[babeltrace.git] / src / plugins / ctf / fs-src / fs.c

/*
 * fs.c
 *
 * Babeltrace CTF file system Reader Component
 *
 * Copyright 2015-2017 Philippe Proulx <pproulx@efficios.com>
 * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#define BT_COMP_LOG_SELF_COMP self_comp
#define BT_LOG_OUTPUT_LEVEL log_level
#define BT_LOG_TAG "PLUGIN/SRC.CTF.FS"
#include "plugins/comp-logging.h"

#include "common/common.h"
#include <babeltrace2/babeltrace.h>
#include "compat/uuid.h"
#include <glib.h>
#include "common/assert.h"
#include <inttypes.h>
#include <stdbool.h>
#include "fs.h"
#include "metadata.h"
#include "data-stream-file.h"
#include "file.h"
#include "../common/metadata/decoder.h"
#include "../common/msg-iter/msg-iter.h"
#include "query.h"

static
int msg_iter_data_set_current_ds_file(struct ctf_fs_msg_iter_data *msg_iter_data)
{
	struct ctf_fs_ds_file_info *ds_file_info;
	int ret = 0;

	BT_ASSERT(msg_iter_data->ds_file_info_index <
		msg_iter_data->ds_file_group->ds_file_infos->len);
	ds_file_info = g_ptr_array_index(
		msg_iter_data->ds_file_group->ds_file_infos,
		msg_iter_data->ds_file_info_index);

	ctf_fs_ds_file_destroy(msg_iter_data->ds_file);
	msg_iter_data->ds_file = ctf_fs_ds_file_create(
		msg_iter_data->ds_file_group->ctf_fs_trace,
		msg_iter_data->pc_msg_iter,
		msg_iter_data->msg_iter,
		msg_iter_data->ds_file_group->stream,
		ds_file_info->path->str,
		msg_iter_data->log_level);
	if (!msg_iter_data->ds_file) {
		ret = -1;
	}

	return ret;
}

static
void ctf_fs_msg_iter_data_destroy(
		struct ctf_fs_msg_iter_data *msg_iter_data)
{
	if (!msg_iter_data) {
		return;
	}

	ctf_fs_ds_file_destroy(msg_iter_data->ds_file);

	if (msg_iter_data->msg_iter) {
		bt_msg_iter_destroy(msg_iter_data->msg_iter);
	}

	g_free(msg_iter_data);
}

static
void set_msg_iter_emits_stream_beginning_end_messages(
		struct ctf_fs_msg_iter_data *msg_iter_data)
{
	bt_msg_iter_set_emit_stream_beginning_message(
		msg_iter_data->ds_file->msg_iter,
		msg_iter_data->ds_file_info_index == 0);
	bt_msg_iter_set_emit_stream_end_message(
		msg_iter_data->ds_file->msg_iter,
		msg_iter_data->ds_file_info_index ==
			msg_iter_data->ds_file_group->ds_file_infos->len - 1);
}

static
bt_self_message_iterator_status ctf_fs_iterator_next_one(
		struct ctf_fs_msg_iter_data *msg_iter_data,
		const bt_message **out_msg)
{
	bt_self_message_iterator_status status;

	BT_ASSERT(msg_iter_data->ds_file);

	while (true) {
		bt_message *msg;

		status = ctf_fs_ds_file_next(msg_iter_data->ds_file, &msg);
		switch (status) {
		case BT_SELF_MESSAGE_ITERATOR_STATUS_OK:
			*out_msg = msg;
			msg = NULL;
			goto end;
		case BT_SELF_MESSAGE_ITERATOR_STATUS_END:
		{
			int ret;

			if (msg_iter_data->ds_file_info_index ==
					msg_iter_data->ds_file_group->ds_file_infos->len - 1) {
				/* End of all group's stream files */
				goto end;
			}

			msg_iter_data->ds_file_info_index++;
			bt_msg_iter_reset_for_next_stream_file(
				msg_iter_data->msg_iter);
			set_msg_iter_emits_stream_beginning_end_messages(
				msg_iter_data);

			/*
			 * Open and start reading the next stream file
			 * within our stream file group.
			 */
			ret = msg_iter_data_set_current_ds_file(msg_iter_data);
			if (ret) {
				status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
				goto end;
			}

			/* Continue the loop to get the next message */
			break;
		}
		default:
			goto end;
		}
	}

end:
	return status;
}

BT_HIDDEN
bt_self_message_iterator_status ctf_fs_iterator_next(
		bt_self_message_iterator *iterator,
		bt_message_array_const msgs, uint64_t capacity,
		uint64_t *count)
{
	bt_self_message_iterator_status status =
		BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
	struct ctf_fs_msg_iter_data *msg_iter_data =
		bt_self_message_iterator_get_data(iterator);
	uint64_t i = 0;

	while (i < capacity && status == BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
		status = ctf_fs_iterator_next_one(msg_iter_data, &msgs[i]);
		if (status == BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
			i++;
		}
	}

	if (i > 0) {
		/*
		 * Even if ctf_fs_iterator_next_one() returned something
		 * else than BT_SELF_MESSAGE_ITERATOR_STATUS_OK, we
		 * accumulated message objects in the output
		 * message array, so we need to return
		 * BT_SELF_MESSAGE_ITERATOR_STATUS_OK so that they are
		 * transfered to downstream. This other status occurs
		 * again the next time muxer_msg_iter_do_next() is
		 * called, possibly without any accumulated
		 * message, in which case we'll return it.
		 */
		*count = i;
		status = BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
	}

	return status;
}

static
int ctf_fs_iterator_reset(struct ctf_fs_msg_iter_data *msg_iter_data)
{
	int ret;

	msg_iter_data->ds_file_info_index = 0;
	ret = msg_iter_data_set_current_ds_file(msg_iter_data);
	if (ret) {
		goto end;
	}

	bt_msg_iter_reset(msg_iter_data->msg_iter);
	set_msg_iter_emits_stream_beginning_end_messages(msg_iter_data);

end:
	return ret;
}

BT_HIDDEN
bt_self_message_iterator_status ctf_fs_iterator_seek_beginning(
		bt_self_message_iterator *it)
{
	struct ctf_fs_msg_iter_data *msg_iter_data =
		bt_self_message_iterator_get_data(it);
	bt_self_message_iterator_status status =
		BT_SELF_MESSAGE_ITERATOR_STATUS_OK;

	BT_ASSERT(msg_iter_data);
	if (ctf_fs_iterator_reset(msg_iter_data)) {
		status = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
	}

	return status;
}

BT_HIDDEN
void ctf_fs_iterator_finalize(bt_self_message_iterator *it)
{
	ctf_fs_msg_iter_data_destroy(
		bt_self_message_iterator_get_data(it));
}

