Add backward ref from bt_stream_pos to bt_trace_descriptor

[babeltrace.git] / formats / ctf / ctf.c

/*
 * BabelTrace - Common Trace Format (CTF)
 *
 * Format registration.
 *
 * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
 *
 * Author: Mathieu Desnoyers <mathieu.desnoyers@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.
 */

#include <babeltrace/format.h>
#include <babeltrace/ctf/types.h>
#include <babeltrace/ctf/metadata.h>
#include <babeltrace/babeltrace-internal.h>
#include <babeltrace/ctf/events-internal.h>
#include <babeltrace/trace-handle-internal.h>
#include <babeltrace/context-internal.h>
#include <babeltrace/uuid.h>
#include <babeltrace/endian.h>
#include <inttypes.h>
#include <stdio.h>
#include <sys/mman.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <glib.h>
#include <unistd.h>
#include <stdlib.h>

#include "metadata/ctf-scanner.h"
#include "metadata/ctf-parser.h"
#include "metadata/ctf-ast.h"
#include "events-private.h"
#include "memstream.h"

#define LOG2_CHAR_BIT   3

/*
 * Length of first attempt at mapping a packet header, in bits.
 */
#define DEFAULT_HEADER_LEN      (getpagesize() * CHAR_BIT)

/*
 * Lenght of packet to write, in bits.
 */
#define WRITE_PACKET_LEN        (getpagesize() * 8 * CHAR_BIT)

#ifndef min
#define min(a, b)       (((a) < (b)) ? (a) : (b))
#endif

#define NSEC_PER_SEC 1000000000ULL

int opt_clock_cycles,
        opt_clock_seconds,
        opt_clock_date,
        opt_clock_gmt;

uint64_t opt_clock_offset;

extern int yydebug;

static
struct bt_trace_descriptor *ctf_open_trace(const char *path, int flags,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence),
                FILE *metadata_fp);
static
struct bt_trace_descriptor *ctf_open_mmap_trace(
                struct bt_mmap_stream_list *mmap_list,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence),
                FILE *metadata_fp);
static
void ctf_set_context(struct bt_trace_descriptor *descriptor,
                struct bt_context *ctx);
static
void ctf_set_handle(struct bt_trace_descriptor *descriptor,
                struct bt_trace_handle *handle);

static
int ctf_close_trace(struct bt_trace_descriptor *descriptor);
static
uint64_t ctf_timestamp_begin(struct bt_trace_descriptor *descriptor,
                struct bt_trace_handle *handle, enum bt_clock_type type);
static
uint64_t ctf_timestamp_end(struct bt_trace_descriptor *descriptor,
                struct bt_trace_handle *handle, enum bt_clock_type type);
static
int ctf_convert_index_timestamp(struct bt_trace_descriptor *tdp);

static
rw_dispatch read_dispatch_table[] = {
        [ CTF_TYPE_INTEGER ] = ctf_integer_read,
        [ CTF_TYPE_FLOAT ] = ctf_float_read,
        [ CTF_TYPE_ENUM ] = ctf_enum_read,
        [ CTF_TYPE_STRING ] = ctf_string_read,
        [ CTF_TYPE_STRUCT ] = ctf_struct_rw,
        [ CTF_TYPE_VARIANT ] = ctf_variant_rw,
        [ CTF_TYPE_ARRAY ] = ctf_array_read,
        [ CTF_TYPE_SEQUENCE ] = ctf_sequence_read,
};

static
rw_dispatch write_dispatch_table[] = {
        [ CTF_TYPE_INTEGER ] = ctf_integer_write,
        [ CTF_TYPE_FLOAT ] = ctf_float_write,
        [ CTF_TYPE_ENUM ] = ctf_enum_write,
        [ CTF_TYPE_STRING ] = ctf_string_write,
        [ CTF_TYPE_STRUCT ] = ctf_struct_rw,
        [ CTF_TYPE_VARIANT ] = ctf_variant_rw,
        [ CTF_TYPE_ARRAY ] = ctf_array_write,
        [ CTF_TYPE_SEQUENCE ] = ctf_sequence_write,
};

static
struct bt_format ctf_format = {
        .open_trace = ctf_open_trace,
        .open_mmap_trace = ctf_open_mmap_trace,
        .close_trace = ctf_close_trace,
        .set_context = ctf_set_context,
        .set_handle = ctf_set_handle,
        .timestamp_begin = ctf_timestamp_begin,
        .timestamp_end = ctf_timestamp_end,
        .convert_index_timestamp = ctf_convert_index_timestamp,
};

static
uint64_t ctf_timestamp_begin(struct bt_trace_descriptor *descriptor,
                struct bt_trace_handle *handle, enum bt_clock_type type)
{
        struct ctf_trace *tin;
        uint64_t begin = ULLONG_MAX;
        int i, j;

        tin = container_of(descriptor, struct ctf_trace, parent);

        if (!tin)
                goto error;

        /* for each stream_class */
        for (i = 0; i < tin->streams->len; i++) {
                struct ctf_stream_declaration *stream_class;

                stream_class = g_ptr_array_index(tin->streams, i);
                if (!stream_class)
                        continue;
                /* for each file_stream */
                for (j = 0; j < stream_class->streams->len; j++) {
                        struct ctf_stream_definition *stream;
                        struct ctf_file_stream *cfs;
                        struct ctf_stream_pos *stream_pos;
                        struct packet_index *index;

                        stream = g_ptr_array_index(stream_class->streams, j);
                        cfs = container_of(stream, struct ctf_file_stream,
                                        parent);
                        stream_pos = &cfs->pos;

                        if (!stream_pos->packet_real_index)
                                goto error;

                        if (stream_pos->packet_real_index->len <= 0)
                                continue;

                        if (type == BT_CLOCK_REAL) {
                                index = &g_array_index(stream_pos->packet_real_index,
                                                struct packet_index,
                                                stream_pos->packet_real_index->len - 1);
                        } else if (type == BT_CLOCK_CYCLES) {
                                index = &g_array_index(stream_pos->packet_cycles_index,
                                                struct packet_index,
                                                stream_pos->packet_real_index->len - 1);

                        } else {
                                goto error;
                        }
                        if (index->timestamp_begin < begin)
                                begin = index->timestamp_begin;
                }
        }

        return begin;

error:
        return -1ULL;
}

static
uint64_t ctf_timestamp_end(struct bt_trace_descriptor *descriptor,
                struct bt_trace_handle *handle, enum bt_clock_type type)
{
        struct ctf_trace *tin;
        uint64_t end = 0;
        int i, j;

        tin = container_of(descriptor, struct ctf_trace, parent);

        if (!tin)
                goto error;

