Commit Graph

61502 Commits

Author SHA1 Message Date
Derrick Stolee
5387fefadc chunk-format: restore duplicate chunk checks
Before refactoring into the chunk-format API, the commit-graph parsing
logic included checks for duplicate chunks. It is unlikely that we would
desire a chunk-based file format that allows duplicate chunk IDs in the
table of contents, so add duplicate checks into
read_table_of_contents().

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
329fac3a36 midx: use 64-bit multiplication for chunk sizes
When calculating the sizes of certain chunks, we should use 64-bit
multiplication always. This allows us to properly predict the chunk
sizes without risk of overflow.

Other possible overflows were discovered by evaluating each
multiplication in midx.c and ensuring that at least one side of the
operator was of type size_t or off_t.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
6ab3b8b8b8 midx: use chunk-format read API
Instead of parsing the table of contents directly, use the chunk-format
API methods read_table_of_contents() and pair_chunk(). In particular, we
can use the return value of pair_chunk() to generate an error when a
required chunk is missing.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
2692c2f6fd commit-graph: use chunk-format read API
Instead of parsing the table of contents directly, use the chunk-format
API methods read_table_of_contents() and pair_chunk(). While the current
implementation loses the duplicate-chunk detection, that will be added
in a future change.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
5f0879f54b chunk-format: create read chunk API
Add the capability to read the table of contents, then pair the chunks
with necessary logic using read_chunk_fn pointers. Callers will be added
in future changes, but the typical outline will be:

 1. initialize a 'struct chunkfile' with init_chunkfile(NULL).
 2. call read_table_of_contents().
 3. for each chunk to parse,
    a. call pair_chunk() to assign a pointer with the chunk position, or
    b. call read_chunk() to run a callback on the chunk start and size.
 4. call free_chunkfile() to clear the 'struct chunkfile' data.

We are re-using the anonymous 'struct chunkfile' data, as it is internal
to the chunk-format API. This gives it essentially two modes: write and
read. If the same struct instance was used for both reads and writes,
then there would be failures.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
63a8f0e9b9 midx: use chunk-format API in write_midx_internal()
The chunk-format API allows writing the table of contents and all chunks
using the anonymous 'struct chunkfile' type. We only need to convert our
local chunk logic to this API for the multi-pack-index writes to share
that logic with the commit-graph file writes.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
c1442410d8 midx: drop chunk progress during write
Most expensive operations in write_midx_internal() use the context
struct's progress member, and these indicate the process of the
expensive operations within the chunk writing methods. However, there is
a competing progress struct that counts the progress over all chunks.
This is not very helpful compared to the others, so drop it.

This also reduces our barriers to combining the chunk writing code with
chunk-format.c.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
0ccd713cb6 midx: return success/failure in chunk write methods
Historically, the chunk-writing methods in midx.c have returned the
amount of data written so the writer method could compare this with the
table of contents. This presents with some interesting issues:

1. If a chunk writing method has a bug that miscalculates the written
   bytes, then we can satisfy the table of contents without actually
   writing the right amount of data to the hashfile. The commit-graph
   writing code checks the hashfile struct directly for a more robust
   verification.

2. There is no way for a chunk writing method to gracefully fail.
   Returning an int presents an opportunity to fail without a die().

3. The current pattern doesn't match chunk_write_fn type exactly, so we
   cannot share code with commit-graph.c

For these reasons, convert the midx chunk writer methods to return an
'int'. Since none of them fail at the moment, they all return 0.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
980f525c3c midx: add num_large_offsets to write_midx_context
In an effort to align write_midx_internal() with the chunk-format API,
continue to group necessary data into "struct write_midx_context". This
change collects the "uint32_t num_large_offsets" into the context. With
this new data, write_midx_large_offsets() now matches the
chunk_write_fn type.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
7a3ada1192 midx: add pack_perm to write_midx_context
In an effort to align write_midx_internal() with the chunk-format API,
continue to group necessary data into "struct write_midx_context". This
change collects the "uint32_t *pack_perm" and large_offsets_needed bit
into the context.

