The last several commits were geared at replacing the include of cache.h
in strbuf.c with an include of git-compat-util.h. Unfortunately, I had
to drop a patch moving some functions from cache.h to object-name.h, due
to excessive conflicts with other in-flight topics.
However, even without that patch, the series of patches so far allows us
to modify a number of C files to replace an include of cache.h with
git-compat-util.h. Do that to reduce our dependencies.
(If we could have kept our object-name.h patch in this series, it would
have also let us reduce the includes in checkout.c and fmt-merge-msg.c
in addition to strbuf.c).
Just to ensure that nothing else was bringing in cache.h, all of the
affected files have been checked to ensure that
gcc -E -I. $SOURCE_FILE | grep '"cache.h"'
found no hits and that
make DEVELOPER=1 ${OBJECT_FILE_FOR_SOURCE_FILE}
successfully compiles without warnings.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
expand_user_path() was renamed to interpolate_path() back in mid-2021,
but reinstated with a #define and a NEEDSWORK comment that we would
eventually want to get rid of it. Do so now.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is another step towards letting us remove the include of cache.h in
strbuf.c. It does mean that we also need to add includes of abspath.h
in a number of C files.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is one step towards making strbuf.c not depend upon cache.h.
Additional steps will follow in subsequent commits.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A number of files were apparently including cache.h solely to get
gettext.h. By making those files explicitly include gettext.h, we can
already drop the include of cache.h in these files. On top of that,
there were some files using cache.h that didn't need to for any reason.
Remove these unnecessary includes.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Looking at things from the opposite angle of the last patch, we had a
few files that were including gettext.h and perhaps needed it at some
point in history, but no longer require it. Remove the include.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Dozens of files made use of gettext functions, without explicitly
including gettext.h. This made it more difficult to find which files
could remove a dependence on cache.h. Make C files explicitly include
gettext.h if they are using it.
However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ever since a64215b6cd ("object.h: stop depending on cache.h; make
cache.h depend on object.h", 2023-02-24), we have a few headers that
could have replaced their include of cache.h with an include of
object.h. Make that change now.
Some C files had to start including cache.h after this change (or some
smaller header it had brought in), because the C files were depending
on things from cache.h but were only formerly implicitly getting
cache.h through one of these headers being modified in this patch.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both 'git for-each-ref --merged=<X>' and 'git branch --merged=<X>' use
the ref-filter machinery to select references or branches (respectively)
that are reachable from a set of commits presented by one or more
--merged arguments. This happens within reach_filter(), which uses the
revision-walk machinery to walk history in a standard way.
However, the commit-reach.c file is full of custom searches that are
more efficient, especially for reachability queries that can terminate
early when reachability is discovered. Add a new
tips_reachable_from_bases() method to commit-reach.c and call it from
within reach_filter() in ref-filter.c. This affects both 'git branch'
and 'git for-each-ref' as tested in p1500-graph-walks.sh.
For the Linux kernel repository, we take an already-fast algorithm and
make it even faster:
Test HEAD~1 HEAD
-------------------------------------------------------------------
1500.5: contains: git for-each-ref --merged 0.13 0.02 -84.6%
1500.6: contains: git branch --merged 0.14 0.02 -85.7%
1500.7: contains: git tag --merged 0.15 0.03 -80.0%
(Note that we remove the iterative 'git rev-list' test from p1500
because it no longer makes sense as a comparison to 'git for-each-ref'
and would just waste time running it for these comparisons.)
The algorithm is implemented in commit-reach.c in the method
tips_reachable_from_base(). This method takes a string_list of tips and
assigns the 'util' for each item with the value 1 if the base commit can
reach those tips.
Like other reachability queries in commit-reach.c, the fastest way to
search for "can A reach B?" is to do a depth-first search up to the
generation number of B, preferring to explore first parents before later
parents. While we must walk all reachable commits up to that generation
number when the answer is "no", the depth-first search can answer "yes"
much faster than other approaches in most cases.
This search becomes trickier when there are multiple targets for the
depth-first search. The commits with lower generation number are more
likely to be within the history of the start commit, but we don't want
to waste time searching commits of low generation number if the commit
target with lowest generation number has already been found.