        /* for each stream_class */
        for (i = 0; i < tin->streams->len; i++) {
                struct ctf_stream_declaration *stream_class;

                stream_class = g_ptr_array_index(tin->streams, i);
                if (!stream_class)
                        continue;
                /* for each file_stream */
                for (j = 0; j < stream_class->streams->len; j++) {
                        struct ctf_stream_definition *stream;
                        struct ctf_file_stream *cfs;
                        struct ctf_stream_pos *stream_pos;
                        struct packet_index *index;

                        stream = g_ptr_array_index(stream_class->streams, j);
                        cfs = container_of(stream, struct ctf_file_stream,
                                        parent);
                        stream_pos = &cfs->pos;

                        if (!stream_pos->packet_real_index)
                                goto error;

                        if (stream_pos->packet_real_index->len <= 0)
                                continue;

                        if (type == BT_CLOCK_REAL) {
                                index = &g_array_index(stream_pos->packet_real_index,
                                                struct packet_index,
                                                stream_pos->packet_real_index->len - 1);
                        } else if (type == BT_CLOCK_CYCLES) {
                                index = &g_array_index(stream_pos->packet_cycles_index,
                                                struct packet_index,
                                                stream_pos->packet_real_index->len - 1);

                        } else {
                                goto error;
                        }
                        if (index->timestamp_end > end)
                                end = index->timestamp_end;
                }
        }

        return end;

error:
        return -1ULL;
}

/*
 * Update stream current timestamp
 */
static
void ctf_update_timestamp(struct ctf_stream_definition *stream,
                          struct definition_integer *integer_definition)
{
        struct declaration_integer *integer_declaration =
                integer_definition->declaration;
        uint64_t oldval, newval, updateval;

        if (unlikely(integer_declaration->len == 64)) {
                stream->prev_cycles_timestamp = stream->cycles_timestamp;
                stream->cycles_timestamp = integer_definition->value._unsigned;
                stream->prev_real_timestamp = ctf_get_real_timestamp(stream,
                                stream->prev_cycles_timestamp);
                stream->real_timestamp = ctf_get_real_timestamp(stream,
                                stream->cycles_timestamp);
                return;
        }
        /* keep low bits */
        oldval = stream->cycles_timestamp;
        oldval &= (1ULL << integer_declaration->len) - 1;
        newval = integer_definition->value._unsigned;
        /* Test for overflow by comparing low bits */
        if (newval < oldval)
                newval += 1ULL << integer_declaration->len;
        /* updateval contains old high bits, and new low bits (sum) */
        updateval = stream->cycles_timestamp;
        updateval &= ~((1ULL << integer_declaration->len) - 1);
        updateval += newval;
        stream->prev_cycles_timestamp = stream->cycles_timestamp;
        stream->cycles_timestamp = updateval;

        /* convert to real timestamp */
        stream->prev_real_timestamp = ctf_get_real_timestamp(stream,
                        stream->prev_cycles_timestamp);
        stream->real_timestamp = ctf_get_real_timestamp(stream,
                        stream->cycles_timestamp);
}

/*
 * Print timestamp, rescaling clock frequency to nanoseconds and
 * applying offsets as needed (unix time).
 */
static
void ctf_print_timestamp_real(FILE *fp,
                        struct ctf_stream_definition *stream,
                        uint64_t timestamp)
{
        uint64_t ts_sec = 0, ts_nsec;

        ts_nsec = timestamp;

        /* Add command-line offset */
        ts_sec += opt_clock_offset;

        ts_sec += ts_nsec / NSEC_PER_SEC;
        ts_nsec = ts_nsec % NSEC_PER_SEC;

        if (!opt_clock_seconds) {
                struct tm tm;
                time_t time_s = (time_t) ts_sec;

                if (!opt_clock_gmt) {
                        struct tm *res;

                        res = localtime_r(&time_s, &tm);
                        if (!res) {
                                fprintf(stderr, "[warning] Unable to get localtime.\n");
                                goto seconds;
                        }
                } else {
                        struct tm *res;

                        res = gmtime_r(&time_s, &tm);
                        if (!res) {
                                fprintf(stderr, "[warning] Unable to get gmtime.\n");
                                goto seconds;
                        }
                }
                if (opt_clock_date) {
                        char timestr[26];
                        size_t res;

                        /* Print date and time */
                        res = strftime(timestr, sizeof(timestr),
                                "%F ", &tm);
                        if (!res) {
                                fprintf(stderr, "[warning] Unable to print ascii time.\n");
                                goto seconds;
                        }
                        fprintf(fp, "%s", timestr);
                }
                /* Print time in HH:MM:SS.ns */
                fprintf(fp, "%02d:%02d:%02d.%09" PRIu64,
                        tm.tm_hour, tm.tm_min, tm.tm_sec, ts_nsec);
                goto end;
        }
seconds:
        fprintf(fp, "%3" PRIu64 ".%09" PRIu64,
                ts_sec, ts_nsec);

end:
        return;
}

/*
 * Print timestamp, in cycles
 */
static
void ctf_print_timestamp_cycles(FILE *fp,
                struct ctf_stream_definition *stream,
                uint64_t timestamp)
{
        fprintf(fp, "%020" PRIu64, timestamp);
}

void ctf_print_timestamp(FILE *fp,
                struct ctf_stream_definition *stream,
                uint64_t timestamp)
{
        if (opt_clock_cycles) {
                ctf_print_timestamp_cycles(fp, stream, timestamp);
        } else {
                ctf_print_timestamp_real(fp, stream, timestamp);
        }
}

static
void print_uuid(FILE *fp, unsigned char *uuid)
{
        int i;

        for (i = 0; i < BABELTRACE_UUID_LEN; i++)
                fprintf(fp, "%x", (unsigned int) uuid[i]);
}

void ctf_print_discarded(FILE *fp, struct ctf_stream_definition *stream,
                int end_stream)
{
        fprintf(fp, "[warning] Tracer discarded %" PRIu64 " events %sbetween [",
                stream->events_discarded,
                end_stream ? "at end of stream " : "");
        if (opt_clock_cycles) {
                ctf_print_timestamp(fp, stream,
                                stream->prev_cycles_timestamp);
                fprintf(fp, "] and [");
                ctf_print_timestamp(fp, stream,
                                stream->prev_cycles_timestamp_end);
        } else {
                ctf_print_timestamp(fp, stream,
                                stream->prev_real_timestamp);
                fprintf(fp, "] and [");
                ctf_print_timestamp(fp, stream,
                                stream->prev_real_timestamp_end);
        }
        fprintf(fp, "] in trace UUID ");
        print_uuid(fp, stream->stream_class->trace->uuid);
        if (stream->stream_class->trace->path[0])
                fprintf(fp, ", at path: \"%s\"",
                        stream->stream_class->trace->path);

        fprintf(fp, ", within stream id %" PRIu64, stream->stream_id);
        if (stream->path[0])
                fprintf(fp, ", at relative path: \"%s\"", stream->path);
        fprintf(fp, ". ");
        fprintf(fp, "You should consider recording a new trace with larger "
                "buffers or with fewer events enabled.\n");
        fflush(fp);
}

static
int ctf_read_event(struct bt_stream_pos *ppos, struct ctf_stream_definition *stream)
{
        struct ctf_stream_pos *pos =
                container_of(ppos, struct ctf_stream_pos, parent);
        struct ctf_stream_declaration *stream_class = stream->stream_class;
        struct ctf_event_definition *event;
        uint64_t id = 0;
        int ret;

