git/commit.h

375 lines
13 KiB
C
Raw Normal View History

#ifndef COMMIT_H
#define COMMIT_H
#include "object.h"
struct signature_check;
struct strbuf;
struct tree;
#define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
#define GENERATION_NUMBER_INFINITY ((1ULL << 63) - 1)
#define GENERATION_NUMBER_V1_MAX 0x3FFFFFFF
#define GENERATION_NUMBER_ZERO 0
commit-graph: implement generation data chunk As discovered by Ævar, we cannot increment graph version to distinguish between generation numbers v1 and v2 [1]. Thus, one of pre-requistes before implementing generation number v2 was to distinguish between graph versions in a backwards compatible manner. We are going to introduce a new chunk called Generation DATa chunk (or GDAT). GDAT will store corrected committer date offsets whereas CDAT will still store topological level. Old Git does not understand GDAT chunk and would ignore it, reading topological levels from CDAT. New Git can parse GDAT and take advantage of newer generation numbers, falling back to topological levels when GDAT chunk is missing (as it would happen with a commit-graph written by old Git). We introduce a test environment variable 'GIT_TEST_COMMIT_GRAPH_NO_GDAT' which forces commit-graph file to be written without generation data chunk to emulate a commit-graph file written by old Git. To minimize the space required to store corrrected commit date, Git stores corrected commit date offsets into the commit-graph file, instea of corrected commit dates. This saves us 4 bytes per commit, decreasing the GDAT chunk size by half, but it's possible for the offset to overflow the 4-bytes allocated for storage. As such overflows are and should be exceedingly rare, we use the following overflow management scheme: We introduce a new commit-graph chunk, Generation Data OVerflow ('GDOV') to store corrected commit dates for commits with offsets greater than GENERATION_NUMBER_V2_OFFSET_MAX. If the offset is greater than GENERATION_NUMBER_V2_OFFSET_MAX, we set the MSB of the offset and the other bits store the position of corrected commit date in GDOV chunk, similar to how Extra Edge List is maintained. We test the overflow-related code with the following repo history: F - N - U / \ U - N - U N \ / N - F - N Where the commits denoted by U have committer date of zero seconds since Unix epoch, the commits denoted by N have committer date of 1112354055 (default committer date for the test suite) seconds since Unix epoch and the commits denoted by F have committer date of (2 ^ 31 - 2) seconds since Unix epoch. The largest offset observed is 2 ^ 31, just large enough to overflow. [1]: https://lore.kernel.org/git/87a7gdspo4.fsf@evledraar.gmail.com/ Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com> Reviewed-by: Taylor Blau <me@ttaylorr.com> Reviewed-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-16 18:11:15 +00:00
#define GENERATION_NUMBER_V2_OFFSET_MAX ((1ULL << 31) - 1)
struct commit_list {
struct commit *item;
struct commit_list *next;
};
/*
* The size of this struct matters in full repo walk operations like
* 'git clone' or 'git gc'. Consider using commit-slab to attach data
* to a commit instead of adding new fields here.
*/
struct commit {
struct object object;
timestamp_t date;
struct commit_list *parents;
/*
* If the commit is loaded from the commit-graph file, then this
* member may be NULL. Only access it through repo_get_commit_tree()
* or get_commit_tree_oid().
*/
struct tree *maybe_tree;
unsigned int index;
};
[PATCH] Avoid wasting memory in git-rev-list As pointed out on the list, git-rev-list can use a lot of memory. One low-hanging fruit is to free the commit buffer for commits that we parse. By default, parse_commit() will save away the buffer, since a lot of cases do want it, and re-reading it continually would be unnecessary. However, in many cases the buffer isn't actually necessary and saving it just wastes memory. We could just free the buffer ourselves, but especially in git-rev-list, we actually end up using the helper functions that automatically add parent commits to the commit lists, so we don't actually control the commit parsing directly. Instead, just make this behaviour of "parse_commit()" a global flag. Maybe this is a bit tasteless, but it's very simple, and it makes a noticable difference in memory usage. Before the change: [torvalds@g5 linux]$ /usr/bin/time git-rev-list v2.6.12..HEAD > /dev/null 0.26user 0.02system 0:00.28elapsed 99%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+3714minor)pagefaults 0swaps after the change: [torvalds@g5 linux]$ /usr/bin/time git-rev-list v2.6.12..HEAD > /dev/null 0.26user 0.00system 0:00.27elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+2433minor)pagefaults 0swaps note how the minor faults have decreased from 3714 pages to 2433 pages. That's all due to the fewer anonymous pages allocated to hold the comment buffers and their metadata. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-09-15 21:43:17 +00:00
extern int save_commit_buffer;
extern int no_graft_file_deprecated_advice;
extern const char *commit_type;
/* While we can decorate any object with a name, it's only used for commits.. */
struct name_decoration {
struct name_decoration *next;
int type;
char name[FLEX_ARRAY];
};
enum decoration_type {
DECORATION_NONE = 0,
DECORATION_REF_LOCAL,
DECORATION_REF_REMOTE,
DECORATION_REF_TAG,
DECORATION_REF_STASH,
DECORATION_REF_HEAD,
DECORATION_GRAFTED,
};
void add_name_decoration(enum decoration_type type, const char *name, struct object *obj);
const struct name_decoration *get_name_decoration(const struct object *obj);
/*
* Look up commit named by "oid" respecting replacement objects.
* Returns NULL if "oid" is not a commit or does not exist.
*/
struct commit *lookup_commit_object(struct repository *r, const struct object_id *oid);
/*
* Look up commit named by "oid" without replacement objects or
* checking for object existence. Returns the requested commit if it
* is found in the object cache, NULL if "oid" is in the object cache
* but is not a commit and a newly allocated unparsed commit object if
* "oid" is not in the object cache.
