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-rw-r--r--reflog.c434
1 files changed, 434 insertions, 0 deletions
diff --git a/reflog.c b/reflog.c
new file mode 100644
index 0000000000..135a1a6e41
--- /dev/null
+++ b/reflog.c
@@ -0,0 +1,434 @@
+#include "cache.h"
+#include "object-store.h"
+#include "reflog.h"
+#include "refs.h"
+#include "revision.h"
+#include "worktree.h"
+
+/* Remember to update object flag allocation in object.h */
+#define INCOMPLETE (1u<<10)
+#define STUDYING (1u<<11)
+#define REACHABLE (1u<<12)
+
+static int tree_is_complete(const struct object_id *oid)
+{
+ struct tree_desc desc;
+ struct name_entry entry;
+ int complete;
+ struct tree *tree;
+
+ tree = lookup_tree(the_repository, oid);
+ 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_object_file(oid, &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_object_file(&entry.oid) ||
+ (S_ISDIR(entry.mode) && !tree_is_complete(&entry.oid))) {
+ 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 *)object_array_pop(&study);
+ if (!c->object.parsed && !parse_object(the_repository, &c->object.oid))
+ 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(get_commit_tree_oid(c))) {
+ 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 */
+ object_array_clear(&study);
+ object_array_clear(&found);
+ return !is_incomplete;
+}
+
+static int keep_entry(struct commit **it, struct object_id *oid)
+{
+ struct commit *commit;
+
+ if (is_null_oid(oid))
+ return 1;
+ commit = lookup_commit_reference_gently(the_repository, oid, 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_policy_cb *cb)
+{
+ struct commit_list *pending;
+ timestamp_t 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 *parent;
+ struct commit *commit = pop_commit(&pending);
+ 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_policy_cb *cb, struct commit *commit, struct object_id *oid)
+{
+ /*
+ * We may or may not have the commit yet - if not, look it
+ * up using the supplied sha1.
+ */
+ if (!commit) {
+ if (is_null_oid(oid))
+ return 0;
+
+ commit = lookup_commit_reference_gently(the_repository, oid,
+ 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);
+}
+
+/*
+ * Return true iff the specified reflog entry should be expired.
+ */
+int should_expire_reflog_ent(struct object_id *ooid, struct object_id *noid,
+ const char *email, timestamp_t timestamp, int tz,
+ const char *message, void *cb_data)
+{
+ struct expire_reflog_policy_cb *cb = cb_data;
+ struct commit *old_commit, *new_commit;
+
+ if (timestamp < cb->cmd.expire_total)
+ return 1;
+
+ old_commit = new_commit = NULL;
+ if (cb->cmd.stalefix &&
+ (!keep_entry(&old_commit, ooid) || !keep_entry(&new_commit, noid)))
+ return 1;
+
+ if (timestamp < cb->cmd.expire_unreachable) {
+ switch (cb->unreachable_expire_kind) {
+ case UE_ALWAYS:
+ return 1;
+ case UE_NORMAL:
+ case UE_HEAD:
+ if (unreachable(cb, old_commit, ooid) || unreachable(cb, new_commit, noid))
+ return 1;
+ break;
+ }
+ }
+
+ if (cb->cmd.recno && --(cb->cmd.recno) == 0)
+ return 1;
+
+ return 0;
+}
+
+int should_expire_reflog_ent_verbose(struct object_id *ooid,
+ struct object_id *noid,
+ const char *email,
+ timestamp_t timestamp, int tz,
+ const char *message, void *cb_data)
+{
+ struct expire_reflog_policy_cb *cb = cb_data;
+ int expire;
+
+ expire = should_expire_reflog_ent(ooid, noid, email, timestamp, tz,
+ message, cb);
+
+ if (!expire)
+ printf("keep %s", message);