BT_HIDDEN
bt_self_message_iterator_status ctf_fs_iterator_init(
		bt_self_message_iterator *self_msg_iter,
		bt_self_component_source *self_comp_src,
		bt_self_component_port_output *self_port)
{
	struct ctf_fs_port_data *port_data;
	struct ctf_fs_msg_iter_data *msg_iter_data = NULL;
	bt_self_message_iterator_status ret =
		BT_SELF_MESSAGE_ITERATOR_STATUS_OK;
	bt_logging_level log_level;
	bt_self_component *self_comp;

	port_data = bt_self_component_port_get_data(
		bt_self_component_port_output_as_self_component_port(
			self_port));
	BT_ASSERT(port_data);
	log_level = port_data->ctf_fs->log_level;
	self_comp = port_data->ctf_fs->self_comp;
	msg_iter_data = g_new0(struct ctf_fs_msg_iter_data, 1);
	if (!msg_iter_data) {
		ret = BT_SELF_MESSAGE_ITERATOR_STATUS_NOMEM;
		goto error;
	}

	msg_iter_data->log_level = log_level;
	msg_iter_data->self_comp = self_comp;
	msg_iter_data->pc_msg_iter = self_msg_iter;
	msg_iter_data->msg_iter = bt_msg_iter_create(
		port_data->ds_file_group->ctf_fs_trace->metadata->tc,
		bt_common_get_page_size(msg_iter_data->log_level) * 8,
		ctf_fs_ds_file_medops, NULL, msg_iter_data->log_level,
		self_comp);
	if (!msg_iter_data->msg_iter) {
		BT_COMP_LOGE_STR("Cannot create a CTF message iterator.");
		ret = BT_SELF_MESSAGE_ITERATOR_STATUS_NOMEM;
		goto error;
	}

	msg_iter_data->ds_file_group = port_data->ds_file_group;
	if (ctf_fs_iterator_reset(msg_iter_data)) {
		ret = BT_SELF_MESSAGE_ITERATOR_STATUS_ERROR;
		goto error;
	}

	bt_self_message_iterator_set_data(self_msg_iter,
		msg_iter_data);
	if (ret != BT_SELF_MESSAGE_ITERATOR_STATUS_OK) {
		goto error;
	}

	msg_iter_data = NULL;
	goto end;

error:
	bt_self_message_iterator_set_data(self_msg_iter, NULL);

end:
	ctf_fs_msg_iter_data_destroy(msg_iter_data);
	return ret;
}

BT_HIDDEN
void ctf_fs_destroy(struct ctf_fs_component *ctf_fs)
{
	if (!ctf_fs) {
		return;
	}

	if (ctf_fs->traces) {
		g_ptr_array_free(ctf_fs->traces, TRUE);
	}

	if (ctf_fs->port_data) {
		g_ptr_array_free(ctf_fs->port_data, TRUE);
	}

	g_free(ctf_fs);
}

static
void port_data_destroy(struct ctf_fs_port_data *port_data)
{
	if (!port_data) {
		return;
	}

	g_free(port_data);
}

static
void port_data_destroy_notifier(void *data) {
	port_data_destroy(data);
}

static
void ctf_fs_trace_destroy(struct ctf_fs_trace *ctf_fs_trace)
{
	if (!ctf_fs_trace) {
		return;
	}

	if (ctf_fs_trace->ds_file_groups) {
		g_ptr_array_free(ctf_fs_trace->ds_file_groups, TRUE);
	}

	BT_TRACE_PUT_REF_AND_RESET(ctf_fs_trace->trace);

	if (ctf_fs_trace->path) {
		g_string_free(ctf_fs_trace->path, TRUE);
	}

	if (ctf_fs_trace->name) {
		g_string_free(ctf_fs_trace->name, TRUE);
	}

	if (ctf_fs_trace->metadata) {
		ctf_fs_metadata_fini(ctf_fs_trace->metadata);
		g_free(ctf_fs_trace->metadata);
	}

	g_free(ctf_fs_trace);
}

static
void ctf_fs_trace_destroy_notifier(void *data)
{
	struct ctf_fs_trace *trace = data;
	ctf_fs_trace_destroy(trace);
}

struct ctf_fs_component *ctf_fs_component_create(bt_logging_level log_level,
		bt_self_component *self_comp)
{
	struct ctf_fs_component *ctf_fs;

	ctf_fs = g_new0(struct ctf_fs_component, 1);
	if (!ctf_fs) {
		goto error;
	}

	ctf_fs->log_level = log_level;
	ctf_fs->self_comp = self_comp;
	ctf_fs->port_data =
		g_ptr_array_new_with_free_func(port_data_destroy_notifier);
	if (!ctf_fs->port_data) {
		goto error;
	}

	ctf_fs->traces =
		g_ptr_array_new_with_free_func(ctf_fs_trace_destroy_notifier);
	if (!ctf_fs->traces) {
		goto error;
	}

	goto end;

error:
	if (ctf_fs) {
		ctf_fs_destroy(ctf_fs);
	}

end:
	return ctf_fs;
}

void ctf_fs_finalize(bt_self_component_source *component)
{
	ctf_fs_destroy(bt_self_component_get_data(
		bt_self_component_source_as_self_component(component)));
}

gchar *ctf_fs_make_port_name(struct ctf_fs_ds_file_group *ds_file_group)
{
	GString *name = g_string_new(NULL);

	/*
	 * The unique port name is generated by concatenating unique identifiers
	 * for:
	 *
	 *   - the trace
	 *   - the stream class
	 *   - the stream
	 */

	/* For the trace, use the uuid if present, else the path. */
	if (ds_file_group->ctf_fs_trace->metadata->tc->is_uuid_set) {
		char uuid_str[BABELTRACE_UUID_STR_LEN];

		bt_uuid_unparse(ds_file_group->ctf_fs_trace->metadata->tc->uuid, uuid_str);
		g_string_assign(name, uuid_str);
	} else {
		g_string_assign(name, ds_file_group->ctf_fs_trace->path->str);
	}

	/*
	 * For the stream class, use the id if present.  We can omit this field
	 * otherwise, as there will only be a single stream class.
	 */
	if (ds_file_group->sc->id != UINT64_C(-1)) {
		g_string_append_printf(name, " | %" PRIu64, ds_file_group->sc->id);
	}

	/* For the stream, use the id if present, else, use the path. */
	if (ds_file_group->stream_id != UINT64_C(-1)) {
		g_string_append_printf(name, " | %" PRIu64, ds_file_group->stream_id);
	} else {
		BT_ASSERT(ds_file_group->ds_file_infos->len == 1);
		struct ctf_fs_ds_file_info *ds_file_info =
			g_ptr_array_index(ds_file_group->ds_file_infos, 0);
		g_string_append_printf(name, " | %s", ds_file_info->path->str);
	}

	return g_string_free(name, FALSE);
}

static
int create_one_port_for_trace(struct ctf_fs_component *ctf_fs,
		struct ctf_fs_trace *ctf_fs_trace,
		struct ctf_fs_ds_file_group *ds_file_group)
{
	int ret = 0;
	struct ctf_fs_port_data *port_data = NULL;
	gchar *port_name;
	bt_logging_level log_level = ctf_fs->log_level;
	bt_self_component *self_comp = ctf_fs->self_comp;

	port_name = ctf_fs_make_port_name(ds_file_group);
	if (!port_name) {
		goto error;
	}

	BT_COMP_LOGI("Creating one port named `%s`", port_name);

	/* Create output port for this file */
	port_data = g_new0(struct ctf_fs_port_data, 1);
	if (!port_data) {
		goto error;
	}

	port_data->ctf_fs = ctf_fs;
	port_data->ds_file_group = ds_file_group;
	ret = bt_self_component_source_add_output_port(
		ctf_fs->self_comp_src, port_name, port_data, NULL);
	if (ret) {
		goto error;
	}

	g_ptr_array_add(ctf_fs->port_data, port_data);
	port_data = NULL;
	goto end;

error:
	ret = -1;

end:
	if (port_name) {
		g_free(port_name);
	}

	port_data_destroy(port_data);
	return ret;
}

static
int create_ports_for_trace(struct ctf_fs_component *ctf_fs,
		struct ctf_fs_trace *ctf_fs_trace)
{
	int ret = 0;
	size_t i;
	bt_logging_level log_level = ctf_fs_trace->log_level;
	bt_self_component *self_comp = ctf_fs_trace->self_comp;

