"git push --force-with-lease" already had enough logic to allow
ensuring that such a push results in creation of a ref (i.e. the
receiving end did not have another push from sideways that would be
discarded by our force-pushing), but didn't expose this possibility
to the users. It does so now.
* jk/push-force-with-lease-creation:
t5533: make it pass on case-sensitive filesystems
push: allow pushing new branches with --force-with-lease
push: add shorthand for --force-with-lease branch creation
Documentation/git-push: fix placeholder formatting
Not-so-recent rewrite of "git am" that started making internal
calls into the commit machinery had an unintended regression, in
that no matter how many seconds it took to apply many patches, the
resulting committer timestamp for the resulting commits were all
the same.
* jk/reset-ident-time-per-commit:
am: reset cached ident date for each patch
The API documentation for hashmap was unclear if hashmap_entry
can be safely discarded without any other consideration. State
that it is safe to do so.
* jc/hashmap-doc-init:
hashmap: clarify that hashmap_entry can safely be discarded
The build procedure learned PAGER_ENV knob that lists what default
environment variable settings to export for popular pagers. This
mechanism is used to tweak the default settings to MORE on FreeBSD.
* ew/build-time-pager-tweaks:
pager: move pager-specific setup into the build
FreeBSD can lie when asked mtime of a directory, which made the
untracked cache code to fall back to a slow-path, which in turn
caused tests in t7063 to fail because it wanted to verify the
behaviour of the fast-path.
* nd/fbsd-lazy-mtime:
t7063: work around FreeBSD's lazy mtime update feature
An entry "git log --decorate" for the tip of the current branch is
shown as "HEAD -> name" (where "name" is the name of the branch);
paint the arrow in the same color as "HEAD", not in the color for
commits.
* nd/log-decorate-color-head-arrow:
log: decorate HEAD -> branch with the same color for arrow and HEAD
The t3700 test about "add --chmod=-x" have been made a bit more
robust and generally cleaned up.
* ib/t3700-add-chmod-x-updates:
t3700: add a test_mode_in_index helper function
t3700: merge two tests into one
t3700: remove unwanted leftover files before running new tests
"git pack-objects" has a few options that tell it not to pack
objects found in certain packfiles, which require it to scan .idx
files of all available packs. The codepaths involved in these
operations have been optimized for a common case of not having any
non-local pack and/or any .kept pack.
* jk/pack-objects-optim:
pack-objects: compute local/ignore_pack_keep early
pack-objects: break out of want_object loop early
find_pack_entry: replace last_found_pack with MRU cache
add generic most-recently-used list
sha1_file: drop free_pack_by_name
t/perf: add tests for many-pack scenarios
"git difftool <paths>..." started in a subdirectory failed to
interpret the paths relative to that directory, which has been
fixed.
* jk/difftool-in-subdir:
difftool: use Git::* functions instead of passing around state
difftool: avoid $GIT_DIR and $GIT_WORK_TREE
difftool: fix argument handling in subdirs
Tests for "git svn" have been taught to reuse the lib-httpd test
infrastructure when testing the subversion integration that
interacts with subversion repositories served over the http://
protocol.
* ew/git-svn-http-tests:
git svn: migrate tests to use lib-httpd
t/t91*: do not say how to avoid the tests
Merge branch 'rs/submodule-config-code-cleanup' into maint
Code cleanup.
* rs/submodule-config-code-cleanup:
submodule-config: fix test binary crashing when no arguments given
submodule-config: combine early return code into one goto
submodule-config: passing name reference for .gitmodule blobs
submodule-config: use explicit empty string instead of strbuf in config_from()
* nd/test-helpers:
t/test-lib.sh: fix running tests with --valgrind
Makefile: use VCSSVN_LIB to refer to svn library
Makefile: drop extra dependencies for test helpers
Merge branch 'ew/find-perl-on-freebsd-in-local' into maint
Recent FreeBSD stopped making perl available at /usr/bin/perl;
switch the default the built-in path to /usr/local/bin/perl on not
too ancient FreeBSD releases.
* ew/find-perl-on-freebsd-in-local:
config.mak.uname: correct perl path on FreeBSD
Merge branch 'ew/daemon-socket-keepalive' into maint
Recent update to "git daemon" tries to enable the socket-level
KEEPALIVE, but when it is spawned via inetd, the standard input
file descriptor may not necessarily be connected to a socket.
