+/**
+ * Append data to an existing session file.
+ *
+ * The session file must have been created with sr_session_save_init()
+ * or sr_session_save() beforehand.
+ *
+ * @param filename The name of the filename to append to. Must not be NULL.
+ * @param buf The data to be appended.
+ * @param unitsize The number of bytes per sample.
+ * @param units The number of samples.
+ *
+ * @retval SR_OK Success
+ * @retval SR_ERR_ARG Invalid arguments
+ * @retval SR_ERR Other errors
+ */
+SR_API int sr_session_append(const char *filename, unsigned char *buf,
+ int unitsize, int units)
+{
+ struct zip *archive;
+ struct zip_source *logicsrc;
+ zip_int64_t num_files;
+ struct zip_file *zf;
+ struct zip_stat zs;
+ struct zip_source *metasrc;
+ GKeyFile *kf;
+ GError *error;
+ gsize len;
+ int chunk_num, next_chunk_num, tmpfile, ret, i;
+ const char *entry_name;
+ char *metafile, tmpname[32], chunkname[16];
+
+ if ((ret = sr_sessionfile_check(filename)) != SR_OK)
+ return ret;
+
+ if (!(archive = zip_open(filename, 0, &ret)))
+ return SR_ERR;
+
+ if (zip_stat(archive, "metadata", 0, &zs) == -1)
+ return SR_ERR;
+
+ metafile = g_malloc(zs.size);
+ zf = zip_fopen_index(archive, zs.index, 0);
+ zip_fread(zf, metafile, zs.size);
+ zip_fclose(zf);
+
+ /*
+ * If the file was only initialized but doesn't yet have any
+ * data it in, it won't have a unitsize field in metadata yet.
+ */
+ error = NULL;
+ kf = g_key_file_new();
+ if (!g_key_file_load_from_data(kf, metafile, zs.size, 0, &error)) {
+ sr_err("Failed to parse metadata: %s.", error->message);
+ return SR_ERR;
+ }
+ g_free(metafile);
+ tmpname[0] = '\0';
+ if (!g_key_file_has_key(kf, "device 1", "unitsize", &error)) {
+ if (error && error->code != G_KEY_FILE_ERROR_KEY_NOT_FOUND) {
+ sr_err("Failed to check unitsize key: %s", error ? error->message : "?");
+ return SR_ERR;
+ }
+ /* Add unitsize field. */
+ g_key_file_set_integer(kf, "device 1", "unitsize", unitsize);
+ metafile = g_key_file_to_data(kf, &len, &error);
+ strcpy(tmpname, "sigrok-meta-XXXXXX");
+ if ((tmpfile = g_mkstemp(tmpname)) == -1)
+ return SR_ERR;
+ if (write(tmpfile, metafile, len) < 0) {
+ sr_dbg("Failed to create new metadata: %s", strerror(errno));
+ g_free(metafile);
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ close(tmpfile);
+ if (!(metasrc = zip_source_file(archive, tmpname, 0, -1))) {
+ sr_err("Failed to create zip source for metadata.");
+ g_free(metafile);
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ if (zip_replace(archive, zs.index, metasrc) == -1) {
+ sr_err("Failed to replace metadata file.");
+ g_free(metafile);
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ g_free(metafile);
+ }
+ g_key_file_free(kf);
+
+ next_chunk_num = 1;
+ num_files = zip_get_num_entries(archive, 0);
+ for (i = 0; i < num_files; i++) {
+ entry_name = zip_get_name(archive, i, 0);
+ if (strncmp(entry_name, "logic-1", 7))
+ continue;
+ if (strlen(entry_name) == 7) {
+ /* This file has no extra chunks, just a single "logic-1".
+ * Rename it to "logic-1-1" * and continue with chunk 2. */
+ if (zip_rename(archive, i, "logic-1-1") == -1) {
+ sr_err("Failed to rename 'logic-1' to 'logic-1-1'.");
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ next_chunk_num = 2;
+ break;
+ } else if (strlen(entry_name) > 8 && entry_name[7] == '-') {
+ chunk_num = strtoull(entry_name + 8, NULL, 10);
+ if (chunk_num >= next_chunk_num)
+ next_chunk_num = chunk_num + 1;
+ }
+ }
+ snprintf(chunkname, 15, "logic-1-%d", next_chunk_num);
+ if (!(logicsrc = zip_source_buffer(archive, buf, units * unitsize, FALSE))) {
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ if (zip_add(archive, chunkname, logicsrc) == -1) {
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ if ((ret = zip_close(archive)) == -1) {
+ sr_info("error saving session file: %s", zip_strerror(archive));
+ unlink(tmpname);
+ return SR_ERR;
+ }
+ unlink(tmpname);
+
+ return SR_OK;
+}
+