1 files changed, 348 insertions, 0 deletions

diff --git a/reflog-walk.c b/reflog-walk.c
new file mode 100644
index 000000000000..3a25b27d8f8d
--- /dev/null
+++ b/reflog-walk.c
@@ -0,0 +1,348 @@
+#include "cache.h"
+#include "commit.h"
+#include "refs.h"
+#include "diff.h"
+#include "revision.h"
+#include "string-list.h"
+#include "reflog-walk.h"
+
+struct complete_reflogs {
+	char *ref;
+	const char *short_ref;
+	struct reflog_info {
+		struct object_id ooid, noid;
+		char *email;
+		timestamp_t timestamp;
+		int tz;
+		char *message;
+	} *items;
+	int nr, alloc;
+};
+
+static int read_one_reflog(struct object_id *ooid, struct object_id *noid,
+		const char *email, timestamp_t timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct complete_reflogs *array = cb_data;
+	struct reflog_info *item;
+
+	ALLOC_GROW(array->items, array->nr + 1, array->alloc);
+	item = array->items + array->nr;
+	oidcpy(&item->ooid, ooid);
+	oidcpy(&item->noid, noid);
+	item->email = xstrdup(email);
+	item->timestamp = timestamp;
+	item->tz = tz;
+	item->message = xstrdup(message);
+	array->nr++;
+	return 0;
+}
+
+static void free_complete_reflog(struct complete_reflogs *array)
+{
+	int i;
+
+	if (!array)
+		return;
+
+	for (i = 0; i < array->nr; i++) {
+		free(array->items[i].email);
+		free(array->items[i].message);
+	}
+	free(array->items);
+	free(array->ref);
+	free(array);
+}
+
+static struct complete_reflogs *read_complete_reflog(const char *ref)
+{
+	struct complete_reflogs *reflogs =
+		xcalloc(1, sizeof(struct complete_reflogs));
+	reflogs->ref = xstrdup(ref);
+	for_each_reflog_ent(ref, read_one_reflog, reflogs);
+	if (reflogs->nr == 0) {
+		const char *name;
+		void *name_to_free;
+		name = name_to_free = resolve_refdup(ref, RESOLVE_REF_READING,
+						     NULL, NULL);
+		if (name) {
+			for_each_reflog_ent(name, read_one_reflog, reflogs);
+			free(name_to_free);
+		}
+	}
+	if (reflogs->nr == 0) {
+		char *refname = xstrfmt("refs/%s", ref);
+		for_each_reflog_ent(refname, read_one_reflog, reflogs);
+		if (reflogs->nr == 0) {
+			free(refname);
+			refname = xstrfmt("refs/heads/%s", ref);
+			for_each_reflog_ent(refname, read_one_reflog, reflogs);
+		}
+		free(refname);
+	}
+	return reflogs;
+}
+
+static int get_reflog_recno_by_time(struct complete_reflogs *array,
+	timestamp_t timestamp)
+{
+	int i;
+	for (i = array->nr - 1; i >= 0; i--)
+		if (timestamp >= array->items[i].timestamp)
+			return i;
+	return -1;
+}
+
+struct commit_reflog {
+	int recno;
+	enum selector_type {
+		SELECTOR_NONE,
+		SELECTOR_INDEX,
+		SELECTOR_DATE
+	} selector;
+	struct complete_reflogs *reflogs;
+};
+
+struct reflog_walk_info {
+	struct commit_reflog **logs;
+	size_t nr, alloc;
+	struct string_list complete_reflogs;
+	struct commit_reflog *last_commit_reflog;
+};
+
+void init_reflog_walk(struct reflog_walk_info **info)
+{
+	*info = xcalloc(1, sizeof(struct reflog_walk_info));
+	(*info)->complete_reflogs.strdup_strings = 1;
+}
+
+int add_reflog_for_walk(struct reflog_walk_info *info,
+		struct commit *commit, const char *name)
+{
+	timestamp_t timestamp = 0;
+	int recno = -1;
+	struct string_list_item *item;
+	struct complete_reflogs *reflogs;
+	char *branch, *at = strchr(name, '@');
+	struct commit_reflog *commit_reflog;
+	enum selector_type selector = SELECTOR_NONE;
+
+	if (commit->object.flags & UNINTERESTING)
+		die("cannot walk reflogs for %s", name);
+
+	branch = xstrdup(name);
+	if (at && at[1] == '{') {
+		char *ep;
+		branch[at - name] = '\0';
+		recno = strtoul(at + 2, &ep, 10);
+		if (*ep != '}') {
+			recno = -1;
+			timestamp = approxidate(at + 2);
+			selector = SELECTOR_DATE;
+		}
+		else
+			selector = SELECTOR_INDEX;
+	} else
+		recno = 0;
+
+	item = string_list_lookup(&info->complete_reflogs, branch);
+	if (item)
+		reflogs = item->util;
+	else {
+		if (*branch == '\0') {
+			free(branch);
+			branch = resolve_refdup("HEAD", 0, NULL, NULL);
+			if (!branch)
+				die("no current branch");
+
+		}
+		reflogs = read_complete_reflog(branch);
+		if (!reflogs || reflogs->nr == 0) {
+			struct object_id oid;
+			char *b;
+			int ret = dwim_log(branch, strlen(branch),
+					   &oid, &b);
+			if (ret > 1)
+				free(b);
+			else if (ret == 1) {
+				free_complete_reflog(reflogs);
+				free(branch);
+				branch = b;
+				reflogs = read_complete_reflog(branch);
+			}
+		}
+		if (!reflogs || reflogs->nr == 0) {
+			free_complete_reflog(reflogs);
+			free(branch);
