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

/*
 * Copyright 2016-2017 - Philippe Proulx <pproulx@efficios.com>
 * Copyright 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 * Copyright 2010-2011 - EfficiOS Inc. and Linux Foundation
 *
 * 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 (ds_file->self_comp)
#define BT_LOG_OUTPUT_LEVEL (ds_file->log_level)
#define BT_LOG_TAG "PLUGIN/SRC.CTF.FS/DS"
#include "logging/comp-logging.h"

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <glib.h>
#include <inttypes.h>
#include "compat/mman.h"
#include "compat/endian.h"
#include <babeltrace2/babeltrace.h>
#include "common/common.h"
#include "file.h"
#include "metadata.h"
#include "../common/msg-iter/msg-iter.h"
#include "common/assert.h"
#include "data-stream-file.h"
#include <string.h>

static inline
size_t remaining_mmap_bytes(struct ctf_fs_ds_file *ds_file)
{
        BT_ASSERT(ds_file->mmap_len >= ds_file->request_offset);
        return ds_file->mmap_len - ds_file->request_offset;
}

static
int ds_file_munmap(struct ctf_fs_ds_file *ds_file)
{
        int ret = 0;

        if (!ds_file || !ds_file->mmap_addr) {
                goto end;
        }

        if (bt_munmap(ds_file->mmap_addr, ds_file->mmap_len)) {
                BT_COMP_LOGE_ERRNO("Cannot memory-unmap file",
                        ": address=%p, size=%zu, file_path=\"%s\", file=%p",
                        ds_file->mmap_addr, ds_file->mmap_len,
                        ds_file->file ? ds_file->file->path->str : "NULL",
                        ds_file->file ? ds_file->file->fp : NULL);
                ret = -1;
                goto end;
        }

        ds_file->mmap_addr = NULL;

end:
        return ret;
}

static
enum bt_msg_iter_medium_status ds_file_mmap_next(
                struct ctf_fs_ds_file *ds_file)
{
        enum bt_msg_iter_medium_status ret =
                        BT_MSG_ITER_MEDIUM_STATUS_OK;

        /* Unmap old region */
        if (ds_file->mmap_addr) {
                if (ds_file_munmap(ds_file)) {
                        goto error;
                }

                /*
                 * mmap_len is guaranteed to be page-aligned except on the
                 * last mapping where it may not be possible (since the file's
                 * size itself may not be a page multiple).
                 */
                ds_file->mmap_offset += ds_file->mmap_len;
                ds_file->request_offset = 0;
        }

        ds_file->mmap_len = MIN(ds_file->file->size - ds_file->mmap_offset,
                        ds_file->mmap_max_len);
        if (ds_file->mmap_len == 0) {
                ret = BT_MSG_ITER_MEDIUM_STATUS_EOF;
                goto end;
        }
        /* Map new region */
        BT_ASSERT(ds_file->mmap_len);
        ds_file->mmap_addr = bt_mmap((void *) 0, ds_file->mmap_len,
                        PROT_READ, MAP_PRIVATE, fileno(ds_file->file->fp),
                        ds_file->mmap_offset, ds_file->log_level);
        if (ds_file->mmap_addr == MAP_FAILED) {
                BT_COMP_LOGE("Cannot memory-map address (size %zu) of file \"%s\" (%p) at offset %jd: %s",
                                ds_file->mmap_len, ds_file->file->path->str,
                                ds_file->file->fp, (intmax_t) ds_file->mmap_offset,
                                strerror(errno));
                goto error;
        }

        goto end;
error:
        ds_file_munmap(ds_file);
        ret = BT_MSG_ITER_MEDIUM_STATUS_ERROR;
end:
        return ret;
}

static
enum bt_msg_iter_medium_status medop_request_bytes(
                size_t request_sz, uint8_t **buffer_addr,
                size_t *buffer_sz, void *data)
{
        enum bt_msg_iter_medium_status status =
                BT_MSG_ITER_MEDIUM_STATUS_OK;
        struct ctf_fs_ds_file *ds_file = data;

        if (request_sz == 0) {
                goto end;
        }

        /*
         * Check if we have at least one memory-mapped byte left. If we don't,
         * mmap the next file.
         */
        if (remaining_mmap_bytes(ds_file) == 0) {
                /* Are we at the end of the file? */
                if (ds_file->mmap_offset >= ds_file->file->size) {
                        BT_COMP_LOGD("Reached end of file \"%s\" (%p)",
                                ds_file->file->path->str, ds_file->file->fp);
                        status = BT_MSG_ITER_MEDIUM_STATUS_EOF;
                        goto end;
                }

