Save and restore error in ctf_fs_iterator_next, muxer_msg_iter_do_next

[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 "logging/comp-logging.h"

#include "common/common.h"
#include <babeltrace2/babeltrace.h>
#include "common/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/metadata/ctf-meta-configure-ir-trace.h"
#include "../common/msg-iter/msg-iter.h"
#include "query.h"
#include "plugins/common/param-validation/param-validation.h"

struct tracer_info {
        const char *name;
        int64_t major;
        int64_t minor;
        int64_t patch;
};

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->self_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) {
                ctf_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)
{
        ctf_msg_iter_set_emit_stream_beginning_message(
                msg_iter_data->ds_file->msg_iter,
                msg_iter_data->ds_file_info_index == 0);
        ctf_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_component_class_message_iterator_next_method_status ctf_fs_iterator_next_one(
                struct ctf_fs_msg_iter_data *msg_iter_data,
                const bt_message **out_msg)
{
        bt_component_class_message_iterator_next_method_status status;

        BT_ASSERT_DBG(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_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK:
                        *out_msg = msg;
                        msg = NULL;
                        goto end;
                case BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_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++;
                        ctf_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_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                                goto end;
                        }

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

end:
        return status;
}

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

        if (G_UNLIKELY(msg_iter_data->next_saved_error)) {
                /*
                 * Last time we were called, we hit an error but had some
                 * messages to deliver, so we stashed the error here.  Return
                 * it now.
                 */
                BT_CURRENT_THREAD_MOVE_ERROR_AND_RESET(msg_iter_data->next_saved_error);
                status = msg_iter_data->next_saved_status;
                goto end;
        }

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

        if (i > 0) {
                /*
                 * Even if ctf_fs_iterator_next_one() returned something
                 * else than BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK, we
                 * accumulated message objects in the output
                 * message array, so we need to return
                 * BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_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.
                 */
                if (status < 0) {
                        /*
                         * Save this error for the next _next call.  Assume that
                         * this component always appends error causes when
                         * returning an error status code, which will cause the
                         * current thread error to be non-NULL.
                         */
                        msg_iter_data->next_saved_error = bt_current_thread_take_error();
                        BT_ASSERT(msg_iter_data->next_saved_error);
                        msg_iter_data->next_saved_status = status;
                }

                *count = i;
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
        }

end:
        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;
        }

        ctf_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_component_class_message_iterator_seek_beginning_method_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_component_class_message_iterator_seek_beginning_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_SEEK_BEGINNING_METHOD_STATUS_OK;

        BT_ASSERT(msg_iter_data);
        if (ctf_fs_iterator_reset(msg_iter_data)) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_SEEK_BEGINNING_METHOD_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_component_class_message_iterator_initialize_method_status ctf_fs_iterator_init(
                bt_self_message_iterator *self_msg_iter,
                bt_self_message_iterator_configuration *config,
                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_component_class_message_iterator_initialize_method_status ret =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INITIALIZE_METHOD_STATUS_OK;
        bt_logging_level log_level;
        bt_self_component *self_comp =
                bt_self_component_source_as_self_component(self_comp_src);

        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;
        msg_iter_data = g_new0(struct ctf_fs_msg_iter_data, 1);
        if (!msg_iter_data) {
                ret = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INITIALIZE_METHOD_STATUS_MEMORY_ERROR;
                goto error;
        }

        msg_iter_data->log_level = log_level;
        msg_iter_data->self_comp = self_comp;
        msg_iter_data->self_msg_iter = self_msg_iter;
        msg_iter_data->msg_iter = ctf_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, self_msg_iter);
        if (!msg_iter_data->msg_iter) {
                BT_COMP_LOGE_APPEND_CAUSE(self_comp, "Cannot create a CTF message iterator.");
                ret = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INITIALIZE_METHOD_STATUS_MEMORY_ERROR;
                goto error;
        }

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

        /*
         * This iterator can seek forward if its stream class has a default
         * clock class.
         */
        if (msg_iter_data->ds_file_group->sc->default_clock_class) {
                bt_self_message_iterator_configuration_set_can_seek_forward(
                        config, true);
        }

        bt_self_message_iterator_set_data(self_msg_iter,
                msg_iter_data);
        if (ret != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INITIALIZE_METHOD_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;
}

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

        g_free(ctf_fs_trace);
}

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

        ctf_fs_trace_destroy(ctf_fs->trace);

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

        goto end;

error:
        ctf_fs_destroy(ctf_fs);
        ctf_fs = NULL;

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[BT_UUID_STR_LEN + 1];

                bt_uuid_to_str(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,
                bt_self_component_source *self_comp_src)
{
        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 =
                bt_self_component_source_as_self_component(self_comp_src);

        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(
                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:
        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,
                bt_self_component_source *self_comp_src)
{
        int ret = 0;
        size_t i;
        bt_logging_level log_level = ctf_fs_trace->log_level;
        bt_self_component *self_comp =
                bt_self_component_source_as_self_component(self_comp_src);

        /* 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, self_comp_src);
                if (ret) {
                        BT_COMP_LOGE_APPEND_CAUSE(self_comp, "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_index_insert_ds_index_entry_sorted(
        struct ctf_fs_ds_index *index,
        struct ctf_fs_ds_index_entry *entry)
{
        guint i;

