Code clean-up and protection against concurrent write access to the
ref namespace.
* mh/safe-create-leading-directories:
rename_tmp_log(): on SCLD_VANISHED, retry
rename_tmp_log(): limit the number of remote_empty_directories() attempts
rename_tmp_log(): handle a possible mkdir/rmdir race
rename_ref(): extract function rename_tmp_log()
remove_dir_recurse(): handle disappearing files and directories
remove_dir_recurse(): tighten condition for removing unreadable dir
lock_ref_sha1_basic(): if locking fails with ENOENT, retry
lock_ref_sha1_basic(): on SCLD_VANISHED, retry
safe_create_leading_directories(): add new error value SCLD_VANISHED
cmd_init_db(): when creating directories, handle errors conservatively
safe_create_leading_directories(): introduce enum for return values
safe_create_leading_directories(): always restore slash at end of loop
safe_create_leading_directories(): split on first of multiple slashes
safe_create_leading_directories(): rename local variable
safe_create_leading_directories(): add explicit "slash" pointer
safe_create_leading_directories(): reduce scope of local variable
safe_create_leading_directories(): fix format of "if" chaining
Fetching from a shallow-cloned repository used to be forbidden,
primarily because the codepaths involved were not carefully vetted
and we did not bother supporting such usage. This attempts to allow
object transfer out of a shallow-cloned repository in a controlled
way (i.e. the receiver become a shallow repository with truncated
history).
* nd/shallow-clone: (31 commits)
t5537: fix incorrect expectation in test case 10
shallow: remove unused code
send-pack.c: mark a file-local function static
git-clone.txt: remove shallow clone limitations
prune: clean .git/shallow after pruning objects
clone: use git protocol for cloning shallow repo locally
send-pack: support pushing from a shallow clone via http
receive-pack: support pushing to a shallow clone via http
smart-http: support shallow fetch/clone
remote-curl: pass ref SHA-1 to fetch-pack as well
send-pack: support pushing to a shallow clone
receive-pack: allow pushes that update .git/shallow
connected.c: add new variant that runs with --shallow-file
add GIT_SHALLOW_FILE to propagate --shallow-file to subprocesses
receive/send-pack: support pushing from a shallow clone
receive-pack: reorder some code in unpack()
fetch: add --update-shallow to accept refs that update .git/shallow
upload-pack: make sure deepening preserves shallow roots
fetch: support fetching from a shallow repository
clone: support remote shallow repository
...
We used to use two separate rules for the normal ref resolution
dwimming and dwimming done to decide which remote ref to grab. The
third parameter to refname_match() selected which rules to use.
When these two rules were harmonized in
2011-11-04 dd621df9cd refs DWIMmery: use the same rule for both "git fetch" and others
, ref_fetch_rules was #defined to avoid potential breakages for
in-flight topics.
It is now safe to remove the backwards-compatibility code, so remove
refname_match()'s third parameter, make ref_rev_parse_rules private to
refs.c, and remove ref_fetch_rules entirely.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach "cat-file --batch" to show delta-base object name for a
packed object that is represented as a delta.
* jk/oi-delta-base:
cat-file: provide %(deltabase) batch format
sha1_object_info_extended: provide delta base sha1s
Add a new possible error result that can be returned by
safe_create_leading_directories() and
safe_create_leading_directories_const(): SCLD_VANISHED. This value
indicates that a file or directory on the path existed at one point
(either it already existed or the function created it), but then it
disappeared. This probably indicates that another process deleted the
directory while we were working. If SCLD_VANISHED is returned, the
caller might want to retry the function call, as there is a chance
that a new attempt will succeed.
Why doesn't safe_create_leading_directories() do the retrying
internally? Because an empty directory isn't really ever safe until
it holds a file. So even if safe_create_leading_directories() were
absolutely sure that the directory existed before it returned, there
would be no guarantee that the directory still existed when the caller
tried to write something in it.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of returning magic integer values (which a couple of callers
go to the trouble of distinguishing), return values from an enum. Add
a docstring.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A caller of sha1_object_info_extended technically has enough
information to determine the base sha1 from the results of
the call. It knows the pack, offset, and delta type of the
object, which is sufficient to find the base.