*/
struct commit *lookup_commit(struct repository *r, const struct object_id *oid);
struct commit *lookup_commit_reference(struct repository *r,
const struct object_id *oid);
struct commit *lookup_commit_reference_gently(struct repository *r,
const struct object_id *oid,
int quiet);
struct commit *lookup_commit_reference_by_name(const char *name);
/*
Convert lookup_commit* to struct object_id Convert lookup_commit, lookup_commit_or_die, lookup_commit_reference, and lookup_commit_reference_gently to take struct object_id arguments. Introduce a temporary in parse_object buffer in order to convert this function. This is required since in order to convert parse_object and parse_object_buffer, lookup_commit_reference_gently and lookup_commit_or_die would need to be converted. Not introducing a temporary would therefore require that lookup_commit_or_die take a struct object_id *, but lookup_commit would take unsigned char *, leaving a confusing and hard-to-use interface. parse_object_buffer will lose this temporary in a later patch. This commit was created with manual changes to commit.c, commit.h, and object.c, plus the following semantic patch: @@ expression E1, E2; @@ - lookup_commit_reference_gently(E1.hash, E2) + lookup_commit_reference_gently(&E1, E2) @@ expression E1, E2; @@ - lookup_commit_reference_gently(E1->hash, E2) + lookup_commit_reference_gently(E1, E2) @@ expression E1; @@ - lookup_commit_reference(E1.hash) + lookup_commit_reference(&E1) @@ expression E1; @@ - lookup_commit_reference(E1->hash) + lookup_commit_reference(E1) @@ expression E1; @@ - lookup_commit(E1.hash) + lookup_commit(&E1) @@ expression E1; @@ - lookup_commit(E1->hash) + lookup_commit(E1) @@ expression E1, E2; @@ - lookup_commit_or_die(E1.hash, E2) + lookup_commit_or_die(&E1, E2) @@ expression E1, E2; @@ - lookup_commit_or_die(E1->hash, E2) + lookup_commit_or_die(E1, E2) Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-06 22:10:10 +00:00
* Look up object named by "oid", dereference tag as necessary,
* get a commit and return it. If "oid" does not dereference to
* a commit, use ref_name to report an error and die.
*/
Convert lookup_commit* to struct object_id Convert lookup_commit, lookup_commit_or_die, lookup_commit_reference, and lookup_commit_reference_gently to take struct object_id arguments. Introduce a temporary in parse_object buffer in order to convert this function. This is required since in order to convert parse_object and parse_object_buffer, lookup_commit_reference_gently and lookup_commit_or_die would need to be converted. Not introducing a temporary would therefore require that lookup_commit_or_die take a struct object_id *, but lookup_commit would take unsigned char *, leaving a confusing and hard-to-use interface. parse_object_buffer will lose this temporary in a later patch. This commit was created with manual changes to commit.c, commit.h, and object.c, plus the following semantic patch: @@ expression E1, E2; @@ - lookup_commit_reference_gently(E1.hash, E2) + lookup_commit_reference_gently(&E1, E2) @@ expression E1, E2; @@ - lookup_commit_reference_gently(E1->hash, E2) + lookup_commit_reference_gently(E1, E2) @@ expression E1; @@ - lookup_commit_reference(E1.hash) + lookup_commit_reference(&E1) @@ expression E1; @@ - lookup_commit_reference(E1->hash) + lookup_commit_reference(E1) @@ expression E1; @@ - lookup_commit(E1.hash) + lookup_commit(&E1) @@ expression E1; @@ - lookup_commit(E1->hash) + lookup_commit(E1) @@ expression E1, E2; @@ - lookup_commit_or_die(E1.hash, E2) + lookup_commit_or_die(&E1, E2) @@ expression E1, E2; @@ - lookup_commit_or_die(E1->hash, E2) + lookup_commit_or_die(E1, E2) Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-06 22:10:10 +00:00
struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name);
int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph);
int repo_parse_commit_internal(struct repository *r, struct commit *item,
int quiet_on_missing, int use_commit_graph);
int repo_parse_commit_gently(struct repository *r,
struct commit *item,
int quiet_on_missing);
static inline int repo_parse_commit(struct repository *r, struct commit *item)
{
return repo_parse_commit_gently(r, item, 0);
}
commit-graph write: don't die if the existing graph is corrupt When the commit-graph is written we end up calling parse_commit(). This will in turn invoke code that'll consult the existing commit-graph about the commit, if the graph is corrupted we die. We thus get into a state where a failing "commit-graph verify" can't be followed-up with a "commit-graph write" if core.commitGraph=true is set, the graph either needs to be manually removed to proceed, or core.commitGraph needs to be set to "false". Change the "commit-graph write" codepath to use a new parse_commit_no_graph() helper instead of parse_commit() to avoid this. The latter will call repo_parse_commit_internal() with use_commit_graph=1 as seen in 177722b344 ("commit: integrate commit graph with commit parsing", 2018-04-10). Not using the old graph at all slows down the writing of the new graph by some small amount, but is a sensible way to prevent an error in the existing commit-graph from spreading. Just fixing the current issue would be likely to result in code that's inadvertently broken in the future. New code might use the commit-graph at a distance. To detect such cases introduce a "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD" setting used when we do our corruption tests, and test that a "write/verify" combo works after every one of our current test cases where we now detect commit-graph corruption. Some of the code changes here might be strictly unnecessary, e.g. I was unable to find cases where the parse_commit() called from write_graph_chunk_data() didn't exit early due to "item->object.parsed" being true in repo_parse_commit_internal() (before the use_commit_graph=1 has any effect). But let's also convert those cases for good measure, we do not have exhaustive tests for all possible types of commit-graph corruption. This might need to be re-visited if we learn to write the commit-graph incrementally, but probably not. Hopefully we'll just start by finding out what commits we have in total, then read the old graph(s) to see what they cover, and finally write a new graph file with everything that's missing. In that case the new graph writing code just needs to continue to use e.g. a parse_commit() that doesn't consult the existing commit-graphs. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-25 12:08:33 +00:00