	/* Create one output port for each stream file group */
	for (i = 0; i < ctf_fs_trace->ds_file_groups->len; i++) {
		struct ctf_fs_ds_file_group *ds_file_group =
			g_ptr_array_index(ctf_fs_trace->ds_file_groups, i);

		ret = create_one_port_for_trace(ctf_fs, ctf_fs_trace,
			ds_file_group);
		if (ret) {
			BT_COMP_LOGE("Cannot create output port.");
			goto end;
		}
	}

end:
	return ret;
}

static
void ctf_fs_ds_file_info_destroy(struct ctf_fs_ds_file_info *ds_file_info)
{
	if (!ds_file_info) {
		return;
	}

	if (ds_file_info->path) {
		g_string_free(ds_file_info->path, TRUE);
	}

	g_free(ds_file_info);
}

static
struct ctf_fs_ds_file_info *ctf_fs_ds_file_info_create(const char *path,
		int64_t begin_ns)
{
	struct ctf_fs_ds_file_info *ds_file_info;

	ds_file_info = g_new0(struct ctf_fs_ds_file_info, 1);
	if (!ds_file_info) {
		goto end;
	}

	ds_file_info->path = g_string_new(path);
	if (!ds_file_info->path) {
		ctf_fs_ds_file_info_destroy(ds_file_info);
		ds_file_info = NULL;
		goto end;
	}

	ds_file_info->begin_ns = begin_ns;

end:
	return ds_file_info;
}

static
void ctf_fs_ds_file_group_destroy(struct ctf_fs_ds_file_group *ds_file_group)
{
	if (!ds_file_group) {
		return;
	}

	if (ds_file_group->ds_file_infos) {
		g_ptr_array_free(ds_file_group->ds_file_infos, TRUE);
	}

	if (ds_file_group->index) {
		if (ds_file_group->index->entries) {
			g_ptr_array_free(ds_file_group->index->entries, TRUE);
		}
		g_free(ds_file_group->index);
	}

	bt_stream_put_ref(ds_file_group->stream);
	g_free(ds_file_group);
}

static
struct ctf_fs_ds_file_group *ctf_fs_ds_file_group_create(
		struct ctf_fs_trace *ctf_fs_trace,
		struct ctf_stream_class *sc,
		uint64_t stream_instance_id,
		struct ctf_fs_ds_index *index)
{
	struct ctf_fs_ds_file_group *ds_file_group;

	ds_file_group = g_new0(struct ctf_fs_ds_file_group, 1);
	if (!ds_file_group) {
		goto error;
	}

	ds_file_group->ds_file_infos = g_ptr_array_new_with_free_func(
		(GDestroyNotify) ctf_fs_ds_file_info_destroy);
	if (!ds_file_group->ds_file_infos) {
		goto error;
	}

	ds_file_group->index = index;

	ds_file_group->stream_id = stream_instance_id;
	BT_ASSERT(sc);
	ds_file_group->sc = sc;
	ds_file_group->ctf_fs_trace = ctf_fs_trace;
	goto end;

error:
	ctf_fs_ds_file_group_destroy(ds_file_group);
	ctf_fs_ds_index_destroy(index);
	ds_file_group = NULL;

end:
	return ds_file_group;
}

/* Replace by g_ptr_array_insert when we depend on glib >= 2.40. */
static
void array_insert(GPtrArray *array, gpointer element, size_t pos)
{
	size_t original_array_len = array->len;

	/* Allocate an unused element at the end of the array. */
	g_ptr_array_add(array, NULL);

	/* If we are not inserting at the end, move the elements by one. */
	if (pos < original_array_len) {
		memmove(&(array->pdata[pos + 1]),
			&(array->pdata[pos]),
			(original_array_len - pos) * sizeof(gpointer));
	}

	/* Insert the value. */
	array->pdata[pos] = element;
}

/*
 * Insert ds_file_info in ds_file_group's list of ds_file_infos at the right
 * place to keep it sorted.
 */

static
void ds_file_group_insert_ds_file_info_sorted(
		struct ctf_fs_ds_file_group *ds_file_group,
		struct ctf_fs_ds_file_info *ds_file_info)
{
	guint i;

	/* Find the spot where to insert this ds_file_info. */
	for (i = 0; i < ds_file_group->ds_file_infos->len; i++) {
		struct ctf_fs_ds_file_info *other_ds_file_info =
			g_ptr_array_index(ds_file_group->ds_file_infos, i);

		if (ds_file_info->begin_ns < other_ds_file_info->begin_ns) {
			break;
		}
	}

	array_insert(ds_file_group->ds_file_infos, ds_file_info, i);
}

static
void ds_file_group_insert_ds_index_entry_sorted(
	struct ctf_fs_ds_file_group *ds_file_group,
	struct ctf_fs_ds_index_entry *entry)
{
	guint i;

	/* Find the spot where to insert this index entry. */
	for (i = 0; i < ds_file_group->index->entries->len; i++) {
		struct ctf_fs_ds_index_entry *other_entry = g_ptr_array_index(
			ds_file_group->index->entries, i);

		if (entry->timestamp_begin_ns < other_entry->timestamp_begin_ns) {
			break;
		}
	}

	array_insert(ds_file_group->index->entries, entry, i);
}

/*
 * Create a new ds_file_info using the provided path, begin_ns and index, then
 * add it to ds_file_group's list of ds_file_infos.
 */

static
int ctf_fs_ds_file_group_add_ds_file_info(
		struct ctf_fs_ds_file_group *ds_file_group,
		const char *path, int64_t begin_ns)
{
	struct ctf_fs_ds_file_info *ds_file_info;
	int ret = 0;

	ds_file_info = ctf_fs_ds_file_info_create(path, begin_ns);
	if (!ds_file_info) {
		goto error;
	}

	ds_file_group_insert_ds_file_info_sorted(ds_file_group, ds_file_info);

	ds_file_info = NULL;
	goto end;

error:
	ctf_fs_ds_file_info_destroy(ds_file_info);
	ret = -1;
end:
	return ret;
}

static
int add_ds_file_to_ds_file_group(struct ctf_fs_trace *ctf_fs_trace,
		const char *path)
{
	int64_t stream_instance_id = -1;
	int64_t begin_ns = -1;
	struct ctf_fs_ds_file_group *ds_file_group = NULL;
	bool add_group = false;
	int ret;
	size_t i;
	struct ctf_fs_ds_file *ds_file = NULL;
	struct ctf_fs_ds_index *index = NULL;
	struct bt_msg_iter *msg_iter = NULL;
	struct ctf_stream_class *sc = NULL;
	struct bt_msg_iter_packet_properties props;
	bt_logging_level log_level = ctf_fs_trace->log_level;
	bt_self_component *self_comp = ctf_fs_trace->self_comp;