        /* We need to check for EOF here for empty files. */
        if (unlikely(pos->offset == EOF))
                return EOF;

        ctf_pos_get_event(pos);

        /* save the current position as a restore point */
        pos->last_offset = pos->offset;

        /*
         * This is the EOF check after we've advanced the position in
         * ctf_pos_get_event.
         */
        if (unlikely(pos->offset == EOF))
                return EOF;
        assert(pos->offset < pos->content_size);

        /* Read event header */
        if (likely(stream->stream_event_header)) {
                struct definition_integer *integer_definition;
                struct bt_definition *variant;

                ret = generic_rw(ppos, &stream->stream_event_header->p);
                if (unlikely(ret))
                        goto error;
                /* lookup event id */
                integer_definition = bt_lookup_integer(&stream->stream_event_header->p, "id", FALSE);
                if (integer_definition) {
                        id = integer_definition->value._unsigned;
                } else {
                        struct definition_enum *enum_definition;

                        enum_definition = bt_lookup_enum(&stream->stream_event_header->p, "id", FALSE);
                        if (enum_definition) {
                                id = enum_definition->integer->value._unsigned;
                        }
                }

                variant = bt_lookup_variant(&stream->stream_event_header->p, "v");
                if (variant) {
                        integer_definition = bt_lookup_integer(variant, "id", FALSE);
                        if (integer_definition) {
                                id = integer_definition->value._unsigned;
                        }
                }
                stream->event_id = id;

                /* lookup timestamp */
                stream->has_timestamp = 0;
                integer_definition = bt_lookup_integer(&stream->stream_event_header->p, "timestamp", FALSE);
                if (integer_definition) {
                        ctf_update_timestamp(stream, integer_definition);
                        stream->has_timestamp = 1;
                } else {
                        if (variant) {
                                integer_definition = bt_lookup_integer(variant, "timestamp", FALSE);
                                if (integer_definition) {
                                        ctf_update_timestamp(stream, integer_definition);
                                        stream->has_timestamp = 1;
                                }
                        }
                }
        }

        /* Read stream-declared event context */
        if (stream->stream_event_context) {
                ret = generic_rw(ppos, &stream->stream_event_context->p);
                if (ret)
                        goto error;
        }

        if (unlikely(id >= stream_class->events_by_id->len)) {
                fprintf(stderr, "[error] Event id %" PRIu64 " is outside range.\n", id);
                return -EINVAL;
        }
        event = g_ptr_array_index(stream->events_by_id, id);
        if (unlikely(!event)) {
                fprintf(stderr, "[error] Event id %" PRIu64 " is unknown.\n", id);
                return -EINVAL;
        }

        /* Read event-declared event context */
        if (event->event_context) {
                ret = generic_rw(ppos, &event->event_context->p);
                if (ret)
                        goto error;
        }

        /* Read event payload */
        if (likely(event->event_fields)) {
                ret = generic_rw(ppos, &event->event_fields->p);
                if (ret)
                        goto error;
        }

        return 0;

error:
        fprintf(stderr, "[error] Unexpected end of stream. Either the trace data stream is corrupted or metadata description does not match data layout.\n");
        return ret;
}

static
int ctf_write_event(struct bt_stream_pos *pos, struct ctf_stream_definition *stream)
{
        struct ctf_stream_declaration *stream_class = stream->stream_class;
        struct ctf_event_definition *event;
        uint64_t id;
        int ret;

        id = stream->event_id;

        /* print event header */
        if (likely(stream->stream_event_header)) {
                ret = generic_rw(pos, &stream->stream_event_header->p);
                if (ret)
                        goto error;
        }

        /* print stream-declared event context */
        if (stream->stream_event_context) {
                ret = generic_rw(pos, &stream->stream_event_context->p);
                if (ret)
                        goto error;
        }

        if (unlikely(id >= stream_class->events_by_id->len)) {
                fprintf(stderr, "[error] Event id %" PRIu64 " is outside range.\n", id);
                return -EINVAL;
        }
        event = g_ptr_array_index(stream->events_by_id, id);
        if (unlikely(!event)) {
                fprintf(stderr, "[error] Event id %" PRIu64 " is unknown.\n", id);
                return -EINVAL;
        }

        /* print event-declared event context */
        if (event->event_context) {
                ret = generic_rw(pos, &event->event_context->p);
                if (ret)
                        goto error;
        }

        /* Read and print event payload */
        if (likely(event->event_fields)) {
                ret = generic_rw(pos, &event->event_fields->p);
                if (ret)
                        goto error;
        }

        return 0;

error:
        fprintf(stderr, "[error] Unexpected end of stream. Either the trace data stream is corrupted or metadata description does not match data layout.\n");
        return ret;
}

int ctf_init_pos(struct ctf_stream_pos *pos, struct bt_trace_descriptor *trace,
                int fd, int open_flags)
{
        pos->fd = fd;
        if (fd >= 0) {
                pos->packet_cycles_index = g_array_new(FALSE, TRUE,
                                                sizeof(struct packet_index));
                pos->packet_real_index = g_array_new(FALSE, TRUE,
                                sizeof(struct packet_index));
        } else {
                pos->packet_cycles_index = NULL;
                pos->packet_real_index = NULL;
        }
        switch (open_flags & O_ACCMODE) {
        case O_RDONLY:
                pos->prot = PROT_READ;
                pos->flags = MAP_PRIVATE;
                pos->parent.rw_table = read_dispatch_table;
                pos->parent.event_cb = ctf_read_event;
                pos->parent.trace = trace;
                break;
        case O_RDWR:
                pos->prot = PROT_WRITE; /* Write has priority */
                pos->flags = MAP_SHARED;
                pos->parent.rw_table = write_dispatch_table;
                pos->parent.event_cb = ctf_write_event;
                pos->parent.trace = trace;
                if (fd >= 0)
                        ctf_packet_seek(&pos->parent, 0, SEEK_SET);     /* position for write */
                break;
        default:
                assert(0);
        }
        return 0;
}

int ctf_fini_pos(struct ctf_stream_pos *pos)
{
        if (pos->prot == PROT_WRITE && pos->content_size_loc)
                *pos->content_size_loc = pos->offset;
        if (pos->base_mma) {
                int ret;