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

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

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

static
void merge_ctf_fs_ds_indexes(struct ctf_fs_ds_index *dest, struct ctf_fs_ds_index *src)
{
        guint i;

        for (i = 0; i < src->entries->len; i++) {
                struct ctf_fs_ds_index_entry *entry =
                        g_ptr_array_index(src->entries, i);

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

                ds_index_insert_ds_index_entry_sorted(dest, entry);
        }
}

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_file_info *ds_file_info = NULL;
        struct ctf_fs_ds_index *index = NULL;
        struct ctf_msg_iter *msg_iter = NULL;
        struct ctf_stream_class *sc = NULL;
        struct ctf_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;
        bt_self_component_class *self_comp_class = ctf_fs_trace->self_comp_class;

        msg_iter = ctf_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, NULL);
        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 = ctf_msg_iter_get_packet_properties(ds_file->msg_iter, &props);
        if (ret) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "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_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                "Cannot convert clock cycles to nanoseconds from origin (`%s`).",
                                path);
                        goto error;
                }
        }

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

        index = ctf_fs_ds_file_build_index(ds_file, ds_file_info);
        if (!index) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(
                        self_comp, self_comp_class,
                        "Failed to index CTF stream file \'%s\'",
                        ds_file->file->path->str);
                goto error;
        }

        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;
                }

                ds_file_group_insert_ds_file_info_sorted(ds_file_group,
                        BT_MOVE_REF(ds_file_info));

                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;
        } else {
                merge_ctf_fs_ds_indexes(ds_file_group->index, index);
        }

        ds_file_group_insert_ds_file_info_sorted(ds_file_group,
                BT_MOVE_REF(ds_file_info));

        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);
        ctf_fs_ds_file_info_destroy(ds_file_info);

        if (msg_iter) {
                ctf_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;
        bt_self_component_class *self_comp_class = ctf_fs_trace->self_comp_class;

        /* 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_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "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) == 0) {
                        /* 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_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                "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_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                "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_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                "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_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_borrow_environment_entry_value_by_name_const(
                trace, "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,
                bt_self_component_class *self_comp_class,
                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;

        /* Only one of them must be set. */
        BT_ASSERT(!self_comp != !self_comp_class);

        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->self_comp_class = self_comp_class;
        ctf_fs_trace->path = g_string_new(path);
        if (!ctf_fs_trace->path) {
                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 = ctf_trace_class_configure_ir_trace(
                        ctf_fs_trace->metadata->tc, ctf_fs_trace->trace);
                if (ret) {
                        goto error;
                }

                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;
}

/* Helper for ctf_fs_component_create_ctf_fs_trace, to handle a single path. */

static
int ctf_fs_component_create_ctf_fs_trace_one_path(
                struct ctf_fs_component *ctf_fs,
                const char *path_param,
                const char *trace_name,
                GPtrArray *traces,
                bt_self_component *self_comp,
                bt_self_component_class *self_comp_class)
{
        struct ctf_fs_trace *ctf_fs_trace;
        int ret;
        GString *norm_path;
        bt_logging_level log_level = ctf_fs->log_level;

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

        ret = path_is_ctf_trace(norm_path->str);
        if (ret < 0) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "Failed to check if path is a CTF trace: path=%s",
                        norm_path->str);
                goto error;
        } else if (ret == 0) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "Path is not a CTF trace (does not contain a metadata file): `%s`.",
                        norm_path->str);
                goto error;
        }

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

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

        g_ptr_array_add(traces, ctf_fs_trace);
        ctf_fs_trace = NULL;

        ret = 0;
        goto end;

error:
        ret = -1;

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

        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. */
        merge_ctf_fs_ds_indexes(dest->index, src->index);
}
/* 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,
                struct ctf_fs_trace **out_trace)
{
        unsigned int winner_count;
        struct ctf_fs_trace *winner;
        guint i, winner_i;
        int ret = 0;

        BT_ASSERT(num_traces >= 2);

        winner_count = metadata_count_stream_and_event_classes(traces[0]);
        winner = traces[0];
        winner_i = 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;
                        winner_i = i;
                }
        }

        /* 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;
                }
        }

        /*
         * Move the winner out of the array, into `*out_trace`.
         */
        *out_trace = winner;
        traces[winner_i] = NULL;

end:
        return ret;
}

enum target_event {
        FIRST_EVENT,
        LAST_EVENT,
};

static
int decode_clock_snapshot_after_event(struct ctf_fs_trace *ctf_fs_trace,
        struct ctf_clock_class *default_cc,
        struct ctf_fs_ds_index_entry *index_entry,
        enum target_event target_event, uint64_t *cs, int64_t *ts_ns)
{
        enum ctf_msg_iter_status iter_status = CTF_MSG_ITER_STATUS_OK;
        struct ctf_fs_ds_file *ds_file = NULL;
        struct ctf_msg_iter *msg_iter = NULL;
        bt_logging_level log_level = ctf_fs_trace->log_level;
        bt_self_component *self_comp = ctf_fs_trace->self_comp;
        int ret = 0;

