This patch enables addressing the CPU cost of loading the index by adding
additional data to the index that will allow us to efficiently multi-
thread the loading and conversion of cache entries.
It accomplishes this by adding an (optional) index extension that is a
table of offsets to blocks of cache entries in the index file. To make
this work for V4 indexes, when writing the cache entries, it periodically
"resets" the prefix-compression by encoding the current entry as if the
path name for the previous entry is completely different and saves the
offset of that entry in the IEOT. Basically, with V4 indexes, it
generates offsets into blocks of prefix-compressed entries.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch helps address the CPU cost of loading the index by loading
the cache extensions on a worker thread in parallel with loading the cache
entries.
In some cases, loading the extensions takes longer than loading the
cache entries so this patch utilizes the new EOIE to start the thread to
load the extensions before loading all the cache entries in parallel.
This is possible because the current extensions don't access the cache
entries in the index_state structure so are OK that they don't all exist
yet.
The CACHE_EXT_TREE, CACHE_EXT_RESOLVE_UNDO, and CACHE_EXT_UNTRACKED
extensions don't even get a pointer to the index so don't have access to the
cache entries.
CACHE_EXT_LINK only uses the index_state to initialize the split index.
CACHE_EXT_FSMONITOR only uses the index_state to save the fsmonitor last
update and dirty flags.
I used p0002-read-cache.sh to generate some performance data:
Test w/100,000 files reduced the time by 0.53%
Test w/1,000,000 files reduced the time by 27.78%
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add support for a new index.threads config setting which will be used to
control the threading code in do_read_index(). A value of 0 will tell the
index code to automatically determine the correct number of threads to use.
A value of 1 will make the code single threaded. A value greater than 1
will set the maximum number of threads to use.
For testing purposes, this setting can be overwritten by setting the
GIT_TEST_INDEX_THREADS=<n> environment variable to a value greater than 0.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The End of Index Entry (EOIE) is used to locate the end of the variable
length index entries and the beginning of the extensions. Code can take
advantage of this to quickly locate the index extensions without having
to parse through all of the index entries.
The EOIE extension is always written out to the index file including to
the shared index when using the split index feature. Because it is always
written out, the SHA checksums in t/t1700-split-index.sh were updated
to reflect its inclusion.
It is written as an optional extension to ensure compatibility with other
git implementations that do not yet support it. It is always written out
to ensure it is available as often as possible to speed up index operations.
Because it must be able to be loaded before the variable length cache
entries and other index extensions, this extension must be written last.
The signature for this extension is { 'E', 'O', 'I', 'E' }.
The extension consists of:
- 32-bit offset to the end of the index entries
- 160-bit SHA-1 over the extension types and their sizes (but not
their contents). E.g. if we have "TREE" extension that is N-bytes
long, "REUC" extension that is M-bytes long, followed by "EOIE",
then the hash would be:
SHA-1("TREE" + <binary representation of N> +
"REUC" + <binary representation of M>)
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch does a clean up pass to minimize the casting required to work
with the memory mapped index (mmap).
It also makes the decoding of network byte order more consistent by using
get_be32() where possible.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update fsck.skipList implementation and documentation.
* ab/fsck-skiplist:
fsck: support comments & empty lines in skipList
fsck: use oidset instead of oid_array for skipList
fsck: use strbuf_getline() to read skiplist file
fsck: add a performance test for skipList
fsck: add a performance test
fsck: document that skipList input must be unabbreviated
fsck: document and test commented & empty line skipList input
fsck: document and test sorted skipList input
fsck tests: add a test for no skipList input
fsck tests: setup of bogus commit object
"git multi-pack-index" learned to detect corruption in the .midx
file it uses, and this feature has been integrated into "git fsck".
* ds/multi-pack-verify:
fsck: verify multi-pack-index
multi-pack-index: report progress during 'verify'
multi-pack-index: verify object offsets
multi-pack-index: fix 32-bit vs 64-bit size check
multi-pack-index: verify oid lookup order
multi-pack-index: verify oid fanout order
multi-pack-index: verify missing pack
multi-pack-index: verify packname order
multi-pack-index: verify corrupt chunk lookup table
multi-pack-index: verify bad header
multi-pack-index: add 'verify' verb
Various tests have been updated to make it easier to swap the
hash function used for object identification.
* bc/hash-independent-tests:
t5318: use test_oid for HASH_LEN
t1407: make hash size independent
t1406: make hash-size independent
t1405: make hash size independent
t1400: switch hard-coded object ID to variable
t1006: make hash size independent
t0064: make hash size independent
t0002: abstract away SHA-1 specific constants
t0000: update tests for SHA-256
t0000: use hash translation table
t: add test functions to translate hash-related values
Test helper binaries clean-up.
