may also be implemented using OFFSETOF_VAR to save hackers the
trouble of using container_of/list_entry macros and without
relying on non-portable `__typeof__'.

v3: use `__typeof__' to avoid clang warnings

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
c8e424c9c9 hashmap: introduce hashmap_free_entries
`hashmap_free_entries' behaves like `container_of' and passes
the offset of the hashmap_entry struct to the internal
`hashmap_free_' function, allowing the function to free any
struct pointer regardless of where the hashmap_entry field
is located.

`hashmap_free' no longer takes any arguments aside from
the hashmap itself.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
87571c3f71 hashmap: use *_entry APIs for iteration
Inspired by list_for_each_entry in the Linux kernel.
Once again, these are somewhat compromised usability-wise
by compilers lacking __typeof__ support.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
939af16eac hashmap_cmp_fn takes hashmap_entry params
Another step in eliminating the requirement of hashmap_entry
being the first member of a struct.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
f23a465132 hashmap_get{,_from_hash} return "struct hashmap_entry *"
Update callers to use hashmap_get_entry, hashmap_get_entry_from_hash
or container_of as appropriate.

This is another step towards eliminating the requirement of
hashmap_entry being the first field in a struct.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:11 +09:00
Eric Wong
26b455f21e hashmap_put takes "struct hashmap_entry *"
This is less error-prone than "void *" as the compiler now
detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
b6c5241606 hashmap_get takes "const struct hashmap_entry *"
This is less error-prone than "const void *" as the compiler
now detects invalid types being passed.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:10 +09:00
Eric Wong
d22245a2e3 hashmap_entry_init takes "struct hashmap_entry *"
C compilers do type checking to make life easier for us.  So
rely on that and update all hashmap_entry_init callers to take
"struct hashmap_entry *" to avoid future bugs while improving
safety and readability.

Signed-off-by: Eric Wong <e@80x24.org>
Reviewed-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-10-07 10:20:09 +09:00
Junio C Hamano
cf861cd7a0 Merge branch 'rs/get-tagged-oid'
Code cleanup.

* rs/get-tagged-oid:
  use get_tagged_oid()
  tag: factor out get_tagged_oid()
2019-09-30 13:19:29 +09:00
René Scharfe
0cc7380d88 log-tree: call load_ref_decorations() in get_name_decoration()
Load a default set of ref name decorations at the first lookup.  This
frees direct and indirect callers from doing so.  They can still do it
if they want to use a filter or are interested in full decorations
instead of the default short ones -- the first load_ref_decorations()
call wins.

This means that the load in builtin/log.c::cmd_log_init_finish() is
respected even if --simplify-by-decoration is given, as the previously
dominating earlier load in handle_revision_opt() is gone.  So a filter
given with --decorate-refs-exclude is used for simplification in that
case, as expected.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-09 11:16:40 -07:00
René Scharfe
dad3f0607b tag: factor out get_tagged_oid()
Add a function for accessing the ID of the object referenced by a tag
safely, i.e. without causing a segfault when encountering a broken tag
where ->tagged is NULL.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-09-05 14:10:18 -07:00
Jeff King
19e8789b23 revision: allow --end-of-options to end option parsing
There's currently no robust way to tell Git that a particular option is
meant to be a revision, and not an option. So if you have a branch
"refs/heads/--foo", you cannot just say:

  git rev-list --foo

You can say:

  git rev-list refs/heads/--foo

But that breaks down if you don't know the refname, and in particular if
you're a script passing along a value from elsewhere. In most programs,
you can use "--" to end option parsing, like this:

  some-prog -- "$revision"

But that doesn't work for the revision parser, because "--" is already
meaningful there: it separates revisions from pathspecs. So we need some
other marker to separate options from revisions.

This patch introduces "--end-of-options", which serves that purpose:

  git rev-list --oneline --end-of-options "$revision"

will work regardless of what's in "$revision" (well, if you say "--" it
may fail, but it won't do something dangerous, like triggering an
unexpected option).