                /* unmap old base */
                ret = munmap_align(pos->base_mma);
                if (ret) {
                        fprintf(stderr, "[error] Unable to unmap old base: %s.\n",
                                strerror(errno));
                        return -1;
                }
        }
        if (pos->packet_cycles_index)
                (void) g_array_free(pos->packet_cycles_index, TRUE);
        if (pos->packet_real_index)
                (void) g_array_free(pos->packet_real_index, TRUE);
        return 0;
}

/*
 * for SEEK_CUR: go to next packet.
 * for SEEK_POS: go to packet numer (index).
 */
void ctf_packet_seek(struct bt_stream_pos *stream_pos, size_t index, int whence)
{
        struct ctf_stream_pos *pos =
                container_of(stream_pos, struct ctf_stream_pos, parent);
        struct ctf_file_stream *file_stream =
                container_of(pos, struct ctf_file_stream, pos);
        int ret;
        off_t off;
        struct packet_index *packet_index;

        if (pos->prot == PROT_WRITE && pos->content_size_loc)
                *pos->content_size_loc = pos->offset;

        if (pos->base_mma) {
                /* unmap old base */
                ret = munmap_align(pos->base_mma);
                if (ret) {
                        fprintf(stderr, "[error] Unable to unmap old base: %s.\n",
                                strerror(errno));
                        assert(0);
                }
                pos->base_mma = NULL;
        }

        /*
         * The caller should never ask for ctf_move_pos across packets,
         * except to get exactly at the beginning of the next packet.
         */
        if (pos->prot == PROT_WRITE) {
                switch (whence) {
                case SEEK_CUR:
                        /* The writer will add padding */
                        pos->mmap_offset += WRITE_PACKET_LEN / CHAR_BIT;
                        break;
                case SEEK_SET:
                        assert(index == 0);     /* only seek supported for now */
                        pos->cur_index = 0;
                        break;
                default:
                        assert(0);
                }
                pos->content_size = -1U;        /* Unknown at this point */
                pos->packet_size = WRITE_PACKET_LEN;
                off = posix_fallocate(pos->fd, pos->mmap_offset,
                                      pos->packet_size / CHAR_BIT);
                assert(off >= 0);
                pos->offset = 0;
        } else {
        read_next_packet:
                switch (whence) {
                case SEEK_CUR:
                {
                        uint64_t events_discarded_diff;

                        if (pos->offset == EOF) {
                                return;
                        }
                        /* For printing discarded event count */
                        packet_index = &g_array_index(pos->packet_cycles_index,
                                        struct packet_index, pos->cur_index);
                        file_stream->parent.prev_cycles_timestamp_end =
                                packet_index->timestamp_end;
                        file_stream->parent.prev_cycles_timestamp =
                                packet_index->timestamp_begin;

                        packet_index = &g_array_index(pos->packet_real_index,
                                        struct packet_index, pos->cur_index);
                        file_stream->parent.prev_real_timestamp_end =
                                                packet_index->timestamp_end;
                        file_stream->parent.prev_real_timestamp =
                                packet_index->timestamp_begin;

                        events_discarded_diff = packet_index->events_discarded;
                        if (pos->cur_index > 0) {
                                packet_index = &g_array_index(pos->packet_real_index,
                                                struct packet_index,
                                                pos->cur_index - 1);
                                events_discarded_diff -= packet_index->events_discarded;
                                /*
                                 * Deal with 32-bit wrap-around if the
                                 * tracer provided a 32-bit field.
                                 */
                                if (packet_index->events_discarded_len == 32) {
                                        events_discarded_diff = (uint32_t) events_discarded_diff;
                                }
                        }
                        file_stream->parent.events_discarded = events_discarded_diff;
                        file_stream->parent.prev_real_timestamp = file_stream->parent.real_timestamp;
                        file_stream->parent.prev_cycles_timestamp = file_stream->parent.cycles_timestamp;
                        /* The reader will expect us to skip padding */
                        ++pos->cur_index;
                        break;
                }
                case SEEK_SET:
                        packet_index = &g_array_index(pos->packet_cycles_index,
                                        struct packet_index, index);
                        pos->last_events_discarded = packet_index->events_discarded;
                        pos->cur_index = index;
                        file_stream->parent.prev_real_timestamp = 0;
                        file_stream->parent.prev_real_timestamp_end = 0;
                        file_stream->parent.prev_cycles_timestamp = 0;
                        file_stream->parent.prev_cycles_timestamp_end = 0;
                        break;
                default:
                        assert(0);
                }
                if (pos->cur_index >= pos->packet_real_index->len) {
                        /*
                         * We need to check if we are in trace read or
                         * called from packet indexing.  In this last
                         * case, the collection is not there, so we
                         * cannot print the timestamps.
                         */
                        if ((&file_stream->parent)->stream_class->trace->collection) {
                                /*
                                 * When a stream reaches the end of the
                                 * file, we need to show the number of
                                 * events discarded ourselves, because
                                 * there is no next event scheduled to
                                 * be printed in the output.
                                 */
                                if (file_stream->parent.events_discarded) {
                                        fflush(stdout);
                                        ctf_print_discarded(stderr,
                                                &file_stream->parent,
                                                1);
                                        file_stream->parent.events_discarded = 0;
                                }
                        }
                        pos->offset = EOF;
                        return;
                }
                packet_index = &g_array_index(pos->packet_cycles_index,
                                struct packet_index,
                                pos->cur_index);
                file_stream->parent.cycles_timestamp = packet_index->timestamp_begin;

                packet_index = &g_array_index(pos->packet_real_index,
                                struct packet_index,
                                pos->cur_index);
                file_stream->parent.real_timestamp = packet_index->timestamp_begin;
                pos->mmap_offset = packet_index->offset;

                /* Lookup context/packet size in index */
                pos->content_size = packet_index->content_size;
                pos->packet_size = packet_index->packet_size;
                if (packet_index->data_offset < packet_index->content_size) {
                        pos->offset = 0;        /* will read headers */
                } else if (packet_index->data_offset == packet_index->content_size) {
                        /* empty packet */
                        pos->offset = packet_index->data_offset;
                        whence = SEEK_CUR;
                        goto read_next_packet;
                } else {
                        pos->offset = EOF;
                        return;
                }
        }
        /* map new base. Need mapping length from header. */
        pos->base_mma = mmap_align(pos->packet_size / CHAR_BIT, pos->prot,
                        pos->flags, pos->fd, pos->mmap_offset);
        if (pos->base_mma == MAP_FAILED) {
                fprintf(stderr, "[error] mmap error %s.\n",
                        strerror(errno));
                assert(0);
        }