* nd/test-tool:
Makefile: add a hint about TEST_BUILTINS_OBJS
t/helper: merge test-dump-fsmonitor into test-tool
t/helper: merge test-parse-options into test-tool
t/helper: merge test-pkt-line into test-tool
t/helper: merge test-dump-untracked-cache into test-tool
t/helper: keep test-tool command list sorted
Split Documentation/config.txt for easier maintenance.
* nd/config-split:
config.txt: move submodule part out to a separate file
config.txt: move sequence.editor out of "core" part
config.txt: move sendemail part out to a separate file
config.txt: move receive part out to a separate file
config.txt: move push part out to a separate file
config.txt: move pull part out to a separate file
config.txt: move gui part out to a separate file
config.txt: move gitcvs part out to a separate file
config.txt: move format part out to a separate file
config.txt: move fetch part out to a separate file
config.txt: follow camelCase naming
In a partial clone, whenever a sparse checkout occurs, the existence of
all blobs in the index is verified, whether they are included or
excluded by the .git/info/sparse-checkout specification. This
significantly degrades performance because a lazy fetch occurs whenever
the existence of a missing blob is checked.
This is because cache_tree_update() checks the existence of all objects
in the index, whether or not CE_SKIP_WORKTREE is set on them. Teach
cache_tree_update() to skip checking CE_SKIP_WORKTREE objects when the
repository is a partial clone. This improves performance for sparse
checkout and also other operations that use cache_tree_update().
Instead of completely removing the check, an argument could be made that
the check should instead be replaced by a check that the blob is
promised, but for performance reasons, I decided not to do this.
If the user needs to verify the repository, it can be done using fsck
(which will notify if a tree points to a missing and non-promised blob,
whether the blob is included or excluded by the sparse-checkout
specification).
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The recently-introduced "core.alternateRefsCommand" allows callers to
specify with high flexibility the tips that they wish to advertise from
alternates. This flexibility comes at the cost of some inconvenience
when the caller only wishes to limit the advertisement to one or more
prefixes.
For example, to advertise only tags, a caller using
'core.alternateRefsCommand' would have to do:
$ git config core.alternateRefsCommand ' \
f() { git -C "$1" for-each-ref \
refs/tags --format="%(objectname)" }; f "$@"'
The above is cumbersome to write, so let's introduce a
"core.alternateRefsPrefixes" to address this common case. Instead, the
caller can run:
$ git config core.alternateRefsPrefixes 'refs/tags'
Which will behave identically to the longer example using
"core.alternateRefsCommand".
Since the value of "core.alternateRefsPrefixes" is appended to 'git
for-each-ref' and then executed, include a "--" before taking the
configured value to avoid misinterpreting arguments as flags to 'git
for-each-ref'.
In the case that the caller wishes to specify multiple prefixes, they
may separate them by whitespace. If "core.alternateRefsCommand" is set,
it will take precedence over "core.alternateRefsPrefixes".
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When in a repository containing one or more alternates, Git would
sometimes like to list references from those alternates. For example,
'git receive-pack' lists the "tips" pointed to by references in those
alternates as special ".have" references.
Listing ".have" references is designed to make pushing changes from
upstream to a fork a lightweight operation, by advertising to the pusher
that the fork already has the objects (via its alternate). Thus, the
client can avoid sending them.
However, when the alternate (upstream, in the previous example) has a
pathologically large number of references, the initial advertisement is
too expensive. In fact, it can dominate any such optimization where the
pusher avoids sending certain objects.
Introduce "core.alternateRefsCommand" in order to provide a facility to
limit or filter alternate references. This can be used, for example, to
filter out references the alternate does not wish to send (for space
concerns, or otherwise) during the initial advertisement.
Let the repository that has alternates configure this command to avoid
trusting the alternate to provide us a safe command to run in the shell.
To find the alternate, pass its absolute path as the first argument.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To list alternate references, 'read_alternate_refs' creates a child
process running 'git for-each-ref' in the alternate's Git directory.
Prepare to run other commands besides 'git for-each-ref' by introducing
and moving the relevant code from 'read_alternate_refs' to
'fill_alternate_refs_command'.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
None of the current callers use the refname parameter we pass to their
callbacks. In theory somebody _could_ do so, but it's actually quite
weird if you think about it: it's a ref in somebody else's repository.
So the name has no meaning locally, and in fact there may be duplicates
if there are multiple alternates.
