An example where this happens is when doing an ls-tree on a tree that
contains a commit link. In that case, find_unique_abbrev is called
to get a non-abbreviated hex sha1, but still, a lookup is done as
to whether the sha1 is in the repository (which ends up looking for
a loose object in .git/objects), while the result of that lookup is
not used when returning a non-abbreviated hex sha1.
Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This reverts commit cdfd94837b, as it
does not just apply to "@" (and forms with modifiers like @{u}
applied to it), but also affects e.g. "refs/heads/@/foo", which it
shouldn't.
The basic idea of giving a short-hand might be good, and the topic
can be retried later, but let's revert to avoid affecting existing
use cases for now for the upcoming release.
We spell config variables in camelCase instead of with_underscores.
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
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
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>
A test that should have failed but didn't revealed a bug that needs
to be corrected.
* jc/t1512-fix:
get_short_sha1(): correctly disambiguate type-limited abbreviation
t1512: correct leftover constants from earlier edition
I attempted to make index_state->cache[] a "const struct cache_entry **"
to find out how existing entries in index are modified and where. The
question I have is what do we do if we really need to keep track of on-disk
changes in the index. The result is
- diff-lib.c: setting CE_UPTODATE
- name-hash.c: setting CE_HASHED
- preload-index.c, read-cache.c, unpack-trees.c and
builtin/update-index: obvious
- entry.c: write_entry() may refresh the checked out entry via
fill_stat_cache_info(). This causes "non-const struct cache_entry
*" in builtin/apply.c, builtin/checkout-index.c and
builtin/checkout.c
- builtin/ls-files.c: --with-tree changes stagemask and may set
CE_UPDATE
Of these, write_entry() and its call sites are probably most
interesting because it modifies on-disk info. But this is stat info
and can be retrieved via refresh, at least for porcelain
commands. Other just uses ce_flags for local purposes.
So, keeping track of "dirty" entries is just a matter of setting a
flag in index modification functions exposed by read-cache.c. Except
unpack-trees, the rest of the code base does not do anything funny
behind read-cache's back.
The actual patch is less valueable than the summary above. But if
anyone wants to re-identify the above sites. Applying this patch, then
this:
diff --git a/cache.h b/cache.h
index 430d021..1692891 100644
--- a/cache.h
+++ b/cache.h
@@ -267,7 +267,7 @@ static inline unsigned int canon_mode(unsigned int mode)
#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)
struct index_state {
- struct cache_entry **cache;
+ const struct cache_entry **cache;
unsigned int version;
unsigned int cache_nr, cache_alloc, cache_changed;
struct string_list *resolve_undo;
will help quickly identify them without bogus warnings.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One test in t1512 that expects a failure incorrectly passed. The
test prepares a commit whose object name begins with ten "0"s, and
also prepares a tag that points at the commit. The object name of
the tag also begins with ten "0"s. There is no other commit-ish
object in the repository whose name begins with such a prefix.
Ideally, in such a repository:
$ git rev-parse --verify 0000000000^{commit}
should yield that commit. If 0000000000 is taken as the commit
0000000000e4f, peeling it to a commmit yields that commit itself,
and if 0000000000 is taken as the tag 0000000000f8f, peeling it to a
commit also yields the same commit, so in that twisted sense, the
extended SHA-1 expression 0000000000^{commit} is unambigous. The
test that expects a failure is to check the above command.
The reason the test expects a failure is that we did not implement
such a "unification" of two candidate objects. What we did (or at
least, meant to) implement was to recognise that a commit-ish is
required to expand 0000000000, and notice that there are two succh
commit-ish, and diagnose the request as ambiguous.
However, there was a bug in the logic to check the candidate
objects. When the code saw 0000000000f8f (a tag) that shared the
shortened prefix (ten "0"s), it tried to make sure that the tag is a
commit-ish by looking at the tag object. Because it incorrectly
used lookup_object() when the tag has not been parsed, however, we
incorrectly declared that the tag is _not_ a commit-ish, leaving the
sole commit in the repository, 0000000000e4f, that has the required
prefix as "unique match", causing the test to pass when it shouldn't.
This fixes the logic to inspect the type of the object a tag refers
to, to make the test that is expected to fail correctly fail.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git cmd <name>", when <name> happens to be a 40-hex string,
directly uses the 40-hex string as an object name, even if a ref
"refs/<some hierarchy>/<name>" exists. This disambiguation order
is unlikely to change, but we should warn about the ambiguity just
like we warn when more than one refs/ hierachies share the same
name.
* nd/warn-ambiguous-object-name:
get_sha1: warn about full or short object names that look like refs
When a reflog notation is used for implicit "current branch", we
did not say which branch and worse said "branch ''".