The name is verbose, but that's probably a good thing; this is meant to
be used for scripted invocations where readability is more important
than terseness.

One alternative would be to introduce an explicit option to mark a
revision, like:

  git rev-list --oneline --revision="$revision"

That's slightly _more_ informative than this commit (because it makes
even something silly like "--" unambiguous). But the pattern of using a
separator like "--" is well established in git and in other commands,
and it makes some scripting tasks simpler like:

  git rev-list --end-of-options "$@"

There's no documentation in this patch, because it will make sense to
describe the feature once it is available everywhere (and support will
be added in further patches).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-06 13:05:39 -07:00
Junio C Hamano
68e65ded5b Merge branch 'jk/check-connected-with-alternates'
The tips of refs from the alternate object store can be used as
starting point for reachability computation now.

* jk/check-connected-with-alternates:
  check_everything_connected: assume alternate ref tips are valid
  object-store.h: move for_each_alternate_ref() from transport.h
2019-07-19 11:30:21 -07:00
Jeff King
39b44ba771 check_everything_connected: assume alternate ref tips are valid
When we receive a remote ref update to sha1 "X", we want to check that
we have all of the objects needed by "X". We can assume that our
repository is not currently corrupted, and therefore if we have a ref
pointing at "Y", we have all of its objects. So we can stop our
traversal from "X" as soon as we hit "Y".

If we make the same non-corruption assumption about any repositories we
use to store alternates, then we can also use their ref tips to shorten
the traversal.

This is especially useful when cloning with "--reference", as we
otherwise do not have any local refs to check against, and have to
traverse the whole history, even though the other side may have sent us
few or no objects. Here are results for the included perf test (which
shows off more or less the maximal savings, getting one new commit and
sharing the whole history):

Test                        HEAD^             HEAD
--------------------------------------------------------------------
[on git.git]
5600.3: clone --reference   2.94(2.86+0.08)   0.09(0.08+0.01) -96.9%
[on linux.git]
5600.3: clone --reference   45.74(45.34+0.41)   0.36(0.30+0.08) -99.2%

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-01 10:11:09 -07:00
Ævar Arnfjörð Bjarmason
44570188a0 grep: don't use PCRE2?_UTF8 with "log --encoding=<non-utf8>"
Fix a bug introduced in 18547aacf5 ("grep/pcre: support utf-8",
2016-06-25) that was missed due to a blindspot in our tests, as
discussed in the previous commit. I then blindly copied the same bug
in 94da9193a6 ("grep: add support for PCRE v2", 2017-06-01) when
adding the PCRE v2 code.

We should not tell PCRE that we're processing UTF-8 just because we're
dealing with non-ASCII. In the case of e.g. "log --encoding=<...>"
under is_utf8_locale() the haystack might be in ISO-8859-1, and the
needle might be in a non-UTF-8 encoding.

Maybe we should be more strict here and die earlier? Should we also be
converting the needle to the encoding in question, and failing if it's
not a string that's valid in that encoding? Maybe.

But for now matching this as non-UTF8 at least has some hope of
producing sensible results, since we know that our default heuristic
of assuming the text to be matched is in the user locale encoding
isn't true when we've explicitly encoded it to be in a different
encoding.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-28 09:11:09 -07:00
Derrick Stolee
1d8e31a3f6 revision: keep topo-walk free of unintersting commits
When updating the topo-order walk in b454241 (revision.c: generation-based
topo-order algorithm, 2018-11-01), the logic was a huge rewrite of the
walk logic. In that massive change, we accidentally included the
UNINTERESTING commits in expand_topo_walk(). This means that a simple
query like

    git rev-list --topo-order HEAD~1..HEAD

will expand the topo walk for all commits reachable from HEAD, and not
just one commit.

This change should speed up these cases, but there is still a need
for corrected commit-date for some A..B queries.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-28 10:39:49 -07:00
Derrick Stolee
1b4d8827ff revision: use generation for A..B --topo-order queries
If a commit-graph exists with computed generation numbers, then a
'git rev-list --topo-order -n <N> <rev>' query will use those generation
numbers to reduce the number of commits walked before writing N commits.

