git/builtin/reflog.c
Junio C Hamano d70e331c0e Merge branch 'jk/prune-mtime'
Tighten the logic to decide that an unreachable cruft is
sufficiently old by covering corner cases such as an ancient object
becoming reachable and then going unreachable again, in which case
its retention period should be prolonged.

* jk/prune-mtime: (28 commits)
  drop add_object_array_with_mode
  revision: remove definition of unused 'add_object' function
  pack-objects: double-check options before discarding objects
  repack: pack objects mentioned by the index
  pack-objects: use argv_array
  reachable: use revision machinery's --indexed-objects code
  rev-list: add --indexed-objects option
  rev-list: document --reflog option
  t5516: test pushing a tag of an otherwise unreferenced blob
  traverse_commit_list: support pending blobs/trees with paths
  make add_object_array_with_context interface more sane
  write_sha1_file: freshen existing objects
  pack-objects: match prune logic for discarding objects
  pack-objects: refactor unpack-unreachable expiration check
  prune: keep objects reachable from recent objects
  sha1_file: add for_each iterators for loose and packed objects
  count-objects: use for_each_loose_file_in_objdir
  count-objects: do not use xsize_t when counting object size
  prune-packed: use for_each_loose_file_in_objdir
  reachable: mark index blobs as SEEN
  ...
2014-10-29 10:07:56 -07:00

783 lines
19 KiB
C

#include "builtin.h"
#include "lockfile.h"
#include "commit.h"
#include "refs.h"
#include "dir.h"
#include "tree-walk.h"
#include "diff.h"
#include "revision.h"
#include "reachable.h"
/*
* reflog expire
*/
static const char reflog_expire_usage[] =
"git reflog expire [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
static const char reflog_delete_usage[] =
"git reflog delete [--verbose] [--dry-run] [--rewrite] [--updateref] <refs>...";
static unsigned long default_reflog_expire;
static unsigned long default_reflog_expire_unreachable;
struct cmd_reflog_expire_cb {
struct rev_info revs;
int dry_run;
int stalefix;
int rewrite;
int updateref;
int verbose;
unsigned long expire_total;
unsigned long expire_unreachable;
int recno;
};
struct expire_reflog_cb {
FILE *newlog;
enum {
UE_NORMAL,
UE_ALWAYS,
UE_HEAD
} unreachable_expire_kind;
struct commit_list *mark_list;
unsigned long mark_limit;
struct cmd_reflog_expire_cb *cmd;
unsigned char last_kept_sha1[20];
};
struct collected_reflog {
unsigned char sha1[20];
char reflog[FLEX_ARRAY];
};
struct collect_reflog_cb {
struct collected_reflog **e;
int alloc;
int nr;
};
#define INCOMPLETE (1u<<10)
#define STUDYING (1u<<11)
#define REACHABLE (1u<<12)
static int tree_is_complete(const unsigned char *sha1)
{
struct tree_desc desc;
struct name_entry entry;
int complete;
struct tree *tree;
tree = lookup_tree(sha1);
if (!tree)
return 0;
if (tree->object.flags & SEEN)
return 1;
if (tree->object.flags & INCOMPLETE)
return 0;
if (!tree->buffer) {
enum object_type type;
unsigned long size;
void *data = read_sha1_file(sha1, &type, &size);
if (!data) {
tree->object.flags |= INCOMPLETE;
return 0;
}
tree->buffer = data;
tree->size = size;
}
init_tree_desc(&desc, tree->buffer, tree->size);
complete = 1;
while (tree_entry(&desc, &entry)) {
if (!has_sha1_file(entry.sha1) ||
(S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
tree->object.flags |= INCOMPLETE;
complete = 0;
}
}
free_tree_buffer(tree);
if (complete)
tree->object.flags |= SEEN;
return complete;
}
static int commit_is_complete(struct commit *commit)
{
struct object_array study;
struct object_array found;
int is_incomplete = 0;
int i;
/* early return */
if (commit->object.flags & SEEN)
return 1;
if (commit->object.flags & INCOMPLETE)
return 0;
/*
* Find all commits that are reachable and are not marked as
* SEEN. Then make sure the trees and blobs contained are
* complete. After that, mark these commits also as SEEN.