Suppress an ENOTSOCK error from setsockopt().
* ew/daemon-socket-keepalive:
Windows: add missing definition of ENOTSOCK
daemon: ignore ENOTSOCK from setsockopt
"git pack-objects" and "git index-pack" mostly operate with off_t
when talking about the offset of objects in a packfile, but there
were a handful of places that used "unsigned long" to hold that
value, leading to an unintended truncation.
* nd/pack-ofs-4gb-limit:
fsck: use streaming interface for large blobs in pack
pack-objects: do not truncate result in-pack object size on 32-bit systems
index-pack: correct "offset" type in unpack_entry_data()
index-pack: report correct bad object offsets even if they are large
index-pack: correct "len" type in unpack_data()
sha1_file.c: use type off_t* for object_info->disk_sizep
pack-objects: pass length to check_pack_crc() without truncation
Merge branch 'rs/notes-merge-no-toctou' into maint
"git notes merge" had a code to see if a path exists (and fails if
it does) and then open the path for writing (when it doesn't).
Replace it with open with O_EXCL.
* rs/notes-merge-no-toctou:
notes-merge: use O_EXCL to avoid overwriting existing files
"git add -N dir/file && git write-tree" produced an incorrect tree
when there are other paths in the same directory that sorts after
"file".
* nd/cache-tree-ita:
cache-tree: do not generate empty trees as a result of all i-t-a subentries
cache-tree.c: fix i-t-a entry skipping directory updates sometimes
test-lib.sh: introduce and use $EMPTY_BLOB
test-lib.sh: introduce and use $EMPTY_TREE
"git blame file" allowed the lineage of lines in the uncommitted,
unadded contents of "file" to be inspected, but it refused when
"file" did not appear in the current commit. When "file" was
created by renaming an existing file (but the change has not been
committed), this restriction was unnecessarily tight.
* mh/blame-worktree:
t/t8003-blame-corner-cases.sh: Use here documents
blame: allow to blame paths freshly added to the index
With GCC 6, the strdup() function is declared with the "nonnull"
attribute, stating that it is not allowed to pass a NULL value as
parameter.
In nedmalloc()'s reimplementation of strdup(), Postel's Law is heeded
and NULL parameters are handled gracefully. GCC 6 complains about that
now because it thinks that NULL cannot be passed to strdup() anyway.
Because the callers in this project of strdup() must be prepared to
call any implementation of strdup() supplied by the platform, so it
is pointless to pretend that it is OK to call it with NULL.
Remove the conditional based on NULL-ness of the input; this
squelches the warning. Check the return value of malloc() instead
to make sure we actually got the memory to write to.
See https://gcc.gnu.org/gcc-6/porting_to.html for details.
Diagnosed-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
use strbuf_addstr() instead of strbuf_addf() with "%s"
Call strbuf_addstr() for adding a simple string to a strbuf instead of
using the heavier strbuf_addf(). This is shorter and documents the
intent more clearly.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allowing PAGER_ENV to be set at build-time allows us to move
pager-specific knowledge out of our build. This allows us to
set a better default for FreeBSD more(1), which pretends not to
understand ANSI color escapes if the MORE environment variable
is left empty, but accepts the same variables as less(1)
Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Eric Wong <e@80x24.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some code in nedmalloc is indented in a funny way that could be
misinterpreted as if a line after a for loop was included in the loop
body, when it is not.
GCC 6 complains about this in DEVELOPER=YepSure mode.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The newly-added test case wants to commit a file "c.t" (note the lower
case) when a previous test case already committed a file "C.t". This
confuses Git to the point that it thinks "c.t" was not staged when "git
add c.t" was called.
Simply make the naming of the test commits consistent with the previous
test cases: use upper-case, and advance in the alphabet.
This came up in local work to rebase the Windows-specific patches to the
current `next` branch. An identical fix was suggested by John Keeping.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
t7063: work around FreeBSD's lazy mtime update feature
Let's start with the commit message of [1] from freebsd.git [2]
Sync timestamp changes for inodes of special files to disk as late
as possible (when the inode is reclaimed). Temporarily only do
this if option UFS_LAZYMOD configured and softupdates aren't
enabled. UFS_LAZYMOD is intentionally left out of
/sys/conf/options.
