When searching for a commit in a commit-graph chain of G graphs with N
commits, the search takes O(G log N) time. If we always add a new tip
graph with every write, the linear G term will start to dominate and
slow the lookup process.
To keep lookups fast, but also keep most incremental writes fast, create
a strategy for merging levels of the commit-graph chain. The strategy is
detailed in the commit-graph design document, but is summarized by these
two conditions:
1. If the number of commits we are adding is more than half the number
of commits in the graph below, then merge with that graph.
2. If we are writing more than 64,000 commits into a single graph,
then merge with all lower graphs.
The numeric values in the conditions above are currently constant, but
can become config options in a future update.
As we merge levels of the commit-graph chain, check that the commits
still exist in the repository. A garbage-collection operation may have
removed those commits from the object store and we do not want to
persist them in the commit-graph chain. This is a non-issue if the
'git gc' process wrote a new, single-level commit-graph file.
After we merge levels, the old graph-{hash}.graph files are no longer
referenced by the commit-graph-chain file. We will expire these files in
a future change.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new "--split" option to the 'git commit-graph write' subcommand. This
option allows the optional behavior of writing a commit-graph chain.
The current behavior will add a tip commit-graph containing any commits that
are not in the existing commit-graph or commit-graph chain. Later changes
will allow merging the chain and expiring out-dated files.
Add a new test script (t5324-split-commit-graph.sh) that demonstrates this
behavior.
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend write_commit_graph() to write a commit-graph chain when given the
COMMIT_GRAPH_SPLIT flag.
This implementation is purposefully simplistic in how it creates a new
chain. The commits not already in the chain are added to a new tip
commit-graph file.
Much of the logic around writing a graph-{hash}.graph file and updating
the commit-graph-chain file is the same as the commit-graph file case.
However, there are several places where we need to do some extra logic
in the split case.
Track the list of graph filenames before and after the planned write.
This will be more important when we start merging graph files, but it
also allows us to upgrade our commit-graph file to the appropriate
graph-{hash}.graph file when we upgrade to a chain of commit-graphs.
Note that we use the eighth byte of the commit-graph header to store the
number of base graph files. This determines the length of the base
graphs chunk.
A subtle change of behavior with the new logic is that we do not write a
commit-graph if we our commit list is empty. This extends to the typical
case, which is reflected in t5318-commit-graph.sh.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The number of chunks in a commit-graph file can change depending on
whether we need the Extra Edges Chunk. We are going to add more optional
chunks, and it will be helpful to rearrange this logic around the chunk
count before doing so.
Specifically, we need to finalize the number of chunks before writing
the commit-graph header. Further, we also need to fill out the chunk
lookup table dynamically and using "num_chunks" as we add optional
chunks is useful for adding optional chunks in the future.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To quickly verify a commit-graph chain is valid on load, we will
read from the new "Base Graphs Chunk" of each file in the chain.
This will prevent accidentally loading incorrect data from manually
editing the commit-graph-chain file or renaming graph-{hash}.graph
files.
The commit_graph struct already had an object_id struct "oid", but
it was never initialized or used. Add a line to read the hash from
the end of the commit-graph file and into the oid member.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare the logic for reading a chain of commit-graphs.
First, look for a file at $OBJDIR/info/commit-graph. If it exists,
then use that file and stop.
Next, look for the chain file at $OBJDIR/info/commit-graphs/commit-graph-chain.
If this file exists, then load the hash values as line-separated values in that
file and load $OBJDIR/info/commit-graphs/graph-{hash[i]}.graph for each hash[i]
in that file. The file is given in order, so the first hash corresponds to the
"base" file and the final hash corresponds to the "tip" file.
