+static GPtrArray *traversed_paths = 0;
+
+/*
+ * traverse_trace_dir() is the callback function for File Tree Walk (nftw).
+ * it receives the path of the current entry (file, dir, link..etc) with
+ * a flag to indicate the type of the entry.
+ * if the entry being visited is a directory and contains a metadata file,
+ * then add the path to a global list to be processed later in
+ * add_traces_recursive.
+ */
+static int traverse_trace_dir(const char *fpath, const struct stat *sb,
+ int tflag, struct FTW *ftwbuf)
+{
+ int dirfd, metafd;
+ int closeret;
+
+ if (tflag != FTW_D)
+ return 0;
+
+ dirfd = open(fpath, 0);
+ if (dirfd < 0) {
+ fprintf(stderr, "[error] [Context] Unable to open trace "
+ "directory file descriptor.\n");
+ return 0; /* partial error */
+ }
+ metafd = openat(dirfd, "metadata", O_RDONLY);
+ if (metafd < 0) {
+ closeret = close(dirfd);
+ if (closeret < 0) {
+ perror("close");
+ return -1;
+ }
+ /* No meta data, just return */
+ return 0;
+ } else {
+ closeret = close(metafd);
+ if (closeret < 0) {
+ perror("close");
+ return -1; /* failure */
+ }
+ closeret = close(dirfd);
+ if (closeret < 0) {
+ perror("close");
+ return -1; /* failure */
+ }
+
+ /* Add path to the global list */
+ if (traversed_paths == NULL) {
+ fprintf(stderr, "[error] [Context] Invalid open path array.\n");
+ return -1;
+ }
+ g_ptr_array_add(traversed_paths, g_string_new(fpath));
+ }
+
+ return 0;
+}
+
+/*
+ * bt_context_add_traces_recursive: Open a trace recursively
+ *
+ * Find each trace present in the subdirectory starting from the given
+ * path, and add them to the context. The packet_seek parameter can be
+ * NULL: this specify to use the default format packet_seek.
+ *
+ * Return: 0 on success, < 0 on failure, > 0 on partial failure.
+ * Unable to open toplevel: failure.
+ * Unable to open some subdirectory or file: warn and continue (partial
+ * failure);
+ */
+int bt_context_add_traces_recursive(struct bt_context *ctx, const char *path,
+ const char *format_str,
+ void (*packet_seek)(struct bt_stream_pos *pos,
+ size_t offset, int whence))
+{
+
+ GArray *trace_ids;
+ int ret = 0;
+
+ /* Should lock traversed_paths mutex here if used in multithread */
+
+ traversed_paths = g_ptr_array_new();
+ trace_ids = g_array_new(FALSE, TRUE, sizeof(int));
+
+ ret = nftw(path, traverse_trace_dir, 10, 0);
+
+ /* Process the array if ntfw did not return a fatal error */
+ if (ret >= 0) {
+ int i;
+
+ for (i = 0; i < traversed_paths->len; i++) {
+ GString *trace_path = g_ptr_array_index(traversed_paths,
+ i);
+ int trace_id = bt_context_add_trace(ctx,
+ trace_path->str,
+ format_str,
+ packet_seek,
+ NULL,
+ NULL);
+ if (trace_id < 0) {
+ fprintf(stderr, "[warning] [Context] cannot open trace \"%s\" from %s "
+ "for reading.\n", trace_path->str, path);
+ /* Allow to skip erroneous traces. */
+ ret = 1; /* partial error */
+ } else {
+ g_array_append_val(trace_ids, trace_id);
+ }
+ g_string_free(trace_path, TRUE);
+ }
+ }
+
+ g_ptr_array_free(traversed_paths, TRUE);
+ traversed_paths = NULL;
+
+ /* Should unlock traversed paths mutex here if used in multithread */
+
+ /*
+ * Return an error if no trace can be opened.
+ */
+ if (trace_ids->len == 0) {
+ fprintf(stderr, "[error] Cannot open any trace for reading.\n\n");
+ ret = -ENOENT; /* failure */
+ }
+ g_array_free(trace_ids, TRUE);
+ return ret;
+}
+
+static
+int trace_pre_handler(struct bt_trace_descriptor *td_write,
+ struct bt_context *ctx)
+{
+ struct ctf_text_stream_pos *sout;
+ struct trace_collection *tc;
+ int ret, i;
+
+ sout = container_of(td_write, struct ctf_text_stream_pos,
+ trace_descriptor);
+
+ if (!sout->parent.pre_trace_cb)
+ return 0;
+
+ tc = ctx->tc;
+ for (i = 0; i < tc->array->len; i++) {
+ struct bt_trace_descriptor *td =
+ g_ptr_array_index(tc->array, i);
+
+ ret = sout->parent.pre_trace_cb(&sout->parent, td);
+ if (ret) {
+ fprintf(stderr, "[error] Writing to trace pre handler failed.\n");
+ goto end;
+ }
+ }
+ ret = 0;
+end:
+ return ret;
+}
+
+static
+int trace_post_handler(struct bt_trace_descriptor *td_write,
+ struct bt_context *ctx)