                status = ds_file_mmap_next(ds_file);
                switch (status) {
                case BT_MSG_ITER_MEDIUM_STATUS_OK:
                        break;
                case BT_MSG_ITER_MEDIUM_STATUS_EOF:
                        goto end;
                default:
                        BT_COMP_LOGE("Cannot memory-map next region of file \"%s\" (%p)",
                                        ds_file->file->path->str,
                                        ds_file->file->fp);
                        goto error;
                }
        }

        *buffer_sz = MIN(remaining_mmap_bytes(ds_file), request_sz);
        BT_ASSERT(ds_file->mmap_addr);
        *buffer_addr = ((uint8_t *) ds_file->mmap_addr) + ds_file->request_offset;
        ds_file->request_offset += *buffer_sz;
        goto end;

error:
        status = BT_MSG_ITER_MEDIUM_STATUS_ERROR;

end:
        return status;
}

static
bt_stream *medop_borrow_stream(bt_stream_class *stream_class, int64_t stream_id,
                void *data)
{
        struct ctf_fs_ds_file *ds_file = data;
        bt_stream_class *ds_file_stream_class;
        bt_stream *stream = NULL;

        ds_file_stream_class = bt_stream_borrow_class(
                ds_file->stream);

        if (stream_class != ds_file_stream_class) {
                /*
                 * Not supported: two packets described by two different
                 * stream classes within the same data stream file.
                 */
                goto end;
        }

        stream = ds_file->stream;

end:
        return stream;
}

static
enum bt_msg_iter_medium_status medop_seek(enum bt_msg_iter_seek_whence whence,
                off_t offset, void *data)
{
        enum bt_msg_iter_medium_status ret =
                        BT_MSG_ITER_MEDIUM_STATUS_OK;
        struct ctf_fs_ds_file *ds_file = data;
        off_t offset_in_mapping, file_size = ds_file->file->size;

        if (whence != BT_MSG_ITER_SEEK_WHENCE_SET ||
                offset < 0 || offset > file_size) {
                BT_COMP_LOGE("Invalid medium seek request: whence=%d, offset=%jd, "
                                "file-size=%jd", (int) whence, (intmax_t) offset,
                                (intmax_t) file_size);
                ret = BT_MSG_ITER_MEDIUM_STATUS_INVAL;
                goto end;
        }

        /* If there is no current mapping, map the right file directly. */
        if (!ds_file->mmap_addr) {
                goto map_requested_offset;
        }

        /*
         * Determine whether or not the destination is contained within the
         * current mapping.
         */
        if (offset < ds_file->mmap_offset ||
                        offset >= ds_file->mmap_offset + ds_file->mmap_len) {
                int unmap_ret;
                BT_COMP_LOGD("Medium seek request cannot be accomodated by the current "
                                "file mapping: offset=%jd, mmap-offset=%jd, "
                                "mmap-len=%zu", (intmax_t) offset, (intmax_t) ds_file->mmap_offset,
                                ds_file->mmap_len);
                unmap_ret = ds_file_munmap(ds_file);
                if (unmap_ret) {
                        ret = BT_MSG_ITER_MEDIUM_STATUS_ERROR;
                        goto end;
                }
                goto map_requested_offset;
        } else {
                ds_file->request_offset = offset - ds_file->mmap_offset;
                goto test_end;
        }

map_requested_offset:
        offset_in_mapping = offset %
                bt_mmap_get_offset_align_size(ds_file->log_level);

        ds_file->mmap_offset = offset - offset_in_mapping;
        ds_file->request_offset = offset_in_mapping;
        ret = ds_file_mmap_next(ds_file);
        if (ret != BT_MSG_ITER_MEDIUM_STATUS_OK) {
                goto end;
        }

test_end:
        ds_file->end_reached = (offset == file_size);
end:
        return ret;
}