The trick here is to take the input commits and sort them by generation
number in ascending order. Track the index within this order as
min_generation_index. When we find a commit, if its index in the list is
equal to min_generation_index, then we can increase the generation
number boundary of our search to the next-lowest value in the list.
With this mechanism, the number of commits to search is minimized with
respect to the depth-first search heuristic. We will walk all commits up
to the minimum generation number of a commit that is _not_ reachable
from the start, but we will walk only the necessary portion of the
depth-first search for the reachable commits of lower generation.
Add extra tests for this behavior in t6600-test-reach.sh as the
interesting data shape of that repository can sometimes demonstrate
corner case bugs.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change implemented the ahead_behind() method, including an
algorithm to compute the ahead/behind values for a number of commit tips
relative to a number of commit bases. Now, integrate that algorithm as
part of 'git for-each-ref' hidden behind a new format atom,
ahead-behind. This naturally extends to 'git branch' and 'git tag'
builtins, as well.
This format allows specifying multiple bases, if so desired, and all
matching references are compared against all of those bases. For this
reason, failing to read a reference provided from these atoms results in
an error.
In order to translate the ahead_behind() method information to the
format output code in ref-filter.c, we must populate arrays of
ahead_behind_count structs. In struct ref_array, we store the full array
that will be passed to ahead_behind(). In struct ref_array_item, we
store an array of pointers that point to the relvant items within the
full array. In this way, we can pull all relevant ahead/behind values
directly when formatting output for a specific item. It also ensures the
lifetime of the ahead_behind_count structs matches the time that the
array is being used.
Add specific tests of the ahead/behind counts in t6600-test-reach.sh, as
it has an interesting repository shape. In particular, its merging
strategy and its use of different commit-graphs would demonstrate over-
counting if the ahead_behind() method did not already account for that
possibility.
Also add tests for the specific for-each-ref, branch, and tag builtins.
In the case of 'git tag', there are intersting cases that happen when
some of the selected tips are not commits. This requires careful logic
around commits_nr in the second loop of filter_ahead_behind(). Also, the
test in t7004 is carefully located to avoid being dependent on the GPG
prereq. It also avoids using the test_commit helper, as that will add
ticks to the time and disrupt the expected timestamps in later tag
tests.
Also add performance tests in a new p1300-graph-walks.sh script. This
will be useful for more uses in the future, but for now compare the
ahead-behind counting algorithm in 'git for-each-ref' to the naive
implementation by running 'git rev-list --count' processes for each
input.
For the Git source code repository, the improvement is already obvious:
Test this tree
---------------------------------------------------------------
1500.2: ahead-behind counts: git for-each-ref 0.07(0.07+0.00)
1500.3: ahead-behind counts: git branch 0.07(0.06+0.00)
1500.4: ahead-behind counts: git tag 0.07(0.06+0.00)
1500.5: ahead-behind counts: git rev-list 1.32(1.04+0.27)
But the standard performance benchmark is the Linux kernel repository,
which demosntrates a significant improvement:
Test this tree
---------------------------------------------------------------
1500.2: ahead-behind counts: git for-each-ref 0.27(0.24+0.02)
1500.3: ahead-behind counts: git branch 0.27(0.24+0.03)
1500.4: ahead-behind counts: git tag 0.28(0.27+0.01)
1500.5: ahead-behind counts: git rev-list 4.57(4.03+0.54)
The 'git rev-list' test exists in this change as a demonstration, but it
will be removed in the next change to avoid wasting time on this
comparison.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fully implement the commit-counting logic required to determine
ahead/behind counts for a batch of commit pairs. This is a new library
method within commit-reach.h. This method will be linked to the
for-each-ref builtin in the next change.
The interface for ahead_behind() uses two arrays. The first array of
commits contains the list of all starting points for the walk. This
includes all tip commits _and_ base commits. The second array specifies
base/tip pairs by pointing to commits within the first array, by index.
The second array also stores the resulting ahead/behind counts for each
of these pairs.