However, the functions to do so are not publicly available,
and the code itself is intimate enough with the pack details
that it should be abstracted away. We could add a public
helper to allow callers to query the delta base separately,
but it is simpler and slightly more efficient to optionally
grab it along with the rest of the object_info data.
For cases where the object is not stored as a delta, we
write the null sha1 into the query field. A careful caller
could check "oi.whence == OI_PACKED && oi.u.packed.is_delta"
before looking at the base sha1, but using the null sha1
provides a simple alternative (and gives a better sanity
check for a non-careful caller than simply returning random
bytes).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This parameter is not used yet, but it will be used to tell
sha1_object_info_extended() if it should perform object
replacement or not.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, there is only one caller to lookup_replace_object()
that can benefit from passing it some flags, but we expect
that there could be more.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The READ_SHA1_FILE_REPLACE flag is more related to using the
lookup_replace_object() function rather than the
read_sha1_file() function.
We also need such a flag to be used with sha1_object_info()
instead of read_sha1_file().
The name LOOKUP_REPLACE_OBJECT is therefore better for this
flag.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This may be needed when a hook is run after a new shallow pack is
received, but .git/shallow is not settled yet. A temporary shallow
file to plug all loose ends should be used instead. GIT_SHALLOW_FILE
is overriden by --shallow-file.
--shallow-file does not work in this case because the hook may spawn
many git subprocesses and the launch commands do not have
--shallow-file as it's a recent addition.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Suppose a fetch or push is requested between two shallow repositories
(with no history deepening or shortening). A pack that contains
necessary objects is transferred over together with .git/shallow of
the sender. The receiver has to determine whether it needs to update
.git/shallow if new refs needs new shallow comits.
The rule here is avoid updating .git/shallow by default. But we don't
want to waste the received pack. If the pack contains two refs, one
needs new shallow commits installed in .git/shallow and one does not,
we keep the latter and reject/warn about the former.
Even if .git/shallow update is allowed, we only add shallow commits
strictly necessary for the former ref (remember the sender can send
more shallow commits than necessary) and pay attention not to
accidentally cut the receiver history short (no history shortening is
asked for)
So the steps to figure out what ref need what new shallow commits are:
1. Split the sender shallow commit list into "ours" and "theirs" list
by has_sha1_file. Those that exist in current repo in "ours", the
remaining in "theirs".
2. Check the receiver .git/shallow, remove from "ours" the ones that
also exist in .git/shallow.
3. Fetch the new pack. Either install or unpack it.
4. Do has_sha1_file on "theirs" list again. Drop the ones that fail
has_sha1_file. Obviously the new pack does not need them.
5. If the pack is kept, remove from "ours" the ones that do not exist
in the new pack.
6. Walk the new refs to answer the question "what shallow commits,
both ours and theirs, are required in .git/shallow in order to add
this ref?". Shallow commits not associated to any refs are removed
from their respective list.
7. (*) Check reachability (from the current refs) of all remaining
commits in "ours". Those reachable are removed. We do not want to
cut any part of our (reachable) history. We only check up
commits. True reachability test is done by
check_everything_connected() at the end as usual.
8. Combine the final "ours" and "theirs" and add them all to
.git/shallow. Install new refs. The case where some hook rejects
some refs on a push is explained in more detail in the push
patches.
Of these steps, #6 and #7 are expensive. Both require walking through
some commits, or in the worst case all commits. And we rather avoid
them in at least common case, where the transferred pack does not
contain any shallow commits that the sender advertises. Let's look at
each scenario:
1) the sender has longer history than the receiver
All shallow commits from the sender will be put into "theirs" list
at step 1 because none of them exists in current repo. In the
common case, "theirs" becomes empty at step 4 and exit early.
2) the sender has shorter history than the receiver
All shallow commits from the sender are likely in "ours" list at
step 1. In the common case, if the new pack is kept, we could empty
"ours" and exit early at step 5.