One caveat put in b454241 (revision.c: generation-based topo-order
algorithm, 2018-11-01) was to not enable the new algorithm for queries
with a revision range "A..B". The logic was placed to walk from "A" and
mark those commits as uninteresting, but the performance was actually
worse than the existing logic in some cases.

The root cause of this performance degradation is that generation
numbers _increase_ the number of commits we walk relative to the
existing heuristic of walking by commit date. While generation numbers
actually guarantee that the algorithm is correct, the existing logic
is very rarely wrong and that added requirement is not worth the cost.

This motivates the planned "corrected commit date" to replace
generation numbers in a future version of Git.

The current change enables the logic to use whatever reachability
index is currently in the commit-graph (generation numbers or
corrected commit date).

The limited flag in struct rev_info forces a full walk of the
commit history (after discovering the A..B range). Previosuly, it
is enabled whenever we see an uninteresting commit. We prevent
enabling the parameter when we are planning to use the reachability
index for a topo-order.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-28 10:39:47 -07:00
Junio C Hamano
d9d65e9f6a Merge branch 'jk/revision-rewritten-parents-in-prio-queue'
Performance fix for "rev-list --parents -- pathspec".

* jk/revision-rewritten-parents-in-prio-queue:
  revision: use a prio_queue to hold rewritten parents
2019-04-25 16:41:18 +09:00
Junio C Hamano
4284497396 Merge branch 'jk/unused-params-even-more'
Code cleanup.

* jk/unused-params-even-more:
  parse_opt_ref_sorting: always use with NONEG flag
  pretty: drop unused strbuf from parse_padding_placeholder()
  pretty: drop unused "type" parameter in needs_rfc2047_encoding()
  parse-options: drop unused ctx parameter from show_gitcomp()
  fetch_pack(): drop unused parameters
  report_path_error(): drop unused prefix parameter
  unpack-trees: drop unused error_type parameters
  unpack-trees: drop name_entry from traverse_by_cache_tree()
  test-date: drop unused "now" parameter from parse_dates()
  update-index: drop unused prefix_length parameter from do_reupdate()
  log: drop unused "len" from show_tagger()
  log: drop unused rev_info from early output
  revision: drop some unused "revs" parameters
2019-04-25 16:41:12 +09:00
Junio C Hamano
31df2c1019 Merge branch 'jk/line-log-with-patch'
"git log -L<from>,<to>:<path>" with "-s" did not suppress the patch
output as it should.  This has been corrected.

* jk/line-log-with-patch:
  line-log: detect unsupported formats
  line-log: suppress diff output with "-s"
2019-04-10 02:14:23 +09:00
Jeff King
8320b1dbe7 revision: use a prio_queue to hold rewritten parents
This patch fixes a quadratic list insertion in rewrite_one() when
pathspec limiting is combined with --parents. What happens is something
like this:

  1. We see that some commit X touches the path, so we try to rewrite
     its parents.

  2. rewrite_one() loops forever, rewriting parents, until it finds a
     relevant parent (or hits the root and decides there are none). The
     heavy lifting is done by process_parent(), which uses
     try_to_simplify_commit() to drop parents.

  3. process_parent() puts any intermediate parents into the
     &revs->commits list, inserting by commit date as usual.

So if commit X is recent, and then there's a large chunk of history that
doesn't touch the path, we may add a lot of commits to &revs->commits.
And insertion by commit date is O(n) in the worst case, making the whole
thing quadratic.

We tried to deal with this long ago in fce87ae538 (Fix quadratic
performance in rewrite_one., 2008-07-12). In that scheme, we cache the
oldest commit in the list; if the new commit to be added is older, we
can start our linear traversal there. This often works well in practice
because parents are older than their descendants, and thus we tend to
add older and older commits as we traverse.