This implementation of ahead_behind() allows multiple bases, if desired.
Even with multiple bases, there is only one commit walk used for
counting the ahead/behind values, saving time when the base/tip ranges
overlap significantly.
This interface for ahead_behind() also makes it very easy to call
ensure_generations_valid() on the entire array of bases and tips. This
call is necessary because it is critical that the walk that counts
ahead/behind values never walks a commit more than once. Without
generation numbers on every commit, there is a possibility that a
commit date skew could cause the walk to revisit a commit and then
double-count it. For this reason, it is strongly recommended that 'git
ahead-behind' is only run in a repository with a commit-graph file that
covers most of the reachable commits, storing precomputed generation
numbers. If no commit-graph exists, this walk will be much slower as it
must walk all reachable commits in ensure_generations_valid() before
performing the counting logic.
It is possible to detect if generation numbers are available at run time
and redirect the implementation to another algorithm that does not
require this property. However, that implementation requires a commit
walk per base/tip pair _and_ can be slower due to the commit date
heuristics required. Such an implementation could be considered in the
future if there is a reason to include it, but most Git hosts should
already be generating a commit-graph file as part of repository
maintenance. Most Git clients should also be generating commit-graph
files as part of background maintenance or automatic GCs.
Now, let's discuss the ahead/behind counting algorithm.
The first array of commits are considered the starting commits. The
index within that array will play a critical role.
We create a new commit slab that maps commits to a bitmap. For a given
commit (anywhere in the history), its bitmap stores information relative
to which of the input commits can reach that commit. The ith bit will be
on if the ith commit from the starting list can reach that commit. It is
important to notice that these bitmaps are not the typical "reachability
bitmaps" that are stored in .bitmap files. Instead of signalling which
objects are reachable from the current commit, they instead signal
"which starting commits can reach me?" It is also important to know that
the bitmap is not necessarily "complete" until we walk that commit. We
will perform a commit walk by generation number in such a way that we
can guarantee the bitmap is correct when we visit that commit.
At the beginning of the ahead_behind() method, we initialize the bitmaps
for each of the starting commits. By enabling the ith bit for the ith
starting commit, we signal "the ith commit can reach itself."
We walk commits by popping the commit with maximum generation number out
of the queue, guaranteeing that we will never walk a child of that
commit in any future steps.
As we walk, we load the bitmap for the current commit and perform two
main steps. The _second_ step examines each parent of the current commit
and adds the current commit's bitmap bits to each parent's bitmap. (We
create a new bitmap for the parent if this is our first time seeing that
parent.) After adding the bits to the parent's bitmap, the parent is
added to the walk queue. Due to this passing of bits to parents, the
current commit has a guarantee that the ith bit is enabled on its bitmap
if and only if the ith commit can reach the current commit.
The first step of the walk is to examine the bitmask on the current
commit and decide which ranges the commit is in or not. Due to the "bit
pushing" in the second step, we have a guarantee that the ith bit of the
current commit's bitmap is on if and only if the ith starting commit can
reach it. For each ahead_behind_count struct, check the base_index and
tip_index to see if those bits are enabled on the current bitmap. If
exactly one bit is enabled, then increment the corresponding 'ahead' or
'behind' count. This increment is the reason we _absolutely need_ to
walk commits at most once.
The only subtle thing to do with this walk is to check to see if a
parent has all bits on in its bitmap, in which case it becomes "stale"
and is marked with the STALE bit. This allows queue_has_nonstale() to be
the terminating condition of the walk, which greatly reduces the number
of commits walked if all of the commits are nearby in history. It avoids
walking a large number of common commits when there is a deep history.
We also use the helper method insert_no_dup() to add commits to the
priority queue without adding them multiple times. This uses the PARENT2
flag. Thus, we must clear both the STALE and PARENT2 bits of all
commits, in case ahead_behind() is called multiple times in the same
process.
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the just-introduced compute_reachable_generation_numbers_1() to
implement a function which dynamically computes topological levels (or
corrected commit dates) for out-of-graph commits.