If the pack is not kept, we hit the expensive step 6 then exit
after "ours" is emptied. There'll be only a handful of objects to
walk in fast-forward case. If it's forced update, we may need to
walk to the bottom.
3) the sender has same .git/shallow as the receiver
This is similar to case 2 except that "ours" should be emptied at
step 2 and exit early.
A fetch after "clone --depth=X" is case 1. A fetch after "clone" (from
a shallow repo) is case 3. Luckily they're cheap for the common case.
A push from "clone --depth=X" falls into case 2, which is expensive.
Some more work may be done at the sender/client side to avoid more
work on the server side: if the transferred pack does not contain any
shallow commits, send-pack should not send any shallow commits to the
receive-pack, effectively turning it into a normal push and avoid all
steps.
This patch implements all steps except #3, already handled by
fetch-pack and receive-pack, #6 and #7, which has their own patch due
to their size.
(*) in previous versions step 7 was put before step 3. I reorder it so
that the common case that keeps the pack does not need to walk
commits at all. In future if we implement faster commit
reachability check (maybe with the help of pack bitmaps or commit
cache), step 7 could become cheap and be moved up before 6 again.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jx/relative-path-regression-fix:
Use simpler relative_path when set_git_dir
relative_path should honor dos-drive-prefix
test: use unambigous leading path (/foo) for MSYS
This function was added in d2b0708 (2008-09-27, add have_git_dir()
function) as a preparation for adbc0b6 (2008-09-30, cygwin: Use native
Win32 API for stat).
However the second referenced commit was reverted in f66450a (2013-06-22,
cygwin: Remove the Win32 l/stat() implementation), so we don't need to
expose this wrapper function any more as a public API.
Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The said function has this signature:
extern int checkout_entry(struct cache_entry *ce,
const struct checkout *state,
char *topath);
At first glance, it might appear that the caller of checkout_entry()
can specify to which path the contents are written out by the last
parameter, and it is tempting to add "const" in front of its type.
In reality, however, topath[] is to point at a buffer to store the
temporary path generated by the callchain originating from this
function, and the temporary path is always short, much shorter than
the buffer prepared by its only caller in builtin/checkout-index.c.
Document the code a bit to clarify so that future callers know how
to use the function better.
Noticed-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"format-patch --from=<whom>" forgot to omit unnecessary in-body
from line, i.e. when <whom> is the same as the real author.
* jk/format-patch-from:
format-patch: print in-body "From" only when needed
Clean up the internal of the name-hash mechanism used to work
around case insensitivity on some filesystems to cleanly fix a
long-standing API glitch where the caller of cache_name_exists()
that ask about a directory with a counted string was required to
have '/' at one location past the end of the string.
* es/name-hash-no-trailing-slash-in-dirs:
dir: revert work-around for retired dangerous behavior
name-hash: stop storing trailing '/' on paths in index_state.dir_hash
employ new explicit "exists in index?" API
name-hash: refactor polymorphic index_name_exists()
Using a relative_path as git_dir first appears in v1.5.6-1-g044bbbc.
It will make git_dir shorter only if git_dir is inside work_tree,
and this will increase performance. But my last refactor effort on
relative_path function (commit v1.8.3-rc2-12-ge02ca72) changed that.
Always use relative_path as git_dir may bring troubles like
$gmane/234434.
Because new relative_path is a combination of original relative_path
from path.c and original path_relative from quote.c, so in order to
restore the origin implementation, save the original relative_path
as remove_leading_path, and call it in setup.c.
Suggested-by: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Instead of typing four capital letters "HEAD", you can say "@" now,
e.g. "git log @".
* fc/at-head:
Add new @ shortcut for HEAD
sha1-name: pass len argument to interpret_branch_name()
Commit a908047 taught format-patch the "--from" option,
which places the author ident into an in-body from header,
and uses the committer ident in the rfc822 from header. The
documentation claims that it will omit the in-body header
when it is the same as the rfc822 header, but the code never
implemented that behavior.