	msg_iter = bt_msg_iter_create(ctf_fs_trace->metadata->tc,
		bt_common_get_page_size(log_level) * 8,
		ctf_fs_ds_file_medops, NULL, log_level, self_comp);
	if (!msg_iter) {
		BT_COMP_LOGE_STR("Cannot create a CTF message iterator.");
		goto error;
	}

	ds_file = ctf_fs_ds_file_create(ctf_fs_trace, NULL, msg_iter,
		NULL, path, log_level);
	if (!ds_file) {
		goto error;
	}

	ret = bt_msg_iter_get_packet_properties(ds_file->msg_iter, &props);
	if (ret) {
		BT_COMP_LOGE("Cannot get stream file's first packet's header and context fields (`%s`).",
			path);
		goto error;
	}

	sc = ctf_trace_class_borrow_stream_class_by_id(ds_file->metadata->tc,
		props.stream_class_id);
	BT_ASSERT(sc);
	stream_instance_id = props.data_stream_id;

	if (props.snapshots.beginning_clock != UINT64_C(-1)) {
		BT_ASSERT(sc->default_clock_class);
		ret = bt_util_clock_cycles_to_ns_from_origin(
			props.snapshots.beginning_clock,
			sc->default_clock_class->frequency,
			sc->default_clock_class->offset_seconds,
			sc->default_clock_class->offset_cycles, &begin_ns);
		if (ret) {
			BT_COMP_LOGE("Cannot convert clock cycles to nanoseconds from origin (`%s`).",
				path);
			goto error;
		}
	}

	index = ctf_fs_ds_file_build_index(ds_file);
	if (!index) {
		BT_COMP_LOGW("Failed to index CTF stream file \'%s\'",
			ds_file->file->path->str);
	}

	if (begin_ns == -1) {
		/*
		 * No beggining timestamp to sort the stream files
		 * within a stream file group, so consider that this
		 * file must be the only one within its group.
		 */
		stream_instance_id = -1;
	}

	if (stream_instance_id == -1) {
		/*
		 * No stream instance ID or no beginning timestamp:
		 * create a unique stream file group for this stream
		 * file because, even if there's a stream instance ID,
		 * there's no timestamp to order the file within its
		 * group.
		 */
		ds_file_group = ctf_fs_ds_file_group_create(ctf_fs_trace,
			sc, UINT64_C(-1), index);
		/* Ownership of index is transferred. */
		index = NULL;

		if (!ds_file_group) {
			goto error;
		}

		ret = ctf_fs_ds_file_group_add_ds_file_info(ds_file_group,
			path, begin_ns);
		if (ret) {
			goto error;
		}

		add_group = true;
		goto end;
	}

	BT_ASSERT(stream_instance_id != -1);
	BT_ASSERT(begin_ns != -1);

	/* Find an existing stream file group with this ID */
	for (i = 0; i < ctf_fs_trace->ds_file_groups->len; i++) {
		ds_file_group = g_ptr_array_index(
			ctf_fs_trace->ds_file_groups, i);

		if (ds_file_group->sc == sc &&
				ds_file_group->stream_id ==
				stream_instance_id) {
			break;
		}

		ds_file_group = NULL;
	}

	if (!ds_file_group) {
		ds_file_group = ctf_fs_ds_file_group_create(ctf_fs_trace,
			sc, stream_instance_id, index);
		/* Ownership of index is transferred. */
		index = NULL;
		if (!ds_file_group) {
			goto error;
		}

		add_group = true;
	}

	ret = ctf_fs_ds_file_group_add_ds_file_info(ds_file_group, path,
		begin_ns);
	if (ret) {
		goto error;
	}

	goto end;

error:
	ctf_fs_ds_file_group_destroy(ds_file_group);
	ds_file_group = NULL;
	ret = -1;

end:
	if (add_group && ds_file_group) {
		g_ptr_array_add(ctf_fs_trace->ds_file_groups, ds_file_group);
	}

	ctf_fs_ds_file_destroy(ds_file);

	if (msg_iter) {
		bt_msg_iter_destroy(msg_iter);
	}

	ctf_fs_ds_index_destroy(index);
	return ret;
}

static
int create_ds_file_groups(struct ctf_fs_trace *ctf_fs_trace)
{
	int ret = 0;
	const char *basename;
	GError *error = NULL;
	GDir *dir = NULL;
	bt_logging_level log_level = ctf_fs_trace->log_level;
	bt_self_component *self_comp = ctf_fs_trace->self_comp;

	/* Check each file in the path directory, except specific ones */
	dir = g_dir_open(ctf_fs_trace->path->str, 0, &error);
	if (!dir) {
		BT_COMP_LOGE("Cannot open directory `%s`: %s (code %d)",
			ctf_fs_trace->path->str, error->message,
			error->code);
		goto error;
	}

	while ((basename = g_dir_read_name(dir))) {
		struct ctf_fs_file *file;

		if (!strcmp(basename, CTF_FS_METADATA_FILENAME)) {
			/* Ignore the metadata stream. */
			BT_COMP_LOGI("Ignoring metadata file `%s" G_DIR_SEPARATOR_S "%s`",
				ctf_fs_trace->path->str, basename);
			continue;
		}

		if (basename[0] == '.') {
			BT_COMP_LOGI("Ignoring hidden file `%s" G_DIR_SEPARATOR_S "%s`",
				ctf_fs_trace->path->str, basename);
			continue;
		}

		/* Create the file. */
		file = ctf_fs_file_create(log_level, self_comp);
		if (!file) {
			BT_COMP_LOGE("Cannot create stream file object for file `%s" G_DIR_SEPARATOR_S "%s`",
				ctf_fs_trace->path->str, basename);
			goto error;
		}

		/* Create full path string. */
		g_string_append_printf(file->path, "%s" G_DIR_SEPARATOR_S "%s",
				ctf_fs_trace->path->str, basename);
		if (!g_file_test(file->path->str, G_FILE_TEST_IS_REGULAR)) {
			BT_COMP_LOGI("Ignoring non-regular file `%s`",
				file->path->str);
			ctf_fs_file_destroy(file);
			file = NULL;
			continue;
		}

		ret = ctf_fs_file_open(file, "rb");
		if (ret) {
			BT_COMP_LOGE("Cannot open stream file `%s`", file->path->str);
			goto error;
		}

		if (file->size == 0) {
			/* Skip empty stream. */
			BT_COMP_LOGI("Ignoring empty file `%s`", file->path->str);
			ctf_fs_file_destroy(file);
			continue;
		}

		ret = add_ds_file_to_ds_file_group(ctf_fs_trace,
			file->path->str);
		if (ret) {
			BT_COMP_LOGE("Cannot add stream file `%s` to stream file group",
				file->path->str);
			ctf_fs_file_destroy(file);
			goto error;
		}

		ctf_fs_file_destroy(file);
	}

	goto end;

error:
	ret = -1;

end:
	if (dir) {
		g_dir_close(dir);
		dir = NULL;
	}

	if (error) {
		g_error_free(error);
	}

	return ret;
}

static
int set_trace_name(bt_trace *trace, const char *name_suffix,
		bt_logging_level log_level, bt_self_component *self_comp)
{
	int ret = 0;
	const bt_trace_class *tc = bt_trace_borrow_class_const(trace);
	const bt_value *val;
	GString *name;

	name = g_string_new(NULL);
	if (!name) {
		BT_COMP_LOGE_STR("Failed to allocate a GString.");
		ret = -1;
		goto end;
	}