Update write_midx_object_offsets() to match chunk_write_fn.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
31bda9a237 midx: add entries to write_midx_context
In an effort to align write_midx_internal() with the chunk-format API,
continue to group necessary data into "struct write_midx_context". This
change collects the "struct pack_midx_entry *entries" list and its count
into the context.

Update write_midx_oid_fanout() and write_midx_oid_lookup() to take the
context directly, as these are easy conversions with this new data.

Only the callers of write_midx_object_offsets() and
write_midx_large_offsets() are updated here, since additional data in
the context before those methods can match chunk_write_fn.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
b4d941420b midx: use context in write_midx_pack_names()
In an effort to align the write_midx_internal() to use the chunk-format
API, start converting chunk writing methods to match chunk_write_fn. The
first case is to convert write_midx_pack_names() to take "void *data".
We already have the necessary data in "struct write_midx_context", so
this conversion is rather mechanical.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
577dc49696 midx: rename pack_info to write_midx_context
In an effort to streamline our chunk-based file formats, align some of
the code structure in write_midx_internal() to be similar to the
patterns in write_commit_graph_file().

Specifically, let's create a "struct write_midx_context" that can be
used as a data parameter to abstract function types.

This change only renames "struct pack_info" to "struct
write_midx_context" and the names of instances from "packs" to "ctx". In
future changes, we will expand the data inside "struct
write_midx_context" and align our chunk-writing method with the
chunk-format API.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
47410aa837 commit-graph: use chunk-format write API
The commit-graph write logic is ready to make use of the chunk-format
write API. Each chunk write method is already in the correct prototype.
We only need to use the 'struct chunkfile' pointer and the correct API
calls.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
570df42610 chunk-format: create chunk format write API
In anticipation of combining the logic from the commit-graph and
multi-pack-index file formats, create a new chunk-format API. Use a
'struct chunkfile' pointer to keep track of data that has been
registered for writes. This struct is anonymous outside of
chunk-format.c to ensure no user attempts to interfere with the data.

The next change will use this API in commit-graph.c, but the general
approach is:

 1. initialize the chunkfile with init_chunkfile(f).
 2. add chunks in the intended writing order with add_chunk().
 3. write any header information to the hashfile f.
 4. write the chunkfile data using write_chunkfile().
 5. free the chunkfile struct using free_chunkfile().

Helped-by: Taylor Blau <me@ttaylorr.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-18 13:38:16 -08:00
Derrick Stolee
eb9071912f commit-graph: anonymize data in chunk_write_fn
In preparation for creating an API around file formats using chunks and
tables of contents, prepare the commit-graph write code to use
prototypes that will match this new API.

Specifically, convert chunk_write_fn to take a "void *data" parameter
instead of the commit-graph-specific "struct write_commit_graph_context"
pointer.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05 15:40:41 -08:00
Abhishek Kumar
5a3b130cad doc: add corrected commit date info
With generation data chunk and corrected commit dates implemented, let's
update the technical documentation for commit-graph.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
8d00d7c3df commit-reach: use corrected commit dates in paint_down_to_common()
091f4cf (commit: don't use generation numbers if not needed,
2018-08-30) changed paint_down_to_common() to use commit dates instead
of generation numbers v1 (topological levels) as the performance
regressed on certain topologies. With generation number v2 (corrected
commit dates) implemented, we no longer have to rely on commit dates and
can use generation numbers.

For example, the command `git merge-base v4.8 v4.9` on the Linux
repository walks 167468 commits, taking 0.135s for committer date and
167496 commits, taking 0.157s for corrected committer date respectively.

While using corrected commit dates, Git walks nearly the same number of
commits as commit date, the process is slower as for each comparision we
have to access a commit-slab (for corrected committer date) instead of
accessing struct member (for committer date).

This change incidentally broke the fragile t6404-recursive-merge test.
t6404-recursive-merge sets up a unique repository where all commits have
the same committer date without a well-defined merge-base.

While running tests with GIT_TEST_COMMIT_GRAPH unset, we use committer
date as a heuristic in paint_down_to_common(). 6404.1 'combined merge
conflicts' merges commits in the order:
- Merge C with B to form an intermediate commit.
- Merge the intermediate commit with A.