The users of this interface really only care about seeing some ref tips,
since that promises that the alternate has the full commit graph
reachable from there. So let's keep the information we pass back to the
bare minimum.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sample code calls `get_revision()' followed by `graph_update()',
but the documentation and source code indicate that `get_revision()'
already calls `graph_update()' for you.
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since stash list accepts git-log options, add the following useful
options that make sense in the context of the `git stash list` command:
--name-status --oneline --patch-with-stat
Signed-off-by: Steven Fernandez <steve@lonetwin.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If only hash literals are given on a "git fetch" command-line, tag
following is not requested, and the fetch is done using protocol v2, a
list of refs is not required from the remote. Therefore, optimize by
invoking transport_get_remote_refs() only if we need the refs.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The built-in bundle transport and the transport helper interface do not
work when transport_fetch_refs() is called immediately after transport
creation. This will be needed in a subsequent patch, so fix this.
Evidence: fetch_refs_from_bundle() relies on data->header being
initialized in get_refs_from_bundle(), and fetch() in transport-helper.c
relies on either data->fetch or data->import being set by get_helper(),
but neither transport_helper_init() nor fetch() calls get_helper().
Up until the introduction of the partial clone feature, this has not
been a problem, because transport_fetch_refs() is always called after
transport_get_remote_refs(). With the introduction of the partial clone
feature, which involves calling transport_fetch_refs() (to fetch objects
by their OIDs) without transport_get_remote_refs(), this is still not a
problem, but only coincidentally - we do not support partially cloning a
bundle, and as for cloning using a transport-helper-using protocol, it
so happens that before transport_fetch_refs() is called, fetch_refs() in
fetch-object.c calls transport_set_option(), which means that the
aforementioned get_helper() is invoked through set_helper_option() in
transport-helper.c.
This could be fixed by fixing the transports themselves, but it doesn't
seem like a good idea to me to open up previously untested code paths;
also, there may be transport helpers in the wild that assume that "list"
is always called before "fetch". Instead, fix this by having
transport_fetch_refs() call transport_get_remote_refs() to ensure that
the latter is always called at least once, unless the transport
explicitly states that it supports fetching without listing refs.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When all refs to be fetched are exact OIDs, it is possible to perform a
fetch without requiring the remote to list refs if protocol v2 is used.
Teach Git to do this.
This currently has an effect only for lazy fetches done from partial
clones. The change necessary to likewise optimize "git fetch <remote>
<sha-1>" will be done in a subsequent patch.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_refs_via_connect() function both performs the handshake
(including determining the protocol version) and obtaining the list of
remote refs. However, the fetch protocol v2 supports fetching objects
without the listing of refs, so make it possible for the user to skip
the listing by creating a new handshake() function. This will be used in
a subsequent commit.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is a common mistake to put positional arguments before flags when
invoking git-rev-list. Order the positional arguments last.
This patch skips git-rev-list invocations which include the --not flag,
since the ordering of flags and positional arguments affects the
behavior. This patch also skips invocations of git-rev-list that occur
in command substitution in which the exit code is discarded, since
fixing those properly will require a more involved cleanup.
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'git ... | foo' will mask any errors or crashes in git, so split up such
pipes in this file.
One testcase uses several separate pipe sequences in a row which are
awkward to split up. Wrap the split-up pipe in a function so the
awkwardness is not repeated. Also change that testcase's surrounding
quotes from double to single to avoid premature string interpolation.
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some pipes in tests lose the exit code of git processes, which can mask
unexpected behavior like crashes. Split these pipes up so that git
commands are only at the end of pipes rather than the beginning or
middle.
The violations fixed in this patch were found in the process of fixing
pipe placement in a prior patch.
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix various places where the ordering was obviously wrong, meaning it
was easy to find with grep.
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of using a line-continuation and pipe on the second line, take
advantage of the shell's implicit line continuation after a pipe
character. So for example, instead of
some long line \
| next line
use
some long line |
next line
And add a blank line before and after the pipe where it aids readability
(it usually does).
This better matches the coding style documented in
Documentation/CodingGuidelines and used in shell scripts elsewhere in
the tree.
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add the following guideline to Documentation/CodingGuidelines:
Break overlong lines after "&&", "||", and "|", not before
them; that way the command can continue to subsequent lines
without backslash at the end.
And the following to t/README (since it is specific to writing tests):
Pipes and $(git ...) should be avoided when they swallow exit
codes of Git processes
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The list of Don'ts for test writing has grown large such that it is hard
to see at a glance which section an item is in. In other words, if I
ignore a little bit of surrounding context, the "don'ts" look like
"do's."
To make the list more readable, prefix "Don't" in front of every first
sentence in the items.