	/*
	 * Check if we have a trace environment string value named `hostname`.
	 * If so, use it as the trace name's prefix.
	 */
	val = bt_trace_class_borrow_environment_entry_value_by_name_const(
		tc, "hostname");
	if (val && bt_value_is_string(val)) {
		g_string_append(name, bt_value_string_get(val));

		if (name_suffix) {
			g_string_append_c(name, G_DIR_SEPARATOR);
		}
	}

	if (name_suffix) {
		g_string_append(name, name_suffix);
	}

	ret = bt_trace_set_name(trace, name->str);
	if (ret) {
		goto end;
	}

	goto end;

end:
	if (name) {
		g_string_free(name, TRUE);
	}

	return ret;
}

static
struct ctf_fs_trace *ctf_fs_trace_create(bt_self_component *self_comp,
		const char *path, const char *name,
		struct ctf_fs_metadata_config *metadata_config,
		bt_logging_level log_level)
{
	struct ctf_fs_trace *ctf_fs_trace;
	int ret;

	ctf_fs_trace = g_new0(struct ctf_fs_trace, 1);
	if (!ctf_fs_trace) {
		goto end;
	}

	ctf_fs_trace->log_level = log_level;
	ctf_fs_trace->self_comp = self_comp;
	ctf_fs_trace->path = g_string_new(path);
	if (!ctf_fs_trace->path) {
		goto error;
	}

	ctf_fs_trace->name = g_string_new(name);
	if (!ctf_fs_trace->name) {
		goto error;
	}

	ctf_fs_trace->metadata = g_new0(struct ctf_fs_metadata, 1);
	if (!ctf_fs_trace->metadata) {
		goto error;
	}

	ctf_fs_metadata_init(ctf_fs_trace->metadata);
	ctf_fs_trace->ds_file_groups = g_ptr_array_new_with_free_func(
		(GDestroyNotify) ctf_fs_ds_file_group_destroy);
	if (!ctf_fs_trace->ds_file_groups) {
		goto error;
	}

	ret = ctf_fs_metadata_set_trace_class(self_comp, ctf_fs_trace,
		metadata_config);
	if (ret) {
		goto error;
	}

	if (ctf_fs_trace->metadata->trace_class) {
		ctf_fs_trace->trace =
			bt_trace_create(ctf_fs_trace->metadata->trace_class);
		if (!ctf_fs_trace->trace) {
			goto error;
		}
	}

	if (ctf_fs_trace->trace) {
		ret = set_trace_name(ctf_fs_trace->trace, name, log_level,
			self_comp);
		if (ret) {
			goto error;
		}
	}

	ret = create_ds_file_groups(ctf_fs_trace);
	if (ret) {
		goto error;
	}

	goto end;

error:
	ctf_fs_trace_destroy(ctf_fs_trace);
	ctf_fs_trace = NULL;

end:
	return ctf_fs_trace;
}

static
int path_is_ctf_trace(const char *path)
{
	GString *metadata_path = g_string_new(NULL);
	int ret = 0;

	if (!metadata_path) {
		ret = -1;
		goto end;
	}

	g_string_printf(metadata_path, "%s" G_DIR_SEPARATOR_S "%s", path, CTF_FS_METADATA_FILENAME);

	if (g_file_test(metadata_path->str, G_FILE_TEST_IS_REGULAR)) {
		ret = 1;
		goto end;
	}

end:
	g_string_free(metadata_path, TRUE);
	return ret;
}

static
int add_trace_path(GList **trace_paths, const char *path,
		bt_logging_level log_level, bt_self_component *self_comp)
{
	GString *norm_path = NULL;
	int ret = 0;

	norm_path = bt_common_normalize_path(path, NULL);
	if (!norm_path) {
		BT_COMP_LOGE("Failed to normalize path `%s`.", path);
		ret = -1;
		goto end;
	}

	// FIXME: Remove or ifdef for __MINGW32__
	if (strcmp(norm_path->str, "/") == 0) {
		BT_COMP_LOGE("Opening a trace in `/` is not supported.");
		ret = -1;
		goto end;
	}

	*trace_paths = g_list_prepend(*trace_paths, norm_path);
	BT_ASSERT(*trace_paths);
	norm_path = NULL;

end:
	if (norm_path) {
		g_string_free(norm_path, TRUE);
	}

	return ret;
}

static
int ctf_fs_find_traces(GList **trace_paths, const char *start_path,
		bt_logging_level log_level, bt_self_component *self_comp)
{
	int ret;
	GError *error = NULL;
	GDir *dir = NULL;
	const char *basename = NULL;

	/* Check if the starting path is a CTF trace itself */
	ret = path_is_ctf_trace(start_path);
	if (ret < 0) {
		goto end;
	}

	if (ret) {
		/*
		 * Stop recursion: a CTF trace cannot contain another
		 * CTF trace.
		 */
		ret = add_trace_path(trace_paths, start_path, log_level,
			self_comp);
		goto end;
	}

	/* Look for subdirectories */
	if (!g_file_test(start_path, G_FILE_TEST_IS_DIR)) {
		/* Starting path is not a directory: end of recursion */
		goto end;
	}

	dir = g_dir_open(start_path, 0, &error);
	if (!dir) {
		if (error->code == G_FILE_ERROR_ACCES) {
			BT_COMP_LOGI("Cannot open directory `%s`: %s (code %d): continuing",
				start_path, error->message, error->code);
			goto end;
		}

		BT_COMP_LOGE("Cannot open directory `%s`: %s (code %d)",
			start_path, error->message, error->code);
		ret = -1;
		goto end;
	}

	while ((basename = g_dir_read_name(dir))) {
		GString *sub_path = g_string_new(NULL);

		if (!sub_path) {
			ret = -1;
			goto end;
		}

		g_string_printf(sub_path, "%s" G_DIR_SEPARATOR_S "%s", start_path, basename);
		ret = ctf_fs_find_traces(trace_paths, sub_path->str,
			log_level, self_comp);
		g_string_free(sub_path, TRUE);
		if (ret) {
			goto end;
		}
	}

end:
	if (dir) {
		g_dir_close(dir);
	}

	if (error) {
		g_error_free(error);
	}

	return ret;
}

static
GList *ctf_fs_create_trace_names(GList *trace_paths, const char *base_path) {
	GList *trace_names = NULL;
	GList *node;
	const char *last_sep;
	size_t base_dist;

	/*
	 * At this point we know that all the trace paths are
	 * normalized, and so is the base path. This means that
	 * they are absolute and they don't end with a separator.
	 * We can simply find the location of the last separator
	 * in the base path, which gives us the name of the actual
	 * directory to look into, and use this location as the
	 * start of each trace name within each trace path.
	 *
	 * For example:
	 *
	 *     Base path: /home/user/my-traces/some-trace
	 *     Trace paths:
	 *       - /home/user/my-traces/some-trace/host1/trace1
	 *       - /home/user/my-traces/some-trace/host1/trace2
	 *       - /home/user/my-traces/some-trace/host2/trace
	 *       - /home/user/my-traces/some-trace/other-trace
	 *
	 * In this case the trace names are:
	 *
	 *       - some-trace/host1/trace1
	 *       - some-trace/host1/trace2
	 *       - some-trace/host2/trace
	 *       - some-trace/other-trace
	 */
	last_sep = strrchr(base_path, G_DIR_SEPARATOR);