This is mainly to avoid almost useless disk i/o on battery powered
machines. It's silly to write to disk (on the next sync or when
the inode becomes inactive) just because someone hit a key or
something wrote to the screen or /dev/null.
PR: 5577 [3]
The short version of that, in the context of t7063, is that when a
directory is updated, its mtime may be updated later, not
immediately. This can be shown with a simple command sequence
One would expect that the date shown in `ls` would be one second from
`date`, but it's 10 seconds later. If we put another `ls -lTd .` in
front of `sleep 10`, then the date of the last `ls` comes as
expected. The first `ls` somehow forces mtime to be updated.
t7063 is really sensitive to directory mtime. When mtime is too "new",
git code suspects racy timestamps and will not trigger the shortcut in
untracked cache, in t7063.24 and eventually be detected in t7063.27
We have two options thanks to this special FreeBSD feature:
1) Stop supporting untracked cache on FreeBSD. Skip t7063 entirely
when running on FreeBSD
2) Work around this problem (using the same 'ls' trick) and continue
to support untracked cache on FreeBSD
I initially wanted to go with 1) because I didn't know the exact
nature of this feature and feared that it would make untracked cache
work unreliably, using the cached version when it should not.
Since the behavior of this thing is clearer now. The picture is not
that bad. If this indeed happens often, untracked cache would assume
racy condition more often and _fall back_ to non-untracked cache code
paths. Which means it may be less effective, but it will not show
wrong things.
This patch goes with option 2.
PS. For those who want to look further in FreeBSD source code, this
flag is now called IN_LAZYMOD. I can see it's effective in ext2 and
ufs. zfs is not affected.
There is an optimization used in "git diff $treeA $treeB" to borrow
an already checked-out copy in the working tree when it is known to
be the same as the blob being compared, expecting that open/mmap of
such a file is faster than reading it from the object store, which
involves inflating and applying delta. This however kicked in even
when the checked-out copy needs to go through the convert-to-git
conversion (including the clean filter), which defeats the whole
point of the optimization. The optimization has been disabled when
the conversion is necessary.
* jk/diff-do-not-reuse-wtf-needs-cleaning:
diff: do not reuse worktree files that need "clean" conversion
* rs/submodule-config-code-cleanup:
submodule-config: fix test binary crashing when no arguments given
submodule-config: combine early return code into one goto
submodule-config: passing name reference for .gitmodule blobs
submodule-config: use explicit empty string instead of strbuf in config_from()
"git push" and "git clone" learned to give better progress meters
to the end user who is waiting on the terminal.
* jk/push-progress:
receive-pack: send keepalives during quiet periods
receive-pack: turn on connectivity progress
receive-pack: relay connectivity errors to sideband
receive-pack: turn on index-pack resolving progress
index-pack: add flag for showing delta-resolution progress
clone: use a real progress meter for connectivity check
check_connected: add progress flag
check_connected: relay errors to alternate descriptor
check_everything_connected: use a struct with named options
check_everything_connected: convert to argv_array
rev-list: add optional progress reporting
check_everything_connected: always pass --quiet to rev-list
"git fetch" exchanges batched have/ack messages between the sender
and the receiver, initially doubling every time and then falling
back to enlarge the window size linearly. The "smart http"
transport, being an half-duplex protocol, outgrows the preset limit
too quickly and becomes inefficient when interacting with a large
repository. The internal mechanism learned to grow the window size
more aggressively when working with the "smart http" transport.
* jt/fetch-large-handshake-window-on-http:
fetch-pack: grow stateless RPC windows exponentially
Users of the parse_options_concat() API function need to allocate
extra slots in advance and fill them with OPT_END() when they want
to decide the set of supported options dynamically, which makes the
code error-prone and hard to read. This has been corrected by tweaking
the API to allocate and return a new copy of "struct option" array.
* jk/parse-options-concat:
parse_options: allocate a new array when concatenating
Dumb http transport on the client side has been optimized.
* ew/http-walker:
list: avoid incompatibility with *BSD sys/queue.h
http-walker: reduce O(n) ops with doubly-linked list
http: avoid disconnecting on 404s for loose objects
http-walker: remove unused parameter from fetch_object
The build procedure for "git persistent-https" helper (in contrib/)
has been updated so that it can be built with more recent versions
of Go.