But this isn't guaranteed, and in fact there's a simple case where it is
not: merges. Imagine we look at the first parent of a merge and see a
very old commit (let's say 3 years old). And on the second parent, as we
go back 3 years in history, we might have many commits. That one
first-parent commit has polluted our oldest-commit cache; it will remain
the oldest while we traverse a huge chunk of history, during which we
have to fall back to the slow, linear method of adding to the list.

Naively, one might imagine that instead of caching the oldest commit,
we'd start at the last-added one. But that just makes some cases faster
while making others slower (and indeed, while it made a real-world test
case much faster, it does quite poorly in the perf test include here).
Fundamentally, these are just heuristics; our worst case is still
quadratic, and some cases will approach that.

Instead, let's use a data structure with better worst-case performance.
Swapping out revs->commits for something else would have repercussions
all over the code base, but we can take advantage of one fact: for the
rewrite_one() case, nobody actually needs to see those commits in
revs->commits until we've finished generating the whole list.

That leaves us with two obvious options:

  1. We can generate the list _unordered_, which should be O(n), and
     then sort it afterwards, which would be O(n log n) total. This is
     "sort-after" below.

  2. We can insert the commits into a separate data structure, like a
     priority queue. This is "prio-queue" below.

I expected that sort-after would be the fastest (since it saves us the
extra step of copying the items into the linked list), but surprisingly
the prio-queue seems to be a bit faster.

Here are timings for the new p0001.6 for all three techniques across a
few repositories, as compared to master:

master              cache-last                sort-after              prio-queue
--------------------------------------------------------------------------------------------
GIT_PERF_REPO=git.git
0.52(0.50+0.02)      0.53(0.51+0.02)  +1.9%   0.37(0.33+0.03) -28.8%  0.37(0.32+0.04) -28.8%

GIT_PERF_REPO=linux.git
20.81(20.74+0.07)   20.31(20.24+0.07) -2.4%   0.94(0.86+0.07) -95.5%  0.91(0.82+0.09) -95.6%

GIT_PERF_REPO=llvm-project.git
83.67(83.57+0.09)    4.23(4.15+0.08) -94.9%   3.21(3.15+0.06) -96.2%  2.98(2.91+0.07) -96.4%

A few items to note:

  - the cache-list tweak does improve the bad case for llvm-project.git
    that started my digging into this problem. But it performs terribly
    on linux.git, barely helping at all.

  - the sort-after and prio-queue techniques work well. They approach
    the timing for running without --parents at all, which is what you'd
    expect (see below for more data).

  - prio-queue just barely outperforms sort-after. As I said, I'm not
    really sure why this is the case, but it is. You can see it even
    more prominently in this real-world case on llvm-project.git:

      git rev-list --parents 07ef786652e7 -- llvm/test/CodeGen/Generic/bswap.ll

    where prio-queue routinely outperforms sort-after by about 7%. One
    guess is that the prio-queue may just be more efficient because it
    uses a compact array.

There are three new perf tests:

  - "rev-list --parents" gives us a baseline for running with --parents.
    This isn't sped up meaningfully here, because the bad case is
    triggered only with simplification. But it's good to make sure we
    don't screw it up (now, or in the future).

  - "rev-list -- dummy" gives us a baseline for just traversing with
    pathspec limiting. This gives a lower bound for the next test (and
    it's also a good thing for us to be checking in general for
    regressions, since we don't seem to have any existing tests).

  - "rev-list --parents -- dummy" shows off the problem (and our fix)

Here are the timings for those three on llvm-project.git, before and
after the fix:

Test                                 master              prio-queue
------------------------------------------------------------------------------
0001.3: rev-list --parents           2.24(2.12+0.12)     2.22(2.11+0.11) -0.9%
0001.5: rev-list -- dummy            2.89(2.82+0.07)     2.92(2.89+0.03) +1.0%
0001.6: rev-list --parents -- dummy  83.67(83.57+0.09)   2.98(2.91+0.07) -96.4%

Changes in the first two are basically noise, and you can see we
approach our lower bound in the final one.