	/* We know there's at least one separator */
	BT_ASSERT(last_sep);

	/* Distance to base */
	base_dist = last_sep - base_path + 1;

	/* Create the trace names */
	for (node = trace_paths; node; node = g_list_next(node)) {
		GString *trace_name = g_string_new(NULL);
		GString *trace_path = node->data;

		BT_ASSERT(trace_name);
		g_string_assign(trace_name, &trace_path->str[base_dist]);
		trace_names = g_list_append(trace_names, trace_name);
	}

	return trace_names;
}

/* Helper for ctf_fs_component_create_ctf_fs_traces, to handle a single path/root. */

static
int ctf_fs_component_create_ctf_fs_traces_one_root(
		struct ctf_fs_component *ctf_fs,
		const char *path_param)
{
	struct ctf_fs_trace *ctf_fs_trace = NULL;
	int ret = 0;
	GString *norm_path = NULL;
	GList *trace_paths = NULL;
	GList *trace_names = NULL;
	GList *tp_node;
	GList *tn_node;
	bt_logging_level log_level = ctf_fs->log_level;
	bt_self_component *self_comp = ctf_fs->self_comp;

	norm_path = bt_common_normalize_path(path_param, NULL);
	if (!norm_path) {
		BT_COMP_LOGE("Failed to normalize path: `%s`.",
			path_param);
		goto error;
	}

	ret = ctf_fs_find_traces(&trace_paths, norm_path->str, log_level,
		self_comp);
	if (ret) {
		goto error;
	}

	if (!trace_paths) {
		BT_COMP_LOGE("No CTF traces recursively found in `%s`.",
			path_param);
		goto error;
	}

	trace_names = ctf_fs_create_trace_names(trace_paths, norm_path->str);
	if (!trace_names) {
		BT_COMP_LOGE("Cannot create trace names from trace paths.");
		goto error;
	}

	for (tp_node = trace_paths, tn_node = trace_names; tp_node;
			tp_node = g_list_next(tp_node),
			tn_node = g_list_next(tn_node)) {
		GString *trace_path = tp_node->data;
		GString *trace_name = tn_node->data;

		ctf_fs_trace = ctf_fs_trace_create(self_comp,
				trace_path->str, trace_name->str,
				&ctf_fs->metadata_config,
				log_level);
		if (!ctf_fs_trace) {
			BT_COMP_LOGE("Cannot create trace for `%s`.",
				trace_path->str);
			goto error;
		}

		g_ptr_array_add(ctf_fs->traces, ctf_fs_trace);
		ctf_fs_trace = NULL;
	}

	goto end;

error:
	ret = -1;
	ctf_fs_trace_destroy(ctf_fs_trace);

end:
	for (tp_node = trace_paths; tp_node; tp_node = g_list_next(tp_node)) {
		if (tp_node->data) {
			g_string_free(tp_node->data, TRUE);
		}
	}

	for (tn_node = trace_names; tn_node; tn_node = g_list_next(tn_node)) {
		if (tn_node->data) {
			g_string_free(tn_node->data, TRUE);
		}
	}

	if (trace_paths) {
		g_list_free(trace_paths);
	}

	if (trace_names) {
		g_list_free(trace_names);
	}

	if (norm_path) {
		g_string_free(norm_path, TRUE);
	}

	return ret;
}

/* GCompareFunc to sort traces by UUID. */

static
gint sort_traces_by_uuid(gconstpointer a, gconstpointer b)
{
	const struct ctf_fs_trace *trace_a = *((const struct ctf_fs_trace **) a);
	const struct ctf_fs_trace *trace_b = *((const struct ctf_fs_trace **) b);

	bool trace_a_has_uuid = trace_a->metadata->tc->is_uuid_set;
	bool trace_b_has_uuid = trace_b->metadata->tc->is_uuid_set;
	gint ret;

	/* Order traces without uuid first. */
	if (!trace_a_has_uuid && trace_b_has_uuid) {
		ret = -1;
	} else if (trace_a_has_uuid && !trace_b_has_uuid) {
		ret = 1;
	} else if (!trace_a_has_uuid && !trace_b_has_uuid) {
		ret = 0;
	} else {
		ret = bt_uuid_compare(trace_a->metadata->tc->uuid, trace_b->metadata->tc->uuid);
	}

	return ret;
}

/*
 * Count the number of stream and event classes defined by this trace's metadata.
 *
 * This is used to determine which metadata is the "latest", out of multiple
 * traces sharing the same UUID.  It is assumed that amongst all these metadatas,
 * a bigger metadata is a superset of a smaller metadata.  Therefore, it is
 * enough to just count the classes.
 */

static
unsigned int metadata_count_stream_and_event_classes(struct ctf_fs_trace *trace)
{
	unsigned int num = trace->metadata->tc->stream_classes->len;
	guint i;

	for (i = 0; i < trace->metadata->tc->stream_classes->len; i++) {
		struct ctf_stream_class *sc = trace->metadata->tc->stream_classes->pdata[i];
		num += sc->event_classes->len;
	}

	return num;
}

/*
 * Merge the src ds_file_group into dest.  This consists of merging their
 * ds_file_infos, making sure to keep the result sorted.
 */

static
void merge_ctf_fs_ds_file_groups(struct ctf_fs_ds_file_group *dest, struct ctf_fs_ds_file_group *src)
{
	guint i;

	for (i = 0; i < src->ds_file_infos->len; i++) {
		struct ctf_fs_ds_file_info *ds_file_info =
			g_ptr_array_index(src->ds_file_infos, i);

		/* Ownership of the ds_file_info is transferred to dest. */
		g_ptr_array_index(src->ds_file_infos, i) = NULL;

		ds_file_group_insert_ds_file_info_sorted(dest, ds_file_info);
	}

	/* Merge both indexes. */
	for (i = 0; i < src->index->entries->len; i++) {
		struct ctf_fs_ds_index_entry *entry = g_ptr_array_index(
			src->index->entries, i);

		/*
		 * Ownership of the ctf_fs_ds_index_entry is transferred to
		 * dest.
		 */
		g_ptr_array_index(src->index->entries, i) = NULL;

		ds_file_group_insert_ds_index_entry_sorted(dest, entry);
	}
}
/* Merge src_trace's data stream file groups into dest_trace's. */

static
int merge_matching_ctf_fs_ds_file_groups(
		struct ctf_fs_trace *dest_trace,
		struct ctf_fs_trace *src_trace)
{

	GPtrArray *dest = dest_trace->ds_file_groups;
	GPtrArray *src = src_trace->ds_file_groups;
	guint s_i;
	int ret = 0;

	/*
	 * Save the initial length of dest: we only want to check against the
	 * original elements in the inner loop.
	 */
	const guint dest_len = dest->len;

	for (s_i = 0; s_i < src->len; s_i++) {
		struct ctf_fs_ds_file_group *src_group = g_ptr_array_index(src, s_i);
		struct ctf_fs_ds_file_group *dest_group = NULL;

		/* A stream instance without ID can't match a stream in the other trace.  */
		if (src_group->stream_id != -1) {
			guint d_i;

			/* Let's search for a matching ds_file_group in the destination.  */
			for (d_i = 0; d_i < dest_len; d_i++) {
				struct ctf_fs_ds_file_group *candidate_dest = g_ptr_array_index(dest, d_i);