* rr/die-on-missing-upstream:
sha1_name: fix error message for @{<N>}, @{<date>}
sha1_name: fix error message for @{u}
Currently, when we try to resolve @{<N>} or @{<date>} when the reflog
doesn't go back far enough, we get errors like:
# on branch master
$ git show @{10000}
fatal: Log for '' only has 7 entries.
$ git show @{10000.days.ago}
warning: Log for '' only goes back to Tue, 21 May 2013 14:14:45 +0530.
...
# detached HEAD case
$ git show @{10000}
fatal: Log for '' only has 2005 entries.
$ git show master@{10000}
fatal: Log for 'master' only has 7 entries.
The empty string '' is confusing and does not convey information
about whose logs we are inspecting. Change this so that we get:
# on branch master
$ git show @{10000}
fatal: Log for 'master' only has 7 entries.
$ git show @{10000.days.ago}
warning: Log for 'master' only goes back to Tue, 21 May 2013 14:14:45 +0530.
...
# detached HEAD case
$ git show @{10000}
fatal: Log for 'HEAD' only has 2005 entries.
$ git show master@{10000}
fatal: Log for 'master' only has 7 entries.
Also one of the message strings given to die() now points into
real_ref that was not used in that fashion, so stop freeing the
underlying storage for it.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Bug-spotted-and-fixed-by: Thomas Rast
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we get 40 hex digits, we immediately assume it's an SHA-1. This
is the right thing to do because we have no way else to specify an
object. If there is a ref with the same object name, it will be
ignored. Warn the user about this case because the ref with full
object name is likely a mistake, for example
git checkout -b $empty_var $(git rev-parse something)
advice.object_name_warning is not documented because frankly people
should not be aware about it until they encounter this situation.
While at there, warn about ambiguation with abbreviated SHA-1 too.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, when no (valid) upstream is configured for a branch, you get
an error like:
$ git show @{u}
error: No upstream configured for branch 'upstream-error'
error: No upstream configured for branch 'upstream-error'
fatal: ambiguous argument '@{u}': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
The "error: " line actually appears twice, and the rest of the error
message is useless. In sha1_name.c:interpret_branch_name(), there is
really no point in processing further if @{u} couldn't be resolved, and
we might as well die() instead of returning an error(). After making
this change, you get:
$ git show @{u}
fatal: No upstream configured for branch 'upstream-error'
Also tweak a few tests in t1507 to expect this output.
This only turns error() that may be called after we know we are
dealing with an @{upstream} marker into die(), without touching
silent error returns "return -1" from the function. Any caller that
wants to handle an error condition itself will not be hurt by this
change, unless they want to see the message from error() and then
exit silently without giving its own message, which needs to be
fixed anyway.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you were on 'frotz' branch before you checked out your current
branch, "git merge @{-1}~22" means the same as "git merge frotz~22".
The strbuf_branchname() function, when interpret_branch_name() gives
up resolving "@{-1}~22" fully, returns "frotz" and tells the caller
that it only resolved "@{-1}" part of the input, mistakes this as a
total failure, and appends the whole thing to the result, yielding
"frotz@{-1}~22", which does not make any sense.
Inspect the return value from interpret_branch_name() a bit more
carefully. When it errored out without consuming anything, we will
get -1 and we should return the whole thing. Otherwise, we should
append the remainder (i.e. "~22" in the earlier example) to the
partially resolved name (i.e. "frotz").
The test suite adds enough number of checkout to make @{-12} in the
last test in t0100 that tried to check "we haven't flipped branches
that many times" error case succeed; raise the number to a hundred.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
And restructure the if/else to factor out the common "is len positive?"
test into a single conditional.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Typing 'HEAD' is tedious, especially when we can use '@' instead.
The reason for choosing '@' is that it follows naturally from the
ref@op syntax (e.g. HEAD@{u}), except we have no ref, and no
operation, and when we don't have those, it makes sens to assume
'HEAD'.
So now we can use 'git show @~1', and all that goody goodness.
Until now '@' was a valid name, but it conflicts with this idea, so
let's make it invalid. Probably very few people, if any, used this name.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This code essentially replaces part of ref with another ref, for example
'@{-1}@{u}' is replaced with 'master@{u}', but this can be reused for
other purposes other than nth prior checkouts.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's trivial to check for them in the @{N} parsing loop.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Through the years the functionality to handle @{-N} and @{u} has moved
around the code, and as a result, code that once made sense, doesn't any
more.
There is no need to call this function recursively with the branch of
@{-N} substituted because dwim_{ref,log} already replaces it.
However, there's one corner-case where @{-N} resolves to a detached
HEAD, in which case we wouldn't get any ref back.
So we parse the nth-prior manually, and deal with it depending on
whether it's a SHA-1, or a ref.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The @-parsing loop unnecessarily checks for the sequence "@{" from
(len - 2) unnecessarily. We can safely check from (len - 4).