Note that we can't fully get rid of the list argument from
process_parents(). Other callers do have lists, and it would be hard to
convert them. They also don't seem to have this problem (probably
because they actually remove items from the list as they loop, meaning
it doesn't grow so large in the first place). So this basically just
drops the "cache_ptr" parameter (which was used only by the one caller
we're fixing here) and replaces it with a prio_queue. Callers are free
to use either data structure, depending on what they're prepared to
handle.

Reported-by: Björn Pettersson A <bjorn.a.pettersson@ericsson.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-04 18:21:54 +09:00
Jeff King
9163399535 revision: drop some unused "revs" parameters
There are several internal helpers that take a rev_info struct but don't
actually look at it. While one could argue that all helpers in
revision.c should take a rev_info struct for consistency, dropping the
unused parameter makes it clear that they don't actually depend on any
other rev options.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-20 18:34:08 +09:00
Jeff King
05314efaea line-log: detect unsupported formats
If you use "log -L" with an output format like "--raw" or "--stat",
we'll silently ignore the format and just output the normal patch.
Let's detect and complain about this, which at least tells the user
what's going on.

The tests here aren't exhaustive over the set of all formats, but it
should at least let us know if somebody breaks the format-checking.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-11 16:31:07 +09:00
Junio C Hamano
c425d361f5 Merge branch 'en/combined-all-paths'
Output from "diff --cc" did not show the original paths when the
merge involved renames.  A new option adds the paths in the
original trees to the output.

* en/combined-all-paths:
  log,diff-tree: add --combined-all-paths option
2019-03-07 09:59:54 +09:00
Elijah Newren
d76ce4f734 log,diff-tree: add --combined-all-paths option
The combined diff format for merges will only list one filename, even if
rename or copy detection is active.  For example, with raw format one
might see:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	describe.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	phooey.c

This doesn't let us know what the original name of bar.sh was in the
first parent, and doesn't let us know what either of the original names
of phooey.c were in either of the parents.  In contrast, for non-merge
commits, raw format does provide original filenames (and a rename score
to boot).  In order to also provide original filenames for merge
commits, add a --combined-all-paths option (which must be used with
either -c or --cc, and is likely only useful with rename or copy
detection active) so that we can print tab-separated filenames when
renames are involved.  This transforms the above output to:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	desc.c	desc.c	desc.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	foo.sh	bar.sh	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	fooey.c	fuey.c	phooey.c

Further, in patch format, this changes the from/to headers so that
instead of just having one "from" header, we get one for each parent.
For example, instead of having

  --- a/phooey.c
  +++ b/phooey.c

we would see

  --- a/fooey.c
  --- a/fuey.c
  +++ b/phooey.c

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-07 20:15:25 -08:00
Junio C Hamano
5fda343321 Merge branch 'ds/push-sparse-tree-walk'
"git pack-objects" learned another algorithm to compute the set of
objects to send, that trades the resulting packfile off to save
traversal cost to favor small pushes.

* ds/push-sparse-tree-walk:
  pack-objects: create GIT_TEST_PACK_SPARSE
  pack-objects: create pack.useSparse setting
  revision: implement sparse algorithm
  list-objects: consume sparse tree walk
  revision: add mark_tree_uninteresting_sparse
2019-02-06 22:05:25 -08:00
Junio C Hamano
7589e63648 Merge branch 'nd/the-index-final'
The assumption to work on the single "in-core index" instance has
been reduced from the library-ish part of the codebase.

* nd/the-index-final:
  cache.h: flip NO_THE_INDEX_COMPATIBILITY_MACROS switch
  read-cache.c: remove the_* from index_has_changes()
  merge-recursive.c: remove implicit dependency on the_repository
  merge-recursive.c: remove implicit dependency on the_index
  sha1-name.c: remove implicit dependency on the_index
  read-cache.c: replace update_index_if_able with repo_&
  read-cache.c: kill read_index()
  checkout: avoid the_index when possible
  repository.c: replace hold_locked_index() with repo_hold_locked_index()
  notes-utils.c: remove the_repository references
  grep: use grep_opt->repo instead of explict repo argument
2019-02-06 22:05:23 -08:00
Junio C Hamano
09b2e40944 Merge branch 'jt/get-reference-with-commit-graph'
Micro-optimize the code that prepares commit objects to be walked
by "git rev-list" when the commit-graph is available.