        BT_ASSERT(ctf_fs_trace);
        BT_ASSERT(ctf_fs_trace->metadata);
        BT_ASSERT(ctf_fs_trace->metadata->tc);

        msg_iter = ctf_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, NULL);
        if (!msg_iter) {
                /* ctf_msg_iter_create() logs errors. */
                ret = -1;
                goto end;
        }

        BT_ASSERT(index_entry);
        BT_ASSERT(index_entry->path);

        ds_file = ctf_fs_ds_file_create(ctf_fs_trace, NULL, msg_iter,
                NULL, index_entry->path, log_level);
        if (!ds_file) {
                BT_COMP_LOGE_APPEND_CAUSE(self_comp, "Failed to create a ctf_fs_ds_file");
                ret = -1;
                goto end;
        }

        /*
         * Turn on dry run mode to prevent the creation and usage of Babeltrace
         * library objects (bt_field, bt_message_*, etc.).
         */
        ctf_msg_iter_set_dry_run(msg_iter, true);

        /* Seek to the beginning of the target packet. */
        iter_status = ctf_msg_iter_seek(ds_file->msg_iter, index_entry->offset);
        if (iter_status) {
                /* ctf_msg_iter_seek() logs errors. */
                ret = -1;
                goto end;
        }

        switch (target_event) {
        case FIRST_EVENT:
                /*
                 * Start to decode the packet until we reach the end of
                 * the first event. To extract the first event's clock
                 * snapshot.
                 */
                iter_status = ctf_msg_iter_curr_packet_first_event_clock_snapshot(
                        ds_file->msg_iter, cs);
                break;
        case LAST_EVENT:
                /* Decode the packet to extract the last event's clock snapshot. */
                iter_status = ctf_msg_iter_curr_packet_last_event_clock_snapshot(
                        ds_file->msg_iter, cs);
                break;
        default:
                bt_common_abort();
        }
        if (iter_status) {
                ret = -1;
                goto end;
        }

        /* Convert clock snapshot to timestamp. */
        ret = bt_util_clock_cycles_to_ns_from_origin(*cs,
                default_cc->frequency, default_cc->offset_seconds,
                default_cc->offset_cycles, ts_ns);
        if (ret) {
                BT_COMP_LOGE_APPEND_CAUSE(self_comp,
                        "Failed to convert clock snapshot to timestamp");
                goto end;
        }

end:
        if (ds_file) {
                ctf_fs_ds_file_destroy(ds_file);
        }
        if (msg_iter) {
                ctf_msg_iter_destroy(msg_iter);
        }

        return ret;
}

static
int decode_packet_first_event_timestamp(struct ctf_fs_trace *ctf_fs_trace,
        struct ctf_clock_class *default_cc,
        struct ctf_fs_ds_index_entry *index_entry, uint64_t *cs, int64_t *ts_ns)
{
        return decode_clock_snapshot_after_event(ctf_fs_trace, default_cc,
                index_entry, FIRST_EVENT, cs, ts_ns);
}

static
int decode_packet_last_event_timestamp(struct ctf_fs_trace *ctf_fs_trace,
        struct ctf_clock_class *default_cc,
        struct ctf_fs_ds_index_entry *index_entry, uint64_t *cs, int64_t *ts_ns)
{
        return decode_clock_snapshot_after_event(ctf_fs_trace, default_cc,
                index_entry, LAST_EVENT, cs, ts_ns);
}

/*
 * Fix up packet index entries for lttng's "event-after-packet" bug.
 * Some buggy lttng tracer versions may emit events with a timestamp that is
 * larger (after) than the timestamp_end of the their packets.
 *
 * To fix up this erroneous data we do the following:
 *  1. If it's not the stream file's last packet: set the packet index entry's
 *      end time to the next packet's beginning time.
 *  2. If it's the stream file's last packet, set the packet index entry's end
 *      time to the packet's last event's time, if any, or to the packet's
 *      beginning time otherwise.
 *
 * Known buggy tracer versions:
 *  - before lttng-ust 2.11.0
 *  - before lttng-module 2.11.0
 *  - before lttng-module 2.10.10
 *  - before lttng-module 2.9.13
 */
static
int fix_index_lttng_event_after_packet_bug(struct ctf_fs_trace *trace)
{
        int ret = 0;
        guint ds_file_group_i;
        GPtrArray *ds_file_groups = trace->ds_file_groups;
        bt_logging_level log_level = trace->log_level;

        for (ds_file_group_i = 0; ds_file_group_i < ds_file_groups->len;
                        ds_file_group_i++) {
                guint entry_i;
                struct ctf_clock_class *default_cc;
                struct ctf_fs_ds_index_entry *last_entry;
                struct ctf_fs_ds_index *index;

                struct ctf_fs_ds_file_group *ds_file_group =
                        g_ptr_array_index(ds_file_groups, ds_file_group_i);

                BT_ASSERT(ds_file_group);
                index = ds_file_group->index;

                BT_ASSERT(index);
                BT_ASSERT(index->entries);
                BT_ASSERT(index->entries->len > 0);

                /*
                 * Iterate over all entries but the last one. The last one is
                 * fixed differently after.
                 */
                for (entry_i = 0; entry_i < index->entries->len - 1;
                                entry_i++) {
                        struct ctf_fs_ds_index_entry *curr_entry, *next_entry;