static inline int repo_parse_commit_no_graph(struct repository *r,
struct commit *commit)
commit-graph write: don't die if the existing graph is corrupt When the commit-graph is written we end up calling parse_commit(). This will in turn invoke code that'll consult the existing commit-graph about the commit, if the graph is corrupted we die. We thus get into a state where a failing "commit-graph verify" can't be followed-up with a "commit-graph write" if core.commitGraph=true is set, the graph either needs to be manually removed to proceed, or core.commitGraph needs to be set to "false". Change the "commit-graph write" codepath to use a new parse_commit_no_graph() helper instead of parse_commit() to avoid this. The latter will call repo_parse_commit_internal() with use_commit_graph=1 as seen in 177722b344 ("commit: integrate commit graph with commit parsing", 2018-04-10). Not using the old graph at all slows down the writing of the new graph by some small amount, but is a sensible way to prevent an error in the existing commit-graph from spreading. Just fixing the current issue would be likely to result in code that's inadvertently broken in the future. New code might use the commit-graph at a distance. To detect such cases introduce a "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD" setting used when we do our corruption tests, and test that a "write/verify" combo works after every one of our current test cases where we now detect commit-graph corruption. Some of the code changes here might be strictly unnecessary, e.g. I was unable to find cases where the parse_commit() called from write_graph_chunk_data() didn't exit early due to "item->object.parsed" being true in repo_parse_commit_internal() (before the use_commit_graph=1 has any effect). But let's also convert those cases for good measure, we do not have exhaustive tests for all possible types of commit-graph corruption. This might need to be re-visited if we learn to write the commit-graph incrementally, but probably not. Hopefully we'll just start by finding out what commits we have in total, then read the old graph(s) to see what they cover, and finally write a new graph file with everything that's missing. In that case the new graph writing code just needs to continue to use e.g. a parse_commit() that doesn't consult the existing commit-graphs. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-25 12:08:33 +00:00
{
return repo_parse_commit_internal(r, commit, 0, 0);
commit-graph write: don't die if the existing graph is corrupt When the commit-graph is written we end up calling parse_commit(). This will in turn invoke code that'll consult the existing commit-graph about the commit, if the graph is corrupted we die. We thus get into a state where a failing "commit-graph verify" can't be followed-up with a "commit-graph write" if core.commitGraph=true is set, the graph either needs to be manually removed to proceed, or core.commitGraph needs to be set to "false". Change the "commit-graph write" codepath to use a new parse_commit_no_graph() helper instead of parse_commit() to avoid this. The latter will call repo_parse_commit_internal() with use_commit_graph=1 as seen in 177722b344 ("commit: integrate commit graph with commit parsing", 2018-04-10). Not using the old graph at all slows down the writing of the new graph by some small amount, but is a sensible way to prevent an error in the existing commit-graph from spreading. Just fixing the current issue would be likely to result in code that's inadvertently broken in the future. New code might use the commit-graph at a distance. To detect such cases introduce a "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD" setting used when we do our corruption tests, and test that a "write/verify" combo works after every one of our current test cases where we now detect commit-graph corruption. Some of the code changes here might be strictly unnecessary, e.g. I was unable to find cases where the parse_commit() called from write_graph_chunk_data() didn't exit early due to "item->object.parsed" being true in repo_parse_commit_internal() (before the use_commit_graph=1 has any effect). But let's also convert those cases for good measure, we do not have exhaustive tests for all possible types of commit-graph corruption. This might need to be re-visited if we learn to write the commit-graph incrementally, but probably not. Hopefully we'll just start by finding out what commits we have in total, then read the old graph(s) to see what they cover, and finally write a new graph file with everything that's missing. In that case the new graph writing code just needs to continue to use e.g. a parse_commit() that doesn't consult the existing commit-graphs. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-25 12:08:33 +00:00
}
void parse_commit_or_die(struct commit *item);
struct buffer_slab;
struct buffer_slab *allocate_commit_buffer_slab(void);
void free_commit_buffer_slab(struct buffer_slab *bs);
/*
* Associate an object buffer with the commit. The ownership of the
* memory is handed over to the commit, and must be free()-able.
*/
void set_commit_buffer(struct repository *r, struct commit *, void *buffer, unsigned long size);
/*
* Get any cached object buffer associated with the commit. Returns NULL
* if none. The resulting memory should not be freed.
*/
const void *get_cached_commit_buffer(struct repository *, const struct commit *, unsigned long *size);
/*
* Get the commit's object contents, either from cache or by reading the object
* from disk. The resulting memory should not be modified, and must be given
* to repo_unuse_commit_buffer when the caller is done.
*/
const void *repo_get_commit_buffer(struct repository *r,
const struct commit *,
unsigned long *size);
/*
* Tell the commit subsystem that we are done with a particular commit buffer.
* The commit and buffer should be the input and return value, respectively,
* from an earlier call to repo_get_commit_buffer. The buffer may or may not be
* freed by this call; callers should not access the memory afterwards.
*/
void repo_unuse_commit_buffer(struct repository *r,
const struct commit *,
const void *buffer);
/*
* Free any cached object buffer associated with the commit.
*/
void free_commit_buffer(struct parsed_object_pool *pool, struct commit *);
struct tree *repo_get_commit_tree(struct repository *, const struct commit *);
struct object_id *get_commit_tree_oid(const struct commit *);
/*
* Release memory related to a commit, including the parent list and
* any cached object buffer.