        /* update trace_packet_header and stream_packet_context */
        if (pos->prot != PROT_WRITE && file_stream->parent.trace_packet_header) {
                /* Read packet header */
                ret = generic_rw(&pos->parent, &file_stream->parent.trace_packet_header->p);
                assert(!ret);
        }
        if (pos->prot != PROT_WRITE && file_stream->parent.stream_packet_context) {
                /* Read packet context */
                ret = generic_rw(&pos->parent, &file_stream->parent.stream_packet_context->p);
                assert(!ret);
        }
}

static
int packet_metadata(struct ctf_trace *td, FILE *fp)
{
        uint32_t magic;
        size_t len;
        int ret = 0;

        len = fread(&magic, sizeof(magic), 1, fp);
        if (len != 1) {
                goto end;
        }
        if (magic == TSDL_MAGIC) {
                ret = 1;
                td->byte_order = BYTE_ORDER;
                CTF_TRACE_SET_FIELD(td, byte_order);
        } else if (magic == GUINT32_SWAP_LE_BE(TSDL_MAGIC)) {
                ret = 1;
                td->byte_order = (BYTE_ORDER == BIG_ENDIAN) ?
                                        LITTLE_ENDIAN : BIG_ENDIAN;
                CTF_TRACE_SET_FIELD(td, byte_order);
        }
end:
        rewind(fp);
        return ret;
}

/*
 * Returns 0 on success, -1 on error.
 */
static
int check_version(unsigned int major, unsigned int minor)
{
        switch (major) {
        case 1:
                switch (minor) {
                case 8:
                        return 0;
                default:
                        goto warning;
                }
        default:
                goto warning;
                
        }

        /* eventually return an error instead of warning */
warning:
        fprintf(stderr, "[warning] Unsupported CTF specification version %u.%u. Trying anyway.\n",
                major, minor);
        return 0;
}

static
int ctf_open_trace_metadata_packet_read(struct ctf_trace *td, FILE *in,
                                        FILE *out)
{
        struct metadata_packet_header header;
        size_t readlen, writelen, toread;
        char buf[4096 + 1];     /* + 1 for debug-mode \0 */
        int ret = 0;

        readlen = fread(&header, header_sizeof(header), 1, in);
        if (readlen < 1)
                return -EINVAL;

        if (td->byte_order != BYTE_ORDER) {
                header.magic = GUINT32_SWAP_LE_BE(header.magic);
                header.checksum = GUINT32_SWAP_LE_BE(header.checksum);
                header.content_size = GUINT32_SWAP_LE_BE(header.content_size);
                header.packet_size = GUINT32_SWAP_LE_BE(header.packet_size);
        }
        if (header.checksum)
                fprintf(stderr, "[warning] checksum verification not supported yet.\n");
        if (header.compression_scheme) {
                fprintf(stderr, "[error] compression (%u) not supported yet.\n",
                        header.compression_scheme);
                return -EINVAL;
        }
        if (header.encryption_scheme) {
                fprintf(stderr, "[error] encryption (%u) not supported yet.\n",
                        header.encryption_scheme);
                return -EINVAL;
        }
        if (header.checksum_scheme) {
                fprintf(stderr, "[error] checksum (%u) not supported yet.\n",
                        header.checksum_scheme);
                return -EINVAL;
        }
        if (check_version(header.major, header.minor) < 0)
                return -EINVAL;
        if (!CTF_TRACE_FIELD_IS_SET(td, uuid)) {
                memcpy(td->uuid, header.uuid, sizeof(header.uuid));
                CTF_TRACE_SET_FIELD(td, uuid);
        } else {
                if (babeltrace_uuid_compare(header.uuid, td->uuid))
                        return -EINVAL;
        }

        if ((header.content_size / CHAR_BIT) < header_sizeof(header))
                return -EINVAL;

        toread = (header.content_size / CHAR_BIT) - header_sizeof(header);

        for (;;) {
                readlen = fread(buf, sizeof(char), min(sizeof(buf) - 1, toread), in);
                if (ferror(in)) {
                        ret = -EINVAL;
                        break;
                }
                if (babeltrace_debug) {
                        buf[readlen] = '\0';
                        fprintf(stderr, "[debug] metadata packet read: %s\n",
                                buf);
                }

                writelen = fwrite(buf, sizeof(char), readlen, out);
                if (writelen < readlen) {
                        ret = -EIO;
                        break;
                }
                if (ferror(out)) {
                        ret = -EINVAL;
                        break;
                }
                toread -= readlen;
                if (!toread) {
                        ret = 0;        /* continue reading next packet */
                        goto read_padding;
                }
        }
        return ret;

read_padding:
        toread = (header.packet_size - header.content_size) / CHAR_BIT;
        ret = fseek(in, toread, SEEK_CUR);
        if (ret < 0) {
                fprintf(stderr, "[warning] Missing padding at end of file\n");
                ret = 0;
        }
        return ret;
}

static
int ctf_open_trace_metadata_stream_read(struct ctf_trace *td, FILE **fp,
                                        char **buf)
{
        FILE *in, *out;
        size_t size, buflen;
        int ret;

        in = *fp;
        /*
         * Using strlen on *buf instead of size of open_memstream
         * because its size includes garbage at the end (after final
         * \0). This is the allocated size, not the actual string size.
         */
        out = babeltrace_open_memstream(buf, &size);
        if (out == NULL) {
                perror("Metadata open_memstream");
                return -errno;
        }
        for (;;) {
                ret = ctf_open_trace_metadata_packet_read(td, in, out);
                if (ret) {
                        break;
                }
                if (feof(in)) {
                        ret = 0;
                        break;
                }
        }
        /* close to flush the buffer */
        ret = babeltrace_close_memstream(buf, &size, out);
        if (ret < 0) {
                int closeret;

                perror("babeltrace_flush_memstream");
                ret = -errno;
                closeret = fclose(in);
                if (closeret) {
                        perror("Error in fclose");
                }
                return ret;
        }
        ret = fclose(in);
        if (ret) {
                perror("Error in fclose");
        }
        /* open for reading */
        buflen = strlen(*buf);
        if (!buflen) {
                *fp = NULL;
                return -ENOENT;
        }
        *fp = babeltrace_fmemopen(*buf, buflen, "rb");
        if (!*fp) {
                perror("Metadata fmemopen");
                return -errno;
        }
        return 0;
}