* pm/build-persistent-https-with-recent-go:
contrib/persistent-https: use Git version for build label
contrib/persistent-https: update ldflags syntax for Go 1.7+
"git merge" in Git v2.9 was taught to forbid merging an unrelated
lines of history by default, but that is exactly the kind of thing
the "--rejoin" mode of "git subtree" (in contrib/) wants to do.
"git subtree" has been taught to use the "--allow-unrelated-histories"
option to override the default.
This strdup was added as part of 58dbfa2 (blame: accept
multiple -L ranges, 2013-08-06) to be consistent with
parse_opt_string_list(), which appends to the same list.
But as of 7a7a517 (parse_opt_string_list: stop allocating
new strings, 2016-06-13), we should stop using strdup (to
match parse_opt_string_list, and for all the reasons
described in that commit; namely that it does nothing useful
and causes us to leak the memory).
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
On Windows, it is already pretty expensive to try to recreate the stat()
data that Git assumes is cheap to obtain. To make things halfway decent
in performance, we even have to skip emulating the inode and to
determine the number of hard links.
This is not a huge problem, usually, as either the size or the mtime or
the ctime are tell-tale enough to say when a file has changed, and even
if not, those changes are typically made after the index file was
written, triggering a rehashing of the files' contents.
The t4130-apply-criss-cross-rename test case, however, requires the
inode to determine that files of equal size were swapped, as renaming
files does not update their mtime. Every once in a while, t4130 fails
on Windows because of this missing piece.
Equal file sizes are not crucial for the test cases, however. Hence,
generate files with different sizes so that there is some property that
the swapped files can be discovered reliably even on Windows.
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
hashmap: clarify that hashmap_entry can safely be discarded
The API documentation said that the hashmap_entry structure to be
embedded in the caller's structure is to be treated as opaque, which
left the reader wondering if it can safely be discarded when it no
longer is necessary. If the hashmap_entry structure had references
to external resources such as allocated memory or an open file
descriptor, merely free(3)ing the containing structure (when the
caller's structure is on the heap) or letting it go out of scope
(when it is on the stack) would end up leaking the external
resource.
Document that there is no need for hashmap_entry_clear() that
corresponds to hashmap_entry_init() to give the API users a little
bit of peace of mind.
When we compute the date to go in author/committer lines of
commits, or tagger lines of tags, we get the current date
once and then cache it for the rest of the program. This is
a good thing in some cases, like "git commit", because it
means we do not racily assign different times to the
author/committer fields of a single commit object.
But as more programs start to make many commits in a single
process (e.g., the recently builtin "git am"), it means that
you'll get long strings of commits with identical committer
timestamps (whereas before, we invoked "git commit" many
times and got true timestamps).
This patch addresses it by letting callers reset the cached
time, which means they'll get a fresh time on their next
call to git_committer_info() or git_author_info(). The first
caller to do so is "git am", which resets the time for each
patch it applies.
It would be nice if we could just do this automatically
before filling in the ident fields of commit and tag
objects. Unfortunately, it's hard to know where a particular
logical operation begins and ends.
For instance, if commit_tree_extended() were to call
reset_ident_date() before getting the committer/author
ident, that doesn't quite work; sometimes the author info is
passed in to us as a parameter, and it may or may not have
come from a previous call to ident_default_date(). So in
those cases, we lose the property that the committer and the
author timestamp always match.
You could similarly put a date-reset at the end of
commit_tree_extended(). That actually works in the current
code base, but it's fragile. It makes the assumption that
after commit_tree_extended() finishes, the caller has no
other operations that would logically want to fall into the
same timestamp.
So instead we provide the tool to easily do the reset, and
let the high-level callers use it to annotate their own
logical operations.
There's no automated test, because it would be inherently
racy (it depends on whether the program takes multiple
seconds to run). But you can see the effect with something
like:
# make a fake 100-patch series
top=$(git rev-parse HEAD)
bottom=$(git rev-list --first-parent -100 HEAD | tail -n 1)
git log --format=email --reverse --first-parent \
--binary -m -p $bottom..$top >patch
# now apply it; this presumably takes multiple seconds
git checkout --detach $bottom
git am <patch
# now count the number of distinct committer times;
# prior to this patch, there would only be one, but
# now we'd typically see several.
git log --format=%ct $bottom.. | sort -u
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Helped-by: Paul Tan <pyokagan@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Depending on the underlying platform a chmod may be a noop. Although it
wouldn't harm the result of the '--chmod=-x' test, there is a more
robust way to make sure the --chmod option works both ways.