*/
void release_commit_memory(struct parsed_object_pool *pool, struct commit *c);
/*
* Disassociate any cached object buffer from the commit, but do not free it.
* The buffer (or NULL, if none) is returned.
*/
const void *detach_commit_buffer(struct commit *, unsigned long *sizep);
/* Find beginning and length of commit subject. */
int find_commit_subject(const char *commit_buffer, const char **subject);
/* Return length of the commit subject from commit log message. */
size_t commit_subject_length(const char *body);
struct commit_list *commit_list_insert(struct commit *item,
struct commit_list **list);
int commit_list_contains(struct commit *item,
struct commit_list *list);
struct commit_list **commit_list_append(struct commit *commit,
struct commit_list **next);
unsigned commit_list_count(const struct commit_list *l);
struct commit_list *commit_list_insert_by_date(struct commit *item,
struct commit_list **list);
void commit_list_sort_by_date(struct commit_list **list);
log: use true parents for diff even when rewriting When using pathspec filtering in combination with diff-based log output, parent simplification happens before the diff is computed. The diff is therefore against the *simplified* parents. This works okay, arguably by accident, in the normal case: simplification reduces to one parent as long as the commit is TREESAME to it. So the simplified parent of any given commit must have the same tree contents on the filtered paths as its true (unfiltered) parent. However, --full-diff breaks this guarantee, and indeed gives pretty spectacular results when comparing the output of git log --graph --stat ... git log --graph --full-diff --stat ... (--graph internally kicks in parent simplification, much like --parents). To fix it, store a copy of the parent list before simplification (in a slab) whenever --full-diff is in effect. Then use the stored parents instead of the simplified ones in the commit display code paths. The latter do not actually check for --full-diff to avoid duplicated code; they just grab the original parents if save_parents() has not been called for this revision walk. For ordinary commits it should be obvious that this is the right thing to do. Merge commits are a bit subtle. Observe that with default simplification, merge simplification is an all-or-nothing decision: either the merge is TREESAME to one parent and disappears, or it is different from all parents and the parent list remains intact. Redundant parents are not pruned, so the existing code also shows them as a merge. So if we do show a merge commit, the parent list just consists of the rewrite result on each parent. Running, e.g., --cc on this in --full-diff mode is not very useful: if any commits were skipped, some hunks will disagree with all sides of the merge (with one side, because commits were skipped; with the others, because they didn't have those changes in the first place). This triggers --cc showing these hunks spuriously. Therefore I believe that even for merge commits it is better to show the diffs wrt. the original parents. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Thomas Rast <trast@inf.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-31 20:13:20 +00:00
/* Shallow copy of the input list */
struct commit_list *copy_commit_list(struct commit_list *list);
/* Modify list in-place to reverse it, returning new head; list will be tail */
struct commit_list *reverse_commit_list(struct commit_list *list);
void free_commit_list(struct commit_list *list);
struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
const char *repo_logmsg_reencode(struct repository *r,
const struct commit *commit,
char **commit_encoding,
const char *output_encoding);
const char *skip_blank_lines(const char *msg);
/** Removes the first commit from a list sorted by date, and adds all
* of its parents.
**/
struct commit *pop_most_recent_commit(struct commit_list **list,
unsigned int mark);
[PATCH] Modify git-rev-list to linearise the commit history in merge order. This patch linearises the GIT commit history graph into merge order which is defined by invariants specified in Documentation/git-rev-list.txt. The linearisation produced by this patch is superior in an objective sense to that produced by the existing git-rev-list implementation in that the linearisation produced is guaranteed to have the minimum number of discontinuities, where a discontinuity is defined as an adjacent pair of commits in the output list which are not related in a direct child-parent relationship. With this patch a graph like this: a4 --- | \ \ | b4 | |/ | | a3 | | | | | a2 | | | | c3 | | | | | c2 | b3 | | | /| | b2 | | | c1 | | / | b1 a1 | | | a0 | | / root Sorts like this: = a4 | c3 | c2 | c1 ^ b4 | b3 | b2 | b1 ^ a3 | a2 | a1 | a0 = root Instead of this: = a4 | c3 ^ b4 | a3 ^ c2 ^ b3 ^ a2 ^ b2 ^ c1 ^ a1 ^ b1 ^ a0 = root A test script, t/t6000-rev-list.sh, includes a test which demonstrates that the linearisation produced by --merge-order has less discontinuities than the linearisation produced by git-rev-list without the --merge-order flag specified. To see this, do the following: cd t ./t6000-rev-list.sh cd trash cat actual-default-order cat actual-merge-order The existing behaviour of git-rev-list is preserved, by default. To obtain the modified behaviour, specify --merge-order or --merge-order --show-breaks on the command line. This version of the patch has been tested on the git repository and also on the linux-2.6 repository and has reasonable performance on both - ~50-100% slower than the original algorithm. This version of the patch has incorporated a functional equivalent of the Linus' output limiting algorithm into the merge-order algorithm itself. This operates per the notes associated with Linus' commit 337cb3fb8da45f10fe9a0c3cf571600f55ead2ce. This version has incorporated Linus' feedback regarding proposed changes to rev-list.c. (see: [PATCH] Factor out filtering in rev-list.c) This version has improved the way sort_first_epoch marks commits as uninteresting. For more details about this change, refer to Documentation/git-rev-list.txt and http://blackcubes.dyndns.org/epoch/. Signed-off-by: Jon Seymour <jon.seymour@gmail.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-06 15:39:40 +00:00
struct commit *pop_commit(struct commit_list **stack);
void clear_commit_marks(struct commit *commit, unsigned int mark);
void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark);