* jt/get-reference-with-commit-graph:
  revision: use commit graph in get_reference()
2019-02-05 14:26:10 -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
Derrick Stolee
d5d2e93577 revision: implement sparse algorithm
When enumerating objects to place in a pack-file during 'git
pack-objects --revs', we discover the "frontier" of commits
that we care about and the boundary with commit we find
uninteresting. From that point, we walk trees to discover which
trees and blobs are uninteresting. Finally, we walk trees from the
interesting commits to find the interesting objects that are
placed in the pack.

This commit introduces a new, "sparse" way to discover the
uninteresting trees. We use the perspective of a single user trying
to push their topic to a large repository. That user likely changed
a very small fraction of the paths in their working directory, but
we spend a lot of time walking all reachable trees.

The way to switch the logic to work in this sparse way is to start
caring about which paths introduce new trees. While it is not
possible to generate a diff between the frontier boundary and all
of the interesting commits, we can simulate that behavior by
inspecting all of the root trees as a whole, then recursing down
to the set of trees at each path.

We already had taken the first step by passing an oidset to
mark_trees_uninteresting_sparse(). We now create a dictionary
whose keys are paths and values are oidsets. We consider the set
of trees that appear at each path. While we inspect a tree, we
add its subtrees to the oidsets corresponding to the tree entry's
path. We also mark trees as UNINTERESTING if the tree we are
parsing is UNINTERESTING.

To actually improve the performance, we need to terminate our
recursion. If the oidset contains only UNINTERESTING trees, then
we do not continue the recursion. This avoids walking trees that
are likely to not be reachable from interesting trees. If the
oidset contains only interesting trees, then we will walk these
trees in the final stage that collects the intersting objects to
place in the pack. Thus, we only recurse if the oidset contains
both interesting and UNINITERESTING trees.

There are a few ways that this is not a universally better option.

First, we can pack extra objects. If someone copies a subtree
from one tree to another, the first tree will appear UNINTERESTING
and we will not recurse to see that the subtree should also be
UNINTERESTING. We will walk the new tree and see the subtree as
a "new" object and add it to the pack. A test is modified to
demonstrate this behavior and to verify that the new logic is
being exercised.

Second, we can have extra memory pressure. If instead of being a
single user pushing a small topic we are a server sending new
objects from across the entire working directory, then we will
gain very little (the recursion will rarely terminate early) but
will spend extra time maintaining the path-oidset dictionaries.

Despite these potential drawbacks, the benefits of the algorithm
are clear. By adding a counter to 'add_children_by_path' and
'mark_tree_contents_uninteresting', I measured the number of
parsed trees for the two algorithms in a variety of repos.

For git.git, I used the following input:

	v2.19.0
	^v2.19.0~10

 Objects to pack: 550
Walked (old alg): 282
Walked (new alg): 130

For the Linux repo, I used the following input:

	v4.18
	^v4.18~10

 Objects to pack:   518
Walked (old alg): 4,836
Walked (new alg):   188

The two repos above are rather "wide and flat" compared to
other repos that I have used in the past. As a comparison,
I tested an old topic branch in the Azure DevOps repo, which
has a much deeper folder structure than the Linux repo.

 Objects to pack:    220
Walked (old alg): 22,804
Walked (new alg):    129

I used the number of walked trees the main metric above because
it is consistent across multiple runs. When I ran my tests, the
performance of the pack-objects command with the same options
could change the end-to-end time by 10x depending on the file
system being warm. However, by repeating the same test on repeat
I could get more consistent timing results. The git.git and
Linux tests were too fast overall (less than 0.5s) to measure
an end-to-end difference. The Azure DevOps case was slow enough
to see the time improve from 15s to 1s in the warm case. The
cold case was 90s to 9s in my testing.