Merge the two separate tests for the --chmod option into one, checking
both permissions on the same file.
Signed-off-by: Ingo Brückl <ib@wupperonline.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
t3700: remove unwanted leftover files before running new tests
When an earlier test that has prerequisite is skipped, files
used by later tests may be left in the working tree in an
unexpected state. For example, a test runs this sequence:
echo foo >xfoo1 && chmod 755 xfoo1
to create an executable file xfoo1, expecting that xfoo1
does not exist before it runs in the test sequence.
However, the absence of this file depends on "git reset
--hard" done in an earlier test, that is skipped when SANITY
prerequisite is not met, and worse yet, xfoo1 originally is
created as a symbolic link, which means the chmod does not
affect the modes of xfoo1 as this test expects.
Fix this by starting the test with "rm -f xfoo1" to make
sure the file is created from scratch, and do the same to
other similar tests.
Signed-off-by: Ingo Brückl <ib@wupperonline.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The result of st_mult() is the same no matter the order of its
arguments. It invokes the macro unsigned_mult_overflows(), which
divides the second parameter by the first one. Pass constants
first to allow that division to be done already at compile time.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
use strbuf_addstr() for adding constant strings to a strbuf
Replace uses of strbuf_addf() for adding strings with more lightweight
strbuf_addstr() calls.
In http-push.c it becomes easier to see what's going on without having
to verfiy that the definition of PROPFIND_ALL_REQUEST doesn't contain
any format specifiers.
Signed-off-by: Rene Scharfe <l.s.r@web.de> Reviewed-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix a case where an html link can be generated from unescaped input
resulting in invalid strict xhtml or potentially injected code.
An overview of a repo with a tag "1.0.0&0.0.1" would previously result
in an unescaped ampersand in the link body.
Signed-off-by: Andreas Brauchli <a.brauchli@elementarea.net> Acked-by: Jakub Narębski <jnareb@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
pack-objects: compute local/ignore_pack_keep early
In want_object_in_pack(), we can exit early from our loop if
neither "local" nor "ignore_pack_keep" are set. If they are,
however, we must examine each pack to see if it has the
object and is non-local or has a ".keep".
It's quite common for there to be no non-local or .keep
packs at all, in which case we know ahead of time that
looking further will be pointless. We can pre-compute this
by simply iterating over the list of packs ahead of time,
and dropping the flags if there are no packs that could
match.
Another similar strategy would be to modify the loop in
want_object_in_pack() to notice that we have already found
the object once, and that we are looping only to check for
"local" and "keep" attributes. If a pack has neither of
those, we can skip the call to find_pack_entry_one(), which
is the expensive part of the loop.
This has two advantages:
- it isn't all-or-nothing; we still get some improvement
when there's a small number of kept or non-local packs,
and a large number of non-kept local packs
- it eliminates any possible race where we add new
non-local or kept packs after our initial scan. In
practice, I don't think this race matters; we already
cache the packed_git information, so somebody who adds a
new pack or .keep file after we've started will not be
noticed at all, unless we happen to need to call
reprepare_packed_git() because a lookup fails.
In other words, we're already racy, and the race is not
a big deal (losing the race means we might include an
object in the pack that would not otherwise be, which is
an acceptable outcome).
However, it also has a disadvantage: we still loop over the
rest of the packs for each object to check their flags. This
is much less expensive than doing the object lookup, but
still not free. So if we wanted to implement that strategy
to cover the non-all-or-nothing cases, we could do so in
addition to this one (so you get the most speedup in the
all-or-nothing case, and the best we can do in the other
cases). But given that the all-or-nothing case is likely the
most common, it is probably not worth the trouble, and we
can revisit this later if evidence points otherwise.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When pack-objects collects the list of objects to pack
(either from stdin, or via its internal rev-list), it
filters each one through want_object_in_pack().
This function loops through each existing packfile, looking
for the object. When we find it, we mark the pack/offset
combo for later use. However, we can't just return "yes, we
want it" at that point. If --honor-pack-keep is in effect,
we must keep looking to find it in _all_ packs, to make sure
none of them has a .keep. Likewise, if --local is in effect,
we must make sure it is not present in any non-local pack.