toposort: rename "lifo" field The primary invariant of sort_in_topological_order() is that a parent commit is not emitted until all children of it are. When traversing a forked history like this with "git log C E": A----B----C \ D----E we ensure that A is emitted after all of B, C, D, and E are done, B has to wait until C is done, and D has to wait until E is done. In some applications, however, we would further want to control how these child commits B, C, D and E on two parallel ancestry chains are shown. Most of the time, we would want to see C and B emitted together, and then E and D, and finally A (i.e. the --topo-order output). The "lifo" parameter of the sort_in_topological_order() function is used to control this behaviour. We start the traversal by knowing two commits, C and E. While keeping in mind that we also need to inspect E later, we pick C first to inspect, and we notice and record that B needs to be inspected. By structuring the "work to be done" set as a LIFO stack, we ensure that B is inspected next, before other in-flight commits we had known that we will need to inspect, e.g. E. When showing in --date-order, we would want to see commits ordered by timestamps, i.e. show C, E, B and D in this order before showing A, possibly mixing commits from two parallel histories together. When "lifo" parameter is set to false, the function keeps the "work to be done" set sorted in the date order to realize this semantics. After inspecting C, we add B to the "work to be done" set, but the next commit we inspect from the set is E which is newer than B. The name "lifo", however, is too strongly tied to the way how the function implements its behaviour, and does not describe what the behaviour _means_. Replace this field with an enum rev_sort_order, with two possible values: REV_SORT_IN_GRAPH_ORDER and REV_SORT_BY_COMMIT_DATE, and update the existing code. The mechanical replacement rule is: "lifo == 0" is equivalent to "sort_order == REV_SORT_BY_COMMIT_DATE" "lifo == 1" is equivalent to "sort_order == REV_SORT_IN_GRAPH_ORDER" Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-06 23:07:14 +00:00
enum rev_sort_order {
REV_SORT_IN_GRAPH_ORDER = 0,
REV_SORT_BY_COMMIT_DATE,
REV_SORT_BY_AUTHOR_DATE
toposort: rename "lifo" field The primary invariant of sort_in_topological_order() is that a parent commit is not emitted until all children of it are. When traversing a forked history like this with "git log C E": A----B----C \ D----E we ensure that A is emitted after all of B, C, D, and E are done, B has to wait until C is done, and D has to wait until E is done. In some applications, however, we would further want to control how these child commits B, C, D and E on two parallel ancestry chains are shown. Most of the time, we would want to see C and B emitted together, and then E and D, and finally A (i.e. the --topo-order output). The "lifo" parameter of the sort_in_topological_order() function is used to control this behaviour. We start the traversal by knowing two commits, C and E. While keeping in mind that we also need to inspect E later, we pick C first to inspect, and we notice and record that B needs to be inspected. By structuring the "work to be done" set as a LIFO stack, we ensure that B is inspected next, before other in-flight commits we had known that we will need to inspect, e.g. E. When showing in --date-order, we would want to see commits ordered by timestamps, i.e. show C, E, B and D in this order before showing A, possibly mixing commits from two parallel histories together. When "lifo" parameter is set to false, the function keeps the "work to be done" set sorted in the date order to realize this semantics. After inspecting C, we add B to the "work to be done" set, but the next commit we inspect from the set is E which is newer than B. The name "lifo", however, is too strongly tied to the way how the function implements its behaviour, and does not describe what the behaviour _means_. Replace this field with an enum rev_sort_order, with two possible values: REV_SORT_IN_GRAPH_ORDER and REV_SORT_BY_COMMIT_DATE, and update the existing code. The mechanical replacement rule is: "lifo == 0" is equivalent to "sort_order == REV_SORT_BY_COMMIT_DATE" "lifo == 1" is equivalent to "sort_order == REV_SORT_IN_GRAPH_ORDER" Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-06 23:07:14 +00:00
};
/*
* Performs an in-place topological sort of list supplied.
*
* invariant of resulting list is:
* a reachable from b => ord(b) < ord(a)
toposort: rename "lifo" field The primary invariant of sort_in_topological_order() is that a parent commit is not emitted until all children of it are. When traversing a forked history like this with "git log C E": A----B----C \ D----E we ensure that A is emitted after all of B, C, D, and E are done, B has to wait until C is done, and D has to wait until E is done. In some applications, however, we would further want to control how these child commits B, C, D and E on two parallel ancestry chains are shown. Most of the time, we would want to see C and B emitted together, and then E and D, and finally A (i.e. the --topo-order output). The "lifo" parameter of the sort_in_topological_order() function is used to control this behaviour. We start the traversal by knowing two commits, C and E. While keeping in mind that we also need to inspect E later, we pick C first to inspect, and we notice and record that B needs to be inspected. By structuring the "work to be done" set as a LIFO stack, we ensure that B is inspected next, before other in-flight commits we had known that we will need to inspect, e.g. E. When showing in --date-order, we would want to see commits ordered by timestamps, i.e. show C, E, B and D in this order before showing A, possibly mixing commits from two parallel histories together. When "lifo" parameter is set to false, the function keeps the "work to be done" set sorted in the date order to realize this semantics. After inspecting C, we add B to the "work to be done" set, but the next commit we inspect from the set is E which is newer than B. The name "lifo", however, is too strongly tied to the way how the function implements its behaviour, and does not describe what the behaviour _means_. Replace this field with an enum rev_sort_order, with two possible values: REV_SORT_IN_GRAPH_ORDER and REV_SORT_BY_COMMIT_DATE, and update the existing code. The mechanical replacement rule is: "lifo == 0" is equivalent to "sort_order == REV_SORT_BY_COMMIT_DATE" "lifo == 1" is equivalent to "sort_order == REV_SORT_IN_GRAPH_ORDER" Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-06 23:07:14 +00:00
* sort_order further specifies:
* REV_SORT_IN_GRAPH_ORDER: try to show a commit on a single-parent
* chain together.