+ else if (cb->dry_run)
+ printf("would prune %s", message);
+ else
+ printf("prune %s", message);
+
+ return expire;
+}
+
+static int push_tip_to_list(const char *refname, const struct object_id *oid,
+ 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(the_repository, oid, 1);
+ if (!tip_commit)
+ return 0;
+ commit_list_insert(tip_commit, list);
+ return 0;
+}
+
+static int is_head(const char *refname)
+{
+ switch (ref_type(refname)) {
+ case REF_TYPE_OTHER_PSEUDOREF:
+ case REF_TYPE_MAIN_PSEUDOREF:
+ if (parse_worktree_ref(refname, NULL, NULL, &refname))
+ BUG("not a worktree ref: %s", refname);
+ break;
+ default:
+ break;
+ }
+ return !strcmp(refname, "HEAD");
+}
+
+void reflog_expiry_prepare(const char *refname,
+ const struct object_id *oid,
+ void *cb_data)
+{
+ struct expire_reflog_policy_cb *cb = cb_data;
+ struct commit_list *elem;
+ struct commit *commit = NULL;
+
+ if (!cb->cmd.expire_unreachable || is_head(refname)) {
+ cb->unreachable_expire_kind = UE_HEAD;
+ } else {
+ commit = lookup_commit(the_repository, oid);
+ if (commit && is_null_oid(&commit->object.oid))
+ commit = NULL;
+ cb->unreachable_expire_kind = commit ? UE_NORMAL : UE_ALWAYS;
+ }
+
+ if (cb->cmd.expire_unreachable <= cb->cmd.expire_total)
+ cb->unreachable_expire_kind = UE_ALWAYS;
+
+ switch (cb->unreachable_expire_kind) {
+ case UE_ALWAYS:
+ return;
+ case UE_HEAD:
+ for_each_ref(push_tip_to_list, &cb->tips);
+ for (elem = cb->tips; elem; elem = elem->next)
+ commit_list_insert(elem->item, &cb->mark_list);
+ break;
+ case UE_NORMAL:
+ commit_list_insert(commit, &cb->mark_list);
+ /* For reflog_expiry_cleanup() below */
+ cb->tip_commit = commit;
+ }
+ cb->mark_limit = cb->cmd.expire_total;
+ mark_reachable(cb);
+}
+
+void reflog_expiry_cleanup(void *cb_data)
+{
+ struct expire_reflog_policy_cb *cb = cb_data;
+ struct commit_list *elem;
+
+ switch (cb->unreachable_expire_kind) {
+ case UE_ALWAYS:
+ return;
+ case UE_HEAD:
+ for (elem = cb->tips; elem; elem = elem->next)
+ clear_commit_marks(elem->item, REACHABLE);
+ free_commit_list(cb->tips);
+ break;
+ case UE_NORMAL:
+ clear_commit_marks(cb->tip_commit, REACHABLE);
+ break;
+ }
+}
+
+int count_reflog_ent(struct object_id *ooid, struct object_id *noid,
+ const char *email, timestamp_t 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;
+}
+
+int reflog_delete(const char *rev, enum expire_reflog_flags flags, int verbose)
+{
+ struct cmd_reflog_expire_cb cmd = { 0 };
+ int status = 0;
+ reflog_expiry_should_prune_fn *should_prune_fn = should_expire_reflog_ent;
+ const char *spec = strstr(rev, "@{");
+ char *ep, *ref;
+ int recno;
+ struct expire_reflog_policy_cb cb = {
+ .dry_run = !!(flags & EXPIRE_REFLOGS_DRY_RUN),
+ };
+
+ if (verbose)
+ should_prune_fn = should_expire_reflog_ent_verbose;
+
+ if (!spec)
+ return error(_("not a reflog: %s"), rev);
+
+ if (!dwim_log(rev, spec - rev, NULL, &ref)) {
+ status |= error(_("no reflog for '%s'"), rev);
+ goto cleanup;
+ }
+
+ recno = strtoul(spec + 2, &ep, 10);
+ if (*ep == '}') {
+ cmd.recno = -recno;
+ for_each_reflog_ent(ref, count_reflog_ent, &cmd);
+ } else {
+ cmd.expire_total = approxidate(spec + 2);
+ for_each_reflog_ent(ref, count_reflog_ent, &cmd);
+ cmd.expire_total = 0;
+ }
+
+ cb.cmd = cmd;
+ status |= reflog_expire(ref, flags,
+ reflog_expiry_prepare,
+ should_prune_fn,
+ reflog_expiry_cleanup,
+ &cb);
+
+ cleanup:
+ free(ref);
+ return status;
+}