                        curr_entry = g_ptr_array_index(index->entries, entry_i);
                        next_entry = g_ptr_array_index(index->entries, entry_i + 1);

                        /*
                         * 1. Set the current index entry `end` timestamp to
                         * the next index entry `begin` timestamp.
                         */
                        curr_entry->timestamp_end = next_entry->timestamp_begin;
                        curr_entry->timestamp_end_ns = next_entry->timestamp_begin_ns;
                }

                /*
                 * 2. Fix the last entry by decoding the last event of the last
                 * packet.
                 */
                last_entry = g_ptr_array_index(index->entries,
                        index->entries->len - 1);
                BT_ASSERT(last_entry);

                BT_ASSERT(ds_file_group->sc->default_clock_class);
                default_cc = ds_file_group->sc->default_clock_class;

                /*
                 * Decode packet to read the timestamp of the last event of the
                 * entry.
                 */
                ret = decode_packet_last_event_timestamp(trace, default_cc,
                        last_entry, &last_entry->timestamp_end,
                        &last_entry->timestamp_end_ns);
                if (ret) {
                        BT_COMP_LOGE_APPEND_CAUSE(trace->self_comp,
                                "Failed to decode stream's last packet to get its last event's clock snapshot.");
                        goto end;
                }
        }

end:
        return ret;
}

/*
 * Fix up packet index entries for barectf's "event-before-packet" bug.
 * Some buggy barectf tracer versions may emit events with a timestamp that is
 * less than the timestamp_begin of the their packets.
 *
 * To fix up this erroneous data we do the following:
 *  1. Starting at the second index entry, set the timestamp_begin of the
 *     current entry to the timestamp of the first event of the packet.
 *  2. Set the previous entry's timestamp_end to the timestamp_begin of the
 *     current packet.
 *
 * Known buggy tracer versions:
 *  - before barectf 2.3.1
 */
static
int fix_index_barectf_event_before_packet_bug(struct ctf_fs_trace *trace)
{
        int ret = 0;
        guint ds_file_group_i;
        GPtrArray *ds_file_groups = trace->ds_file_groups;
        bt_logging_level log_level = trace->log_level;

        for (ds_file_group_i = 0; ds_file_group_i < ds_file_groups->len;
                        ds_file_group_i++) {
                guint entry_i;
                struct ctf_clock_class *default_cc;
                struct ctf_fs_ds_file_group *ds_file_group =
                        g_ptr_array_index(ds_file_groups, ds_file_group_i);

                struct ctf_fs_ds_index *index = ds_file_group->index;

                BT_ASSERT(index);
                BT_ASSERT(index->entries);
                BT_ASSERT(index->entries->len > 0);

                BT_ASSERT(ds_file_group->sc->default_clock_class);
                default_cc = ds_file_group->sc->default_clock_class;

                /*
                 * 1. Iterate over the index, starting from the second entry
                 * (index = 1).
                 */
                for (entry_i = 1; entry_i < index->entries->len;
                                entry_i++) {
                        struct ctf_fs_ds_index_entry *curr_entry, *prev_entry;
                        prev_entry = g_ptr_array_index(index->entries, entry_i - 1);
                        curr_entry = g_ptr_array_index(index->entries, entry_i);
                        /*
                         * 2. Set the current entry `begin` timestamp to the
                         * timestamp of the first event of the current packet.
                         */
                        ret = decode_packet_first_event_timestamp(trace, default_cc,
                                curr_entry, &curr_entry->timestamp_begin,
                                &curr_entry->timestamp_begin_ns);
                        if (ret) {
                                BT_COMP_LOGE_APPEND_CAUSE(trace->self_comp,
                                        "Failed to decode first event's clock snapshot");
                                goto end;
                        }

                        /*
                         * 3. Set the previous entry `end` timestamp to the
                         * timestamp of the first event of the current packet.
                         */
                        prev_entry->timestamp_end = curr_entry->timestamp_begin;
                        prev_entry->timestamp_end_ns = curr_entry->timestamp_begin_ns;
                }
        }
end:
        return ret;
}

/*
 * When using the lttng-crash feature it's likely that the last packets of each
 * stream have their timestamp_end set to zero. This is caused by the fact that
 * the tracer crashed and was not able to properly close the packets.
 *
 * To fix up this erroneous data we do the following:
 * For each index entry, if the entry's timestamp_end is 0 and the
 * timestamp_begin is not 0:
 *  - If it's the stream file's last packet: set the packet index entry's end
 *    time to the packet's last event's time, if any, or to the packet's
 *    beginning time otherwise.
 *  - If it's not the stream file's last packet: set the packet index
 *    entry's end time to the next packet's beginning time.
 *
 * Affected versions:
 * - All current and future lttng-ust and lttng-modules versions.
 */
static
int fix_index_lttng_crash_quirk(struct ctf_fs_trace *trace)
{
        int ret = 0;
        guint ds_file_group_idx;
        GPtrArray *ds_file_groups = trace->ds_file_groups;
        bt_logging_level log_level = trace->log_level;

        for (ds_file_group_idx = 0; ds_file_group_idx < ds_file_groups->len;
                        ds_file_group_idx++) {
                guint entry_idx;
                struct ctf_clock_class *default_cc;
                struct ctf_fs_ds_index_entry *last_entry;
                struct ctf_fs_ds_index *index;

                struct ctf_fs_ds_file_group *ds_file_group =
                        g_ptr_array_index(ds_file_groups, ds_file_group_idx);