* If some of the objects that are needed to complete this
* commit are missing, mark this commit as INCOMPLETE.
*/
memset(&study, 0, sizeof(study));
memset(&found, 0, sizeof(found));
add_object_array(&commit->object, NULL, &study);
add_object_array(&commit->object, NULL, &found);
commit->object.flags |= STUDYING;
while (study.nr) {
struct commit *c;
struct commit_list *parent;
c = (struct commit *)study.objects[--study.nr].item;
if (!c->object.parsed && !parse_object(c->object.sha1))
c->object.flags |= INCOMPLETE;
if (c->object.flags & INCOMPLETE) {
is_incomplete = 1;
break;
}
else if (c->object.flags & SEEN)
continue;
for (parent = c->parents; parent; parent = parent->next) {
struct commit *p = parent->item;
if (p->object.flags & STUDYING)
continue;
p->object.flags |= STUDYING;
add_object_array(&p->object, NULL, &study);
add_object_array(&p->object, NULL, &found);
}
}
if (!is_incomplete) {
/*
* make sure all commits in "found" array have all the
* necessary objects.
*/
for (i = 0; i < found.nr; i++) {
struct commit *c =
(struct commit *)found.objects[i].item;
if (!tree_is_complete(c->tree->object.sha1)) {
is_incomplete = 1;
c->object.flags |= INCOMPLETE;
}
}
if (!is_incomplete) {
/* mark all found commits as complete, iow SEEN */
for (i = 0; i < found.nr; i++)
found.objects[i].item->flags |= SEEN;
}
}
/* clear flags from the objects we traversed */
for (i = 0; i < found.nr; i++)
found.objects[i].item->flags &= ~STUDYING;
if (is_incomplete)
commit->object.flags |= INCOMPLETE;
else {
/*
* If we come here, we have (1) traversed the ancestry chain
* from the "commit" until we reach SEEN commits (which are
* known to be complete), and (2) made sure that the commits
* encountered during the above traversal refer to trees that
* are complete. Which means that we know *all* the commits
* we have seen during this process are complete.
*/
for (i = 0; i < found.nr; i++)
found.objects[i].item->flags |= SEEN;
}
/* free object arrays */
free(study.objects);
free(found.objects);
return !is_incomplete;
}
static int keep_entry(struct commit **it, unsigned char *sha1)
{
struct commit *commit;
if (is_null_sha1(sha1))
return 1;
commit = lookup_commit_reference_gently(sha1, 1);
if (!commit)
return 0;
/*
* Make sure everything in this commit exists.
*
* We have walked all the objects reachable from the refs
* and cache earlier. The commits reachable by this commit
* must meet SEEN commits -- and then we should mark them as
* SEEN as well.
*/
if (!commit_is_complete(commit))
return 0;
*it = commit;
return 1;
}
/*
* Starting from commits in the cb->mark_list, mark commits that are
* reachable from them. Stop the traversal at commits older than
* the expire_limit and queue them back, so that the caller can call
* us again to restart the traversal with longer expire_limit.