This will be useful for the ahead-behind algorithm we are about to
introduce, which needs accurate topological levels on _all_ commits
reachable from the tips in order to avoid over-counting.
Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit_graph_generation() method used to report a value of
GENERATION_NUMBER_INFINITY if the commit_graph_data_slab had an instance
for the given commit but the graph_pos indicated the commit was not in
the commit-graph file.
However, an upcoming change will introduce the ability to set generation
values in-memory without writing the commit-graph file. Thus, we can no
longer trust 'graph_pos' to indicate whether or not the generation
member can be trusted.
Instead, trust the 'generation' member if the commit has a value in the
slab _and_ the 'generation' member is non-zero. Otherwise, treat it as
GENERATION_NUMBER_INFINITY.
This only makes a difference for a very old case for the commit-graph:
the very first Git release to write commit-graph files wrote zeroes in
the topological level positions. If we are parsing a commit-graph with
all zeroes, those commits will now appear to have
GENERATION_NUMBER_INFINITY (as if they were not parsed from the
commit-graph).
I attempted several variations to work around the need for providing an
uninitialized 'generation' member, but this was the best one I found. It
does require a change to a verification test in t5318 because it reports
a different error than the one about non-zero generation numbers.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change introduced the generic algorithm
compute_reachable_generation_numbers() and used it as the core
functionality of compute_topological_levels(). Now, use it as the core
functionality of compute_generation_numbers().
The main difference here is that we use generation version 2, which is
used in to toggle the logic in compute_generation_from_max() for
computing the corrected commit date based on the corrected commit dates
of the parent commits (and the commit date of the current commit). It
also uses different methods for (get|set)_generation in the vtable in
order to store and access the value in the correct places.
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This patch extracts the common code used to compute topological levels
and corrected committer dates into a common routine,
compute_reachable_generation_numbers(). For ease of reading, it only
modifies compute_topological_levels() to use this new routine, leaving
compute_generation_numbers() to be modified in the next change.
This new routine dispatches to call the necessary functions to get and
set the generation number for a given commit through a vtable (the
compute_generation_info struct).
Computing the generation number itself is done in
compute_generation_from_max(), which dispatches its implementation based
on the generation version requested, or issuing a BUG() for unrecognized
generation versions. This does not use a vtable because the logic
depends only on the generation number version, not where the data is
being loaded from or being stored to. This is a subtle point that will
make more sense in a future change that modifies the in-memory
generation values instead of just preparing values for writing to a
commit-graph file.
This change looks like it adds a lot of new code. However, two upcoming
changes will be quite small due to the work being done in this change.
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The for-each-ref builtin can take a list of ref patterns, but if none
match, it still succeeds (but with no output). Add an explicit test that
demonstrates that behavior.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a user wishes to input a large list of patterns to 'git
for-each-ref' (likely a long list of exact refs) there are frequently
system limits on the number of command-line arguments.
Add a new --stdin option to instead read the patterns from standard
input. Add tests that check that any unrecognized arguments are
considered an error when --stdin is provided. Also, an empty pattern
list is interpreted as the complete ref set.
When reading from stdin, we populate the filter.name_patterns array
dynamically as opposed to pointing to the 'argv' array directly. This is
simple when using a strvec, as it is NULL-terminated in the same way. We
then free the memory directly from the strvec.
Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use designated initializers in the expansions of the OPT_* macros to
make it more readable which one-letter macro parameter initializes
which field in the resulting 'struct option'.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename the 'help' parameter as it matches one of the fields in 'struct
option', and, while at it, rename all other parameters to the usual
one-letter name used in similar macro definitions.
Furthermore, put all parameters in the replacement list between
parentheses, like all other OPT_* macros do.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the various OPT_* macros the 'f' parameter is usually used to
specify flags, while the 'cb' parameter is used to specify a callback
function. OPT_CALLBACK and OPT_NUMBER_CALLBACKS, however, are
inconsistent with the rest, as they use 'f' to specify their callback
function.