As a result, the sum effort of these calls is effectively
O(nr_objects * nr_packs). In an ordinary repository, we have
only a handful of packs, and this doesn't make a big
difference. But in pathological cases, it can slow the
counting phase to a crawl.
This patch notices the case that we have neither "--local"
nor "--honor-pack-keep" in effect and breaks out of the loop
early, after finding the first instance. Note that our worst
case is still "objects * packs" (i.e., we might find each
object in the last pack we look in), but in practice we will
often break out early. On an "average" repo, my git.git with
8 packs, this shows a modest 2% (a few dozen milliseconds)
improvement in the counting-objects phase of "git
pack-objects --all <foo" (hackily instrumented by sticking
exit(0) right after list_objects).
But in a much more pathological case, it makes a bigger
difference. I ran the same command on a real-world example
with ~9 million objects across 1300 packs. The counting time
dropped from 413s to 45s, an improvement of about 89%.
Note that this patch won't do anything by itself for a
normal "git gc", as it uses both --honor-pack-keep and
--local.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
find_pack_entry: replace last_found_pack with MRU cache
Each pack has an index for looking up entries in O(log n)
time, but if we have multiple packs, we have to scan through
them linearly. This can produce a measurable overhead for
some operations.
We dealt with this long ago in f7c22cc (always start looking
up objects in the last used pack first, 2007-05-30), which
keeps what is essentially a 1-element most-recently-used
cache. In theory, we should be able to do better by keeping
a similar but longer cache, that is the same length as the
pack-list itself.
Since we now have a convenient generic MRU structure, we can
plug it in and measure. Here are the numbers for running
p5303 against linux.git:
The main numbers of interest here are the rev-list ones
(since that is exercising the normal object lookup code
path). The single-pack case shouldn't improve at all; the
260ms speedup there is just part of the run-to-run noise
(but it's important to note that we didn't make anything
worse with the overhead of maintaining our cache). In the
50-pack case, we see similar results. There may be a slight
improvement, but it's mostly within the noise.
The 1000-pack case does show a big improvement, though. That
carries over to the repack case, as well. Even though we
haven't touched its pack-search loop yet, it does still do a
lot of normal object lookups (e.g., for the internal
revision walk), and so improves.
As a point of reference, I also ran the 1000-pack test
against a version of HEAD^ with the last_found_pack
optimization disabled. It takes ~60s, so that gives an
indication of how much even the single-element cache is
helping.
For comparison, here's a smaller repository, git.git:
You can see that the percentage improvement is similar.
That's because the lookup we are optimizing is roughly
O(nr_objects * nr_packs). Since the number of packs is
constant in both tests, we'd expect the improvement to be
linear in the number of objects. But the whole process is
also linear in the number of objects, so the improvement
is a constant factor.
The exact improvement does also depend on the contents of
the packs. In p5303, the extra packs all have 5 first-parent
commits in them, which is a reasonable simulation of a
pushed-to repository. But it also means that only 250
first-parent commits are in those packs (compared to almost
50,000 total in linux.git), and the rest are in the huge
"base" pack. So once we start looking at history in taht big
pack, that's where we'll find most everything, and even the
1-element cache gets close to 100% cache hits. You could
almost certainly show better numbers with a more
pathological case (e.g., distributing the objects more
evenly across the packs). But that's simply not that
realistic a scenario, so it makes more sense to focus on
these numbers.
The implementation itself is a straightforward application
of the MRU code. We provide an MRU-ordered list of packs
that shadows the packed_git list. This is easy to do because
we only create and revise the pack list in one place. The
"reprepare" code path actually drops the whole MRU and
replaces it for simplicity. It would be more efficient to
just add new entries, but there's not much point in
optimizing here; repreparing happens rarely, and only after
doing a lot of other expensive work. The key things to keep
optimized are traversal (which is just a normal linked list,
albeit with one extra level of indirection over the regular
packed_git list), and marking (which is a constant number of
pointer assignments, though slightly more than the old
last_found_pack was; it doesn't seem to create a measurable
slowdown, though).
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few places in Git that would benefit from a fast
most-recently-used cache (e.g., the list of packs, which we
search linearly but would like to order based on locality).
This patch introduces a generic list that can be used to
store arbitrary pointers in most-recently-used order.
The implementation is just a doubly-linked list, where
"marking" an item as used moves it to the front of the list.
Insertion and marking are O(1), and iteration is O(n).