                BT_ASSERT(ds_file_group);
                index = ds_file_group->index;

                BT_ASSERT(ds_file_group->sc->default_clock_class);
                default_cc = ds_file_group->sc->default_clock_class;

                BT_ASSERT(index);
                BT_ASSERT(index->entries);
                BT_ASSERT(index->entries->len > 0);

                last_entry = g_ptr_array_index(index->entries,
                        index->entries->len - 1);
                BT_ASSERT(last_entry);


                /* 1. Fix the last entry first. */
                if (last_entry->timestamp_end == 0 &&
                                last_entry->timestamp_begin != 0) {
                        /*
                         * Decode packet to read the timestamp of the
                         * last event of the stream file.
                         */
                        ret = decode_packet_last_event_timestamp(trace,
                                default_cc, last_entry,
                                &last_entry->timestamp_end,
                                &last_entry->timestamp_end_ns);
                        if (ret) {
                                BT_COMP_LOGE_APPEND_CAUSE(trace->self_comp,
                                        "Failed to decode last event's clock snapshot");
                                goto end;
                        }
                }

                /* Iterate over all entries but the last one. */
                for (entry_idx = 0; entry_idx < index->entries->len - 1;
                                entry_idx++) {
                        struct ctf_fs_ds_index_entry *curr_entry, *next_entry;
                        curr_entry = g_ptr_array_index(index->entries, entry_idx);
                        next_entry = g_ptr_array_index(index->entries, entry_idx + 1);

                        if (curr_entry->timestamp_end == 0 &&
                                        curr_entry->timestamp_begin != 0) {
                                /*
                                 * 2. Set the current index entry `end` timestamp to
                                 * the next index entry `begin` timestamp.
                                 */
                                curr_entry->timestamp_end = next_entry->timestamp_begin;
                                curr_entry->timestamp_end_ns = next_entry->timestamp_begin_ns;
                        }
                }
        }

end:
        return ret;
}

/*
 * Extract the tracer information necessary to compare versions.
 * Returns 0 on success, and -1 if the extraction is not successful because the
 * necessary fields are absents in the trace metadata.
 */
static
int extract_tracer_info(struct ctf_fs_trace *trace,
                struct tracer_info *current_tracer_info)
{
        int ret = 0;
        struct ctf_trace_class_env_entry *entry;

        /* Clear the current_tracer_info struct */
        memset(current_tracer_info, 0, sizeof(*current_tracer_info));

        /*
         * To compare 2 tracer versions, at least the tracer name and it's
         * major version are needed. If one of these is missing, consider it an
         * extraction failure.
         */
        entry = ctf_trace_class_borrow_env_entry_by_name(
                trace->metadata->tc, "tracer_name");
        if (!entry || entry->type != CTF_TRACE_CLASS_ENV_ENTRY_TYPE_STR) {
                goto missing_bare_minimum;
        }

        /* Set tracer name. */
        current_tracer_info->name = entry->value.str->str;

        entry = ctf_trace_class_borrow_env_entry_by_name(
                trace->metadata->tc, "tracer_major");
        if (!entry || entry->type != CTF_TRACE_CLASS_ENV_ENTRY_TYPE_INT) {
                goto missing_bare_minimum;
        }

        /* Set major version number. */
        current_tracer_info->major = entry->value.i;

        entry = ctf_trace_class_borrow_env_entry_by_name(
                trace->metadata->tc, "tracer_minor");
        if (!entry || entry->type != CTF_TRACE_CLASS_ENV_ENTRY_TYPE_INT) {
                goto end;
        }

        /* Set minor version number. */
        current_tracer_info->minor = entry->value.i;

        entry = ctf_trace_class_borrow_env_entry_by_name(
                trace->metadata->tc, "tracer_patch");
        if (!entry) {
                /*
                 * If `tracer_patch` doesn't exist `tracer_patchlevel` might.
                 * For example, `lttng-modules` uses entry name
                 * `tracer_patchlevel`.
                 */
                entry = ctf_trace_class_borrow_env_entry_by_name(
                        trace->metadata->tc, "tracer_patchlevel");
        }

        if (!entry || entry->type != CTF_TRACE_CLASS_ENV_ENTRY_TYPE_INT) {
                goto end;
        }