Rename their callback macro parameters to 'cb' to avoid the
inconsistency.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The headers 'diagnose.h', 'list-objects-filter-options.h',
'ref-filter.h' and 'remote.h' declare option parsing callback
functions with a 'struct option*' parameter, and 'revision.h' declares
an option parsing helper function taking 'struct parse_opt_ctx_t*' and
'struct option*' parameters. These headers all include
'parse-options.h', although they don't need any of the type
definitions from that header file. Furthermore,
'list-objects-filter-options.h' and 'ref-filter.h' also define some
OPT_* macros to initialize a 'struct option', but these don't
necessitate the inclusion of parse-options.h in these headers either,
because these macros are only expanded in source files.
Remove these unnecessary inclusions of parse-options.h and use forward
declarations to declare the necessary types.
After this patch none of the header files include parse-options.h
anymore.
With these changes, the build time after modifying only
parse-options.h is reduced by about 30%, and the number of targets
built is almost 20% less:
Before:
$ touch parse-options.h && time make -j4 |wc -l
353
real 1m1.527s
user 3m32.205s
sys 0m15.903s
After:
289
real 0m39.285s
user 2m12.540s
sys 0m11.164s
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The builtins 'ls-remote', 'pack-objects', 'receive-pack', 'reflog' and
'send-pack' use parse_options(), but their source files don't directly
include 'parse-options.h'. Furthermore, the source files
'diagnose.c', 'list-objects-filter-options.c', 'remote.c' and
'send-pack.c' define option parsing callback functions, while
'revision.c' defines an option parsing helper function, and thus need
access to various fields in 'struct option' and 'struct
parse_opt_ctx_t', but they don't directly include 'parse-options.h'
either. They all can still be built, of course, because they include
one of the header files that does include 'parse-options.h' (though
unnecessarily, see the next commit).
Add those missing includes to these files, as our general rule is that
"a C file must directly include the header files that declare the
functions and the types it uses".
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to print updated references during a fetch, the two different
call sites that do this will first call `format_display()` followed by a
call to `fputs()`. This is needlessly roundabout now that we have the
`display_state` structure that encapsulates all of the printing logic
for references.
Move displaying the reference updates into `format_display()` and rename
it to `display_ref_update()` to better match its new purpose, which
finalizes the conversion to make both the formatting and printing logic
of reference updates self-contained. This will make it easier to add new
output formats and printing to a different file descriptor than stderr.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fetching from a remote, we not only print the actual references
that have changed, but will also print the URL from which we have
fetched them to standard output. The logic to handle this is duplicated
across two different callsites with some non-trivial logic to compute
the anonymized URL. Furthermore, we're using global state to track
whether we have already shown the URL to the user or not.
Refactor the code by moving it into `format_display()`. Like this, we
can convert the global variable into a member of `display_state`. And
second, we can deduplicate the logic to compute the anonymized URL.
This also works as expected when fetching from multiple remotes, for
example via a group of remotes, as we do this by forking a standalone
git-fetch(1) process per remote that is to be fetched.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function `format_display()` is used to print a single reference
update to a buffer which will then ultimately be printed by the caller.
This architecture causes us to duplicate some logic across the different
callsites of this function. This makes it hard to follow the code as
some parts of the logic are located in one place, while other parts of
the logic are located in a different place. Furthermore, by having the
logic scattered around it becomes quite hard to implement a new output
format for the reference updates.
We can make the logic a whole lot easier to understand by making the
`format_display()` function self-contained so that it handles formatting
and printing of the references. This will eventually allow us to easily
implement a completely different output format, but also opens the door
to conditionally print to either stdout or stderr depending on the
output format.
As a first step towards that goal we move the formatting directive used
by both callers to print a single reference update into this function.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before printing the name of the local references that would be updated
by a fetch we first prettify the reference name. This is done at the
calling side so that `format_display()` never sees the full name of the
local reference. This restricts our ability to introduce new output
formats that might want to print the full reference name.
Right now, all callsites except one are prettifying the reference name
anyway. And the only callsite that doesn't passes `FETCH_HEAD` as the
hardcoded reference name to `format_display()`, which would never be
changed by a call to `prettify_refname()` anyway. So let's refactor the
code to pass in the full local reference name and then prettify it in
the formatting code.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-fetch(1) command supports printing references either in "full"
or "compact" format depending on the `fetch.ouput` config key. The
format that is to be used is tracked in a global variable.