BT_HIDDEN
struct bt_msg_iter_medium_ops ctf_fs_ds_file_medops = {
        .request_bytes = medop_request_bytes,
        .borrow_stream = medop_borrow_stream,
        .seek = medop_seek,
};

static
int convert_cycles_to_ns(struct ctf_clock_class *clock_class,
                uint64_t cycles, int64_t *ns)
{
        return bt_util_clock_cycles_to_ns_from_origin(cycles,
                        clock_class->frequency, clock_class->offset_seconds,
                        clock_class->offset_cycles, ns);
}

static
struct ctf_fs_ds_index *build_index_from_idx_file(
                struct ctf_fs_ds_file *ds_file,
                struct ctf_fs_ds_file_info *file_info)
{
        int ret;
        gchar *directory = NULL;
        gchar *basename = NULL;
        GString *index_basename = NULL;
        gchar *index_file_path = NULL;
        GMappedFile *mapped_file = NULL;
        gsize filesize;
        const char *mmap_begin = NULL, *file_pos = NULL;
        const struct ctf_packet_index_file_hdr *header = NULL;
        struct ctf_fs_ds_index *index = NULL;
        struct ctf_fs_ds_index_entry *index_entry = NULL, *prev_index_entry = NULL;
        uint64_t total_packets_size = 0;
        size_t file_index_entry_size;
        size_t file_entry_count;
        size_t i;
        struct ctf_stream_class *sc;
        struct bt_msg_iter_packet_properties props;

        BT_COMP_LOGI("Building index from .idx file of stream file %s",
                        ds_file->file->path->str);
        ret = bt_msg_iter_get_packet_properties(ds_file->msg_iter, &props);
        if (ret) {
                BT_COMP_LOGI_STR("Cannot read first packet's header and context fields.");
                goto error;
        }

        sc = ctf_trace_class_borrow_stream_class_by_id(ds_file->metadata->tc,
                props.stream_class_id);
        BT_ASSERT(sc);
        if (!sc->default_clock_class) {
                BT_COMP_LOGI_STR("Cannot find stream class's default clock class.");
                goto error;
        }

        /* Look for index file in relative path index/name.idx. */
        basename = g_path_get_basename(ds_file->file->path->str);
        if (!basename) {
                BT_COMP_LOGE("Cannot get the basename of datastream file %s",
                                ds_file->file->path->str);
                goto error;
        }

        directory = g_path_get_dirname(ds_file->file->path->str);
        if (!directory) {
                BT_COMP_LOGE("Cannot get dirname of datastream file %s",
                                ds_file->file->path->str);
                goto error;
        }

        index_basename = g_string_new(basename);
        if (!index_basename) {
                BT_COMP_LOGE_STR("Cannot allocate index file basename string");
                goto error;
        }

        g_string_append(index_basename, ".idx");
        index_file_path = g_build_filename(directory, "index",
                        index_basename->str, NULL);
        mapped_file = g_mapped_file_new(index_file_path, FALSE, NULL);
        if (!mapped_file) {
                BT_COMP_LOGD("Cannot create new mapped file %s",
                                index_file_path);
                goto error;
        }

        /*
         * The g_mapped_file API limits us to 4GB files on 32-bit.
         * Traces with such large indexes have never been seen in the wild,
         * but this would need to be adjusted to support them.
         */
        filesize = g_mapped_file_get_length(mapped_file);
        if (filesize < sizeof(*header)) {
                BT_COMP_LOGW("Invalid LTTng trace index file: "
                        "file size (%zu bytes) < header size (%zu bytes)",
                        filesize, sizeof(*header));
                goto error;
        }

        mmap_begin = g_mapped_file_get_contents(mapped_file);
        header = (struct ctf_packet_index_file_hdr *) mmap_begin;

        file_pos = g_mapped_file_get_contents(mapped_file) + sizeof(*header);
        if (be32toh(header->magic) != CTF_INDEX_MAGIC) {
                BT_COMP_LOGW_STR("Invalid LTTng trace index: \"magic\" field validation failed");
                goto error;
        }

        file_index_entry_size = be32toh(header->packet_index_len);
        file_entry_count = (filesize - sizeof(*header)) / file_index_entry_size;
        if ((filesize - sizeof(*header)) % file_index_entry_size) {
                BT_COMP_LOGW("Invalid LTTng trace index: the index's size after the header "
                        "(%zu bytes) is not a multiple of the index entry size "
                        "(%zu bytes)", (filesize - sizeof(*header)),
                        sizeof(*header));
                goto error;
        }

        index = ctf_fs_ds_index_create(ds_file->log_level, ds_file->self_comp);
        if (!index) {
                goto error;
        }

        for (i = 0; i < file_entry_count; i++) {
                struct ctf_packet_index *file_index =
                                (struct ctf_packet_index *) file_pos;
                uint64_t packet_size = be64toh(file_index->packet_size);

                if (packet_size % CHAR_BIT) {
                        BT_COMP_LOGW("Invalid packet size encountered in LTTng trace index file");
                        goto error;
                }

                index_entry = g_new0(struct ctf_fs_ds_index_entry, 1);
                if (!index_entry) {
                        goto error;
                }