* REV_SORT_BY_COMMIT_DATE: show eligible commits in committer-date order.
*/
toposort: rename "lifo" field The primary invariant of sort_in_topological_order() is that a parent commit is not emitted until all children of it are. When traversing a forked history like this with "git log C E": A----B----C \ D----E we ensure that A is emitted after all of B, C, D, and E are done, B has to wait until C is done, and D has to wait until E is done. In some applications, however, we would further want to control how these child commits B, C, D and E on two parallel ancestry chains are shown. Most of the time, we would want to see C and B emitted together, and then E and D, and finally A (i.e. the --topo-order output). The "lifo" parameter of the sort_in_topological_order() function is used to control this behaviour. We start the traversal by knowing two commits, C and E. While keeping in mind that we also need to inspect E later, we pick C first to inspect, and we notice and record that B needs to be inspected. By structuring the "work to be done" set as a LIFO stack, we ensure that B is inspected next, before other in-flight commits we had known that we will need to inspect, e.g. E. When showing in --date-order, we would want to see commits ordered by timestamps, i.e. show C, E, B and D in this order before showing A, possibly mixing commits from two parallel histories together. When "lifo" parameter is set to false, the function keeps the "work to be done" set sorted in the date order to realize this semantics. After inspecting C, we add B to the "work to be done" set, but the next commit we inspect from the set is E which is newer than B. The name "lifo", however, is too strongly tied to the way how the function implements its behaviour, and does not describe what the behaviour _means_. Replace this field with an enum rev_sort_order, with two possible values: REV_SORT_IN_GRAPH_ORDER and REV_SORT_BY_COMMIT_DATE, and update the existing code. The mechanical replacement rule is: "lifo == 0" is equivalent to "sort_order == REV_SORT_BY_COMMIT_DATE" "lifo == 1" is equivalent to "sort_order == REV_SORT_IN_GRAPH_ORDER" Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-06 23:07:14 +00:00
void sort_in_topological_order(struct commit_list **, enum rev_sort_order);
struct commit_graft {
struct object_id oid;
int nr_parent; /* < 0 if shallow commit */
struct object_id parent[FLEX_ARRAY]; /* more */
};
typedef int (*each_commit_graft_fn)(const struct commit_graft *, void *);
struct commit_graft *read_graft_line(struct strbuf *line);
/* commit_graft_pos returns an index into r->parsed_objects->grafts. */
int commit_graft_pos(struct repository *r, const struct object_id *oid);
int register_commit_graft(struct repository *r, struct commit_graft *, int);
void prepare_commit_graft(struct repository *r);
struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid);
void reset_commit_grafts(struct repository *r);
struct commit *get_fork_point(const char *refname, struct commit *commit);
/* largest positive number a signed 32-bit integer can contain */
#define INFINITE_DEPTH 0x7fffffff
struct oid_array;
shallow.c: the 8 steps to select new commits for .git/shallow 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>
2013-12-05 13:02:35 +00:00
struct ref;
int for_each_commit_graft(each_commit_graft_fn, void *);
int interactive_add(const char **argv, const char *prefix, int patch);
struct commit_extra_header {
struct commit_extra_header *next;
char *key;
char *value;
size_t len;
};
void append_merge_tag_headers(struct commit_list *parents,
struct commit_extra_header ***tail);
int commit_tree(const char *msg, size_t msg_len,
const struct object_id *tree,
struct commit_list *parents, struct object_id *ret,
const char *author, const char *sign_commit);
int commit_tree_extended(const char *msg, size_t msg_len,
const struct object_id *tree,
struct commit_list *parents, struct object_id *ret,
const char *author, const char *committer,
const char *sign_commit, struct commit_extra_header *);
struct commit_extra_header *read_commit_extra_headers(struct commit *, const char **);
void free_commit_extra_headers(struct commit_extra_header *extra);
/*
* Search the commit object contents given by "msg" for the header "key".
* Reads up to "len" bytes of "msg".
* Returns a pointer to the start of the header contents, or NULL. The length
* of the header, up to the first newline, is returned via out_len.
*
* Note that some headers (like mergetag) may be multi-line. It is the caller's
* responsibility to parse further in this case!
*/
const char *find_header_mem(const char *msg, size_t len,
const char *key,
size_t *out_len);
const char *find_commit_header(const char *msg, const char *key,
size_t *out_len);
/* Find the end of the log message, the right place for a new trailer. */
size_t ignore_non_trailer(const char *buf, size_t len);
typedef int (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
void *cb_data);
int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
struct merge_remote_desc {
struct object *obj; /* the named object, could be a tag */
char name[FLEX_ARRAY];
};
struct merge_remote_desc *merge_remote_util(struct commit *);
void set_merge_remote_desc(struct commit *commit,
const char *name, struct object *obj);
/*
* Given "name" from the command line to merge, find the commit object
* and return it, while storing merge_remote_desc in its ->util field,
* to allow callers to tell if we are told to merge a tag.
*/
struct commit *get_merge_parent(const char *name);
int parse_signed_commit(const struct commit *commit,
struct strbuf *message, struct strbuf *signature,
const struct git_hash_algo *algop);
int remove_signature(struct strbuf *buf);
/*
* Check the signature of the given commit. The result of the check is stored
* in sig->check_result, 'G' for a good signature, 'U' for a good signature
* from an untrusted signer, 'B' for a bad signature and 'N' for no signature
* at all. This may allocate memory for sig->gpg_output, sig->gpg_status,
* sig->signer and sig->key.