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'at' is always 0, since we can reach this point only if
!len && reflog_len, and len=at when reflog is assigned.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There was no good way to ask "I have a random string that came from
outside world. I want to turn it into a 40-hex object name while
making sure such an object exists". A new peeling suffix ^{object}
can be used for that purpose, together with "rev-parse --verify".
* jc/sha1-name-object-peeler:
peel_onion(): teach $foo^{object} peeler
peel_onion: disambiguate to favor tree-ish when we know we want a tree-ish
A string that names an object can be suffixed with ^{type} peeler to
say "I have this object name; peel it until you get this type. If
you cannot do so, it is an error". v1.8.2^{commit} asks for a commit
that is pointed at an annotated tag v1.8.2; v1.8.2^{tree} unwraps it
further to the top-level tree object. A special suffix ^{} (i.e. no
type specified) means "I do not care what it unwraps to; just peel
annotated tag until you get something that is not a tag".
When you have a random user-supplied string, you can turn it to a
bare 40-hex object name, and cause it to error out if such an object
does not exist, with:
git rev-parse --verify "$userstring^{}"
for most objects, but this does not yield the tag object name when
$userstring refers to an annotated tag.
Introduce a new suffix, ^{object}, that only makes sure the given
name refers to an existing object. Then
git rev-parse --verify "$userstring^{object}"
becomes a way to make sure $userstring refers to an existing object.
This is necessary because the plumbing "rev-parse --verify" is only
about "make sure the argument is something we can feed to get_sha1()
and turn it into a raw 20-byte object name SHA-1" and is not about
"make sure that 20-byte object name SHA-1 refers to an object that
exists in our object store". When the given $userstring is already
a 40-hex, by definition "rev-parse --verify $userstring" can turn it
into a raw 20-byte object name. With "$userstring^{object}", we can
make sure that the 40-hex string names an object that exists in our
object store before "--verify" kicks in.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function already knows when interpreting $foo^{commit} to tell
the underlying get_sha1_1() to expect a commit-ish while evaluating
$foo. Teach it to do the same when asked for $foo^{tree}; we are
expecting a tree-ish and $foo should be disambiguated in favor of a
tree-ish, discarding a possible ambiguous match with a blob object.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An internal function used to implement "git checkout @{-1}" was
hard to use correctly.
* jc/reflog-reverse-walk:
refs.c: fix fread error handling
reflog: add for_each_reflog_ent_reverse() API
for_each_recent_reflog_ent(): simplify opening of a reflog file
for_each_reflog_ent(): extract a helper to process a single entry
The only caller of diagnose_invalid_sha1_path() extracts a substring from
an object name by creating a NUL-terminated copy of the interesting part.
Add a length parameter to the function and thus avoid the need for an
allocation, thereby simplifying the code.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git checkout -" is a short-hand for "git checkout @{-1}" and the
"@{nth}" notation for a negative number is to find nth previous
checkout in the reflog of the HEAD to determine the name of the
branch the user was on. We would want to find the nth most recent
reflog entry that matches "checkout: moving from X to Y" for this.
Unfortunately, reflog is implemented as an append-only file, and the
API to iterate over its entries, for_each_reflog_ent(), reads the
file in order, giving the entries from the oldest to newer. For the
purpose of finding nth most recent one, this API forces us to record
the last n entries in a rotating buffer and give the result out only
after we read everything. To optimize for a common case of finding
the nth most recent one for a small value of n, we also have a side
API for_each_recent_reflog_ent() that starts reading near the end of
the file, but it still has to read the entries in the "wrong" order.
The implementation of understanding @{-1} uses this interface.
This all becomes unnecessary if we add an API to let us iterate over
reflog entries in the reverse order, from the newest to older.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teaches the object name parser things like a "git describe" output
is always a commit object, "A" in "git log A" must be a committish,
and "A" and "B" in "git log A...B" both must be committish, etc., to
prolong the lifetime of abbreviated object names.
* jc/sha1-name-more: (27 commits)
t1512: match the "other" object names
t1512: ignore whitespaces in wc -l output
rev-parse --disambiguate=<prefix>
rev-parse: A and B in "rev-parse A..B" refer to committish
reset: the command takes committish
commit-tree: the command wants a tree and commits
apply: --build-fake-ancestor expects blobs
sha1_name.c: add support for disambiguating other types
revision.c: the "log" family, except for "show", takes committish
revision.c: allow handle_revision_arg() to take other flags
sha1_name.c: introduce get_sha1_committish()
sha1_name.c: teach lookup context to get_sha1_with_context()
sha1_name.c: many short names can only be committish
sha1_name.c: get_sha1_1() takes lookup flags
sha1_name.c: get_describe_name() by definition groks only commits
sha1_name.c: teach get_short_sha1() a commit-only option
sha1_name.c: allow get_short_sha1() to take other flags
get_sha1(): fix error status regression
sha1_name.c: restructure disambiguation of short names
sha1_name.c: correct misnamed "canonical" and "res"
...