*/
static void mark_reachable(struct expire_reflog_cb *cb)
{
struct commit *commit;
struct commit_list *pending;
unsigned long expire_limit = cb->mark_limit;
struct commit_list *leftover = NULL;
for (pending = cb->mark_list; pending; pending = pending->next)
pending->item->object.flags &= ~REACHABLE;
pending = cb->mark_list;
while (pending) {
struct commit_list *entry = pending;
struct commit_list *parent;
pending = entry->next;
commit = entry->item;
free(entry);
if (commit->object.flags & REACHABLE)
continue;
if (parse_commit(commit))
continue;
commit->object.flags |= REACHABLE;
if (commit->date < expire_limit) {
commit_list_insert(commit, &leftover);
continue;
}
commit->object.flags |= REACHABLE;
parent = commit->parents;
while (parent) {
commit = parent->item;
parent = parent->next;
if (commit->object.flags & REACHABLE)
continue;
commit_list_insert(commit, &pending);
}
}
cb->mark_list = leftover;
}
static int unreachable(struct expire_reflog_cb *cb, struct commit *commit, unsigned char *sha1)
{
/*
* We may or may not have the commit yet - if not, look it
* up using the supplied sha1.
*/
if (!commit) {
if (is_null_sha1(sha1))
return 0;
commit = lookup_commit_reference_gently(sha1, 1);
/* Not a commit -- keep it */
if (!commit)
return 0;
}
/* Reachable from the current ref? Don't prune. */
if (commit->object.flags & REACHABLE)
return 0;
if (cb->mark_list && cb->mark_limit) {
cb->mark_limit = 0; /* dig down to the root */
mark_reachable(cb);
}
return !(commit->object.flags & REACHABLE);
}
static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct expire_reflog_cb *cb = cb_data;
struct commit *old, *new;
if (timestamp < cb->cmd->expire_total)
goto prune;
if (cb->cmd->rewrite)
osha1 = cb->last_kept_sha1;
old = new = NULL;
if (cb->cmd->stalefix &&
(!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
goto prune;
if (timestamp < cb->cmd->expire_unreachable) {
if (cb->unreachable_expire_kind == UE_ALWAYS)
goto prune;
if (unreachable(cb, old, osha1) || unreachable(cb, new, nsha1))
goto prune;
}
if (cb->cmd->recno && --(cb->cmd->recno) == 0)
goto prune;
if (cb->newlog) {
char sign = (tz < 0) ? '-' : '+';
int zone = (tz < 0) ? (-tz) : tz;
fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
sha1_to_hex(osha1), sha1_to_hex(nsha1),
email, timestamp, sign, zone,
message);
hashcpy(cb->last_kept_sha1, nsha1);
}
if (cb->cmd->verbose)
printf("keep %s", message);
return 0;
prune:
if (!cb->newlog)
printf("would prune %s", message);
else if (cb->cmd->verbose)
printf("prune %s", message);
return 0;
}
static int push_tip_to_list(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
{
struct commit_list **list = cb_data;
struct commit *tip_commit;
if (flags & REF_ISSYMREF)
return 0;
tip_commit = lookup_commit_reference_gently(sha1, 1);
if (!tip_commit)
return 0;
commit_list_insert(tip_commit, list);
return 0;
}
static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
{
struct cmd_reflog_expire_cb *cmd = cb_data;
struct expire_reflog_cb cb;
struct ref_lock *lock;
char *log_file, *newlog_path = NULL;
struct commit *tip_commit;
struct commit_list *tips;
int status = 0;
memset(&cb, 0, sizeof(cb));
/*
* we take the lock for the ref itself to prevent it from
* getting updated.