+			return -1;
+		}
+		string_list_insert(&info->complete_reflogs, branch)->util
+			= reflogs;
+	}
+	free(branch);
+
+	commit_reflog = xcalloc(1, sizeof(struct commit_reflog));
+	if (recno < 0) {
+		commit_reflog->recno = get_reflog_recno_by_time(reflogs, timestamp);
+		if (commit_reflog->recno < 0) {
+			free(commit_reflog);
+			return -1;
+		}
+	} else
+		commit_reflog->recno = reflogs->nr - recno - 1;
+	commit_reflog->selector = selector;
+	commit_reflog->reflogs = reflogs;
+
+	ALLOC_GROW(info->logs, info->nr + 1, info->alloc);
+	info->logs[info->nr++] = commit_reflog;
+
+	return 0;
+}
+
+void get_reflog_selector(struct strbuf *sb,
+			 struct reflog_walk_info *reflog_info,
+			 const struct date_mode *dmode, int force_date,
+			 int shorten)
+{
+	struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
+	struct reflog_info *info;
+	const char *printed_ref;
+
+	if (!commit_reflog)
+		return;
+
+	if (shorten) {
+		if (!commit_reflog->reflogs->short_ref)
+			commit_reflog->reflogs->short_ref
+				= shorten_unambiguous_ref(commit_reflog->reflogs->ref, 0);
+		printed_ref = commit_reflog->reflogs->short_ref;
+	} else {
+		printed_ref = commit_reflog->reflogs->ref;
+	}
+
+	strbuf_addf(sb, "%s@{", printed_ref);
+	if (commit_reflog->selector == SELECTOR_DATE ||
+	    (commit_reflog->selector == SELECTOR_NONE && force_date)) {
+		info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
+		strbuf_addstr(sb, show_date(info->timestamp, info->tz, dmode));
+	} else {
+		strbuf_addf(sb, "%d", commit_reflog->reflogs->nr
+			    - 2 - commit_reflog->recno);
+	}
+
+	strbuf_addch(sb, '}');
+}
+
+void get_reflog_message(struct strbuf *sb,
+			struct reflog_walk_info *reflog_info)
+{
+	struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
+	struct reflog_info *info;
+	size_t len;
+
+	if (!commit_reflog)
+		return;
+
+	info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
+	len = strlen(info->message);
+	if (len > 0)
+		len--; /* strip away trailing newline */
+	strbuf_add(sb, info->message, len);
+}
+
+const char *get_reflog_ident(struct reflog_walk_info *reflog_info)
+{
+	struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
+	struct reflog_info *info;
+
+	if (!commit_reflog)
+		return NULL;
+
+	info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
+	return info->email;
+}
+
+timestamp_t get_reflog_timestamp(struct reflog_walk_info *reflog_info)
+{
+	struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
+	struct reflog_info *info;
+
+	if (!commit_reflog)
+		return 0;
+
+	info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
+	return info->timestamp;
+}
+
+void show_reflog_message(struct reflog_walk_info *reflog_info, int oneline,
+			 const struct date_mode *dmode, int force_date)
+{
+	if (reflog_info && reflog_info->last_commit_reflog) {
+		struct commit_reflog *commit_reflog = reflog_info->last_commit_reflog;
+		struct reflog_info *info;
+		struct strbuf selector = STRBUF_INIT;
+
+		info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
+		get_reflog_selector(&selector, reflog_info, dmode, force_date, 0);
+		if (oneline) {
+			printf("%s: %s", selector.buf, info->message);
+		}
+		else {
+			printf("Reflog: %s (%s)\nReflog message: %s",
+			       selector.buf, info->email, info->message);
+		}
+
+		strbuf_release(&selector);
+	}
+}
+
+int reflog_walk_empty(struct reflog_walk_info *info)
+{
+	return !info || !info->nr;
+}
+
+static struct commit *next_reflog_commit(struct commit_reflog *log)
+{
+	for (; log->recno >= 0; log->recno--) {
+		struct reflog_info *entry = &log->reflogs->items[log->recno];
+		struct object *obj = parse_object(the_repository,
+						  &entry->noid);
+
+		if (obj && obj->type == OBJ_COMMIT)
+			return (struct commit *)obj;
+	}
+	return NULL;
+}
+
+static timestamp_t log_timestamp(struct commit_reflog *log)
+{
+	return log->reflogs->items[log->recno].timestamp;
+}
+
+struct commit *next_reflog_entry(struct reflog_walk_info *walk)
+{
+	struct commit_reflog *best = NULL;
+	struct commit *best_commit = NULL;
+	size_t i;
+
+	for (i = 0; i < walk->nr; i++) {
+		struct commit_reflog *log = walk->logs[i];
+		struct commit *commit = next_reflog_commit(log);
+
+		if (!commit)
+			continue;
+
+		if (!best || log_timestamp(log) > log_timestamp(best)) {
+			best = log;
+			best_commit = commit;
+		}
+	}
+
+	if (best) {
+		best->recno--;
+		walk->last_commit_reflog = best;
+		return best_commit;
+	}
+
+	return NULL;
+}