        /* Set patch version number. */
        current_tracer_info->patch = entry->value.i;

        goto end;

missing_bare_minimum:
        ret = -1;
end:
        return ret;
}

static
bool is_tracer_affected_by_lttng_event_after_packet_bug(
                struct tracer_info *curr_tracer_info)
{
        bool is_affected = false;

        if (strcmp(curr_tracer_info->name, "lttng-ust") == 0) {
                if (curr_tracer_info->major < 2) {
                        is_affected = true;
                } else if (curr_tracer_info->major == 2) {
                        /* fixed in lttng-ust 2.11.0 */
                        if (curr_tracer_info->minor < 11) {
                                is_affected = true;
                        }
                }
        } else if (strcmp(curr_tracer_info->name, "lttng-modules") == 0) {
                if (curr_tracer_info->major < 2) {
                        is_affected = true;
                } else if (curr_tracer_info->major == 2) {
                        /* fixed in lttng-modules 2.11.0 */
                        if (curr_tracer_info->minor == 10) {
                                /* fixed in lttng-modules 2.10.10 */
                                if (curr_tracer_info->patch < 10) {
                                        is_affected = true;
                                }
                        } else if (curr_tracer_info->minor == 9) {
                                /* fixed in lttng-modules 2.9.13 */
                                if (curr_tracer_info->patch < 13) {
                                        is_affected = true;
                                }
                        } else if (curr_tracer_info->minor < 9) {
                                is_affected = true;
                        }
                }
        }

        return is_affected;
}

static
bool is_tracer_affected_by_barectf_event_before_packet_bug(
                struct tracer_info *curr_tracer_info)
{
        bool is_affected = false;

        if (strcmp(curr_tracer_info->name, "barectf") == 0) {
                if (curr_tracer_info->major < 2) {
                        is_affected = true;
                } else if (curr_tracer_info->major == 2) {
                        if (curr_tracer_info->minor < 3) {
                                is_affected = true;
                        } else if (curr_tracer_info->minor == 3) {
                                /* fixed in barectf 2.3.1 */
                                if (curr_tracer_info->patch < 1) {
                                        is_affected = true;
                                }
                        }
                }
        }

        return is_affected;
}

static
bool is_tracer_affected_by_lttng_crash_quirk(
                struct tracer_info *curr_tracer_info)
{
        bool is_affected = false;

        /* All LTTng tracer may be affected by this lttng crash quirk. */
        if (strcmp(curr_tracer_info->name, "lttng-ust") == 0) {
                is_affected = true;
        } else if (strcmp(curr_tracer_info->name, "lttng-modules") == 0) {
                is_affected = true;
        }

        return is_affected;
}

/*
 * Looks for trace produced by known buggy tracers and fix up the index
 * produced earlier.
 */
static
int fix_packet_index_tracer_bugs(struct ctf_fs_component *ctf_fs,
                bt_self_component *self_comp,
                bt_self_component_class *self_comp_class)
{
        int ret = 0;
        struct tracer_info current_tracer_info;
        bt_logging_level log_level = ctf_fs->log_level;

        ret = extract_tracer_info(ctf_fs->trace, &current_tracer_info);
        if (ret) {
                /*
                 * A trace may not have all the necessary environment
                 * entries to do the tracer version comparison.
                 * At least, the tracer name and major version number
                 * are needed. Failing to extract these entries is not
                 * an error.
                 */
                ret = 0;
                BT_LOGI_STR("Cannot extract tracer information necessary to compare with buggy versions.");
                goto end;;
        }

        /* Check if the trace may be affected by old tracer bugs. */
        if (is_tracer_affected_by_lttng_event_after_packet_bug(
                        &current_tracer_info)) {
                BT_LOGI_STR("Trace may be affected by LTTng tracer packet timestamp bug. Fixing up.");
                ret = fix_index_lttng_event_after_packet_bug(ctf_fs->trace);
                if (ret) {
                        BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(
                                self_comp, self_comp_class,
                                "Failed to fix LTTng event-after-packet bug.");
                        goto end;
                }
                ctf_fs->trace->metadata->tc->quirks.lttng_event_after_packet = true;
        }

        if (is_tracer_affected_by_barectf_event_before_packet_bug(
                        &current_tracer_info)) {
                BT_LOGI_STR("Trace may be affected by barectf tracer packet timestamp bug. Fixing up.");
                ret = fix_index_barectf_event_before_packet_bug(ctf_fs->trace);
                if (ret) {
                        BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(
                                self_comp, self_comp_class,
                                "Failed to fix barectf event-before-packet bug.");
                        goto end;
                }
                ctf_fs->trace->metadata->tc->quirks.barectf_event_before_packet = true;
        }

        if (is_tracer_affected_by_lttng_crash_quirk(
                        &current_tracer_info)) {
                ret = fix_index_lttng_crash_quirk(ctf_fs->trace);
                if (ret) {
                        BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(
                                self_comp, self_comp_class,
                                "Failed to fix lttng-crash timestamp quirks.");
                        goto end;
                }
                ctf_fs->trace->metadata->tc->quirks.lttng_crash = true;
        }

end:
        return ret;
}

static
gint compare_ds_file_groups_by_first_path(gconstpointer a, gconstpointer b)
{
        struct ctf_fs_ds_file_group * const *ds_file_group_a = a;
        struct ctf_fs_ds_file_group * const *ds_file_group_b = b;
        const struct ctf_fs_ds_file_info *first_ds_file_info_a;
        const struct ctf_fs_ds_file_info *first_ds_file_info_b;