static
int ctf_open_trace_metadata_read(struct ctf_trace *td,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence), FILE *metadata_fp)
{
        struct ctf_scanner *scanner;
        struct ctf_file_stream *metadata_stream;
        FILE *fp;
        char *buf = NULL;
        int ret = 0, closeret;

        metadata_stream = g_new0(struct ctf_file_stream, 1);
        metadata_stream->pos.last_offset = LAST_OFFSET_POISON;

        if (packet_seek) {
                metadata_stream->pos.packet_seek = packet_seek;
        } else {
                fprintf(stderr, "[error] packet_seek function undefined.\n");
                ret = -1;
                goto end_free;
        }

        if (metadata_fp) {
                fp = metadata_fp;
                metadata_stream->pos.fd = -1;
        } else {
                td->metadata = &metadata_stream->parent;
                metadata_stream->pos.fd = openat(td->dirfd, "metadata", O_RDONLY);
                if (metadata_stream->pos.fd < 0) {
                        fprintf(stderr, "Unable to open metadata.\n");
                        ret = -1;
                        goto end_free;
                }

                fp = fdopen(metadata_stream->pos.fd, "r");
                if (!fp) {
                        fprintf(stderr, "[error] Unable to open metadata stream.\n");
                        perror("Metadata stream open");
                        ret = -errno;
                        goto end_stream;
                }
                /* fd now belongs to fp */
                metadata_stream->pos.fd = -1;
        }
        if (babeltrace_debug)
                yydebug = 1;

        if (packet_metadata(td, fp)) {
                ret = ctf_open_trace_metadata_stream_read(td, &fp, &buf);
                if (ret) {
                        /* Warn about empty metadata */
                        fprintf(stderr, "[warning] Empty metadata.\n");
                        goto end_packet_read;
                }
                td->metadata_string = buf;
                td->metadata_packetized = 1;
        } else {
                unsigned int major, minor;
                ssize_t nr_items;

                td->byte_order = BYTE_ORDER;

                /* Check text-only metadata header and version */
                nr_items = fscanf(fp, "/* CTF %u.%u", &major, &minor);
                if (nr_items < 2)
                        fprintf(stderr, "[warning] Ill-shapen or missing \"/* CTF x.y\" header for text-only metadata.\n");
                if (check_version(major, minor) < 0) {
                        ret = -EINVAL;
                        goto end_packet_read;
                }
                rewind(fp);
        }

        scanner = ctf_scanner_alloc(fp);
        if (!scanner) {
                fprintf(stderr, "[error] Error allocating scanner\n");
                ret = -ENOMEM;
                goto end_scanner_alloc;
        }
        ret = ctf_scanner_append_ast(scanner);
        if (ret) {
                fprintf(stderr, "[error] Error creating AST\n");
                goto end;
        }

        if (babeltrace_debug) {
                ret = ctf_visitor_print_xml(stderr, 0, &scanner->ast->root);
                if (ret) {
                        fprintf(stderr, "[error] Error visiting AST for XML output\n");
                        goto end;
                }
        }

        ret = ctf_visitor_semantic_check(stderr, 0, &scanner->ast->root);
        if (ret) {
                fprintf(stderr, "[error] Error in CTF semantic validation %d\n", ret);
                goto end;
        }
        ret = ctf_visitor_construct_metadata(stderr, 0, &scanner->ast->root,
                        td, td->byte_order);
        if (ret) {
                fprintf(stderr, "[error] Error in CTF metadata constructor %d\n", ret);
                goto end;
        }
end:
        ctf_scanner_free(scanner);
end_scanner_alloc:
end_packet_read:
        if (fp) {
                closeret = fclose(fp);
                if (closeret) {
                        perror("Error on fclose");
                }
        }
end_stream:
        if (metadata_stream->pos.fd >= 0) {
                closeret = close(metadata_stream->pos.fd);
                if (closeret) {
                        perror("Error on metadata stream fd close");
                }
        }
end_free:
        if (ret)
                g_free(metadata_stream);
        return ret;
}

static
struct ctf_event_definition *create_event_definitions(struct ctf_trace *td,
                                                  struct ctf_stream_definition *stream,
                                                  struct ctf_event_declaration *event)
{
        struct ctf_event_definition *stream_event = g_new0(struct ctf_event_definition, 1);

        if (event->context_decl) {
                struct bt_definition *definition =
                        event->context_decl->p.definition_new(&event->context_decl->p,
                                stream->parent_def_scope, 0, 0, "event.context");
                if (!definition) {
                        goto error;
                }
                stream_event->event_context = container_of(definition,
                                        struct definition_struct, p);
                stream->parent_def_scope = stream_event->event_context->p.scope;
        }
        if (event->fields_decl) {
                struct bt_definition *definition =
                        event->fields_decl->p.definition_new(&event->fields_decl->p,
                                stream->parent_def_scope, 0, 0, "event.fields");
                if (!definition) {
                        goto error;
                }
                stream_event->event_fields = container_of(definition,
                                        struct definition_struct, p);
                stream->parent_def_scope = stream_event->event_fields->p.scope;
        }
        stream_event->stream = stream;
        return stream_event;

error:
        if (stream_event->event_fields)
                bt_definition_unref(&stream_event->event_fields->p);
        if (stream_event->event_context)
                bt_definition_unref(&stream_event->event_context->p);
        return NULL;
}

static
int create_stream_definitions(struct ctf_trace *td, struct ctf_stream_definition *stream)
{
        struct ctf_stream_declaration *stream_class;
        int ret;
        int i;

        if (stream->stream_definitions_created)
                return 0;

        stream_class = stream->stream_class;

        if (stream_class->packet_context_decl) {
                struct bt_definition *definition =
                        stream_class->packet_context_decl->p.definition_new(&stream_class->packet_context_decl->p,
                                stream->parent_def_scope, 0, 0, "stream.packet.context");
                if (!definition) {
                        ret = -EINVAL;
                        goto error;
                }
                stream->stream_packet_context = container_of(definition,
                                                struct definition_struct, p);
                stream->parent_def_scope = stream->stream_packet_context->p.scope;
        }
        if (stream_class->event_header_decl) {
                struct bt_definition *definition =
                        stream_class->event_header_decl->p.definition_new(&stream_class->event_header_decl->p,
                                stream->parent_def_scope, 0, 0, "stream.event.header");
                if (!definition) {
                        ret = -EINVAL;
                        goto error;
                }
                stream->stream_event_header =
                        container_of(definition, struct definition_struct, p);
                stream->parent_def_scope = stream->stream_event_header->p.scope;
        }
        if (stream_class->event_context_decl) {
                struct bt_definition *definition =
                        stream_class->event_context_decl->p.definition_new(&stream_class->event_context_decl->p,
                                stream->parent_def_scope, 0, 0, "stream.event.context");
                if (!definition) {
                        ret = -EINVAL;
                        goto error;
                }
                stream->stream_event_context =
                        container_of(definition, struct definition_struct, p);
                stream->parent_def_scope = stream->stream_event_context->p.scope;
        }
        stream->events_by_id = g_ptr_array_new();
        g_ptr_array_set_size(stream->events_by_id, stream_class->events_by_id->len);
        for (i = 0; i < stream->events_by_id->len; i++) {
                struct ctf_event_declaration *event = g_ptr_array_index(stream_class->events_by_id, i);
                struct ctf_event_definition *stream_event;

