When creating a pack using objects that reside in existing packs, we try
to avoid recomputing futile delta between an object (trg) and a candidate
for its base object (src) if they are stored in the same packfile, and trg
is not recorded as a delta already. This heuristics makes sense because it
is likely that we tried to express trg as a delta based on src but it did
not produce a good delta when we created the existing pack.
As the pack heuristics prefer producing delta to remove data, and Linus's
law dictates that the size of a file grows over time, we tend to record
the newest version of the file as inflated, and older ones as delta
against it.
When creating a thin-pack to transfer recent history, it is likely that we
will try to send an object that is recorded in full, as it is newer. But
the heuristics to avoid recomputing futile delta effectively forbids us
from attempting to express such an object as a delta based on another
object. Sending an object in full is often more expensive than sending a
suboptimal delta based on other objects, and it is even more so if we
could use an object we know the receiving end already has (i.e. preferred
base object) as the delta base.
Tweak the recomputation avoidance logic, so that we do not punt on
computing delta against a preferred base object.
The effect of this change can be seen on two simulated upload-pack
workloads. The first is based on 44 reflog entries from my git.git
origin/master reflog, and represents the packs that kernel.org sent me git
updates for the past month or two. The second workload represents much
larger fetches, going from git's v1.0.0 tag to v1.1.0, then v1.1.0 to
v1.2.0, and so on.
The table below shows the average generated pack size and the average CPU
time consumed for each dataset, both before and after the patch:
dataset
| reflog | tags
---------------------------------
before | 53358 | 2750977
size after | 32398 | 2668479
change | -39% | -3%
---------------------------------
before | 0.18 | 1.12
CPU after | 0.18 | 1.15
change | +0% | +3%
This patch makes a much bigger difference for packs with a shorter slice
of history (since its effect is seen at the boundaries of the pack) though
it has some benefit even for larger packs.
Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function frees the individual "struct match_attr"s we
have allocated, but forgot to free the array holding their
pointers, leading to a minor memory leak (but it can add up
after checking attributes for paths in many directories).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add commit message to avoid commit's aborting due to the lack of
commit message, not because there are INTENT_TO_ADD entries in index.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The description of rerere.enabled left the user in the dark as to who
might create an rr-cache directory. Add a note that simply invoking
rerere does this.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Thas would de-dent the body of a function that has grown rather large over
time, making it a bit easier to read.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In prepare_attr_stack, we pop the old elements of the stack
(which were left from a previous lookup and may or may not
be useful to us). Our loop to do so checks that we never
reach the top of the stack. However, the code immediately
afterwards will segfault if we did actually reach the top of
the stack.
Fortunately, this is not an actual bug, since we will never
pop all of the stack elements (we will always keep the root
gitattributes, as well as the builtin ones). So the extra
check in the loop condition simply clutters the code and
makes the intent less clear. Let's get rid of it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we prepare the attribute stack for a lookup on a path,
we start with the cached stack from the previous lookup
(because it is common to do several lookups in the same
directory hierarchy). So the first thing we must do in
preparing the stack is to pop any entries that point to
directories we are no longer interested in.
For example, if our stack contains gitattributes for:
foo/bar/baz
foo/bar
foo
but we want to do a lookup in "foo/bar/bleep", then we want
to pop the top element, but retain the others.
To do this we walk down the stack from the top, popping
elements that do not match our lookup directory. However,
the test do this simply checked strncmp, meaning we would
mistake "foo/bar/baz" as a leading directory of
"foo/bar/baz_plus". We must also check that the character
after our match is '/', meaning we matched the whole path
component.
There are two special cases to consider:
1. The top of our attr stack has the empty path. So we
must not check for '/', but rather special-case the
empty path, which always matches.
2. Typically when matching paths in this way, you would
also need to check for a full string match (i.e., the
character after is '\0'). We don't need to do so in
this case, though, because our path string is actually
just the directory component of the path to a file
(i.e., we know that it terminates with "/", because the
filename comes after that).
Helped-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sendemail.multiedit variable is meant to be a boolean.
However, it is not marked as such in the code, which means
we store its value literally. Thus in the do_edit function,
perl ends up coercing it to a boolean value according to
perl rules, not git rules. This works for "0", but "false",
"no", or "off" will erroneously be interpreted as true.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jn/maint-gitweb-utf8-fix:
gitweb: Fix fallback mode of to_utf8 subroutine
gitweb: Output valid utf8 in git_blame_common('data')
gitweb: esc_html() site name for title in OPML
gitweb: Call to_utf8() on input string in chop_and_escape_str()
The wording seems to suggest that creating the directory is needed and the
setting of rerere.enabled is only for disabling the feature by setting it
to 'false'. But the configuration is meant to be the primary control and
setting it to 'true' will enable it; the rr-cache directory will be
created as necessary and the user does not have to create it.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Subsequently we assume that there is only one pack. Currently this is
true only by accident. Pass '-a -d' to repack in order to guarantee that
assumption to hold true.
The prune-packed command is now redundant since repack -d already calls
it.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-1.7.7:
docs: describe behavior of relative submodule URLs
Documentation: read-tree --prefix works with existing subtrees
Add MYMETA.json to perl/.gitignore
Since the relative submodule URLs have been introduced in f31a522a2d, they
do not conform to the rules for resolving relative URIs but rather to
those of relative directories.
Document that behavior.
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-repo if interupted at the exact wrong time will generate zero
length bundles- literal empty files. git-repo is wrong here, but
git fetch shouldn't effectively spin loop if pointed at a zero
length bundle.
Signed-off-by: Brian Harring <ferringb@chromium.org>
Helped-by: Johannes Sixt
Helped-by: Nguyen Thai Ngoc Duy
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 34110cd4 (Make 'unpack_trees()' have a separate source and
destination index) it is no longer true that a subdirectory with
the same prefix must not exist.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ExtUtils::MakeMaker generates MYMETA.json in addition to MYMETA.yml
since version 6.57_07. As it suggests, it is just meta information about
the build and is cleaned up with 'make clean', so it should be ignored.
Signed-off-by: Jack Nagel <jacknagel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Contains accumulated fixes since 1.7.8 that have been merged to the
'master' branch in preparation for the 1.7.9 release.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jc/checkout-m-twoway:
t/t2023-checkout-m.sh: fix use of test_must_fail
checkout_merged(): squelch false warning from some gcc
Test 'checkout -m -- path'
checkout -m: no need to insist on having all 3 stages
* jn/maint-sequencer-fixes:
revert: stop creating and removing sequencer-old directory
Revert "reset: Make reset remove the sequencer state"
revert: do not remove state until sequence is finished
revert: allow single-pick in the middle of cherry-pick sequence
revert: pass around rev-list args in already-parsed form
revert: allow cherry-pick --continue to commit before resuming
revert: give --continue handling its own function
* jk/maint-mv:
mv: be quiet about overwriting
mv: improve overwrite warning
mv: make non-directory destination error more clear
mv: honor --verbose flag
docs: mention "-k" for both forms of "git mv"
Junio C Hamano