This implementation assumes that all of the graph-{hash}.graph files are in
the same object directory as the commit-graph-chain file. This will be updated
in a future change. This change is purposefully simple so we can isolate the
different concerns.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The helper function commit_compare() actually compares object_id
structs, not commits. A future change to commit-graph.c will need
to sort commit structs, so rename this function in advance.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To prepare for a chain of commit-graph files, augment the
commit_graph struct to point to a base commit_graph. As we load
commits from the graph, we may actually want to read from a base
file according to the graph position.
The "graph position" of a commit is given by concatenating the
lexicographic commit orders from each of the commit-graph files in
the chain. This means that we must distinguish two values:
* lexicographic index : the position within the lexicographic
order in a single commit-graph file.
* graph position: the position within the concatenated order
of multiple commit-graph files
Given the lexicographic index of a commit in a graph, we can
compute the graph position by adding the number of commits in
the lower-level graphs. To find the lexicographic index of
a commit, we subtract the number of commits in lower-level graphs.
While here, change insert_parent_or_die() to take a uint32_t
position, as that is the type used by its only caller and that
makes more sense with the limits in the commit-graph format.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a basic description of commit-graph chains. More details about the
feature will be added as we add functionality. This introduction gives a
high-level overview to the goals of the feature and the basic layout of
commit-graph chains.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the conversion of 'stash show' to C in dc7bd382b1 ("stash: convert
show to builtin", 2019-02-25), 'git stash show <n>', where n is the
index of a stash got broken, if n is not a file or a valid revision by
itself.
'stash show' accepts any flag 'git diff' accepts for changing the
output format. Internally we use 'setup_revisions()' to parse these
command line flags. Currently we pass the whole argv through to
'setup_revisions()', which includes the stash index.
As the stash index is not a valid revision or a file in the working
tree in most cases however, this 'setup_revisions()' call (and thus
the whole command) ends up failing if we use this form of 'git stash
show'.
Instead of passing the whole argv to 'setup_revisions()', only pass
the flags (and the command name) through, while excluding the stash
reference. The stash reference is parsed (and validated) in
'get_stash_info()' already.
This separate parsing also means that we currently do produce the
correct output if the command succeeds.
Reported-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch, "git branch" would put "(HEAD detached...)" and "(no
branch, rebasing...)" lines before all the other branches *in most
cases* except for when using Chinese-language messages. zh_CN generally
uses a full-width "(" symbol (codepoint FF08) to match the full-width
proportions of Chinese characters, and the translated strings we had did
use them. This meant that the detached HEAD line would appear after all
local refs and even after the remote refs if there were any.
AFAIK, it is sometimes not jarring to see the half-width parenthesis in
"full-width" text as in the CJK languages, for instance when there are
no characters preceding or following the parenthesized text fragment. By
removing the parenthesis from the localizable text, we can share strings
with wt-status.c and remove a cautionary comment to translators.
Remove the ( from the localizable portion of messages so the sorting
happens properly regardless of locale.
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Matthew DeVore <matvore@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We started including stdio.h to pick up the declaration of "FILE" in
f26a001226 (Enable wt-status output to a given FILE pointer.,
2007-09-17). But there's no need, since headers can assume that
git-compat-util.h has been included, which covers stdio.
This should just be redundant, and not hurting anything (like pulling in
includes out of order) because C files are supposed to always include
git-compat-util.h first. But it's worth cleaning up to model good
behavior.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's no reason verify-tag.c needs to include signal.h. It's already
in git-compat-util.h, which we properly include as the first header.
And there doesn't seem to be a particular reason for this include; it's
just an artifact from the file creation in 2ae68fcb78 (Make verify-tag a
builtin., 2007-07-27).
Likewise verify-commit.c has the same issue, probably because it was
created using verify-tag as a template in d07b00b7f3 (verify-commit:
scriptable commit signature verification, 2014-06-23).