With GIT_TEST_COMMIT_GRAPH=1, we write a commit-graph and subsequently
use the corrected committer date, which changes the order in which
commits are merged:
- Merge A with B to form an intermediate commit.
- Merge the intermediate commit with C.

While resulting repositories are equivalent, 6404.4 'virtual trees were
processed' fails with GIT_TEST_COMMIT_GRAPH=1 as we are selecting
different merge-bases and thus have different object ids for the
intermediate commits.

As this has already causes problems (as noted in 859fdc0 (commit-graph:
define GIT_TEST_COMMIT_GRAPH, 2018-08-29)), we disable commit graph
within t6404-recursive-merge.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
1fdc383c5c commit-graph: use generation v2 only if entire chain does
Since there are released versions of Git that understand generation
numbers in the commit-graph's CDAT chunk but do not understand the GDAT
chunk, the following scenario is possible:

1. "New" Git writes a commit-graph with the GDAT chunk.
2. "Old" Git writes a split commit-graph on top without a GDAT chunk.

If each layer of split commit-graph is treated independently, as it was
the case before this commit, with Git inspecting only the current layer
for chunk_generation_data pointer, commits in the lower layer (one with
GDAT) whould have corrected commit date as their generation number,
while commits in the upper layer would have topological levels as their
generation. Corrected commit dates usually have much larger values than
topological levels. This means that if we take two commits, one from the
upper layer, and one reachable from it in the lower layer, then the
expectation that the generation of a parent is smaller than the
generation of a child would be violated.

It is difficult to expose this issue in a test. Since we _start_ with
artificially low generation numbers, any commit walk that prioritizes
generation numbers will walk all of the commits with high generation
number before walking the commits with low generation number. In all the
cases I tried, the commit-graph layers themselves "protect" any
incorrect behavior since none of the commits in the lower layer can
reach the commits in the upper layer.

This issue would manifest itself as a performance problem in this case,
especially with something like "git log --graph" since the low
generation numbers would cause the in-degree queue to walk all of the
commits in the lower layer before allowing the topo-order queue to write
anything to output (depending on the size of the upper layer).

Therefore, When writing the new layer in split commit-graph, we write a
GDAT chunk only if the topmost layer has a GDAT chunk. This guarantees
that if a layer has GDAT chunk, all lower layers must have a GDAT chunk
as well.

Rewriting layers follows similar approach: if the topmost layer below
the set of layers being rewritten (in the split commit-graph chain)
exists, and it does not contain GDAT chunk, then the result of rewrite
does not have GDAT chunks either.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
e8b63005c4 commit-graph: implement generation data chunk
As discovered by Ævar, we cannot increment graph version to
distinguish between generation numbers v1 and v2 [1]. Thus, one of
pre-requistes before implementing generation number v2 was to
distinguish between graph versions in a backwards compatible manner.

We are going to introduce a new chunk called Generation DATa chunk (or
GDAT). GDAT will store corrected committer date offsets whereas CDAT
will still store topological level.

Old Git does not understand GDAT chunk and would ignore it, reading
topological levels from CDAT. New Git can parse GDAT and take advantage
of newer generation numbers, falling back to topological levels when
GDAT chunk is missing (as it would happen with a commit-graph written
by old Git).

We introduce a test environment variable 'GIT_TEST_COMMIT_GRAPH_NO_GDAT'
which forces commit-graph file to be written without generation data
chunk to emulate a commit-graph file written by old Git.

To minimize the space required to store corrrected commit date, Git
stores corrected commit date offsets into the commit-graph file, instea
of corrected commit dates. This saves us 4 bytes per commit, decreasing
the GDAT chunk size by half, but it's possible for the offset to
overflow the 4-bytes allocated for storage. As such overflows are and
should be exceedingly rare, we use the following overflow management
scheme:

We introduce a new commit-graph chunk, Generation Data OVerflow ('GDOV')
to store corrected commit dates for commits with offsets greater than
GENERATION_NUMBER_V2_OFFSET_MAX.