                /* Set path to stream file. */
                index_entry->path = file_info->path->str;

                /* Convert size in bits to bytes. */
                packet_size /= CHAR_BIT;
                index_entry->packet_size = packet_size;

                index_entry->offset = be64toh(file_index->offset);
                if (i != 0 && index_entry->offset < prev_index_entry->offset) {
                        BT_COMP_LOGW("Invalid, non-monotonic, packet offset encountered in LTTng trace index file: "
                                "previous offset=%" PRIu64 ", current offset=%" PRIu64,
                                prev_index_entry->offset, index_entry->offset);
                        goto error;
                }

                index_entry->timestamp_begin = be64toh(file_index->timestamp_begin);
                index_entry->timestamp_end = be64toh(file_index->timestamp_end);
                if (index_entry->timestamp_end < index_entry->timestamp_begin) {
                        BT_COMP_LOGW("Invalid packet time bounds encountered in LTTng trace index file (begin > end): "
                                "timestamp_begin=%" PRIu64 "timestamp_end=%" PRIu64,
                                index_entry->timestamp_begin,
                                index_entry->timestamp_end);
                        goto error;
                }

                /* Convert the packet's bound to nanoseconds since Epoch. */
                ret = convert_cycles_to_ns(sc->default_clock_class,
                                index_entry->timestamp_begin,
                                &index_entry->timestamp_begin_ns);
                if (ret) {
                        BT_COMP_LOGI_STR("Failed to convert raw timestamp to nanoseconds since Epoch during index parsing");
                        goto error;
                }
                ret = convert_cycles_to_ns(sc->default_clock_class,
                                index_entry->timestamp_end,
                                &index_entry->timestamp_end_ns);
                if (ret) {
                        BT_COMP_LOGI_STR("Failed to convert raw timestamp to nanoseconds since Epoch during LTTng trace index parsing");
                        goto error;
                }

                total_packets_size += packet_size;
                file_pos += file_index_entry_size;

                g_ptr_array_add(index->entries, index_entry);
                prev_index_entry = index_entry;
        }

        /* Validate that the index addresses the complete stream. */
        if (ds_file->file->size != total_packets_size) {
                BT_COMP_LOGW("Invalid LTTng trace index file; indexed size != stream file size: "
                        "file-size=%" PRIu64 ", total-packets-size=%" PRIu64,
                        ds_file->file->size, total_packets_size);
                goto error;
        }
end:
        g_free(directory);
        g_free(basename);
        g_free(index_file_path);
        if (index_basename) {
                g_string_free(index_basename, TRUE);
        }
        if (mapped_file) {
                g_mapped_file_unref(mapped_file);
        }
        return index;
error:
        ctf_fs_ds_index_destroy(index);
        g_free(index_entry);
        index = NULL;
        goto end;
}

static
int init_index_entry(struct ctf_fs_ds_index_entry *entry,
                struct ctf_fs_ds_file *ds_file,
                struct bt_msg_iter_packet_properties *props,
                off_t packet_size, off_t packet_offset)
{
        int ret = 0;
        struct ctf_stream_class *sc;

        sc = ctf_trace_class_borrow_stream_class_by_id(ds_file->metadata->tc,
                props->stream_class_id);
        BT_ASSERT(sc);
        BT_ASSERT(packet_offset >= 0);
        entry->offset = packet_offset;
        BT_ASSERT(packet_size >= 0);
        entry->packet_size = packet_size;

        if (props->snapshots.beginning_clock != UINT64_C(-1)) {
                entry->timestamp_begin = props->snapshots.beginning_clock;

                /* Convert the packet's bound to nanoseconds since Epoch. */
                ret = convert_cycles_to_ns(sc->default_clock_class,
                                           props->snapshots.beginning_clock,
                                           &entry->timestamp_begin_ns);
                if (ret) {
                        BT_COMP_LOGI_STR("Failed to convert raw timestamp to nanoseconds since Epoch.");
                        goto end;
                }
        } else {
                entry->timestamp_begin = UINT64_C(-1);
                entry->timestamp_begin_ns = UINT64_C(-1);
        }

        if (props->snapshots.end_clock != UINT64_C(-1)) {
                entry->timestamp_end = props->snapshots.end_clock;