These includes are probably just redundant, and not hurting anything by
circumventing the order that git-compat-util.h tries to impose, since
we'll always have loaded git-compat-util by the time we get to these. So
this is just a cleanup, and shouldn't fix or break any platforms.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
0620b39b3b ("compat: add a mkstemps() compatibility function", 2009-05-31)
included a function based on code from libiberty which would result in
undefined behaviour in platforms where timeval's tv_usec is a 32-bit signed
type as shown by:
wrapper.c:505:31: runtime error: left shift of 594546 by 16 places cannot be represented in type '__darwin_suseconds_t' (aka 'int')
interestingly the version of this code from gcc never had this bug and the
code had a cast that would had prevented the issue (at least in 64-bit
platforms) but was misapplied.
change the cast to uint64_t so it also works in 32-bit platforms.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The interpret-trailers program does not do the usual loading of config
via git_default_config(), and thus does not respect many of the usual
options. In particular, we will not load core.commentChar, even though
the underlying trailer code uses its value.
This can be seen in the accompanying test, where setting
core.commentChar to anything besides "#" results in a failure to treat
the comments correctly.
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Command mode options that the user can choose one among many are
listed like this in the documentation:
git am (--continue | --skip | --abort | --quit)
They are listed on a single line and in parenthesis, because they
are not optional.
But documentation pages for some commands deviate from this norm.
Fix the merge and rebase docs to match this style.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert calls of memcpy(3) to use COPY_ARRAY, which shortens and
simplifies the code a bit.
Patch generated by Coccinelle and contrib/coccinelle/array.cocci.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current semantic patch for COPY_ARRAY transforms memcpy(3) calls on
pointers, but Coccinelle distinguishes them from arrays. It already
contains three rules to handle the options for sizeof (i.e. source,
destination and type), and handling arrays as source and destination
would require four times as many rules if we enumerated all cases.
We also don't handle array subscripts, and supporting that would
increase the number of rules by another factor of four. (An isomorphism
telling Coccinelle that "sizeof x[...]" is equivalent to "sizeof *x"
would be nice..)
Support arrays and array subscripts, but keep the number of rules down
by adding normalization steps: First turn array subscripts into
derefences, then determine the types of expressions used with sizeof and
replace them with these types, and then convert the different possible
combinations of arrays and pointers with memcpy(3) to COPY_ARRAY.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
883e248b8a ("fsmonitor: teach git to optionally utilize a file system
monitor to speed up detecting new or changed files.", 2017-09-22) uses
an int in a loop that would wrap if index_state->cache_nr (unsigned)
is bigger than INT_MAX
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If hashes like strhash() are updated, for example to use a different
hash algorithm, we should not have to be updating t0011 to change out
the hashes.
As long as hashmap can store and retrieve values, and that it performs
well, we should not care what are the values of the hashes. Let's just
focus on the externally visible behavior instead.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Get rid of the static hash() function in oidmap.c which is redundant
with sha1hash(). Use sha1hash() directly instead.
Let's be more consistent and not use several hash functions doing
nearly exactly the same thing.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add actual tests for operations using `struct oidmap` from oidmap.{c,h}.
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This new helper is very similar to "test-hashmap.c" and will help
test how `struct oidmap` from oidmap.{c,h} can be used.
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When creating a partial clone, the object filtering criteria is
recorded for the origin of the clone, but this incorrectly used a
hardcoded name "origin" to name that remote; it has been corrected
to honor the "--origin <name>" option.
* xl/record-partial-clone-origin:
clone: respect user supplied origin name when setting up partial clone
"git request-pull" learned to warn when the ref we ask them to pull
from in the local repository and in the published repository are
different.
* pb/request-pull-verify-remote-ref:
request-pull: warn if the remote object is not the same as the local one
request-pull: quote regex metacharacters in local ref
The command line to invoke a "git cat-file" command from inside
"git p4" was not properly quoted to protect a caret and running a
broken command on Windows, which has been corrected.
* mm/p4-unshelve-windows-fix:
p4 unshelve: fix "Not a valid object name HEAD0" on Windows
"git help git" was hard to discover (well, at least for some
people).