These improvements will have even larger benefits in the super-
large Windows repository. In our experiments, we see the
"Enumerate objects" phase of pack-objects taking 60-80% of the
end-to-end time of non-trivial pushes, taking longer than the
network time to send the pack and the server time to verify the
pack.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-17 13:44:42 -08:00
Derrick Stolee
f1f5de442f revision: add mark_tree_uninteresting_sparse
In preparation for a new algorithm that walks fewer trees when
creating a pack from a set of revisions, create a method that
takes an oidset of tree oids and marks reachable objects as
UNINTERESTING.

The current implementation uses the existing
mark_tree_uninteresting to recursively walk the trees and blobs.
This will walk the same number of trees as the old mechanism. To
ensure that mark_tree_uninteresting walks the tree, we need to
remove the UNINTERESTING flag before calling the method. This
implementation will be replaced entirely in a later commit.

There is one new assumption in this approach: we are also given
the oids of the interesting trees. This implementation does not
use those trees at the moment, but we will use them in a later
rewrite of this method.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-17 13:44:37 -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
f2b6aa98be Merge branch 'nd/indentation-fix'
Code cleanup.

* nd/indentation-fix:
  Indent code with TABs
2019-01-14 15:29:32 -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
d6f05a435f Merge branch 'nd/attr-pathspec-in-tree-walk'
The traversal over tree objects has learned to honor
":(attr:label)" pathspec match, which has been implemented only for
enumerating paths on the filesystem.

* nd/attr-pathspec-in-tree-walk:
  tree-walk: support :(attr) matching
  dir.c: move, rename and export match_attrs()
  pathspec.h: clean up "extern" in function declarations
  tree-walk.c: make tree_entry_interesting() take an index
  tree.c: make read_tree*() take 'struct repository *'
2019-01-14 15:29:28 -08:00
Junio C Hamano
c333fe7368 Merge branch 'md/list-lazy-objects-fix'
"git rev-list --exclude-promisor-objects" had to take an object
that does not exist locally (and is lazily available) from the
command line without barfing, but the code dereferenced NULL.

* md/list-lazy-objects-fix:
  list-objects.c: don't segfault for missing cmdline objects
2019-01-14 15:29:28 -08:00
Nguyễn Thái Ngọc Duy
3a7a698e93 sha1-name.c: remove implicit dependency on the_index
This kills the_index dependency in get_oid_with_context() but for
get_oid() and friends, they still assume the_repository (which also
means the_index).

Unfortunately the widespread use of get_oid() will make it hard to
make the conversion now. We probably will add repo_get_oid() at some
point and limit the use of get_oid() in builtin/ instead of forcing
all get_oid() call sites to carry struct repository.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14 12:13:04 -08:00
Nguyễn Thái Ngọc Duy
e1ff0a32e4 read-cache.c: kill read_index()
read_index() shares the same problem as hold_locked_index(): it
assumes $GIT_DIR/index. Move all call sites to repo_read_index()
instead. read_index_preload() and read_index_unmerged() are also
killed as a consequence.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-14 12:13:04 -08:00
Jonathan Tan
ec0c5798ee revision: use commit graph in get_reference()
When fetching into a repository, a connectivity check is first made by
check_exist_and_connected() in builtin/fetch.c that runs:

  git rev-list --objects --stdin --not --all --quiet <(list of objects)

If the client repository has many refs, this command can be slow,
regardless of the nature of the server repository or what is being
fetched. A profiler reveals that most of the time is spent in
setup_revisions() (approx. 60/63), and of the time spent in
setup_revisions(), most of it is spent in parse_object() (approx.
49/60). This is because setup_revisions() parses the target of every ref
(from "--all"), and parse_object() reads the buffer of the object.

Reading the buffer is unnecessary if the repository has a commit graph
and if the ref points to a commit (which is typically the case). This
patch uses the commit graph wherever possible; on my computer, when I
run the above command with a list of 1 object on a many-ref repository,
I get a speedup from 1.8s to 1.0s.

