+/* Scan through a journal segment to extract correctly-written items (those
+ * that pass sanity checks and have a valid checksum). */
+static void bluesky_replay_scan_journal(const char *buf, size_t len)
+{
+ const struct log_header *header;
+ off_t offset = 0;
+
+ while (validate_journal_item(buf, len, offset)) {
+ header = (const struct log_header *)(buf + offset);
+ size_t size = GUINT32_FROM_LE(header->size);
+ offset += sizeof(struct log_header) + size + sizeof(struct log_footer);
+ }
+}
+
+static void bluesky_replay_scan_journal2(BlueSkyFS *fs, GList **objects,
+ int log_seq,
+ const char *buf, size_t len)
+{
+ const struct log_header *header;
+ off_t offset = 0;
+
+ while (validate_journal_item(buf, len, offset)) {
+ header = (const struct log_header *)(buf + offset);
+ g_print("In replay found valid item at offset %zd\n", offset);
+ size_t size = GUINT32_FROM_LE(header->size);
+
+ g_mutex_lock(fs->lock);
+ BlueSkyCloudLog *log_item;
+ log_item = g_hash_table_lookup(fs->locations, &header->id);
+ if (log_item == NULL) {
+ log_item = bluesky_cloudlog_new(fs, &header->id);
+ g_hash_table_insert(fs->locations, &log_item->id, log_item);
+ g_mutex_lock(log_item->lock);
+ } else {
+ bluesky_cloudlog_ref(log_item);
+ g_mutex_lock(log_item->lock);
+ }
+ g_mutex_unlock(fs->lock);
+ *objects = g_list_prepend(*objects, log_item);
+
+ bluesky_string_unref(log_item->data);
+ log_item->location_flags = CLOUDLOG_JOURNAL;
+ log_item->data = NULL;
+ log_item->log_seq = log_seq;
+ log_item->log_offset = offset + sizeof(struct log_header);
+ log_item->log_size = header->size;
+ g_mutex_unlock(log_item->lock);
+
+ offset += sizeof(struct log_header) + size + sizeof(struct log_footer);
+ }
+}
+
+void bluesky_replay(BlueSkyFS *fs)
+{
+ BlueSkyLog *log = fs->log;
+ GList *logfiles = directory_contents(log->log_directory);
+
+ /* Scan through log files in reverse order to find the most recent commit
+ * record. */
+ logfiles = g_list_reverse(logfiles);
+ while (logfiles != NULL) {
+ char *filename = g_strdup_printf("%s/%s", log->log_directory,
+ (char *)logfiles->data);
+ g_print("Scanning file %s\n", filename);
+ GMappedFile *map = g_mapped_file_new(filename, FALSE, NULL);
+ if (map == NULL) {
+ g_warning("Mapping logfile %s failed!\n", filename);
+ } else {
+ bluesky_replay_scan_journal(g_mapped_file_get_contents(map),
+ g_mapped_file_get_length(map));
+ g_mapped_file_unref(map);
+ }
+ g_free(filename);
+
+ g_free(logfiles->data);
+ logfiles = g_list_delete_link(logfiles, logfiles);
+ }
+ g_list_foreach(logfiles, (GFunc)g_free, NULL);
+ g_list_free(logfiles);
+
+ /* Now, scan forward starting from the given point in the log to
+ * reconstruct all filesystem state. As we reload objects we hold a
+ * reference to each loaded object. At the end we free all these
+ * references, so that any objects which were not linked into persistent
+ * filesystem data structures are freed. */
+ GList *objects = NULL;
+ int seq_num = 0;
+ while (TRUE) {
+ char *filename = g_strdup_printf("%s/journal-%08d",
+ log->log_directory, seq_num);
+ g_print("Replaying file %s\n", filename);
+ GMappedFile *map = g_mapped_file_new(filename, FALSE, NULL);
+ g_free(filename);
+ if (map == NULL) {
+ g_warning("Mapping logfile failed, assuming end of journal\n");
+ break;
+ }
+
+ bluesky_replay_scan_journal2(fs, &objects, seq_num,
+ g_mapped_file_get_contents(map),
+ g_mapped_file_get_length(map));
+ g_mapped_file_unref(map);
+ seq_num++;
+ }
+
+ while (objects != NULL) {
+ bluesky_cloudlog_unref((BlueSkyCloudLog *)objects->data);
+ objects = g_list_delete_link(objects, objects);
+ }
+}