De-globalize the variable by moving it into the `display_state`
structure.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to print references in proper columns we need to calculate the
width of the reference column before starting to print the references.
This is done with the help of a global variable `refcol_width`.
Refactor the code to instead use a new structure `display_state` that
contains the computed width and plumb it through the stack as required.
This is only the first step towards de-globalizing the state required to
print references.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
WM_ABORT_ALL and WM_ABORT_TO_STARSTAR are used internally to limit
backtracking when a match fails, they are not of interest to the caller
and so should not be public.
Suggested-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code changed in this commit is designed to check if the pattern
starts with "**/" or contains "/**/" (see 3a078dec33 (wildmatch: fix
"**" special case, 2013-01-01)). Unfortunately when the pattern begins
with "**/" `prev_p = p - 2` is evaluated when `p` points to the second
"*" and so the subtraction is undefined according to section 6.5.6 of
the C standard because the result does not point within the same object
as `p`. Fix this by avoiding the subtraction unless it is well defined.
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When dowild() cannot match a '*' or '/**/' wildcard then it must return
WM_ABORT_TO_STARSTAR or WM_ABORT_ALL respectively. Failure to observe
this results in unnecessary backtracking and the time taken for a failed
match increases exponentially with the number of wildcards in the
pattern [1]. Unfortunately in some instances dowild() returns WM_NOMATCH
for a failed match resulting in long match times for patterns containing
multiple wildcards as can be seen in the following benchmark.
(Note that the timings in the Benchmark 1 are really measuring the time
to execute test-tool rather than the time to match the pattern)
Benchmark 1: t/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a"
Time (mean ± σ): 22.8 ms ± 1.7 ms [User: 12.1 ms, System: 10.6 ms]
Range (min … max): 19.4 ms … 26.9 ms 113 runs
Warning: Ignoring non-zero exit code.
Benchmark 2: t/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a*a*a*a*a*a*a*a*a"
Time (mean ± σ): 5.244 s ± 0.228 s [User: 5.229 s, System: 0.010 s]
Range (min … max): 4.969 s … 5.707 s 10 runs
Warning: Ignoring non-zero exit code.
Summary
't/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a"' ran
230.37 ± 20.04 times faster than 't/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a*a*a*a*a*a*a*a*a"'
The security implications are limited as it only affects operations that
are potentially DoS vectors. For example by creating a blob containing
such a pattern a malicious user can exploit this behavior to use large
amounts of CPU time on a remote server by pushing the blob and then
creating a new clone with --filter=sparse:oid. However this filter type
is usually disabled as it is known to consume large amounts of CPU time
even without this bug.
The WM_MATCH changed in the first hunk of this patch comes from the
original implementation imported from rsync in 5230f605e1 (Import
wildmatch from rsync, 2012-10-15). Compared to the others converted here
it is fairly harmless as it only triggers at the end of the pattern and
so will only cause a single unnecessary backtrack. The others introduced
by 6f1a31f0aa (wildmatch: advance faster in <asterisk> + <literal>
patterns, 2013-01-01) and 46983441ae (wildmatch: make a special case for
"*/" with FNM_PATHNAME, 2013-01-01) are more pernicious and will cause
exponential behavior.
A new test is added to protect against future regressions.
[1] https://research.swtch.com/glob
Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Tests in t1507-rev-parse-upstream.sh compare files "expect" and "actual"
to assert the output of "git rev-parse", "git show", and "git log".
However, two of the tests '@{reflog}-parsing does not look beyond colon'
and '@{upstream}-parsing does not look beyond colon' don't inspect the
contents of the created files.
Assert output of "git rev-parse" in tests in t1507-rev-parse-upstream.sh
to improve test coverage.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some tests in file t1404-update-ref-errors.sh create file "unchanged" as
the expected side for a test_cmp assertion at the end of the test for
output of "git for-each-ref". Test 'no bogus intermediate values during
delete' also creates a file named "unchanged" using "git for-each-ref".