        BT_ASSERT((*ds_file_group_a)->ds_file_infos->len > 0);
        BT_ASSERT((*ds_file_group_b)->ds_file_infos->len > 0);
        first_ds_file_info_a = (*ds_file_group_a)->ds_file_infos->pdata[0];
        first_ds_file_info_b = (*ds_file_group_b)->ds_file_infos->pdata[0];
        return strcmp(first_ds_file_info_a->path->str,
                first_ds_file_info_b->path->str);
}

int ctf_fs_component_create_ctf_fs_trace(
                struct ctf_fs_component *ctf_fs,
                const bt_value *paths_value,
                const bt_value *trace_name_value,
                bt_self_component *self_comp,
                bt_self_component_class *self_comp_class)
{
        int ret = 0;
        uint64_t i;
        bt_logging_level log_level = ctf_fs->log_level;
        GPtrArray *traces;
        const char *trace_name;

        BT_ASSERT(bt_value_get_type(paths_value) == BT_VALUE_TYPE_ARRAY);
        BT_ASSERT(!bt_value_array_is_empty(paths_value));

        traces = g_ptr_array_new_with_free_func(ctf_fs_trace_destroy_notifier);
        if (!traces) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "Failed to allocate a GPtrArray.");
                goto error;
        }

        trace_name = trace_name_value ? bt_value_string_get(trace_name_value) : NULL;

        /* Start by creating a separate ctf_fs_trace object for each path. */
        for (i = 0; i < bt_value_array_get_length(paths_value); i++) {
                const bt_value *path_value = bt_value_array_borrow_element_by_index_const(paths_value, i);
                const char *input = bt_value_string_get(path_value);

                ret = ctf_fs_component_create_ctf_fs_trace_one_path(ctf_fs,
                        input, trace_name, traces, self_comp, self_comp_class);
                if (ret) {
                        goto end;
                }
        }

        if (traces->len > 1) {
                struct ctf_fs_trace *first_trace = (struct ctf_fs_trace *) traces->pdata[0];
                const uint8_t *first_trace_uuid = first_trace->metadata->tc->uuid;
                struct ctf_fs_trace *trace;

                /*
                 * We have more than one trace, they must all share the same
                 * UUID, verify that.
                 */
                for (i = 0; i < traces->len; i++) {
                        struct ctf_fs_trace *this_trace =
                                (struct ctf_fs_trace *) traces->pdata[i];
                        const uint8_t *this_trace_uuid = this_trace->metadata->tc->uuid;

                        if (!this_trace->metadata->tc->is_uuid_set) {
                                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                        "Multiple traces given, but a trace does not have a UUID: path=%s",
                                        this_trace->path->str);
                                goto error;
                        }

                        if (bt_uuid_compare(first_trace_uuid, this_trace_uuid) != 0) {
                                char first_trace_uuid_str[BT_UUID_STR_LEN + 1];
                                char this_trace_uuid_str[BT_UUID_STR_LEN + 1];

                                bt_uuid_to_str(first_trace_uuid, first_trace_uuid_str);
                                bt_uuid_to_str(this_trace_uuid, this_trace_uuid_str);

                                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                        "Multiple traces given, but UUIDs don't match: "
                                        "first-trace-uuid=%s, first-trace-path=%s, "
                                        "trace-uuid=%s, trace-path=%s",
                                        first_trace_uuid_str, first_trace->path->str,
                                        this_trace_uuid_str, this_trace->path->str);
                                goto error;
                        }
                }

                ret = merge_ctf_fs_traces((struct ctf_fs_trace **) traces->pdata,
                        traces->len, &trace);
                if (ret) {
                        BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                                "Failed to merge traces with the same UUID.");
                        goto error;
                }

                ctf_fs->trace = trace;
        } else {
                /* Just one trace, it may or may not have a UUID, both are fine. */
                ctf_fs->trace = traces->pdata[0];
                traces->pdata[0] = NULL;
        }

        ret = fix_packet_index_tracer_bugs(ctf_fs, self_comp, self_comp_class);
        if (ret) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "Failed to fix packet index tracer bugs.");
        }

        /*
         * Sort data stream file groups by first data stream file info
         * path to get a deterministic order. This order influences the
         * order of the output ports. It also influences the order of
         * the automatic stream IDs if the trace's packet headers do not
         * contain a `stream_instance_id` field, in which case the data
         * stream file to stream ID association is always the same,
         * whatever the build and the system.
         *
         * Having a deterministic order here can help debugging and
         * testing.
         */
        g_ptr_array_sort(ctf_fs->trace->ds_file_groups,
                compare_ds_file_groups_by_first_path);
        goto end;
error:
        ret = -1;

end:
        g_ptr_array_free(traces, TRUE);
        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_APPEND_CAUSE(self_comp,
                                "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_APPEND_CAUSE(self_comp, "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;
}

static const struct bt_param_validation_value_descr inputs_elem_descr = {
        .type = BT_VALUE_TYPE_STRING,
};

static const struct bt_param_validation_map_value_entry_descr fs_params_entries_descr[] = {
        { "inputs", BT_PARAM_VALIDATION_MAP_VALUE_ENTRY_MANDATORY, {
                BT_VALUE_TYPE_ARRAY,
                .array = {
                        .min_length = 1,
                        .max_length = BT_PARAM_VALIDATION_INFINITE,
                        .element_type = &inputs_elem_descr,
                }
        }},
        { "trace-name", BT_PARAM_VALIDATION_MAP_VALUE_ENTRY_OPTIONAL, { .type = BT_VALUE_TYPE_STRING } },
        { "clock-class-offset-s", BT_PARAM_VALIDATION_MAP_VALUE_ENTRY_OPTIONAL, { .type = BT_VALUE_TYPE_SIGNED_INTEGER } },
        { "clock-class-offset-ns", BT_PARAM_VALIDATION_MAP_VALUE_ENTRY_OPTIONAL, { .type = BT_VALUE_TYPE_SIGNED_INTEGER } },
        { "force-clock-class-origin-unix-epoch", BT_PARAM_VALIDATION_MAP_VALUE_ENTRY_OPTIONAL, { .type = BT_VALUE_TYPE_BOOL } },
        BT_PARAM_VALIDATION_MAP_VALUE_ENTRY_END
};