                if (!event)
                        continue;
                stream_event = create_event_definitions(td, stream, event);
                if (!stream_event)
                        goto error_event;
                g_ptr_array_index(stream->events_by_id, i) = stream_event;
        }
        return 0;

error_event:
        for (i = 0; i < stream->events_by_id->len; i++) {
                struct ctf_event_definition *stream_event = g_ptr_array_index(stream->events_by_id, i);
                if (stream_event)
                        g_free(stream_event);
        }
        g_ptr_array_free(stream->events_by_id, TRUE);
error:
        if (stream->stream_event_context)
                bt_definition_unref(&stream->stream_event_context->p);
        if (stream->stream_event_header)
                bt_definition_unref(&stream->stream_event_header->p);
        if (stream->stream_packet_context)
                bt_definition_unref(&stream->stream_packet_context->p);
        return ret;
}

static
int create_stream_one_packet_index(struct ctf_stream_pos *pos,
                        struct ctf_trace *td,
                        struct ctf_file_stream *file_stream,
                        size_t filesize)
{
        struct packet_index packet_index;
        struct ctf_stream_declaration *stream;
        uint64_t stream_id = 0;
        uint64_t packet_map_len = DEFAULT_HEADER_LEN, tmp_map_len;
        int first_packet = 0;
        int len_index;
        int ret;

begin:
        if (!pos->mmap_offset) {
                first_packet = 1;
        }

        if (filesize - pos->mmap_offset < (packet_map_len >> LOG2_CHAR_BIT)) {
                packet_map_len = (filesize - pos->mmap_offset) << LOG2_CHAR_BIT;
        }

        if (pos->base_mma) {
                /* unmap old base */
                ret = munmap_align(pos->base_mma);
                if (ret) {
                        fprintf(stderr, "[error] Unable to unmap old base: %s.\n",
                                strerror(errno));
                        return ret;
                }
                pos->base_mma = NULL;
        }
        /* map new base. Need mapping length from header. */
        pos->base_mma = mmap_align(packet_map_len >> LOG2_CHAR_BIT, PROT_READ,
                         MAP_PRIVATE, pos->fd, pos->mmap_offset);
        assert(pos->base_mma != MAP_FAILED);
        /*
         * Use current mapping size as temporary content and packet
         * size.
         */
        pos->content_size = packet_map_len;
        pos->packet_size = packet_map_len;
        pos->offset = 0;        /* Position of the packet header */

        packet_index.offset = pos->mmap_offset;
        packet_index.content_size = 0;
        packet_index.packet_size = 0;
        packet_index.timestamp_begin = 0;
        packet_index.timestamp_end = 0;
        packet_index.events_discarded = 0;
        packet_index.events_discarded_len = 0;

        /* read and check header, set stream id (and check) */
        if (file_stream->parent.trace_packet_header) {
                /* Read packet header */
                ret = generic_rw(&pos->parent, &file_stream->parent.trace_packet_header->p);
                if (ret) {
                        if (ret == -EFAULT)
                                goto retry;
                        return ret;
                }
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.trace_packet_header->declaration, g_quark_from_static_string("magic"));
                if (len_index >= 0) {
                        struct bt_definition *field;
                        uint64_t magic;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.trace_packet_header, len_index);
                        magic = bt_get_unsigned_int(field);
                        if (magic != CTF_MAGIC) {
                                fprintf(stderr, "[error] Invalid magic number 0x%" PRIX64 " at packet %u (file offset %zd).\n",
                                                magic,
                                                file_stream->pos.packet_cycles_index->len,
                                                (ssize_t) pos->mmap_offset);
                                return -EINVAL;
                        }
                }

                /* check uuid */
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.trace_packet_header->declaration, g_quark_from_static_string("uuid"));
                if (len_index >= 0) {
                        struct definition_array *defarray;
                        struct bt_definition *field;
                        uint64_t i;
                        uint8_t uuidval[BABELTRACE_UUID_LEN];

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.trace_packet_header, len_index);
                        assert(field->declaration->id == CTF_TYPE_ARRAY);
                        defarray = container_of(field, struct definition_array, p);
                        assert(bt_array_len(defarray) == BABELTRACE_UUID_LEN);

                        for (i = 0; i < BABELTRACE_UUID_LEN; i++) {
                                struct bt_definition *elem;

                                elem = bt_array_index(defarray, i);
                                uuidval[i] = bt_get_unsigned_int(elem);
                        }
                        ret = babeltrace_uuid_compare(td->uuid, uuidval);
                        if (ret) {
                                fprintf(stderr, "[error] Unique Universal Identifiers do not match.\n");
                                return -EINVAL;
                        }
                }

                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.trace_packet_header->declaration, g_quark_from_static_string("stream_id"));
                if (len_index >= 0) {
                        struct bt_definition *field;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.trace_packet_header, len_index);
                        stream_id = bt_get_unsigned_int(field);
                }
        }

        if (!first_packet && file_stream->parent.stream_id != stream_id) {
                fprintf(stderr, "[error] Stream ID is changing within a stream: expecting %" PRIu64 ", but packet has %" PRIu64 "\n",
                        stream_id,
                        file_stream->parent.stream_id);
                return -EINVAL;
        }
        if (first_packet) {
                file_stream->parent.stream_id = stream_id;
                if (stream_id >= td->streams->len) {
                        fprintf(stderr, "[error] Stream %" PRIu64 " is not declared in metadata.\n", stream_id);
                        return -EINVAL;
                }
                stream = g_ptr_array_index(td->streams, stream_id);
                if (!stream) {
                        fprintf(stderr, "[error] Stream %" PRIu64 " is not declared in metadata.\n", stream_id);
                        return -EINVAL;
                }
                file_stream->parent.stream_class = stream;
                ret = create_stream_definitions(td, &file_stream->parent);
                if (ret)
                        return ret;
        }

        if (file_stream->parent.stream_packet_context) {
                /* Read packet context */
                ret = generic_rw(&pos->parent, &file_stream->parent.stream_packet_context->p);
                if (ret) {
                        if (ret == -EFAULT)
                                goto retry;
                        return ret;
                }
                /* read content size from header */
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.stream_packet_context->declaration, g_quark_from_static_string("content_size"));
                if (len_index >= 0) {
                        struct bt_definition *field;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.stream_packet_context, len_index);
                        packet_index.content_size = bt_get_unsigned_int(field);
                } else {
                        /* Use file size for packet size */
                        packet_index.content_size = filesize * CHAR_BIT;
                }