* po/git-help-on-git-itself:
Doc: git.txt: remove backticks from link and add git-scm.com/docs
git.c: show usage for accessing the git(1) help page
A new tutorial targetting specifically aspiring git-core
developers.
* es/first-contrib-tutorial:
doc: add some nit fixes to MyFirstContribution
documentation: add anchors to MyFirstContribution
documentation: add tutorial for first contribution
The data collected by fsmonitor was not properly written back to
the on-disk index file, breaking t7519 tests occasionally, which
has been corrected.
* js/fsmonitor-unflake:
mark_fsmonitor_valid(): mark the index as changed if needed
fill_stat_cache_info(): prepare for an fsmonitor fix
Prepare use of reachability index in topological walker that works
on a range (A..B).
* ds/topo-traversal-using-commit-graph:
revision: keep topo-walk free of unintersting commits
revision: use generation for A..B --topo-order queries
The pattern "git diff/grep" use to extract funcname and words
boundary for Matlab has been extend to cover Octave, which is more
or less equivalent.
* bl/userdiff-octave:
userdiff: fix grammar and style issues
userdiff: add Octave
"git clone --recurse-submodules" learned to set up the submodules
to ignore commit object names recorded in the superproject gitlink
and instead use the commits that happen to be at the tip of the
remote-tracking branches from the get-go, by passing the new
"--remote-submodules" option.
* ba/clone-remote-submodules:
clone: add `--remote-submodules` flag
"git merge --squash" is designed to update the working tree and the
index without creating the commit, and this cannot be countermanded
by adding the "--commit" option; the command now refuses to work
when both options are given.
* vv/merge-squash-with-explicit-commit:
merge: refuse --commit with --squash
"git bundle verify" needs to see if prerequisite objects exist in
the receiving repository, but the command did not check if we are
in a repository upfront, which has been corrected.
* js/bundle-verify-require-object-store:
bundle verify: error out if called without an object database
"git am -i --resolved" segfaulted after trying to see a commit as
if it were a tree, which has been corrected.
* jk/am-i-resolved-fix:
am: fix --interactive HEAD tree resolution
am: drop tty requirement for --interactive
am: read interactive input from stdin
am: simplify prompt response handling
The server side support for "git fetch" used to show incorrect
value for the HEAD symbolic ref when the namespace feature is in
use, which has been corrected.
* jk/HEAD-symref-in-xfer-namespaces:
upload-pack: strip namespace from symref data
"git update-server-info" used to leave stale packfiles in its
output, which has been corrected.
* ew/server-info-remove-crufts:
server-info: do not list unlinked packs
This one slipped through the review of a9279c6785 (sequencer: do not
squash 'reword' commits when we hit conflicts, 2018-06-19).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A "merge -c" instruction during "git rebase --rebase-merges" should
give the user a chance to edit the log message, even when there is
otherwise no need to create a new merge and replace the existing
one (i.e. fast-forward instead), but did not. Which has been
corrected.
* pw/rebase-edit-message-for-replayed-merge:
rebase -r: always reword merge -c
The way of specifying the path to find dynamic libraries at runtime
has been simplified. The old default to pass -R/path/to/dir has been
replaced with the new default to pass -Wl,-rpath,/path/to/dir,
which is the more recent GCC uses. Those who need to build with an
old GCC can still use "CC_LD_DYNPATH=-R"
* ab/deprecate-R-for-dynpath:
Makefile: remove the NO_R_TO_GCC_LINKER flag
The ownership rule for the file descriptor to fast-import remote
backend was mixed up, leading to unrelated file descriptor getting
closed, which has been fixed.
* mh/import-transport-fd-fix:
Use xmmap_gently instead of xmmap in use_pack
dup() the input fd for fast-import used for remote helpers
"git update-server-info" learned not to rewrite the file with the
same contents.
* ew/update-server-info:
update-server-info: avoid needless overwrites