bool read_src_fs_parameters(const bt_value *params,
                const bt_value **inputs,
                const bt_value **trace_name,
                struct ctf_fs_component *ctf_fs,
                bt_self_component *self_comp,
                bt_self_component_class *self_comp_class) {
        bool ret;
        const bt_value *value;
        bt_logging_level log_level = ctf_fs->log_level;
        enum bt_param_validation_status validate_value_status;
        gchar *error = NULL;

        validate_value_status = bt_param_validation_validate(params,
                fs_params_entries_descr, &error);
        if (validate_value_status != BT_PARAM_VALIDATION_STATUS_OK) {
                BT_COMP_OR_COMP_CLASS_LOGE_APPEND_CAUSE(self_comp, self_comp_class,
                        "%s", error);
                ret = false;
                goto end;
        }

        /* inputs parameter */
        *inputs = bt_value_map_borrow_entry_value_const(params, "inputs");

        /* clock-class-offset-s parameter */
        value = bt_value_map_borrow_entry_value_const(params,
                "clock-class-offset-s");
        if (value) {
                ctf_fs->metadata_config.clock_class_offset_s =
                        bt_value_integer_signed_get(value);
        }

        /* clock-class-offset-ns parameter */
        value = bt_value_map_borrow_entry_value_const(params,
                "clock-class-offset-ns");
        if (value) {
                ctf_fs->metadata_config.clock_class_offset_ns =
                        bt_value_integer_signed_get(value);
        }

        /* force-clock-class-origin-unix-epoch parameter */
        value = bt_value_map_borrow_entry_value_const(params,
                "force-clock-class-origin-unix-epoch");
        if (value) {
                ctf_fs->metadata_config.force_clock_class_origin_unix_epoch =
                        bt_value_bool_get(value);
        }

        /* trace-name parameter */
        *trace_name = bt_value_map_borrow_entry_value_const(params, "trace-name");

        ret = true;

end:
        g_free(error);
        return ret;
}

static
struct ctf_fs_component *ctf_fs_create(
        const bt_value *params,
        bt_self_component_source *self_comp_src)
{
        struct ctf_fs_component *ctf_fs = NULL;
        const bt_value *inputs_value;
        const bt_value *trace_name_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, &inputs_value, &trace_name_value,
                        ctf_fs, self_comp, NULL)) {
                goto error;
        }

        bt_self_component_set_data(self_comp, ctf_fs);

        if (ctf_fs_component_create_ctf_fs_trace(ctf_fs, inputs_value,
                        trace_name_value, self_comp, NULL)) {
                goto error;
        }

        if (create_streams_for_trace(ctf_fs->trace)) {
                goto error;
        }

        if (create_ports_for_trace(ctf_fs, ctf_fs->trace, self_comp_src)) {
                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_component_class_initialize_method_status ctf_fs_init(
                bt_self_component_source *self_comp_src,
                bt_self_component_source_configuration *config,
                const bt_value *params, __attribute__((unused)) void *init_method_data)
{
        struct ctf_fs_component *ctf_fs;
        bt_component_class_initialize_method_status ret =
                BT_COMPONENT_CLASS_INITIALIZE_METHOD_STATUS_OK;

        ctf_fs = ctf_fs_create(params, self_comp_src);
        if (!ctf_fs) {
                ret = BT_COMPONENT_CLASS_INITIALIZE_METHOD_STATUS_ERROR;
        }

        return ret;
}

BT_HIDDEN
bt_component_class_query_method_status ctf_fs_query(
                bt_self_component_class_source *comp_class,
                bt_private_query_executor *priv_query_exec,
                const char *object, const bt_value *params,
                __attribute__((unused)) void *method_data,
                const bt_value **result)
{
        bt_component_class_query_method_status status =
                BT_COMPONENT_CLASS_QUERY_METHOD_STATUS_OK;
        bt_logging_level log_level = bt_query_executor_get_logging_level(
                bt_private_query_executor_as_query_executor_const(
                        priv_query_exec));

        if (strcmp(object, "metadata-info") == 0) {
                status = metadata_info_query(comp_class, params, log_level,
                        result);
        } else if (strcmp(object, "babeltrace.trace-infos") == 0) {
                status = trace_infos_query(comp_class, params, log_level,
                        result);
        } else if (!strcmp(object, "babeltrace.support-info")) {
                status = support_info_query(comp_class, params, log_level, result);
        } else {
                BT_LOGE("Unknown query object `%s`", object);
                status = BT_COMPONENT_CLASS_QUERY_METHOD_STATUS_UNKNOWN_OBJECT;
                goto end;
        }
end:
        return status;
}