                /* Convert the packet's bound to nanoseconds since Epoch. */
                ret = convert_cycles_to_ns(sc->default_clock_class,
                                           props->snapshots.end_clock,
                                           &entry->timestamp_end_ns);
                if (ret) {
                        BT_COMP_LOGI_STR("Failed to convert raw timestamp to nanoseconds since Epoch.");
                        goto end;
                }
        } else {
                entry->timestamp_end = UINT64_C(-1);
                entry->timestamp_end_ns = UINT64_C(-1);
        }

end:
        return ret;
}

static
struct ctf_fs_ds_index *build_index_from_stream_file(
                struct ctf_fs_ds_file *ds_file,
                struct ctf_fs_ds_file_info *file_info)
{
        int ret;
        struct ctf_fs_ds_index *index = NULL;
        enum bt_msg_iter_status iter_status = BT_MSG_ITER_STATUS_OK;
        off_t current_packet_offset_bytes = 0;

        BT_COMP_LOGI("Indexing stream file %s", ds_file->file->path->str);

        index = ctf_fs_ds_index_create(ds_file->log_level, ds_file->self_comp);
        if (!index) {
                goto error;
        }

        while (true) {
                off_t current_packet_size_bytes;
                struct ctf_fs_ds_index_entry *index_entry;
                struct bt_msg_iter_packet_properties props;

                if (current_packet_offset_bytes < 0) {
                        BT_COMP_LOGE_STR("Cannot get the current packet's offset.");
                        goto error;
                } else if (current_packet_offset_bytes > ds_file->file->size) {
                        BT_COMP_LOGE_STR("Unexpected current packet's offset (larger than file).");
                        goto error;
                } else if (current_packet_offset_bytes == ds_file->file->size) {
                        /* No more data */
                        break;
                }

                iter_status = bt_msg_iter_seek(ds_file->msg_iter,
                                current_packet_offset_bytes);
                if (iter_status != BT_MSG_ITER_STATUS_OK) {
                        goto error;
                }

                iter_status = bt_msg_iter_get_packet_properties(
                        ds_file->msg_iter, &props);
                if (iter_status != BT_MSG_ITER_STATUS_OK) {
                        goto error;
                }

                if (props.exp_packet_total_size >= 0) {
                        current_packet_size_bytes =
                                (uint64_t) props.exp_packet_total_size / 8;
                } else {
                        current_packet_size_bytes = ds_file->file->size;
                }

                if (current_packet_offset_bytes + current_packet_size_bytes >
                                ds_file->file->size) {
                        BT_COMP_LOGW("Invalid packet size reported in file: stream=\"%s\", "
                                        "packet-offset=%jd, packet-size-bytes=%jd, "
                                        "file-size=%jd",
                                        ds_file->file->path->str,
                                        (intmax_t) current_packet_offset_bytes,
                                        (intmax_t) current_packet_size_bytes,
                                        (intmax_t) ds_file->file->size);
                        goto error;
                }

                index_entry = g_new0(struct ctf_fs_ds_index_entry, 1);
                if (!index_entry) {
                        BT_COMP_LOGE_STR("Failed to allocate a new index entry.");
                        goto error;
                }

                /* Set path to stream file. */
                index_entry->path = file_info->path->str;

                ret = init_index_entry(index_entry, ds_file, &props,
                        current_packet_size_bytes, current_packet_offset_bytes);
                if (ret) {
                        g_free(index_entry);
                        goto error;
                }

                g_ptr_array_add(index->entries, index_entry);

                current_packet_offset_bytes += current_packet_size_bytes;
                BT_COMP_LOGD("Seeking to next packet: current-packet-offset=%jd, "
                        "next-packet-offset=%jd",
                        (intmax_t) (current_packet_offset_bytes - current_packet_size_bytes),
                        (intmax_t) current_packet_offset_bytes);
        }

end:
        return index;

error:
        ctf_fs_ds_index_destroy(index);
        index = NULL;
        goto end;
}