There's no lookup support provided; if you need fast
lookups, you are better off with a different data structure
in the first place.
There is also no deletion support. This would not be hard to
do, but it's not necessary for handling pack structs, which
are created and never removed.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The point of this function is to drop an entry from the
"packed_git" cache that points to a file we might be
overwriting, because our contents may not be the same (and
hence the only caller was pack-objects as it moved a
temporary packfile into place).
In older versions of git, this could happen because the
names of packfiles were derived from the set of objects they
contained, not the actual bits on disk. But since 1190a1a
(pack-objects: name pack files after trailer hash,
2013-12-05), the name reflects the actual bits on disk, and
any two packfiles with the same name can be used
interchangeably.
Dropping this function not only saves a few lines of code,
it makes the lifetime of "struct packed_git" much easier to
reason about: namely, we now do not ever free these structs.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git's pack storage does efficient (log n) lookups in a
single packfile's index, but if we have multiple packfiles,
we have to linearly search each for a given object. This
patch introduces some timing tests for cases where we have a
large number of packs, so that we can measure any
improvements we make in the following patches.
The main thing we want to time is object lookup. To do this,
we measure "git rev-list --objects --all", which does a
fairly large number of object lookups (essentially one per
object in the repository).
However, we also measure the time to do a full repack, which
is interesting for two reasons. One is that in addition to
the usual pack lookup, it has its own linear iteration over
the list of packs. And two is that because it it is the tool
one uses to go from an inefficient many-pack situation back
to a single pack, we care about its performance not only at
marginal numbers of packs, but at the extreme cases (e.g.,
if you somehow end up with 5,000 packs, it is the only way
to get back to 1 pack, so we need to make sure it performs
well).
We measure the performance of each command in three
scenarios: 1 pack, 50 packs, and 1,000 packs.
The 1-pack case is a baseline; any optimizations we do to
handle multiple packs cannot possibly perform better than
this.
The 50-pack case is as far as Git should generally allow
your repository to go, if you have auto-gc enabled with the
default settings. So this represents the maximum performance
improvement we would expect under normal circumstances.
The 1,000-pack case is hopefully rare, though I have seen it
in the wild where automatic maintenance was broken for some
time (and the repository continued to receive pushes). This
represents cases where we care less about general
performance, but want to make sure that a full repack
command does not take excessively long.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: use Git::* functions instead of passing around state
Call Git::command() and friends directly wherever possible.
This makes it clear that these operations can be invoked directly
without needing to manage the current directory and related GIT_*
environment variables.
Eliminate find_repository() since we can now use wc_path() and
not worry about side-effects involving environment variables.
Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Environment variables are global and hard to reason about.
Use the `--git-dir` and `--work-tree` arguments when invoking `git`
instead of relying on the environment.
Add a test to ensure that difftool's dir-diff feature works when these
variables are present in the environment.
Signed-off-by: David Aguilar <davvid@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
rebase-interactive: trim leading whitespace from progress count
Interactive rebase uses 'wc -l' to write the current patch number
in a progress report. Some implementations of 'wc -l' produce spaces
before the number, leading to ugly output such as
Rebasing ( 3/8)
Remove the spaces using a trivial arithmetic evaluation.
Before 9588c52 (i18n: rebase-interactive: mark strings for
translation) this was not a problem because printf was used to
generate the text. Since that commit, the count is interpolated
directly from a shell variable into the text, where the spaces
remain. The total number of patches does not have this problem
even though it is interpolated from a shell variable in the same
manner, because the variable is set by an arithmetic evaluation.
Later in the script, there is a virtually identical case where
leading spaces are trimmed, but it uses a pattern substitution:
I did not choose this idiom because it adds a line of code, and
there is already an arithmetic evaluation in the vicinity of the
line that is changed here.
Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule-config: passing name reference for .gitmodule blobs
Commit 959b5455 (submodule: implement a config API for lookup of
.gitmodules values, 2015-08-18) implemented the initial version of the
submodule config cache. During development of that initial version we
extracted the function gitmodule_sha1_from_commit(). During that process
we missed that the strbuf rev was still used in config_from() and now is
left empty. Lets fix this by also returning this string.
This means that now when reading .gitmodules from revisions, the error
messages also contain a reference to the blob they are from.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net> Reviewed-by: Stefan Beller <sbeller@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>