This patch completes the feature by comparing the two idents
and doing nothing when they are the same (this is the same
as simply omitting the in-body header, as the two are by
definition indistinguishable in this case). This makes it
reasonable to turn on "--from" all the time (if it matches
your particular workflow), rather than only using it when
exporting other people's patches.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Depending upon the absence or presence of a trailing '/' on the incoming
pathname, index_name_exists() checks either if a file is present in the
index or if a directory is represented within the index. Each caller
explicitly chooses the mode of operation by adding or removing a
trailing '/' before invoking index_name_exists().
Since these two modes of operations are disjoint and have no code in
common (one searches index_state.name_hash; the other dir_hash), they
can be represented more naturally as distinct functions: one to search
for a file, and one for a directory.
Splitting index searching into two functions relieves callers of the
artificial burden of having to add or remove a slash to select the mode
of operation; instead they just call the desired function. A subsequent
patch will take advantage of this benefit in order to eliminate the
requirement that the incoming pathname for a directory search must have
a trailing slash.
(In order to avoid disturbing in-flight topics, index_name_exists() is
retained as a thin wrapper dispatching either to index_dir_exists() or
index_file_exists().)
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git config" did not provide a way to set or access numbers larger
than a native "int" on the platform; it now provides 64-bit signed
integers on all platforms.
* jk/config-int-range-check:
git-config: always treat --int as 64-bit internally
config: make numeric parsing errors more clear
config: set errno in numeric git_parse_* functions
config: properly range-check integer values
config: factor out integer parsing from range checks
The code that reads from a region that mmaps an on-disk index
assumed that "int"/"short" are always 32/16 bits.
* tg/index-struct-sizes:
read-cache: use fixed width integer types
"git mv A B" when moving a submodule A does "the right thing",
inclusing relocating its working tree and adjusting the paths in
the .gitmodules file.
* jl/submodule-mv: (53 commits)
rm: delete .gitmodules entry of submodules removed from the work tree
mv: update the path entry in .gitmodules for moved submodules
submodule.c: add .gitmodules staging helper functions
mv: move submodules using a gitfile
mv: move submodules together with their work trees
rm: do not set a variable twice without intermediate reading.
t6131 - skip tests if on case-insensitive file system
parse_pathspec: accept :(icase)path syntax
pathspec: support :(glob) syntax
pathspec: make --literal-pathspecs disable pathspec magic
pathspec: support :(literal) syntax for noglob pathspec
kill limit_pathspec_to_literal() as it's only used by parse_pathspec()
parse_pathspec: preserve prefix length via PATHSPEC_PREFIX_ORIGIN
parse_pathspec: make sure the prefix part is wildcard-free
rename field "raw" to "_raw" in struct pathspec
tree-diff: remove the use of pathspec's raw[] in follow-rename codepath
remove match_pathspec() in favor of match_pathspec_depth()
remove init_pathspec() in favor of parse_pathspec()
remove diff_tree_{setup,release}_paths
convert common_prefix() to use struct pathspec
...
Allow a safer "rewind of the remote tip" push than blind "--force",
by requiring that the overwritten remote ref to be unchanged since
the new history to replace it was prepared.
The machinery is more or less ready. The "--force" option is again
the big red button to override any safety, thanks to J6t's sanity
(the original round allowed --lockref to defeat --force).
The logic to choose the default implemented here is fragile
(e.g. "git fetch" after seeing a failure will update the
remote-tracking branch and will make the next "push" pass,
defeating the safety pretty easily). It is suitable only for the
simplest workflows, and it may hurt users more than it helps them.
* jc/push-cas:
push: teach --force-with-lease to smart-http transport
send-pack: fix parsing of --force-with-lease option
t5540/5541: smart-http does not support "--force-with-lease"
t5533: test "push --force-with-lease"
push --force-with-lease: tie it all together
push --force-with-lease: implement logic to populate old_sha1_expect[]
remote.c: add command line option parser for "--force-with-lease"
builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN
cache.h: move remote/connect API out of it
When you run "git config --int", the maximum size of integer
you get depends on how git was compiled, and what it
considers to be an "int".