The new option allows you to feed an ambiguous prefix and enumerate
all the objects that share it as a prefix of their object names.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This teaches the revision parser that in "$name:$path" (used for a
blob object name), "$name" must be a tree-ish.
There are many more places where we know what types of objects are
called for. This patch adds support for "commit", "treeish", "tree",
and "blob", which could be used in the following contexts:
- "git apply --build-fake-ancestor" reads the "index" lines from
the patch; they must name blob objects (not even "blob-ish");
- "git commit-tree" reads a tree object name (not "tree-ish"), and
zero or more commit object names (not "committish");
- "git reset $rev" wants a committish; "git reset $rev -- $path"
wants a treeish.
They will come in later patches in the series.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many callers know that the user meant to name a committish by
syntactical positions where the object name appears. Calling this
function allows the machinery to disambiguate shorter-than-unique
abbreviated object names between committish and others.
Note that this does NOT error out when the named object is not a
committish. It is merely to give a hint to the disambiguation
machinery.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function takes user input string and returns the object name
(binary SHA-1) with mode bits and path when the object was looked
up in a tree.
Additionally give hints to help disambiguation of abbreviated object
names when the caller knows what it is looking for.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We know that the token "$name" that appear in "$name^{commit}",
"$name^4", "$name~4" etc. can only name a committish (either a
commit or a tag that peels to a commit). Teach get_short_sha1() to
take advantage of that knowledge when disambiguating an abbreviated
SHA-1 given as an object name.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is to pass the disambiguation hints from the caller down the
callchain. Nothing is changed in this step, as everybody just
passes 0 in the flag.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach get_describe_name() to pass the disambiguation hint down the
callchain to get_short_sha1().
Also add tests to show various syntactic elements that we could take
advantage of the object type information to help disambiguration of
abbreviated object names. Many of them are marked as broken, and
some of them will be fixed in later patches in this series.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the caller knows that the parameter is meant to name a commit,
e.g. "56789a" in describe name "v1.2.3-4-g56789a", pass that as a
hint so that lower level can use it to disambiguate objects when
there is only one commit whose name begins with 56789a even if there
are objects of other types whose names share the same prefix.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of a separate "int quietly" argument, make it take "unsigned
flags" so that we can pass other options to it.
The bit assignment of this flag word is exposed in cache.h because
the mechanism will be exposed to callers of the higher layer in
later commits in this series.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In finish_object_disambiguation(), if the candidate hasn't been
checked, there are two cases:
- It is the first and only object that match the prefix; or
- It replaced another object that matched the prefix but that
object did not satisfy ds->fn() callback.
And the former case we set ds->candidate_ok to true without doing
anything else, while for the latter we check the candidate, which
may set ds->candidate_ok to false.
At this point in the code, ds->candidate_ok can be false only if
this last-round check found that the candidate does not pass the
check, because the state after update_candidates() returns cannot
satisfy
!ds->ambiguous && ds->candidate_exists && ds->candidate_checked
and !ds->canidate_ok at the same time.
Hence, when we execute this "return", we know we have seen more than
one object that match the prefix (and none of them satisfied ds->fn),
meaning that we should say "the short name is ambiguous", not "there
is no object that matches the prefix".
Noticed by Jeff King.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We try to find zero, one or more matches from loose objects and
packed objects independently and then decide if the given short
object name is unique across them.
Instead, introduce a "struct disambiguate_state" that keeps track of
what we have found so far, that can be one of:
- We have seen one object that _could_ be what we are looking for;
- We have also checked that object for additional constraints (if any),
and found that the object satisfies it;
- We have also checked that object for additional constraints (if any),
and found that the object does not satisfy it; or
- We have seen more than one objects that satisfy the constraints.
and pass it to the enumeration functions for loose and packed
objects. The disambiguation state can optionally take a callback
function that takes a candidate object name and reports if the
object satisifies additional criteria (e.g. when the caller knows
that the short name must refer to a commit, this mechanism can be
used to check the type of the given object).
Compared to the earlier attempt, this round avoids the optional
check if there is only one candidate that matches the short name in
the first place.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are hexadecimal and binary representation of the short object
name given to the callchain as its input. Rename them with _pfx
suffix to make it clear they are prefixes, and call them hex and bin
respectively.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extract the logic to find object(s) that match a given prefix inside
a single pack into a separate helper function, and give it a bit more
comment.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This variable points at the element we are currently looking at, and
does not have anything to do with the current time which the name
"now" implies.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are only two callers, and they will benefit from being able to
pass disambiguation hints to underlying get_sha1_with_context() API
once it happens.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