				/* Can't match a stream instance without ID.  */
				if (candidate_dest->stream_id == -1) {
					continue;
				}

				/*
				 * If the two groups have the same stream instance id
				 * and belong to the same stream class (stream instance
				 * ids are per-stream class), they represent the same
				 * stream instance.
				 */
				if (candidate_dest->stream_id != src_group->stream_id ||
						candidate_dest->sc->id != src_group->sc->id) {
					continue;
				}

				dest_group = candidate_dest;
				break;
			}
		}

		/*
		 * Didn't find a friend in dest to merge our src_group into?
		 * Create a new empty one. This can happen if a stream was
		 * active in the source trace chunk but not in the destination
		 * trace chunk.
		 */
		if (!dest_group) {
			struct ctf_stream_class *sc;
			struct ctf_fs_ds_index *index;

			sc = ctf_trace_class_borrow_stream_class_by_id(
				dest_trace->metadata->tc, src_group->sc->id);
			BT_ASSERT(sc);

			index = ctf_fs_ds_index_create(dest_trace->log_level,
				dest_trace->self_comp);
			if (!index) {
				ret = -1;
				goto end;
			}

			dest_group = ctf_fs_ds_file_group_create(dest_trace, sc,
				src_group->stream_id, index);
			/* Ownership of index is transferred. */
			index = NULL;
			if (!dest_group) {
				ret = -1;
				goto end;
			}

			g_ptr_array_add(dest_trace->ds_file_groups, dest_group);
		}

		BT_ASSERT(dest_group);
		merge_ctf_fs_ds_file_groups(dest_group, src_group);
	}

end:
	return ret;
}

/*
 * Collapse the given traces, which must all share the same UUID, in a single
 * one.
 *
 * The trace with the most expansive metadata is chosen and all other traces
 * are merged into that one.  The array slots of all the traces that get merged
 * in the chosen one are set to NULL, so only the slot of the chosen trace
 * remains non-NULL.
 */

static
int merge_ctf_fs_traces(struct ctf_fs_trace **traces, unsigned int num_traces)
{
	unsigned int winner_count;
	struct ctf_fs_trace *winner;
	guint i;
	int ret = 0;
	char uuid_str[BABELTRACE_UUID_STR_LEN];

	BT_ASSERT(num_traces >= 2);

	winner_count = metadata_count_stream_and_event_classes(traces[0]);
	winner = traces[0];

	/* Find the trace with the largest metadata. */
	for (i = 1; i < num_traces; i++) {
		struct ctf_fs_trace *candidate;
		unsigned int candidate_count;

		candidate = traces[i];

		/* A bit of sanity check. */
		BT_ASSERT(bt_uuid_compare(winner->metadata->tc->uuid, candidate->metadata->tc->uuid) == 0);

		candidate_count = metadata_count_stream_and_event_classes(candidate);

		if (candidate_count > winner_count) {
			winner_count = candidate_count;
			winner = candidate;
		}
	}

	/* Merge all the other traces in the winning trace. */
	for (i = 0; i < num_traces; i++) {
		struct ctf_fs_trace *trace = traces[i];

		/* Don't merge the winner into itself. */
		if (trace == winner) {
			continue;
		}

		/* Merge trace's data stream file groups into winner's. */
		ret = merge_matching_ctf_fs_ds_file_groups(winner, trace);
		if (ret) {
			goto end;
		}

		/* Free the trace that got merged into winner, clear the slot in the array. */
		ctf_fs_trace_destroy(trace);
		traces[i] = NULL;
	}

	/* Use the string representation of the UUID as the trace name. */
	bt_uuid_unparse(winner->metadata->tc->uuid, uuid_str);
	g_string_printf(winner->name, "%s", uuid_str);

end:
	return ret;
}

/*
 * Merge all traces of `ctf_fs` that share the same UUID in a single trace.
 * Traces with no UUID are not merged.
 */

static
int merge_traces_with_same_uuid(struct ctf_fs_component *ctf_fs)
{
	GPtrArray *traces = ctf_fs->traces;
	guint range_start_idx = 0;
	unsigned int num_traces = 0;
	guint i;
	int ret = 0;

	/* Sort the traces by uuid, then collapse traces with the same uuid in a single one. */
	g_ptr_array_sort(traces, sort_traces_by_uuid);

	/* Find ranges of consecutive traces that share the same UUID.  */
	while (range_start_idx < traces->len) {
		guint range_len;
		struct ctf_fs_trace *range_start_trace = g_ptr_array_index(traces, range_start_idx);

		/* Exclusive end of range. */
		guint range_end_exc_idx = range_start_idx + 1;

		while (range_end_exc_idx < traces->len) {
			struct ctf_fs_trace *this_trace = g_ptr_array_index(traces, range_end_exc_idx);

			if (!range_start_trace->metadata->tc->is_uuid_set ||
				(bt_uuid_compare(range_start_trace->metadata->tc->uuid, this_trace->metadata->tc->uuid) != 0)) {
				break;
			}

			range_end_exc_idx++;
		}

		/* If we have two or more traces with matching UUIDs, merge them. */
		range_len = range_end_exc_idx - range_start_idx;
		if (range_len > 1) {
			struct ctf_fs_trace **range_start = (struct ctf_fs_trace **) &traces->pdata[range_start_idx];
			ret = merge_ctf_fs_traces(range_start, range_len);
			if (ret) {
				goto end;
			}
		}

		num_traces++;
		range_start_idx = range_end_exc_idx;
	}

	/* Clear any NULL slot (traces that got merged in another one) in the array.  */
	for (i = 0; i < traces->len;) {
		if (g_ptr_array_index(traces, i) == NULL) {
			g_ptr_array_remove_index_fast(traces, i);
		} else {
			i++;
		}
	}

	BT_ASSERT(num_traces == traces->len);

end:
	return ret;
}

int ctf_fs_component_create_ctf_fs_traces(bt_self_component_source *self_comp,
		struct ctf_fs_component *ctf_fs,
		const bt_value *paths_value)
{
	int ret = 0;
	uint64_t i;

	for (i = 0; i < bt_value_array_get_size(paths_value); i++) {
		const bt_value *path_value = bt_value_array_borrow_element_by_index_const(paths_value, i);
		const char *path = bt_value_string_get(path_value);

		ret = ctf_fs_component_create_ctf_fs_traces_one_root(ctf_fs,
			path);
		if (ret) {
			goto end;
		}
	}

	ret = merge_traces_with_same_uuid(ctf_fs);

end:
	return ret;
}

static
GString *get_stream_instance_unique_name(
		struct ctf_fs_ds_file_group *ds_file_group)
{
	GString *name;
	struct ctf_fs_ds_file_info *ds_file_info;

	name = g_string_new(NULL);
	if (!name) {
		goto end;
	}

	/*
	 * If there's more than one stream file in the stream file
	 * group, the first (earliest) stream file's path is used as
	 * the stream's unique name.
	 */
	BT_ASSERT(ds_file_group->ds_file_infos->len > 0);
	ds_file_info = g_ptr_array_index(ds_file_group->ds_file_infos, 0);
	g_string_assign(name, ds_file_info->path->str);

end:
	return name;
}

/* Create the IR stream objects for ctf_fs_trace. */

static
int create_streams_for_trace(struct ctf_fs_trace *ctf_fs_trace)
{
	int ret;
	GString *name = NULL;
	guint i;
	bt_logging_level log_level = ctf_fs_trace->log_level;
	bt_self_component *self_comp = ctf_fs_trace->self_comp;