*/
lock = lock_any_ref_for_update(ref, sha1, 0, NULL);
if (!lock)
return error("cannot lock ref '%s'", ref);
log_file = git_pathdup("logs/%s", ref);
if (!reflog_exists(ref))
goto finish;
if (!cmd->dry_run) {
newlog_path = git_pathdup("logs/%s.lock", ref);
cb.newlog = fopen(newlog_path, "w");
}
cb.cmd = cmd;
if (!cmd->expire_unreachable || !strcmp(ref, "HEAD")) {
tip_commit = NULL;
cb.unreachable_expire_kind = UE_HEAD;
} else {
tip_commit = lookup_commit_reference_gently(sha1, 1);
if (!tip_commit)
cb.unreachable_expire_kind = UE_ALWAYS;
else
cb.unreachable_expire_kind = UE_NORMAL;
}
if (cmd->expire_unreachable <= cmd->expire_total)
cb.unreachable_expire_kind = UE_ALWAYS;
cb.mark_list = NULL;
tips = NULL;
if (cb.unreachable_expire_kind != UE_ALWAYS) {
if (cb.unreachable_expire_kind == UE_HEAD) {
struct commit_list *elem;
for_each_ref(push_tip_to_list, &tips);
for (elem = tips; elem; elem = elem->next)
commit_list_insert(elem->item, &cb.mark_list);
} else {
commit_list_insert(tip_commit, &cb.mark_list);
}
cb.mark_limit = cmd->expire_total;
mark_reachable(&cb);
}
for_each_reflog_ent(ref, expire_reflog_ent, &cb);
if (cb.unreachable_expire_kind != UE_ALWAYS) {
if (cb.unreachable_expire_kind == UE_HEAD) {
struct commit_list *elem;
for (elem = tips; elem; elem = elem->next)
clear_commit_marks(elem->item, REACHABLE);
free_commit_list(tips);
} else {
clear_commit_marks(tip_commit, REACHABLE);
}
}
finish:
if (cb.newlog) {
if (fclose(cb.newlog)) {
status |= error("%s: %s", strerror(errno),
newlog_path);
unlink(newlog_path);
} else if (cmd->updateref &&
(write_in_full(lock->lock_fd,
sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
write_str_in_full(lock->lock_fd, "\n") != 1 ||
close_ref(lock) < 0)) {
status |= error("Couldn't write %s",
lock->lk->filename.buf);
unlink(newlog_path);
} else if (rename(newlog_path, log_file)) {
status |= error("cannot rename %s to %s",
newlog_path, log_file);
unlink(newlog_path);
} else if (cmd->updateref && commit_ref(lock)) {
status |= error("Couldn't set %s", lock->ref_name);
} else {
adjust_shared_perm(log_file);
}
}
free(newlog_path);
free(log_file);
unlock_ref(lock);
return status;
}
static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
{
struct collected_reflog *e;
struct collect_reflog_cb *cb = cb_data;
size_t namelen = strlen(ref);
e = xmalloc(sizeof(*e) + namelen + 1);
hashcpy(e->sha1, sha1);
memcpy(e->reflog, ref, namelen + 1);
ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
cb->e[cb->nr++] = e;
return 0;
}
static struct reflog_expire_cfg {
struct reflog_expire_cfg *next;
unsigned long expire_total;
unsigned long expire_unreachable;
size_t len;
char pattern[FLEX_ARRAY];
} *reflog_expire_cfg, **reflog_expire_cfg_tail;
static struct reflog_expire_cfg *find_cfg_ent(const char *pattern, size_t len)
{
struct reflog_expire_cfg *ent;
if (!reflog_expire_cfg_tail)
reflog_expire_cfg_tail = &reflog_expire_cfg;
for (ent = reflog_expire_cfg; ent; ent = ent->next)
if (ent->len == len &&
!memcmp(ent->pattern, pattern, len))
return ent;
ent = xcalloc(1, (sizeof(*ent) + len));
memcpy(ent->pattern, pattern, len);
ent->len = len;
*reflog_expire_cfg_tail = ent;
reflog_expire_cfg_tail = &(ent->next);
return ent;
}
static int parse_expire_cfg_value(const char *var, const char *value, unsigned long *expire)
{
if (!value)
return config_error_nonbool(var);
if (parse_expiry_date(value, expire))
return error(_("%s' for '%s' is not a valid timestamp"),
value, var);