If the offset is greater than GENERATION_NUMBER_V2_OFFSET_MAX, we set
the MSB of the offset and the other bits store the position of corrected
commit date in GDOV chunk, similar to how Extra Edge List is maintained.

We test the overflow-related code with the following repo history:

           F - N - U
          /         \
U - N - U            N
         \          /
	  N - F - N

Where the commits denoted by U have committer date of zero seconds
since Unix epoch, the commits denoted by N have committer date of
1112354055 (default committer date for the test suite) seconds since
Unix epoch and the commits denoted by F have committer date of
(2 ^ 31 - 2) seconds since Unix epoch.

The largest offset observed is 2 ^ 31, just large enough to overflow.

[1]: https://lore.kernel.org/git/87a7gdspo4.fsf@evledraar.gmail.com/

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
c1a09119f6 commit-graph: implement corrected commit date
With most of preparations done, let's implement corrected commit date.

The corrected commit date for a commit is defined as:

* A commit with no parents (a root commit) has corrected commit date
  equal to its committer date.
* A commit with at least one parent has corrected commit date equal to
  the maximum of its commit date and one more than the largest corrected
  commit date among its parents.

As a special case, a root commit with timestamp of zero (01.01.1970
00:00:00Z) has corrected commit date of one, to be able to distinguish
from GENERATION_NUMBER_ZERO (that is, an uncomputed corrected commit
date).

To minimize the space required to store corrected commit date, Git
stores corrected commit date offsets into the commit-graph file. The
corrected commit date offset for a commit is defined as the difference
between its corrected commit date and actual commit date.

Storing corrected commit date requires sizeof(timestamp_t) bytes, which
in most cases is 64 bits (uintmax_t). However, corrected commit date
offsets can be safely stored using only 32-bits. This halves the size
of GDAT chunk, which is a reduction of around 6% in the size of
commit-graph file.

However, using offsets be problematic if a commit is malformed but valid
and has committer date of 0 Unix time, as the offset would be the same
as corrected commit date and thus require 64-bits to be stored properly.

While Git does not write out offsets at this stage, Git stores the
corrected commit dates in member generation of struct commit_graph_data.
It will begin writing commit date offsets with the introduction of
generation data chunk.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
d7f92784c6 commit-graph: return 64-bit generation number
In a preparatory step for introducing corrected commit dates, let's
return timestamp_t values from commit_graph_generation(), use
timestamp_t for local variables and define GENERATION_NUMBER_INFINITY
as (2 ^ 63 - 1) instead.

We rename GENERATION_NUMBER_MAX to GENERATION_NUMBER_V1_MAX to
represent the largest topological level we can store in the commit data
chunk.

With corrected commit dates implemented, we will have two such *_MAX
variables to denote the largest offset and largest topological level
that can be stored.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
72a2bfcaf0 commit-graph: add a slab to store topological levels
In a later commit we will introduce corrected commit date as the
generation number v2. Corrected commit dates will be stored in the new
seperate Generation Data chunk. However, to ensure backwards
compatibility with "Old" Git we need to continue to write generation
number v1 (topological levels) to the commit data chunk. Thus, we need
to compute and store both versions of generation numbers to write the
commit-graph file.

Therefore, let's introduce a commit-slab `topo_level_slab` to store
topological levels; corrected commit date will be stored in the member
`generation` of struct commit_graph_data.

The macros `GENERATION_NUMBER_INFINITY` and `GENERATION_NUMBER_ZERO`
mark commits not in the commit-graph file and commits written by a
version of Git that did not compute generation numbers respectively.
Generation numbers are computed identically for both kinds of commits.

A "slab-miss" should return `GENERATION_NUMBER_INFINITY` as the commit
is not in the commit-graph file. However, since the slab is
zero-initialized, it returns 0 (or rather `GENERATION_NUMBER_ZERO`).
Thus, we no longer need to check if the topological level of a commit is
`GENERATION_NUMBER_INFINITY`.