BT_HIDDEN
struct ctf_fs_ds_file *ctf_fs_ds_file_create(
                struct ctf_fs_trace *ctf_fs_trace,
                bt_self_message_iterator *pc_msg_iter,
                struct bt_msg_iter *msg_iter,
                bt_stream *stream, const char *path,
                bt_logging_level log_level)
{
        int ret;
        const size_t offset_align = bt_mmap_get_offset_align_size(log_level);
        struct ctf_fs_ds_file *ds_file = g_new0(struct ctf_fs_ds_file, 1);

        if (!ds_file) {
                goto error;
        }

        ds_file->log_level = log_level;
        ds_file->self_comp = ctf_fs_trace->self_comp;
        ds_file->pc_msg_iter = pc_msg_iter;
        ds_file->file = ctf_fs_file_create(log_level, ds_file->self_comp);
        if (!ds_file->file) {
                goto error;
        }

        ds_file->stream = stream;
        bt_stream_get_ref(ds_file->stream);
        ds_file->metadata = ctf_fs_trace->metadata;
        g_string_assign(ds_file->file->path, path);
        ret = ctf_fs_file_open(ds_file->file, "rb");
        if (ret) {
                goto error;
        }

        ds_file->msg_iter = msg_iter;
        bt_msg_iter_set_medops_data(ds_file->msg_iter, ds_file);
        if (!ds_file->msg_iter) {
                goto error;
        }

        ds_file->mmap_max_len = offset_align * 2048;

        goto end;

error:
        /* Do not touch "borrowed" file. */
        ctf_fs_ds_file_destroy(ds_file);
        ds_file = NULL;

end:
        return ds_file;
}

BT_HIDDEN
struct ctf_fs_ds_index *ctf_fs_ds_file_build_index(
                struct ctf_fs_ds_file *ds_file,
                struct ctf_fs_ds_file_info *file_info)
{
        struct ctf_fs_ds_index *index;

        index = build_index_from_idx_file(ds_file, file_info);
        if (index) {
                goto end;
        }

        BT_COMP_LOGI("Failed to build index from .index file; "
                "falling back to stream indexing.");
        index = build_index_from_stream_file(ds_file, file_info);
end:
        return index;
}

BT_HIDDEN
struct ctf_fs_ds_index *ctf_fs_ds_index_create(bt_logging_level log_level,
                bt_self_component *self_comp)
{
        struct ctf_fs_ds_index *index = g_new0(struct ctf_fs_ds_index, 1);

        if (!index) {
                BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
                        "Failed to allocate index");
                goto error;
        }

        index->entries = g_ptr_array_new_with_free_func((GDestroyNotify) g_free);
        if (!index->entries) {
                BT_COMP_LOG_CUR_LVL(BT_LOG_ERROR, log_level, self_comp,
                        "Failed to allocate index entries.");
                goto error;
        }

        goto end;

error:
        ctf_fs_ds_index_destroy(index);
        index = NULL;
end:
        return index;
}

BT_HIDDEN
void ctf_fs_ds_file_destroy(struct ctf_fs_ds_file *ds_file)
{
        if (!ds_file) {
                return;
        }

        bt_stream_put_ref(ds_file->stream);
        (void) ds_file_munmap(ds_file);

        if (ds_file->file) {
                ctf_fs_file_destroy(ds_file->file);
        }

        g_free(ds_file);
}

BT_HIDDEN
bt_component_class_message_iterator_next_method_status ctf_fs_ds_file_next(
                struct ctf_fs_ds_file *ds_file,
                bt_message **msg)
{
        enum bt_msg_iter_status msg_iter_status;
        bt_component_class_message_iterator_next_method_status status;

        msg_iter_status = bt_msg_iter_get_next_message(
                ds_file->msg_iter, ds_file->pc_msg_iter, msg);

        switch (msg_iter_status) {
        case BT_MSG_ITER_STATUS_EOF:
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END;
                break;
        case BT_MSG_ITER_STATUS_OK:
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
                break;
        case BT_MSG_ITER_STATUS_AGAIN:
                /*
                 * Should not make it this far as this is
                 * medium-specific; there is nothing for the user to do
                 * and it should have been handled upstream.
                 */
                abort();
        case BT_MSG_ITER_STATUS_INVAL:
        case BT_MSG_ITER_STATUS_ERROR:
        default:
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                break;
        }
        return status;
}

BT_HIDDEN
void ctf_fs_ds_index_destroy(struct ctf_fs_ds_index *index)
{
        if (!index) {
                return;
        }

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