This is almost useful, because your scripts calling "git
config" will behave similarly to git internally. But relying
on this is dubious; you have to actually know how git treats
each value internally (e.g., int versus unsigned long),
which is not documented and is subject to change. And even
if you know it is "unsigned long", we do not have a
git-config option to match that behavior.
Furthermore, you may simply be asking git to store a value
on your behalf (e.g., configuration for a hook). In that
case, the relevant range check has nothing at all to do with
git, but rather with whatever scripting tools you are using
(and git has no way of knowing what the appropriate range is
there).
Not only is the range check useless, but it is actively
harmful, as there is no way at all for scripts to look
at config variables with large values. For instance, one
cannot reliably get the value of pack.packSizeLimit via
git-config. On an LP64 system, git happily uses a 64-bit
"unsigned long" internally to represent the value, but the
script cannot read any value over 2G.
Ideally, the "--int" option would simply represent an
arbitrarily large integer. For practical purposes, however,
a 64-bit integer is large enough, and is much easier to
implement (and if somebody overflows it, we will still
notice the problem, and not simply return garbage).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is useful to make sure we don't step outside the boundaries of what
we are interpreting at the moment. For example while interpreting
foobar@{u}~1, the job of interpret_branch_name() ends right before ~1,
but there's no way to figure that out inside the function, unless the
len argument is passed.
So let's do that.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the fixed width integer types uint16_t and uint32_t for on-disk
structures; unsigned short and unsigned int do not have a guaranteed
size.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If somebody wants to only know on-disk footprint of an object
without having to know its type or payload size, we can bypass a
lot of code to cheaply learn it.
* jk/cat-file-batch-optim:
Fix some sparse warnings
sha1_object_info_extended: pass object_info to helpers
sha1_object_info_extended: make type calculation optional
packed_object_info: make type lookup optional
packed_object_info: hoist delta type resolution to helper
sha1_loose_object_info: make type lookup optional
sha1_object_info_extended: rename "status" to "type"
cat-file: disable object/refname ambiguity check for batch mode
Add "interactive" mode to "git clean".
The early part to refactor relative path related helper functions
looked sensible.
* jx/clean-interactive:
test: run testcases with POSIX absolute paths on Windows
test: add t7301 for git-clean--interactive
git-clean: add documentation for interactive git-clean
git-clean: add ask each interactive action
git-clean: add select by numbers interactive action
git-clean: add filter by pattern interactive action
git-clean: use a git-add-interactive compatible UI
git-clean: add colors to interactive git-clean
git-clean: show items of del_list in columns
git-clean: add support for -i/--interactive
git-clean: refactor git-clean into two phases
write_name{_quoted_relative,}(): remove redundant parameters
quote_path_relative(): remove redundant parameter
quote.c: substitute path_relative with relative_path
path.c: refactor relative_path(), not only strip prefix
test: add test cases for relative_path
Allow configuration data to be read from in-tree blob objects,
which would help working in a bare repository and submodule
updates.
* hv/config-from-blob:
do not die when error in config parsing of buf occurs
teach config --blob option to parse config from database
config: make parsing stack struct independent from actual data source
config: drop cf validity check in get_next_char()
config: factor out config file stack management
When "git" is spawned in such a way that any of the low 3 file
descriptors is closed, our first open() may yield file descriptor 2,
and writing error message to it would screw things up in a big way.
* tr/protect-low-3-fds:
git: ensure 0/1/2 are open in main()
daemon/shell: refactor redirection of 0/1/2 from /dev/null
"git cat-file --batch-check=<format>" is added, primarily to allow
on-disk footprint of objects in packfiles (often they are a lot
smaller than their true size, when expressed as deltas) to be
reported.
* jk/in-pack-size-measurement:
pack-revindex: radix-sort the revindex
pack-revindex: use unsigned to store number of objects
cat-file: split --batch input lines on whitespace
cat-file: add %(objectsize:disk) format atom
cat-file: add --batch-check=<format>
cat-file: refactor --batch option parsing
cat-file: teach --batch to stream blob objects
t1006: modernize output comparisons
teach sha1_object_info_extended a "disk_size" query
zero-initialize object_info structs
Both daemon.c and shell.c contain logic to open FDs 0/1/2 from
/dev/null if they are not already open. Move the function in daemon.c
to setup.c and use it in shell.c, too.