return 0;
}
/* expiry timer slot */
#define EXPIRE_TOTAL 01
#define EXPIRE_UNREACH 02
static int reflog_expire_config(const char *var, const char *value, void *cb)
{
const char *pattern, *key;
int pattern_len;
unsigned long expire;
int slot;
struct reflog_expire_cfg *ent;
if (parse_config_key(var, "gc", &pattern, &pattern_len, &key) < 0)
return git_default_config(var, value, cb);
if (!strcmp(key, "reflogexpire")) {
slot = EXPIRE_TOTAL;
if (parse_expire_cfg_value(var, value, &expire))
return -1;
} else if (!strcmp(key, "reflogexpireunreachable")) {
slot = EXPIRE_UNREACH;
if (parse_expire_cfg_value(var, value, &expire))
return -1;
} else
return git_default_config(var, value, cb);
if (!pattern) {
switch (slot) {
case EXPIRE_TOTAL:
default_reflog_expire = expire;
break;
case EXPIRE_UNREACH:
default_reflog_expire_unreachable = expire;
break;
}
return 0;
}
ent = find_cfg_ent(pattern, pattern_len);
if (!ent)
return -1;
switch (slot) {
case EXPIRE_TOTAL:
ent->expire_total = expire;
break;
case EXPIRE_UNREACH:
ent->expire_unreachable = expire;
break;
}
return 0;
}
static void set_reflog_expiry_param(struct cmd_reflog_expire_cb *cb, int slot, const char *ref)
{
struct reflog_expire_cfg *ent;
if (slot == (EXPIRE_TOTAL|EXPIRE_UNREACH))
return; /* both given explicitly -- nothing to tweak */
for (ent = reflog_expire_cfg; ent; ent = ent->next) {
if (!wildmatch(ent->pattern, ref, 0, NULL)) {
if (!(slot & EXPIRE_TOTAL))
cb->expire_total = ent->expire_total;
if (!(slot & EXPIRE_UNREACH))
cb->expire_unreachable = ent->expire_unreachable;
return;
}
}
/*
* If unconfigured, make stash never expire
*/
if (!strcmp(ref, "refs/stash")) {
if (!(slot & EXPIRE_TOTAL))
cb->expire_total = 0;
if (!(slot & EXPIRE_UNREACH))
cb->expire_unreachable = 0;
return;
}
/* Nothing matched -- use the default value */
if (!(slot & EXPIRE_TOTAL))
cb->expire_total = default_reflog_expire;
if (!(slot & EXPIRE_UNREACH))
cb->expire_unreachable = default_reflog_expire_unreachable;
}
static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
{
struct cmd_reflog_expire_cb cb;
unsigned long now = time(NULL);
int i, status, do_all;
int explicit_expiry = 0;
default_reflog_expire_unreachable = now - 30 * 24 * 3600;
default_reflog_expire = now - 90 * 24 * 3600;
git_config(reflog_expire_config, NULL);
save_commit_buffer = 0;
do_all = status = 0;
memset(&cb, 0, sizeof(cb));
cb.expire_total = default_reflog_expire;
cb.expire_unreachable = default_reflog_expire_unreachable;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
cb.dry_run = 1;
else if (starts_with(arg, "--expire=")) {
if (parse_expiry_date(arg + 9, &cb.expire_total))
die(_("'%s' is not a valid timestamp"), arg);
explicit_expiry |= EXPIRE_TOTAL;
}
else if (starts_with(arg, "--expire-unreachable=")) {
if (parse_expiry_date(arg + 21, &cb.expire_unreachable))
die(_("'%s' is not a valid timestamp"), arg);
explicit_expiry |= EXPIRE_UNREACH;
}
else if (!strcmp(arg, "--stale-fix"))
cb.stalefix = 1;
else if (!strcmp(arg, "--rewrite"))
cb.rewrite = 1;
else if (!strcmp(arg, "--updateref"))
cb.updateref = 1;
else if (!strcmp(arg, "--all"))
do_all = 1;
else if (!strcmp(arg, "--verbose"))
cb.verbose = 1;
else if (!strcmp(arg, "--")) {
i++;
break;
}
else if (arg[0] == '-')
usage(reflog_expire_usage);
else
break;
}
/*
* We can trust the commits and objects reachable from refs
* even in older repository. We cannot trust what's reachable
* from reflog if the repository was pruned with older git.