Also, the "Keep in mind" list is out of place and awkward, because it
was a very short "list" beneath two very long ones, and it seemed easy
to miss under the list of "don'ts," and it only had one item. So move
this item to the list of "do's" and phrase as "Remember..."
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While writing a commit-graph file, we store the full list of
commits in a flat list. We use this list for sorting and ensuring
we are closed under reachability.
The initial allocation assumed that (at most) one in four objects
is a commit. This is a dramatic over-count for many repos,
especially large ones. Since we grow the repo dynamically, reduce
this count by a factor of eight. We still set it to a minimum of
1024 before allocating.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`graph_verify()`, `graph_read()` and `graph_write()` do the hard work of
`cmd_commit_graph()`. As soon as these return, so does
`cmd_commit_graph()`.
`strbuf_getline()` may allocate memory in the strbuf, yet return EOF.
We need to release the strbuf or UNLEAK it. Go for the latter since we
are close to returning from `graph_write()`.
`graph_write()` also fails to free the strings in the string list. They
have been added to the list with `strdup_strings` set to 0. We could
flip `strdup_strings` before clearing the list, which is our usual hack
in situations like this. But since we are about to exit, let's just
UNLEAK the whole string list instead.
UNLEAK `graph` in `graph_verify`. While at it, and for consistency,
UNLEAK in `graph_read()` as well, and remove an unnecessary UNLEAK just
before dying.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The write_commit_graph() method in commit-graph.c leaks some lits
and strings during execution. In addition, a list of strings is
leaked in write_commit_graph_reachable(). Clean these up so our
memory checking is cleaner.
Further, if we use a list of pack-files to find the commits, we
can leak the packed_git structs after scanning them for commits.
Running the following commands demonstrates the leak before and
the fix after:
* valgrind --leak-check=full ./git commit-graph write --reachable
* valgrind --leak-check=full ./git commit-graph write --stdin-packs
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Free the hashmap items as well as the hashmap itself. This was found
with asan.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is obvious in retrospect, it was found with asan.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Don't duplicate the indentation string if we're not going to use it.
This was found with asan.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When adjusting the start of the string to take account of the change
in indentation the code was not checking that the string being
adjusted was in fact longer than the indentation change. This was
detected by asan.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Running
git diff --color-moved-ws=allow-indentation-change v2.18.0 v2.19.0
results in a crash due to a double free. This happens when two
potential moved blocks start with consecutive lines. As
pmb_advance_or_null_multi_match() advances it copies the ws_delta from
the last matching line to the next. When the first of our consecutive
lines is advanced its ws_delta well be copied to the second,
overwriting the ws_delta of the block containing the second line. Then
when the second line is advanced it will copy the new ws_delta to the
line below it and so on. Eventually one of these blocks will stop
matching and the ws_delta will be freed. From then on the other block
is in a use-after-free state and when it stops matching it will try to
free the ws_delta that has already been freed by the other block.
The solution is to store the ws_delta in the array of potential moved
blocks rather than with the lines. This means that it no longer needs
to be copied around and one block cannot overwrite the ws_delta of
another. Additionally it saves some malloc/free calls as we don't keep
allocating and freeing ws_deltas.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is no need to inline oidset_init(), as it's typically only called
twice in the lifetime of an oidset (once at the beginning and at the end
by oidset_clear()) and kh_resize_* is quite big, so move its definition
to oidset.c. Document it while we're at it.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reimplement oidset using khash.h in order to reduce its memory footprint
and make it faster.
Performance of a command that mainly checks for duplicate objects using
an oidset, with master and Clang 6.0.1:
$ cmd="./git-cat-file --batch-all-objects --unordered --buffer --batch-check='%(objectname)'"
$ /usr/bin/time $cmd >/dev/null
0.22user 0.03system 0:00.25elapsed 99%CPU (0avgtext+0avgdata 48484maxresident)k
0inputs+0outputs (0major+11204minor)pagefaults 0swaps
$ hyperfine "$cmd"
Benchmark #1: ./git-cat-file --batch-all-objects --unordered --buffer --batch-check='%(objectname)'
Time (mean ± σ): 250.0 ms ± 6.0 ms [User: 225.9 ms, System: 23.6 ms]
Range (min … max): 242.0 ms … 261.1 ms
And with this patch:
$ /usr/bin/time $cmd >/dev/null
0.14user 0.00system 0:00.15elapsed 100%CPU (0avgtext+0avgdata 41396maxresident)k
0inputs+0outputs (0major+8318minor)pagefaults 0swaps
$ hyperfine "$cmd"
Benchmark #1: ./git-cat-file --batch-all-objects --unordered --buffer --batch-check='%(objectname)'
Time (mean ± σ): 151.9 ms ± 4.9 ms [User: 130.5 ms, System: 21.2 ms]
Range (min … max): 148.2 ms … 170.4 ms
Initial-patch-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function for releasing the khash-internal allocations, but not the
khash structure itself. It can be used with on-stack khash structs.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tip_oids_contain() lazily loads refs into an oidset at its first call.