*/
int check_commit_signature(const struct commit *commit, struct signature_check *sigc);
/* record author-date for each commit object */
struct author_date_slab;
void record_author_date(struct author_date_slab *author_date,
struct commit *commit);
int compare_commits_by_author_date(const void *a_, const void *b_, void *unused);
/*
* Verify a single commit with check_commit_signature() and die() if it is not
* a good signature. This isn't really suitable for general use, but is a
* helper to implement consistent logic for pull/merge --verify-signatures.
gpg-interface: add minTrustLevel as a configuration option Previously, signature verification for merge and pull operations checked if the key had a trust-level of either TRUST_NEVER or TRUST_UNDEFINED in verify_merge_signature(). If that was the case, the process die()d. The other code paths that did signature verification relied entirely on the return code from check_commit_signature(). And signatures made with a good key, irregardless of its trust level, was considered valid by check_commit_signature(). This difference in behavior might induce users to erroneously assume that the trust level of a key in their keyring is always considered by Git, even for operations where it is not (e.g. during a verify-commit or verify-tag). The way it worked was by gpg-interface.c storing the result from the key/signature status *and* the lowest-two trust levels in the `result` member of the signature_check structure (the last of these status lines that were encountered got written to `result`). These are documented in GPG under the subsection `General status codes` and `Key related`, respectively [1]. The GPG documentation says the following on the TRUST_ status codes [1]: """ These are several similar status codes: - TRUST_UNDEFINED <error_token> - TRUST_NEVER <error_token> - TRUST_MARGINAL [0 [<validation_model>]] - TRUST_FULLY [0 [<validation_model>]] - TRUST_ULTIMATE [0 [<validation_model>]] For good signatures one of these status lines are emitted to indicate the validity of the key used to create the signature. The error token values are currently only emitted by gpgsm. """ My interpretation is that the trust level is conceptionally different from the validity of the key and/or signature. That seems to also have been the assumption of the old code in check_signature() where a result of 'G' (as in GOODSIG) and 'U' (as in TRUST_NEVER or TRUST_UNDEFINED) were both considered a success. The two cases where a result of 'U' had special meaning were in verify_merge_signature() (where this caused git to die()) and in format_commit_one() (where it affected the output of the %G? format specifier). I think it makes sense to refactor the processing of TRUST_ status lines such that users can configure a minimum trust level that is enforced globally, rather than have individual parts of git (e.g. merge) do it themselves (except for a grace period with backward compatibility). I also think it makes sense to not store the trust level in the same struct member as the key/signature status. While the presence of a TRUST_ status code does imply that the signature is good (see the first paragraph in the included snippet above), as far as I can tell, the order of the status lines from GPG isn't well-defined; thus it would seem plausible that the trust level could be overwritten with the key/signature status if they were stored in the same member of the signature_check structure. This patch introduces a new configuration option: gpg.minTrustLevel. It consolidates trust-level verification to gpg-interface.c and adds a new `trust_level` member to the signature_check structure. Backward-compatibility is maintained by introducing a special case in verify_merge_signature() such that if no user-configurable gpg.minTrustLevel is set, then the old behavior of rejecting TRUST_UNDEFINED and TRUST_NEVER is enforced. If, on the other hand, gpg.minTrustLevel is set, then that value overrides the old behavior. Similarly, the %G? format specifier will continue show 'U' for signatures made with a key that has a trust level of TRUST_UNDEFINED or TRUST_NEVER, even though the 'U' character no longer exist in the `result` member of the signature_check structure. A new format specifier, %GT, is also introduced for users that want to show all possible trust levels for a signature. Another approach would have been to simply drop the trust-level requirement in verify_merge_signature(). This would also have made the behavior consistent with other parts of git that perform signature verification. However, requiring a minimum trust level for signing keys does seem to have a real-world use-case. For example, the build system used by the Qubes OS project currently parses the raw output from verify-tag in order to assert a minimum trust level for keys used to sign git tags [2]. [1] https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=blob;f=doc/doc/DETAILS;h=bd00006e933ac56719b1edd2478ecd79273eae72;hb=refs/heads/master [2] https://github.com/QubesOS/qubes-builder/blob/9674c1991deef45b1a1b1c71fddfab14ba50dccf/scripts/verify-git-tag#L43 Signed-off-by: Hans Jerry Illikainen <hji@dyntopia.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-27 13:55:57 +00:00
*
* The check_trust parameter is meant for backward-compatibility. The GPG
* interface verifies key trust with a default trust level that is below the
* default trust level for merge operations. Its value should be non-zero if
* the user hasn't set a minimum trust level explicitly in their configuration.
*
* If the user has set a minimum trust level, then that value should be obeyed
* and check_trust should be zero, even if the configured trust level is below
* the default trust level for merges.