We will add a pointer to the slab in `struct write_commit_graph_context`
and `struct commit_graph` to populate the slab in
`fill_commit_graph_info` if the commit has a pre-computed topological
level as in case of split commit-graphs.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
c0ef139843 t6600-test-reach: generalize *_three_modes
In a preparatory step to implement generation number v2, we add tests to
ensure Git can read and parse commit-graph files without Generation Data
chunk. These files represent commit-graph files written by Old Git and
are neccesary for backward compatability.

We extend run_three_modes() and test_three_modes() to *_all_modes() with
the fourth mode being "commit-graph without generation data chunk".

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
f90fca638e commit-graph: consolidate fill_commit_graph_info
Both fill_commit_graph_info() and fill_commit_in_graph() parse
information present in commit data chunk. Let's simplify the
implementation by calling fill_commit_graph_info() within
fill_commit_in_graph().

fill_commit_graph_info() used to not load committer data from commit data
chunk. However, with the upcoming switch to using corrected committer
date as generation number v2, we will have to load committer date to
compute generation number value anyway.

e51217e15 (t5000: test tar files that overflow ustar headers,
30-06-2016) introduced a test 'generate tar with future mtime' that
creates a commit with committer date of (2^36 + 1) seconds since
EPOCH. The CDAT chunk provides 34-bits for storing committer date, thus
committer time overflows into generation number (within CDAT chunk) and
has undefined behavior.

The test used to pass as fill_commit_graph_info() would not set struct
member `date` of struct commit and load committer date from the object
database, generating a tar file with the expected mtime.

However, with corrected commit date, we will load the committer date
from CDAT chunk (truncated to lower 34-bits to populate the generation
number. Thus, Git sets date and generates tar file with the truncated
mtime.

The ustar format (the header format used by most modern tar programs)
only has room for 11 (or 12, depending on some implementations) octal
digits for the size and mtime of each file.

As the CDAT chunk is overflow by 12-octal digits but not 11-octal
digits, we split the existing tests to test both implementations
separately and add a new explicit test for 11-digit implementation.

To test the 11-octal digit implementation, we create a future commit
with committer date of 2^34 - 1, which overflows 11-octal digits without
overflowing 34-bits of the Commit Date chunks.

To test the 12-octal digit implementation, the smallest committer date
possible is 2^36 + 1, which overflows the CDAT chunk and thus
commit-graph must be disabled for the test.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
2f9bbb6d91 revision: parse parent in indegree_walk_step()
In indegree_walk_step(), we add unvisited parents to the indegree queue.
However, parents are not guaranteed to be parsed. As the indegree queue
sorts by generation number, let's parse parents before inserting them to
ensure the correct priority order.

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00
Abhishek Kumar
e30c5ee76c commit-graph: fix regression when computing Bloom filters
Before computing Bloom filters, the commit-graph machinery uses
commit_gen_cmp to sort commits by generation order for improved diff
performance. 3d11275505 (commit-graph: examine commits by generation
number, 2020-03-30) claims that this sort can reduce the time spent to
compute Bloom filters by nearly half.

But since c49c82aa4c (commit: move members graph_pos, generation to a
slab, 2020-06-17), this optimization is broken, since asking for a
'commit_graph_generation()' directly returns GENERATION_NUMBER_INFINITY
while writing.

Not all hope is lost, though: 'commit_gen_cmp()' falls back to
comparing commits by their date when they have equal generation number,
and so since c49c82aa4c is purely a date comparison function. This
heuristic is good enough that we don't seem to loose appreciable
performance while computing Bloom filters.

Applying this patch (compared with v2.30.0) speeds up computing Bloom
filters by factors ranging from 0.40% to 5.19% on various repositories [1].

So, avoid the useless 'commit_graph_generation()' while writing by
instead accessing the slab directly. This returns the newly-computed
generation numbers, and allows us to avoid the heuristic by directly
comparing generation numbers.

[1]: https://lore.kernel.org/git/20210105094535.GN8396@szeder.dev/

Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:17 -08:00
Junio C Hamano
71ca53e812 Git 2.30
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-27 15:15:23 -08:00
Junio C Hamano
f6bf36dc9c Merge branch 'pb/doc-git-linkit-fix'
Docfix.

