[PATCH 13/24] backup-log: add prune command

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 backup-log.c         | 71 ++++++++++++++++++++++++++++++++++++++++++++
 backup-log.h         |  3 ++
 builtin/backup-log.c | 17 +++++++++++
 3 files changed, 91 insertions(+)

diff --git a/backup-log.c b/backup-log.c
index 49f2ce68fe..5e38725981 100644
--- a/backup-log.c
+++ b/backup-log.c
@@ -1,6 +1,8 @@
 #include "cache.h"
 #include "backup-log.h"
+#include "blob.h"
 #include "lockfile.h"
+#include "object-store.h"
 #include "strbuf.h"
 
 void bkl_append(struct strbuf *output, const char *path,
@@ -217,3 +219,72 @@ int bkl_parse_file(const char *path,
 	strbuf_release(&sb);
 	return ret;
 }
+
+struct prune_options {
+	struct repository *repo;
+	FILE *fp;
+	timestamp_t expire;
+	struct strbuf copy;
+};
+
+static int good_oid(struct repository *r, const struct object_id *oid)
+{
+	if (is_null_oid(oid))
+		return 1;
+
+	return oid_object_info(r, oid, NULL) == OBJ_BLOB;
+}
+
+static int prune_parse(struct strbuf *line, void *data)
+{
+	struct prune_options *opts = data;
+	struct bkl_entry entry;
+
+	strbuf_reset(&opts->copy);
+	strbuf_addbuf(&opts->copy, line);
+
+	if (bkl_parse_entry(line, &entry))
+		return -1;
+
+	if (entry.timestamp < opts->expire)
+		return 0;
+
+	if (oideq(&entry.old_oid, &entry.new_oid))
+		return 0;
+
+	if (!good_oid(opts->repo, &entry.old_oid) ||
+	    !good_oid(opts->repo, &entry.new_oid))
+		return 0;
+
+	if (!opts->fp)
+		return -1;
+
+	fputs(opts->copy.buf, opts->fp);
+	return 0;
+}
+
+int bkl_prune(struct repository *r, const char *path, timestamp_t expire)
+{
+	struct lock_file lk;
+	struct prune_options opts;
+	int ret;
+
+	ret = hold_lock_file_for_update(&lk, path, 0);
+	if (ret == -1) {
+		if (errno == ENOTDIR || errno == ENOENT)
+			return 0;
+		return error(_("failed to lock '%s'"), path);
+	}
+	opts.repo = r;
+	opts.expire = expire;
+	opts.fp = fdopen_lock_file(&lk, "w");
+	strbuf_init(&opts.copy, 0);
+
+	ret = bkl_parse_file(path, prune_parse, &opts);
+	if (ret < 0)
+		rollback_lock_file(&lk);
+	else
+		ret = commit_lock_file(&lk);
+	strbuf_release(&opts.copy);
+	return ret;
+}
diff --git a/backup-log.h b/backup-log.h
index c9de9c687c..06fe706f81 100644
--- a/backup-log.h
+++ b/backup-log.h
@@ -3,6 +3,7 @@
 
 #include "cache.h"
 
+struct repository;
 struct strbuf;
 
 struct bkl_entry
@@ -29,4 +30,6 @@ int bkl_parse_file(const char *path,
 		   int (*parse)(struct strbuf *line, void *data),
 		   void *data);
 
+int bkl_prune(struct repository *r, const char *id, timestamp_t expire);
+
 #endif
diff --git a/builtin/backup-log.c b/builtin/backup-log.c
index 2496d73ba5..2291124c38 100644
--- a/builtin/backup-log.c
+++ b/builtin/backup-log.c
@@ -301,6 +301,21 @@ static int log_(int argc, const char **argv,
 	return ret;
 }
 
+static int prune(int argc, const char **argv,
+		 const char *prefix, const char *log_path)
+{
+	timestamp_t expire = time(NULL) - 90 * 24 * 3600;
+	struct option options[] = {
+		OPT_EXPIRY_DATE(0, "expire", &expire,
+				N_("expire objects older than <time>")),
+		OPT_END()
+	};
+
+	argc = parse_options(argc, argv, prefix, options, backup_log_usage, 0);
+
+	return bkl_prune(the_repository, log_path, expire);
+}
+
 static char *log_id_to_path(const char *id)
 {
 	if (!strcmp(id, "index"))
@@ -346,6 +361,8 @@ int cmd_backup_log(int argc, const char **argv, const char *prefix)
 		return diff(argc, argv, prefix, log_path);
 	else if (!strcmp(argv[0], "log"))
 		return log_(argc, argv, prefix, log_path);
+	else if (!strcmp(argv[0], "prune"))
+		return prune(argc, argv, prefix, log_path);
 	else
 		die(_("unknown subcommand: %s"), argv[0]);
 
-- 
2.20.0.rc2.486.g9832c05c3d