git/commit.h

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3.0 KiB
C
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#ifndef COMMIT_H
#define COMMIT_H
#include "object.h"
#include "tree.h"
struct commit_list {
struct commit *item;
struct commit_list *next;
};
struct commit {
struct object object;
unsigned long date;
struct commit_list *parents;
struct tree *tree;
char *buffer;
};
[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>
2005-09-16 01:43:17 +04:00
extern int save_commit_buffer;
extern const char *commit_type;
struct commit *lookup_commit(const unsigned char *sha1);
struct commit *lookup_commit_reference(const unsigned char *sha1);
struct commit *lookup_commit_reference_gently(const unsigned char *sha1,
int quiet);
int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size);
int parse_commit(struct commit *item);
struct commit_list * commit_list_insert(struct commit *item, struct commit_list **list_p);
struct commit_list * insert_by_date(struct commit *item, struct commit_list **list);
void free_commit_list(struct commit_list *list);
void sort_by_date(struct commit_list **list);
/* Commit formats */
enum cmit_fmt {
CMIT_FMT_RAW,
CMIT_FMT_MEDIUM,
CMIT_FMT_DEFAULT = CMIT_FMT_MEDIUM,
CMIT_FMT_SHORT,
CMIT_FMT_FULL,
CMIT_FMT_FULLER,
CMIT_FMT_ONELINE,
CMIT_FMT_UNSPECIFIED,
};
extern enum cmit_fmt get_commit_format(const char *arg);
extern unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *, unsigned long len, char *buf, unsigned long space, int abbrev);
/** 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 19:39:40 +04:00
struct commit *pop_commit(struct commit_list **stack);
void clear_commit_marks(struct commit *commit, 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 19:39:40 +04:00
int count_parents(struct commit * commit);
/*
* Performs an in-place topological sort of list supplied.
*
* Pre-conditions for sort_in_topological_order:
* all commits in input list and all parents of those
* commits must have object.util == NULL
*
* Pre-conditions for sort_in_topological_order_fn:
* all commits in input list and all parents of those
* commits must have getter(commit) == NULL
*
* Post-conditions:
* invariant of resulting list is:
* a reachable from b => ord(b) < ord(a)
* in addition, when lifo == 0, commits on parallel tracks are
* sorted in the dates order.
*/
typedef void (*topo_sort_set_fn_t)(struct commit*, void *data);
typedef void* (*topo_sort_get_fn_t)(struct commit*);
void topo_sort_default_setter(struct commit *c, void *data);
void *topo_sort_default_getter(struct commit *c);
void sort_in_topological_order(struct commit_list ** list, int lifo);
void sort_in_topological_order_fn(struct commit_list ** list, int lifo,
topo_sort_set_fn_t setter,
topo_sort_get_fn_t getter);
struct commit_graft {
unsigned char sha1[20];
int nr_parent;
unsigned char parent[FLEX_ARRAY][20]; /* more */
};
struct commit_graft *read_graft_line(char *buf, int len);
int register_commit_graft(struct commit_graft *, int);
int read_graft_file(const char *graft_file);
#endif /* COMMIT_H */