* pb/doc-git-linkit-fix:
  git.txt: fix typos in 'linkgit' macro invocation
2020-12-27 15:14:32 -08:00
Junio C Hamano
371065cc22 l10n for Git 2.30.0 round 2
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Merge tag 'l10n-2.30.0-rnd2' of https://github.com/git-l10n/git-po

l10n for Git 2.30.0 round 2

* tag 'l10n-2.30.0-rnd2' of https://github.com/git-l10n/git-po:
  l10n: zh_CN: for git v2.30.0 l10n round 1 and 2
  l10n: zh_TW.po: v2.30.0 round 2 (1 untranslated)
  l10n: pl.po: add translation and set team leader
  l10n: pl.po: started Polish translation
  l10n: de.po: Update German translation for Git 2.30.0
  l10n: Update Catalan translation
  l10n: bg.po: Updated Bulgarian translation (5037t)
  l10n: fr.po v2.30.0 rnd 2
  l10n: tr: v2.30.0-r2
  l10n: sv.po: Update Swedish translation (5037t0f0u)
  l10n: vi.po(5037t): v2.30.0 rnd 2
  l10n: git.pot: v2.30.0 round 2 (1 new, 2 removed)
  l10n: Update Catalan translation
  l10n: fr.po: v2.30.0 rnd 1
  l10n: fr.po Fix a typo
  l10n: fr fix misleading message
  l10n: tr: v2.30.0-r1
  l10n: sv.po: Update Swedish translation (5038t0f0u)
  l10n: git.pot: v2.30.0 round 1 (70 new, 45 removed)
2020-12-27 15:01:16 -08:00
Jiang Xin
d13389bf27 l10n: zh_CN: for git v2.30.0 l10n round 1 and 2
Translate 71 new messages (5037t0f0u) for git 2.30.0.

Reviewed-by: 依云 <lilydjwg@gmail.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
2020-12-27 19:23:27 +08:00
Jiang Xin
ecc0c5841b Merge branch 'l10n/zh_TW/201223' of github.com:l10n-tw/git-po
* 'l10n/zh_TW/201223' of github.com:l10n-tw/git-po:
  l10n: zh_TW.po: v2.30.0 round 2 (1 untranslated)
2020-12-25 15:12:02 +08:00
pan93412
6806dd88f3 l10n: zh_TW.po: v2.30.0 round 2 (1 untranslated)
Signed-off-by: pan93412 <pan93412@gmail.com>
2020-12-25 12:16:13 +08:00
Arusekk
b77b318bd2 l10n: pl.po: add translation and set team leader
Signed-off-by: Arusekk <arek_koz@o2.pl>
2020-12-23 23:51:43 +01:00
Junio C Hamano
4a0de43f49 Git 2.30-rc2
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-23 13:59:46 -08:00
Junio C Hamano
73583204d9 Merge branch 'nk/refspecs-negative-fix'
Hotfix for recent regression.

* nk/refspecs-negative-fix:
  negative-refspec: improve comment on query_matches_negative_refspec
  negative-refspec: fix segfault on : refspec
2020-12-23 13:59:46 -08:00
Junio C Hamano
7a50265295 Merge branch 'ma/maintenance-crontab-fix'
Hotfix for a topic of this cycle.

* ma/maintenance-crontab-fix:
  t7900-maintenance: test for magic markers
  gc: fix handling of crontab magic markers
  git-maintenance.txt: add missing word
2020-12-23 13:59:46 -08:00
Junio C Hamano
04cd999638 Merge branch 'dl/checkout-p-merge-base'
Fix to a regression introduced during this cycle.

* dl/checkout-p-merge-base:
  checkout -p: handle tree arguments correctly again
2020-12-23 13:59:46 -08:00
Junio C Hamano
d076224363 Merge branch 'js/no-more-prepare-for-main-in-test'
Test coverage fix.