*/
gpg-interface: add minTrustLevel as a configuration option Previously, signature verification for merge and pull operations checked if the key had a trust-level of either TRUST_NEVER or TRUST_UNDEFINED in verify_merge_signature(). If that was the case, the process die()d. The other code paths that did signature verification relied entirely on the return code from check_commit_signature(). And signatures made with a good key, irregardless of its trust level, was considered valid by check_commit_signature(). This difference in behavior might induce users to erroneously assume that the trust level of a key in their keyring is always considered by Git, even for operations where it is not (e.g. during a verify-commit or verify-tag). The way it worked was by gpg-interface.c storing the result from the key/signature status *and* the lowest-two trust levels in the `result` member of the signature_check structure (the last of these status lines that were encountered got written to `result`). These are documented in GPG under the subsection `General status codes` and `Key related`, respectively [1]. The GPG documentation says the following on the TRUST_ status codes [1]: """ These are several similar status codes: - TRUST_UNDEFINED <error_token> - TRUST_NEVER <error_token> - TRUST_MARGINAL [0 [<validation_model>]] - TRUST_FULLY [0 [<validation_model>]] - TRUST_ULTIMATE [0 [<validation_model>]] For good signatures one of these status lines are emitted to indicate the validity of the key used to create the signature. The error token values are currently only emitted by gpgsm. """ My interpretation is that the trust level is conceptionally different from the validity of the key and/or signature. That seems to also have been the assumption of the old code in check_signature() where a result of 'G' (as in GOODSIG) and 'U' (as in TRUST_NEVER or TRUST_UNDEFINED) were both considered a success. The two cases where a result of 'U' had special meaning were in verify_merge_signature() (where this caused git to die()) and in format_commit_one() (where it affected the output of the %G? format specifier). I think it makes sense to refactor the processing of TRUST_ status lines such that users can configure a minimum trust level that is enforced globally, rather than have individual parts of git (e.g. merge) do it themselves (except for a grace period with backward compatibility). I also think it makes sense to not store the trust level in the same struct member as the key/signature status. While the presence of a TRUST_ status code does imply that the signature is good (see the first paragraph in the included snippet above), as far as I can tell, the order of the status lines from GPG isn't well-defined; thus it would seem plausible that the trust level could be overwritten with the key/signature status if they were stored in the same member of the signature_check structure. This patch introduces a new configuration option: gpg.minTrustLevel. It consolidates trust-level verification to gpg-interface.c and adds a new `trust_level` member to the signature_check structure. Backward-compatibility is maintained by introducing a special case in verify_merge_signature() such that if no user-configurable gpg.minTrustLevel is set, then the old behavior of rejecting TRUST_UNDEFINED and TRUST_NEVER is enforced. If, on the other hand, gpg.minTrustLevel is set, then that value overrides the old behavior. Similarly, the %G? format specifier will continue show 'U' for signatures made with a key that has a trust level of TRUST_UNDEFINED or TRUST_NEVER, even though the 'U' character no longer exist in the `result` member of the signature_check structure. A new format specifier, %GT, is also introduced for users that want to show all possible trust levels for a signature. Another approach would have been to simply drop the trust-level requirement in verify_merge_signature(). This would also have made the behavior consistent with other parts of git that perform signature verification. However, requiring a minimum trust level for signing keys does seem to have a real-world use-case. For example, the build system used by the Qubes OS project currently parses the raw output from verify-tag in order to assert a minimum trust level for keys used to sign git tags [2]. [1] https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=blob;f=doc/doc/DETAILS;h=bd00006e933ac56719b1edd2478ecd79273eae72;hb=refs/heads/master [2] https://github.com/QubesOS/qubes-builder/blob/9674c1991deef45b1a1b1c71fddfab14ba50dccf/scripts/verify-git-tag#L43 Signed-off-by: Hans Jerry Illikainen <hji@dyntopia.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-27 13:55:57 +00:00
void verify_merge_signature(struct commit *commit, int verbose,
int check_trust);
int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused);
int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused);
LAST_ARG_MUST_BE_NULL
hooks: fix an obscure TOCTOU "did we just run a hook?" race Fix a Time-of-check to time-of-use (TOCTOU) race in code added in 680ee550d72 (commit: skip discarding the index if there is no pre-commit hook, 2017-08-14). This obscure race condition can occur if we e.g. ran the "pre-commit" hook and it modified the index, but hook_exists() returns false later on (e.g., because the hook itself went away, the directory became unreadable, etc.). Then we won't call discard_cache() when we should have. The race condition itself probably doesn't matter, and users would have been unlikely to run into it in practice. This problem has been noted on-list when 680ee550d72 was discussed[1], but had not been fixed. This change is mainly intended to improve the readability of the code involved, and to make reasoning about it more straightforward. It wasn't as obvious what we were trying to do here, but by having an "invoked_hook" it's clearer that e.g. our discard_cache() is happening because of the earlier hook execution. Let's also change this for the push-to-checkout hook. Now instead of checking if the hook exists and either doing a push to checkout or a push to deploy we'll always attempt a push to checkout. If the hook doesn't exist we'll fall back on push to deploy. The same behavior as before, without the TOCTOU race. See 0855331941b (receive-pack: support push-to-checkout hook, 2014-12-01) for the introduction of the previous behavior. This leaves uses of hook_exists() in two places that matter. The "reference-transaction" check in refs.c, see 67541597670 (refs: implement reference transaction hook, 2020-06-19), and the "prepare-commit-msg" hook, see 66618a50f9c (sequencer: run 'prepare-commit-msg' hook, 2018-01-24). In both of those cases we're saving ourselves CPU time by not preparing data for the hook that we'll then do nothing with if we don't have the hook. So using this "invoked_hook" pattern doesn't make sense in those cases. The "reference-transaction" and "prepare-commit-msg" hook also aren't racy. In those cases we'll skip the hook runs if we race with a new hook being added, whereas in the TOCTOU races being fixed here we were incorrectly skipping the required post-hook logic. 1. https://lore.kernel.org/git/20170810191613.kpmhzg4seyxy3cpq@sigill.intra.peff.net/ Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-07 12:33:46 +00:00
int run_commit_hook(int editor_is_used, const char *index_file,
int *invoked_hook, const char *name, ...);
/* Sign a commit or tag buffer, storing the result in a header. */
int sign_with_header(struct strbuf *buf, const char *keyid);
/* Parse the signature out of a header. */
int parse_buffer_signed_by_header(const char *buffer,
unsigned long size,
struct strbuf *payload,
struct strbuf *signature,
const struct git_hash_algo *algop);
#endif /* COMMIT_H */