However, the file isn't used for any assertions in the test. Instead,
"git rev-parse" is used to compare the reference with variable $D.
Don't create unused file "unchanged" in test 'no bogus intermediate
values during delete' of t1404-update-ref-errors.sh.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In t1400-update-ref.sh test 'transaction can create and delete' creates
files "expect" and "actual", but doesn't compare them. Similarly, test
'transaction cannot restart ongoing transaction' redirects output of
"git update-ref" to file "actual", but doesn't check its contents with
any assertions.
Assert output of "git update-ref" in tests to improve test coverage in
t1400-update-ref.sh.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test 'gitdir selection on unsupported repo' in t1302-repo-version.sh
writes output of a "git config" invocation to file "actual". However,
the test doesn't have any assertions for the file. The file was used by
this test until commit b9605bc4f2 (config: only read .git/config from
configured repos, 2016-09-12), before which "git config" was expected to
print the bogus value of "core.repositoryformatversion" to standard
output.
Don't redirect output of "git config" to file "actual" in test 'gitdir
selection on unsupported repo'.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Builtin "git mktree" writes the the object name of the tree object built
to the standard output. Tests 'mktree refuses to read ls-tree -r output
(1)' and 'mktree refuses to read ls-tree -r output (2)' in
"t1010-mktree.sh" redirect output of "git mktree" to a file, but don't
use its contents in assertions.
Don't redirect output of "git mktree" to file "actual" in tests that
assert that an invocation of "git mktree" must fail.
Output of "git mktree" is empty when it refuses to build a tree object.
So, alternatively, the test could assert that the output is empty.
However, there isn't a good reason for the user to expect the command to
be silent in such cases, so we shouldn't enforce it. The user shouldn't
use the output of a failing command anyway.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test "cat-file $arg1 $arg2 error on missing full OID" in
t1006-cat-file.sh compares files "expect.err" and "err.actual" to assert
the expected error output of "git cat-file". A similar test in the same
file named "cat-file $arg1 $arg2 error on missing short OID" also
creates these two files, but doesn't use them in assertions.
Assert error output of "git cat-file" in test "cat-file $arg1 $arg2
error on missing short OID" of t1006-cat-file.sh to improve test
coverage.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test 'reset should work' in t1005-read-tree-reset.sh compares two files
"expect" and "actual" to assert the expected output of "git ls-files".
Several other tests in the same file also create files "expect" and
"actual", but don't use them in assertions.
Assert output of "git ls-files" in t1005-read-tree-reset.sh to improve
test coverage.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git add -p" while the index is unmerged sometimes failed to parse
the diff output it internally produces and died, which has been
corrected.
* jk/add-p-unmerged-fix:
add-patch: handle "* Unmerged path" lines
After "git pull" that is configured with pull.rebase=false
merge.ff=only fails due to our end having our own development, give
advice messages to get out of the "Not possible to fast-forward"
state.
* fc/advice-diverged-history:
advice: add diverging advice for novices
The code to parse "git rebase -X<opt>" was not prepared to see an
unparsable option string, which has been corrected.
* ab/fix-strategy-opts-parsing:
sequencer.c: fix overflow & segfault in parse_strategy_opts()
Once we start running, we assumed that the list of alternate object
databases would never change. Hook into the machinery used to
update the list of packfiles during runtime to update this list as
well.
* ds/reprepare-alternates-when-repreparing-packfiles:
object-file: reprepare alternates when necessary
"git format-patch" learned to write a log-message only output file
for empty commits.
* jk/format-patch-change-format-for-empty-commits:
format-patch: output header for empty commits
"git bundle" learned that "-" is a common way to say that the input
comes from the standard input and/or the output goes to the
standard output. It used to work only for output and only from the
root level of the working tree.
* jk/bundle-use-dash-for-stdfiles:
parse-options: use prefix_filename_except_for_dash() helper
parse-options: consistently allocate memory in fix_filename()
bundle: don't blindly apply prefix_filename() to "-"
bundle: document handling of "-" as stdin
bundle: let "-" mean stdin for reading operations