	for (i = 0; i < ctf_fs_trace->ds_file_groups->len; i++) {
		struct ctf_fs_ds_file_group *ds_file_group =
			g_ptr_array_index(ctf_fs_trace->ds_file_groups, i);
		name = get_stream_instance_unique_name(ds_file_group);

		if (!name) {
			goto error;
		}

		if (ds_file_group->sc->ir_sc) {
			BT_ASSERT(ctf_fs_trace->trace);

			if (ds_file_group->stream_id == UINT64_C(-1)) {
				/* No stream ID: use 0 */
				ds_file_group->stream = bt_stream_create_with_id(
					ds_file_group->sc->ir_sc,
					ctf_fs_trace->trace,
					ctf_fs_trace->next_stream_id);
				ctf_fs_trace->next_stream_id++;
			} else {
				/* Specific stream ID */
				ds_file_group->stream = bt_stream_create_with_id(
					ds_file_group->sc->ir_sc,
					ctf_fs_trace->trace,
					(uint64_t) ds_file_group->stream_id);
			}
		} else {
			ds_file_group->stream = NULL;
		}

		if (!ds_file_group->stream) {
			BT_COMP_LOGE("Cannot create stream for DS file group: "
				"addr=%p, stream-name=\"%s\"",
				ds_file_group, name->str);
			goto error;
		}

		ret = bt_stream_set_name(ds_file_group->stream,
			name->str);
		if (ret) {
			BT_COMP_LOGE("Cannot set stream's name: "
				"addr=%p, stream-name=\"%s\"",
				ds_file_group->stream, name->str);
			goto error;
		}

		g_string_free(name, TRUE);
		name = NULL;
	}

	ret = 0;
	goto end;

error:
	ret = -1;

end:

	if (name) {
		g_string_free(name, TRUE);
	}
	return ret;
}

/*
 * Validate the "paths" parameter passed to this component.  It must be
 * present, and it must be an array of strings.
 */

static
bool validate_paths_parameter(struct ctf_fs_component *ctf_fs,
		const bt_value *paths)
{
	bool ret;
	bt_value_type type;
	uint64_t i;
	bt_logging_level log_level = ctf_fs->log_level;
	bt_self_component *self_comp = ctf_fs->self_comp;

	if (!paths) {
		BT_COMP_LOGE("missing \"paths\" parameter");
		goto error;
	}

	type = bt_value_get_type(paths);
	if (type != BT_VALUE_TYPE_ARRAY) {
		BT_COMP_LOGE("`paths` parameter: expecting array value: type=%s",
			bt_common_value_type_string(type));
		goto error;
	}

	for (i = 0; i < bt_value_array_get_size(paths); i++) {
		const bt_value *elem;

		elem = bt_value_array_borrow_element_by_index_const(paths, i);
		type = bt_value_get_type(elem);
		if (type != BT_VALUE_TYPE_STRING) {
			BT_COMP_LOGE("`paths` parameter: expecting string value: index=%" PRIu64 ", type=%s",
				i, bt_common_value_type_string(type));
			goto error;
		}
	}

	ret = true;
	goto end;

error:
	ret = false;

end:
	return ret;
}

bool read_src_fs_parameters(const bt_value *params,
		const bt_value **paths, struct ctf_fs_component *ctf_fs) {
	bool ret;
	const bt_value *value;
	bt_logging_level log_level = ctf_fs->log_level;
	bt_self_component *self_comp = ctf_fs->self_comp;

	/* paths parameter */
	*paths = bt_value_map_borrow_entry_value_const(params, "paths");
	if (!validate_paths_parameter(ctf_fs, *paths)) {
		goto error;
	}

	/* clock-class-offset-s parameter */
	value = bt_value_map_borrow_entry_value_const(params,
		"clock-class-offset-s");
	if (value) {
		if (!bt_value_is_signed_integer(value)) {
			BT_COMP_LOGE("clock-class-offset-s must be an integer");
			goto error;
		}
		ctf_fs->metadata_config.clock_class_offset_s =
			bt_value_signed_integer_get(value);
	}

	/* clock-class-offset-ns parameter */
	value = bt_value_map_borrow_entry_value_const(params,
		"clock-class-offset-ns");
	if (value) {
		if (!bt_value_is_signed_integer(value)) {
			BT_COMP_LOGE("clock-class-offset-ns must be an integer");
			goto error;
		}
		ctf_fs->metadata_config.clock_class_offset_ns =
			bt_value_signed_integer_get(value);
	}


	ret = true;
	goto end;

error:
	ret = false;

end:
	return ret;
}

static
struct ctf_fs_component *ctf_fs_create(
		bt_self_component_source *self_comp_src,
		const bt_value *params)
{
	struct ctf_fs_component *ctf_fs = NULL;
	guint i;
	const bt_value *paths_value;
	bt_self_component *self_comp =
		bt_self_component_source_as_self_component(self_comp_src);

	ctf_fs = ctf_fs_component_create(bt_component_get_logging_level(
		bt_self_component_as_component(self_comp)), self_comp);
	if (!ctf_fs) {
		goto error;
	}

	if (!read_src_fs_parameters(params, &paths_value, ctf_fs)) {
		goto error;
	}

	bt_self_component_set_data(self_comp, ctf_fs);
	ctf_fs->self_comp = self_comp;
	ctf_fs->self_comp_src = self_comp_src;

	if (ctf_fs_component_create_ctf_fs_traces(self_comp_src, ctf_fs, paths_value)) {
		goto error;
	}

	for (i = 0; i < ctf_fs->traces->len; i++) {
		struct ctf_fs_trace *trace = g_ptr_array_index(ctf_fs->traces, i);

		if (create_streams_for_trace(trace)) {
			goto error;
		}

		if (create_ports_for_trace(ctf_fs, trace)) {
			goto error;
		}
	}

	goto end;

error:
	ctf_fs_destroy(ctf_fs);
	ctf_fs = NULL;
	bt_self_component_set_data(self_comp, NULL);

end:
	return ctf_fs;
}

BT_HIDDEN
bt_self_component_status ctf_fs_init(
		bt_self_component_source *self_comp,
		const bt_value *params, __attribute__((unused)) void *init_method_data)
{
	struct ctf_fs_component *ctf_fs;
	bt_self_component_status ret = BT_SELF_COMPONENT_STATUS_OK;

	ctf_fs = ctf_fs_create(self_comp, params);
	if (!ctf_fs) {
		ret = BT_SELF_COMPONENT_STATUS_ERROR;
	}

	return ret;
}

BT_HIDDEN
bt_query_status ctf_fs_query(
		bt_self_component_class_source *comp_class,
		const bt_query_executor *query_exec,
		const char *object, const bt_value *params,
		bt_logging_level log_level,
		const bt_value **result)
{
	bt_query_status status = BT_QUERY_STATUS_OK;

	if (!strcmp(object, "metadata-info")) {
		status = metadata_info_query(comp_class, params, log_level,
			result);
	} else if (!strcmp(object, "trace-info")) {
		status = trace_info_query(comp_class, params, log_level,
			result);
	} else {
		BT_LOGE("Unknown query object `%s`", object);
		status = BT_QUERY_STATUS_INVALID_OBJECT;
		goto end;
	}
end:
	return status;
}