*/
if (cb.stalefix) {
init_revisions(&cb.revs, prefix);
if (cb.verbose)
printf("Marking reachable objects...");
mark_reachable_objects(&cb.revs, 0, 0, NULL);
if (cb.verbose)
putchar('\n');
}
if (do_all) {
struct collect_reflog_cb collected;
int i;
memset(&collected, 0, sizeof(collected));
for_each_reflog(collect_reflog, &collected);
for (i = 0; i < collected.nr; i++) {
struct collected_reflog *e = collected.e[i];
set_reflog_expiry_param(&cb, explicit_expiry, e->reflog);
status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
free(e);
}
free(collected.e);
}
for (; i < argc; i++) {
char *ref;
unsigned char sha1[20];
if (!dwim_log(argv[i], strlen(argv[i]), sha1, &ref)) {
status |= error("%s points nowhere!", argv[i]);
continue;
}
set_reflog_expiry_param(&cb, explicit_expiry, ref);
status |= expire_reflog(ref, sha1, 0, &cb);
}
return status;
}
static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
const char *email, unsigned long timestamp, int tz,
const char *message, void *cb_data)
{
struct cmd_reflog_expire_cb *cb = cb_data;
if (!cb->expire_total || timestamp < cb->expire_total)
cb->recno++;
return 0;
}
static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
{
struct cmd_reflog_expire_cb cb;
int i, status = 0;
memset(&cb, 0, sizeof(cb));
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
cb.dry_run = 1;
else if (!strcmp(arg, "--rewrite"))
cb.rewrite = 1;
else if (!strcmp(arg, "--updateref"))
cb.updateref = 1;
else if (!strcmp(arg, "--verbose"))
cb.verbose = 1;
else if (!strcmp(arg, "--")) {
i++;
break;
}
else if (arg[0] == '-')
usage(reflog_delete_usage);
else
break;
}
if (argc - i < 1)
return error("Nothing to delete?");
for ( ; i < argc; i++) {
const char *spec = strstr(argv[i], "@{");
unsigned char sha1[20];
char *ep, *ref;
int recno;
if (!spec) {
status |= error("Not a reflog: %s", argv[i]);
continue;
}
if (!dwim_log(argv[i], spec - argv[i], sha1, &ref)) {
status |= error("no reflog for '%s'", argv[i]);
continue;
}
recno = strtoul(spec + 2, &ep, 10);
if (*ep == '}') {
cb.recno = -recno;
for_each_reflog_ent(ref, count_reflog_ent, &cb);
} else {
cb.expire_total = approxidate(spec + 2);
for_each_reflog_ent(ref, count_reflog_ent, &cb);
cb.expire_total = 0;
}
status |= expire_reflog(ref, sha1, 0, &cb);
free(ref);
}
return status;
}
/*
* main "reflog"
*/
static const char reflog_usage[] =
"git reflog [ show | expire | delete ]";
int cmd_reflog(int argc, const char **argv, const char *prefix)
{
if (argc > 1 && !strcmp(argv[1], "-h"))
usage(reflog_usage);
/* With no command, we default to showing it. */
if (argc < 2 || *argv[1] == '-')
return cmd_log_reflog(argc, argv, prefix);
if (!strcmp(argv[1], "show"))
return cmd_log_reflog(argc - 1, argv + 1, prefix);
if (!strcmp(argv[1], "expire"))
return cmd_reflog_expire(argc - 1, argv + 1, prefix);
if (!strcmp(argv[1], "delete"))
return cmd_reflog_delete(argc - 1, argv + 1, prefix);
return cmd_log_reflog(argc, argv, prefix);
}