git/builtin-gc.c

245 строки
5.7 KiB
C
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/*
* git gc builtin command
*
* Cleanup unreachable files and optimize the repository.
*
* Copyright (c) 2007 James Bowes
*
* Based on git-gc.sh, which is
*
* Copyright (c) 2006 Shawn O. Pearce
*/
#include "builtin.h"
#include "cache.h"
#include "parse-options.h"
#include "run-command.h"
#define FAILED_RUN "failed to run %s"
static const char * const builtin_gc_usage[] = {
"git-gc [options]",
NULL
};
static int pack_refs = 1;
static int aggressive_window = -1;
static int gc_auto_threshold = 6700;
static int gc_auto_pack_limit = 20;
#define MAX_ADD 10
static const char *argv_pack_refs[] = {"pack-refs", "--all", "--prune", NULL};
static const char *argv_reflog[] = {"reflog", "expire", "--all", NULL};
static const char *argv_repack[MAX_ADD] = {"repack", "-d", "-l", NULL};
static const char *argv_prune[] = {"prune", NULL};
static const char *argv_rerere[] = {"rerere", "gc", NULL};
static int gc_config(const char *var, const char *value)
{
if (!strcmp(var, "gc.packrefs")) {
if (!strcmp(value, "notbare"))
pack_refs = -1;
else
pack_refs = git_config_bool(var, value);
return 0;
}
if (!strcmp(var, "gc.aggressivewindow")) {
aggressive_window = git_config_int(var, value);
return 0;
}
if (!strcmp(var, "gc.auto")) {
gc_auto_threshold = git_config_int(var, value);
return 0;
}
if (!strcmp(var, "gc.autopacklimit")) {
gc_auto_pack_limit = git_config_int(var, value);
return 0;
}
return git_default_config(var, value);
}
static void append_option(const char **cmd, const char *opt, int max_length)
{
int i;
for (i = 0; cmd[i]; i++)
;
if (i + 2 >= max_length)
die("Too many options specified");
cmd[i++] = opt;
cmd[i] = NULL;
}
static int too_many_loose_objects(void)
{
/*
* Quickly check if a "gc" is needed, by estimating how
* many loose objects there are. Because SHA-1 is evenly
* distributed, we can check only one and get a reasonable
* estimate.
*/
char path[PATH_MAX];
const char *objdir = get_object_directory();
DIR *dir;
struct dirent *ent;
int auto_threshold;
int num_loose = 0;
int needed = 0;
if (gc_auto_threshold <= 0)
return 0;
if (sizeof(path) <= snprintf(path, sizeof(path), "%s/17", objdir)) {
warning("insanely long object directory %.*s", 50, objdir);
return 0;
}
dir = opendir(path);
if (!dir)
return 0;
auto_threshold = (gc_auto_threshold + 255) / 256;
while ((ent = readdir(dir)) != NULL) {
if (strspn(ent->d_name, "0123456789abcdef") != 38 ||
ent->d_name[38] != '\0')
continue;
if (++num_loose > auto_threshold) {
needed = 1;
break;
}
}
closedir(dir);
return needed;
}
static int too_many_packs(void)
{
struct packed_git *p;
int cnt;
if (gc_auto_pack_limit <= 0)
return 0;
prepare_packed_git();
for (cnt = 0, p = packed_git; p; p = p->next) {
char path[PATH_MAX];
size_t len;
int keep;
if (!p->pack_local)
continue;
len = strlen(p->pack_name);
if (PATH_MAX <= len + 1)
continue; /* oops, give up */
memcpy(path, p->pack_name, len-5);
memcpy(path + len - 5, ".keep", 6);
keep = access(p->pack_name, F_OK) && (errno == ENOENT);
if (keep)
continue;
/*
* Perhaps check the size of the pack and count only
* very small ones here?
*/
cnt++;
}
return gc_auto_pack_limit <= cnt;
}
static int need_to_gc(void)
{
/*
* Setting gc.auto and gc.autopacklimit to 0 or negative can
* disable the automatic gc.
*/
if (gc_auto_threshold <= 0 && gc_auto_pack_limit <= 0)
return 0;
/*
* If there are too many loose objects, but not too many
* packs, we run "repack -d -l". If there are too many packs,
* we run "repack -A -d -l". Otherwise we tell the caller
* there is no need.
*/
if (too_many_packs())
append_option(argv_repack, "-A", MAX_ADD);
else if (!too_many_loose_objects())
return 0;
return 1;
}
int cmd_gc(int argc, const char **argv, const char *prefix)
{
int prune = 0;
int aggressive = 0;
int auto_gc = 0;
char buf[80];
struct option builtin_gc_options[] = {
OPT_BOOLEAN(0, "prune", &prune, "prune unreferenced objects"),
OPT_BOOLEAN(0, "aggressive", &aggressive, "be more thorough (increased runtime)"),
OPT_BOOLEAN(0, "auto", &auto_gc, "enable auto-gc mode"),
OPT_END()
};
git_config(gc_config);
if (pack_refs < 0)
pack_refs = !is_bare_repository();
argc = parse_options(argc, argv, builtin_gc_options, builtin_gc_usage, 0);
if (argc > 0)
usage_with_options(builtin_gc_usage, builtin_gc_options);
if (aggressive) {
append_option(argv_repack, "-f", MAX_ADD);
if (aggressive_window > 0) {
sprintf(buf, "--window=%d", aggressive_window);
append_option(argv_repack, buf, MAX_ADD);
}
}
if (auto_gc) {
/*
* Auto-gc should be least intrusive as possible.
*/
prune = 0;
if (!need_to_gc())
return 0;
fprintf(stderr, "Packing your repository for optimum "
"performance. You may also\n"
"run \"git gc\" manually. See "
"\"git help gc\" for more information.\n");
} else {
/*
* Use safer (for shared repos) "-A" option to
* repack when not pruning. Auto-gc makes its
* own decision.
*/
if (prune)
append_option(argv_repack, "-a", MAX_ADD);
else
append_option(argv_repack, "-A", MAX_ADD);
}
if (pack_refs && run_command_v_opt(argv_pack_refs, RUN_GIT_CMD))
return error(FAILED_RUN, argv_pack_refs[0]);
if (run_command_v_opt(argv_reflog, RUN_GIT_CMD))
return error(FAILED_RUN, argv_reflog[0]);
if (run_command_v_opt(argv_repack, RUN_GIT_CMD))
return error(FAILED_RUN, argv_repack[0]);
if (prune && run_command_v_opt(argv_prune, RUN_GIT_CMD))
return error(FAILED_RUN, argv_prune[0]);
if (run_command_v_opt(argv_rerere, RUN_GIT_CMD))
return error(FAILED_RUN, argv_rerere[0]);
if (auto_gc && too_many_loose_objects())
warning("There are too many unreachable loose objects; "
"run 'git prune' to remove them.");
return 0;
}