It abuses the internal (sub)member .map.tablesize of that oidset to
check if it has done that already.
Determine if the oidset needs to be populated upfront and then do that
instead. This duplicates a loop, but simplifies the existing one by
separating concerns between the two.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the code to determine if a request is unmatched to its own little
helper. This allows us to reuse it in a subsequent patch.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A partial clone with missing trees can be obtained using "git clone
--filter=tree:none <repo>". In such a repository, when a tree needs to
be lazily fetched, any tree or blob it directly or indirectly references
is fetched as well, regardless of whether the original command required
those objects, or if the local repository already had some of them.
This is because the fetch protocol, which the lazy fetch uses, does not
allow clients to request that only the wanted objects be sent, which
would be the ideal solution. This patch implements a partial solution:
specify the "blob:none" filter, somewhat reducing the fetch payload.
This change has no effect when lazily fetching blobs (due to how filters
work). And if lazily fetching a commit (such repositories are difficult
to construct and is not a use case we support very well, but it is
possible), referenced commits and trees are still fetched - only the
blobs are not fetched.
The necessary code change is done in fetch_pack() instead of somewhere
closer to where the "filter" instruction is written to the wire so that
only one part of the code needs to be changed in order for users of all
protocol versions to benefit from this optimization.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fetch_pack() is invoked as part of another Git command (due to a
lazy fetch from a partial clone, for example), it uses object flags that
may already be used by the outer Git command.
The commit that introduced the lazy fetch feature (88e2f9ed8e
("introduce fetch-object: fetch one promisor object", 2017-12-05)) tried
to avoid this overlap, but it did not avoid it totally. It was
successful in avoiding writing COMPLETE, but did not avoid reading
COMPLETE, and did not avoid writing and reading ALTERNATE.
Ensure that no flags are written or read by fetch_pack() in the case
where it is used to perform a lazy fetch. To do this, it is sufficient
to avoid checking completeness of wanted refs (unnecessary in the case
of lazy fetches), and to avoid negotiation-related work (in the current
implementation, already, no negotiation is performed). After that was
done, the lack of overlap was verified by checking all direct and
indirect usages of COMPLETE and ALTERNATE - that they are read or
written only if no_dependents is false.
There are other possible solutions to this issue:
(1) Split fetch-pack.{c,h} into a flag-using part and a non-flag-using
part, and whenever no_dependents is set, only use the
non-flag-using part.
(2) Make fetch_pack() be able to be used with arbitrary repository
objects. fetch_pack() should then create its own repository object
based on the given repository object, with its own object
hashtable, so that the flags do not conflict.
(1) is possible but invasive - some functions would need to be split;
and such invasiveness would potentially be unnecessary if we ever were
to need (2) anyway. (2) would be useful if we were to support, say,
submodules that were partial clones themselves, but I don't know when or
if the Git project plans to support those.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Quite some time ago, a last plea to the XP users out there who want to
see Windows XP support in Git for Windows, asking them to get engaged
and help, vanished into the depths of the universe.
We tried for a long time to play nice with the last remaining XP users
who somehow manage to build Git from source, but a recent update of
mingw-w64 (7.0.0.5233.e0c09544 -> 7.0.0.5245.edf66197) finally dropped
the last sign of XP support, and Git for Windows' SDK is no longer able
to build core Git's `master` branch as a consequence. (Git for Windows'
`master` branch already bumped the minimum Windows version to Vista a
while ago, so it is fine.)
It is time to require Windows Vista or later to build Git from source.
This, incidentally, lets us use quite a few nice new APIs.
It also means that we no longer need the inet_pton() and inet_ntop()
emulation, which is nice.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously, we only ever declared a target Windows version if compiling
with Visual C.
Which meant that we were relying on the MinGW headers to guess which
Windows version we want to target...
Let's be explicit about it, in particular because we actually want to
bump the target Windows version to Vista (which we will do in the next
commit).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Windows Vista (and later) actually have a working poll(), but we still
cannot use it because it only works on sockets.
So let's detect when we are targeting Windows Vista and undefine those
constants, and define `pollfd` so that we can declare our own pollfd
struct.
We also need to make sure that we override those constants *after*
`winsock2.h` has been `#include`d (otherwise we would not really
override those constants).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