Another way to accomplish this effect would be to modify parse_object()
to use the commit graph if possible; however, I did not want to change
parse_object()'s current behavior of always checking the object
signature of the returned object.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-28 10:39:48 -08:00
Nguyễn Thái Ngọc Duy
ec36c42a63 Indent code with TABs
We indent with TABs and sometimes for fine alignment, TABs followed by
spaces, but never all spaces (unless the indentation is less than 8
columns). Indenting with spaces slips through in some places. Fix
them.

Imported code and compat/ are left alone on purpose. The former should
remain as close as upstream as possible. The latter pretty much has
separate maintainers, it's up to them to decide.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-09 12:37:32 +09:00
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
Matthew DeVore
4cf67869b2 list-objects.c: don't segfault for missing cmdline objects
When a command is invoked with both --exclude-promisor-objects,
--objects-edge-aggressive, and a missing object on the command line,
the rev_info.cmdline array could get a NULL pointer for the value of
an 'item' field. Prevent dereferencing of a NULL pointer in that
situation.

Properly handle --ignore-missing. If it is not passed, die when an
object is missing. Otherwise, just silently ignore it.

Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-12-06 10:10:13 +09:00
Nguyễn Thái Ngọc Duy
67022e0214 tree-walk.c: make tree_entry_interesting() take an index
In order to support :(attr) when matching pathspec on a tree,
tree_entry_interesting() needs to take an index (because
git_check_attr() needs it). This is the preparation step for it. This
also makes it clearer what index we fall back to when looking up
attributes during an unpack-trees operation: the source index.

This also fixes revs->pruning.repo initialization that should have
been done in 2abf350385 (revision.c: remove implicit dependency on
the_index - 2018-09-21). Without it, skip_uninteresting() will
dereference a NULL pointer through this call chain

  get_revision(revs)
  get_revision_internal
  get_revision_1
  try_to_simplify_commit
  rev_compare_tree
  diff_tree_oid(..., &revs->pruning)
  ll_diff_tree_oid
  diff_tree_paths
  ll_diff_tree
  skip_uninteresting

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-19 10:50:33 +09:00
Junio C Hamano
62ca33e02a Merge branch 'ds/reachable-topo-order'
The revision walker machinery learned to take advantage of the
commit generation numbers stored in the commit-graph file.

* ds/reachable-topo-order:
  t6012: make rev-list tests more interesting
  revision.c: generation-based topo-order algorithm
  commit/revisions: bookkeeping before refactoring
  revision.c: begin refactoring --topo-order logic
  test-reach: add rev-list tests
  test-reach: add run_three_modes method
  prio-queue: add 'peek' operation
2018-11-18 18:23:52 +09:00
Junio C Hamano
f22838aa7a Merge branch 'jk/misc-unused-fixes'
Assorted fixes for bugs found while auditing -Wunused-parameter
warnings.

* jk/misc-unused-fixes:
  approxidate: fix NULL dereference in date_time()
  pathspec: handle non-terminated strings with :(attr)
  approxidate: handle pending number for "specials"
  rev-list: handle flags for --indexed-objects
2018-11-13 22:37:26 +09:00
Junio C Hamano
e146cc97be Merge branch 'nd/per-worktree-ref-iteration'
The code to traverse objects for reachability, used to decide what
objects are unreferenced and expendable, have been taught to also
consider per-worktree refs of other worktrees as starting points to
prevent data loss.

* nd/per-worktree-ref-iteration:
  git-worktree.txt: correct linkgit command name
  reflog expire: cover reflog from all worktrees
  fsck: check HEAD and reflog from other worktrees
  fsck: move fsck_head_link() to get_default_heads() to avoid some globals
  revision.c: better error reporting on ref from different worktrees
  revision.c: correct a parameter name
  refs: new ref types to make per-worktree refs visible to all worktrees
  Add a place for (not) sharing stuff between worktrees
  refs.c: indent with tabs, not spaces
2018-11-13 22:37:26 +09:00