* js/no-more-prepare-for-main-in-test:
  tests: drop the `PREPARE_FOR_MAIN_BRANCH` prereq
  t9902: use `main` as initial branch name
  t6302: use `main` as initial branch name
  t5703: use `main` as initial branch name
  t5510: use `main` as initial branch name
  t5505: finalize transitioning to using the branch name `main`
  t3205: finalize transitioning to using the branch name `main`
  t3203: complete the transition to using the branch name `main`
  t3201: finalize transitioning to using the branch name `main`
  t3200: finish transitioning to the initial branch name `main`
  t1400: use `main` as initial branch name
2020-12-23 13:59:46 -08:00
Junio C Hamano
c46f849f8a Merge branch 'jx/pack-redundant-on-single-pack'
"git pack-redandant" when there is only one packfile used to crash,
which has been corrected.

* jx/pack-redundant-on-single-pack:
  pack-redundant: fix crash when one packfile in repo
2020-12-23 13:59:46 -08:00
m4sk1n
f6d254c157 l10n: pl.po: started Polish translation
Signed-off-by: Arusekk <arek_koz@o2.pl>
2020-12-23 22:51:30 +01:00
Matthias Rüster
6fe3d27d00 l10n: de.po: Update German translation for Git 2.30.0
Reviewed-by: Ralf Thielow <ralf.thielow@gmail.com>
Reviewed-by: Phillip Szelat <phillip.szelat@gmail.com>
Signed-off-by: Matthias Rüster <matthias.ruester@gmail.com>
2020-12-23 13:41:53 +01:00
Jiang Xin
4953317e6b Merge branch 'master' of github.com:Softcatala/git-po
* 'master' of github.com:Softcatala/git-po:
  l10n: Update Catalan translation
2020-12-23 08:44:44 +08:00
Philippe Blain
5bed7f66c4 git.txt: fix typos in 'linkgit' macro invocation
The 'linkgit' Asciidoc macro is misspelled as 'linkit' in the
description of 'GIT_SEQUENCE_EDITOR' since the addition of that variable
to git(1) in 902a126eca (doc: mention GIT_SEQUENCE_EDITOR and
'sequence.editor' more, 2020-08-31). Also, it uses two colons instead of
one.

Fix that.

Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-22 12:02:29 -08:00
Jordi Mas
9d82565c2e l10n: Update Catalan translation
Signed-off-by: Jordi Mas <jmas@softcatala.org>
2020-12-22 18:04:53 +01:00
Alexander Shopov
da0e79d6fa l10n: bg.po: Updated Bulgarian translation (5037t)
Signed-off-by: Alexander Shopov <ash@kambanaria.org>
2020-12-22 17:49:18 +01:00
Nipunn Koorapati
773c694142 negative-refspec: improve comment on query_matches_negative_refspec
Comment did not adequately explain how the two loops work
together to achieve the goal of querying for matching of any
negative refspec.

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 22:49:36 -08:00
Nipunn Koorapati
18f9c98845 negative-refspec: fix segfault on : refspec
The logic added to check for negative pathspec match by c0192df630
(refspec: add support for negative refspecs, 2020-09-30) looks at
refspec->src assuming it is never NULL, however when
remote.origin.push is set to ":", then refspec->src is NULL,
causing a segfault within strcmp.

Tell git to handle matching refspec by adding the needle to the
set of positively matched refspecs, since matching ":" refspecs
match anything as src.

Add test for matching refspec pushes fetch-negative-refspec
both individually and in combination with a negative refspec.

Signed-off-by: Nipunn Koorapati <nipunn@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 22:49:36 -08:00
Jiang Xin
44840426ec Merge branch 'fr_2.30_rnd2' of github.com:jnavila/git
* 'fr_2.30_rnd2' of github.com:jnavila/git:
  l10n: fr.po v2.30.0 rnd 2
2020-12-22 08:46:17 +08:00
Martin Ågren
a52df25a54 t7900-maintenance: test for magic markers
When we insert our "BEGIN" and "END" markers into the cron table, it's
so that a Git version from many years into the future would be able to
identify this region in the cron table. Let's add a test to make sure
that these markers don't ever change.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-12-21 14:33:09 -08:00