While there, remove a 'not' that inverted the meaning of the comment.
The point is indeed to *avoid* messing up.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
:(glob)path differs from plain pathspec that it uses wildmatch with
WM_PATHNAME while the other uses fnmatch without FNM_PATHNAME. The
difference lies in how '*' (and '**') is processed.
With the introduction of :(glob) and :(literal) and their global
options --[no]glob-pathspecs, the user can:
- make everything literal by default via --noglob-pathspecs
--literal-pathspecs cannot be used for this purpose as it
disables _all_ pathspec magic.
- individually turn on globbing with :(glob)
- make everything globbing by default via --glob-pathspecs
- individually turn off globbing with :(literal)
The implication behind this is, there is no way to gain the default
matching behavior (i.e. fnmatch without FNM_PATHNAME). You either get
new globbing or literal. The old fnmatch behavior is considered
deprecated and discouraged to use.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepending prefix to pathspec is a trick to workaround the fact that
commands can be executed in a subdirectory, but all git commands run
at worktree's root. The prefix part should always be treated as
literal string. Make it so.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each caller of sha1_object_info_extended sets up an
object_info struct to tell the function which elements of
the object it wants to get. Until now, getting the type of
the object has always been required (and it is returned via
the return type rather than a pointer in object_info).
This can involve actually opening a loose object file to
determine its type, or following delta chains to determine a
packed file's base type. These effects produce a measurable
slow-down when doing a "cat-file --batch-check" that does
not include %(objecttype).
This patch adds a "typep" query to struct object_info, so
that it can be optionally queried just like size and
disk_size. As a result, the return type of the function is
no longer the object type, but rather 0/-1 for success/error.
As there are only three callers total, we just fix up each
caller rather than keep a compatibility wrapper:
1. The simpler sha1_object_info wrapper continues to
always ask for and return the type field.
2. The istream_source function wants to know the type, and
so always asks for it.
3. The cat-file batch code asks for the type only when
%(objecttype) is part of the format string.
On linux.git, the best-of-five for running:
$ git rev-list --objects --all >objects
$ time git cat-file --batch-check='%(objectsize:disk)'
on a fully packed repository goes from:
real 0m8.680s
user 0m8.160s
sys 0m0.512s
to:
real 0m7.205s
user 0m6.580s
sys 0m0.608s
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A common use of "cat-file --batch-check" is to feed a list
of objects from "rev-list --objects" or a similar command.
In this instance, all of our input objects are 40-byte sha1
ids. However, cat-file has always allowed arbitrary revision
specifiers, and feeds the result to get_sha1().
Fortunately, get_sha1() recognizes a 40-byte sha1 before
doing any hard work trying to look up refs, meaning this
scenario should end up spending very little time converting
the input into an object sha1. However, since 798c35f
(get_sha1: warn about full or short object names that look
like refs, 2013-05-29), when we encounter this case, we
spend the extra effort to do a refname lookup anyway, just
to print a warning. This is further exacerbated by ca91993
(get_packed_ref_cache: reload packed-refs file when it
changes, 2013-06-20), which makes individual ref lookup more
expensive by requiring a stat() of the packed-refs file for
each missing ref.
With no patches, this is the time it takes to run:
$ git rev-list --objects --all >objects
$ time git cat-file --batch-check='%(objectname)' <objects
on the linux.git repository:
real 1m13.494s
user 0m25.924s
sys 0m47.532s
If we revert ca91993, the packed-refs up-to-date check, it
gets a little better:
real 0m54.697s
user 0m21.692s
sys 0m32.916s
but we are still spending quite a bit of time on ref lookup
(and we would not want to revert that patch, anyway, which
has correctness issues). If we revert 798c35f, disabling
the warning entirely, we get a much more reasonable time:
real 0m7.452s
user 0m6.836s
sys 0m0.608s
This patch does the moral equivalent of this final case (and
gets similar speedups). We introduce a global flag that
callers of get_sha1() can use to avoid paying the price for
the warning.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