                /* read packet size from header */
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.stream_packet_context->declaration, g_quark_from_static_string("packet_size"));
                if (len_index >= 0) {
                        struct bt_definition *field;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.stream_packet_context, len_index);
                        packet_index.packet_size = bt_get_unsigned_int(field);
                } else {
                        /* Use content size if non-zero, else file size */
                        packet_index.packet_size = packet_index.content_size ? : filesize * CHAR_BIT;
                }

                /* read timestamp begin from header */
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.stream_packet_context->declaration, g_quark_from_static_string("timestamp_begin"));
                if (len_index >= 0) {
                        struct bt_definition *field;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.stream_packet_context, len_index);
                        packet_index.timestamp_begin = bt_get_unsigned_int(field);
                        if (file_stream->parent.stream_class->trace->collection) {
                                packet_index.timestamp_begin =
                                        ctf_get_real_timestamp(
                                                &file_stream->parent,
                                                packet_index.timestamp_begin);
                        }
                }

                /* read timestamp end from header */
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.stream_packet_context->declaration, g_quark_from_static_string("timestamp_end"));
                if (len_index >= 0) {
                        struct bt_definition *field;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.stream_packet_context, len_index);
                        packet_index.timestamp_end = bt_get_unsigned_int(field);
                        if (file_stream->parent.stream_class->trace->collection) {
                                packet_index.timestamp_end =
                                        ctf_get_real_timestamp(
                                                &file_stream->parent,
                                                packet_index.timestamp_end);
                        }
                }

                /* read events discarded from header */
                len_index = bt_struct_declaration_lookup_field_index(file_stream->parent.stream_packet_context->declaration, g_quark_from_static_string("events_discarded"));
                if (len_index >= 0) {
                        struct bt_definition *field;

                        field = bt_struct_definition_get_field_from_index(file_stream->parent.stream_packet_context, len_index);
                        packet_index.events_discarded = bt_get_unsigned_int(field);
                        packet_index.events_discarded_len = bt_get_int_len(field);
                }
        } else {
                /* Use file size for packet size */
                packet_index.content_size = filesize * CHAR_BIT;
                /* Use content size if non-zero, else file size */
                packet_index.packet_size = packet_index.content_size ? : filesize * CHAR_BIT;
        }

        /* Validate content size and packet size values */
        if (packet_index.content_size > packet_index.packet_size) {
                fprintf(stderr, "[error] Content size (%" PRIu64 " bits) is larger than packet size (%" PRIu64 " bits).\n",
                        packet_index.content_size, packet_index.packet_size);
                return -EINVAL;
        }

        if (packet_index.packet_size > ((uint64_t) filesize - packet_index.offset) * CHAR_BIT) {
                fprintf(stderr, "[error] Packet size (%" PRIu64 " bits) is larger than remaining file size (%" PRIu64 " bits).\n",
                        packet_index.packet_size, ((uint64_t) filesize - packet_index.offset) * CHAR_BIT);
                return -EINVAL;
        }

        /* Save position after header and context */
        packet_index.data_offset = pos->offset;

        /* add index to packet array */
        g_array_append_val(file_stream->pos.packet_cycles_index, packet_index);

        pos->mmap_offset += packet_index.packet_size >> LOG2_CHAR_BIT;

        return 0;

        /* Retry with larger mapping */
retry:
        if (packet_map_len == ((filesize - pos->mmap_offset) << LOG2_CHAR_BIT)) {
                /*
                 * Reached EOF, but still expecting header/context data.
                 */
                fprintf(stderr, "[error] Reached end of file, but still expecting header or context fields.\n");
                return -EFAULT;
        }
        /* Double the mapping len, and retry */
        tmp_map_len = packet_map_len << 1;
        if (tmp_map_len >> 1 != packet_map_len) {
                /* Overflow */
                return -EFAULT;
        }
        packet_map_len = tmp_map_len;
        goto begin;
}

static
int create_stream_packet_index(struct ctf_trace *td,
                        struct ctf_file_stream *file_stream)
{
        struct ctf_stream_pos *pos;
        struct stat filestats;
        int ret;

        pos = &file_stream->pos;

        ret = fstat(pos->fd, &filestats);
        if (ret < 0)
                return ret;

        for (pos->mmap_offset = 0; pos->mmap_offset < filestats.st_size; ) {
                ret = create_stream_one_packet_index(pos, td, file_stream,
                        filestats.st_size);
                if (ret)
                        return ret;
        }
        return 0;
}

static
int create_trace_definitions(struct ctf_trace *td, struct ctf_stream_definition *stream)
{
        int ret;

        if (td->packet_header_decl) {
                struct bt_definition *definition =
                        td->packet_header_decl->p.definition_new(&td->packet_header_decl->p,
                                stream->parent_def_scope, 0, 0, "trace.packet.header");
                if (!definition) {
                        ret = -EINVAL;
                        goto error;
                }
                stream->trace_packet_header = 
                        container_of(definition, struct definition_struct, p);
                stream->parent_def_scope = stream->trace_packet_header->p.scope;
        }

        return 0;

error:
        return ret;
}

/*
 * Note: many file streams can inherit from the same stream class
 * description (metadata).
 */
static
int ctf_open_file_stream_read(struct ctf_trace *td, const char *path, int flags,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence))
{
        int ret, fd, closeret;
        struct ctf_file_stream *file_stream;
        struct stat statbuf;

        fd = openat(td->dirfd, path, flags);
        if (fd < 0) {
                perror("File stream openat()");
                ret = fd;
                goto error;
        }

        /* Don't try to mmap subdirectories. Skip them, return success. */
        ret = fstat(fd, &statbuf);
        if (ret) {
                perror("File stream fstat()");
                goto fstat_error;
        }
        if (S_ISDIR(statbuf.st_mode)) {
                fprintf(stderr, "[warning] Skipping directory '%s' found in trace\n", path);
                ret = 0;
                goto fd_is_dir_ok;
        }

        file_stream = g_new0(struct ctf_file_stream, 1);
        file_stream->pos.last_offset = LAST_OFFSET_POISON;

        strncpy(file_stream->parent.path, path, PATH_MAX);
        file_stream->parent.path[PATH_MAX - 1] = '\0';

        if (packet_seek) {
                file_stream->pos.packet_seek = packet_seek;
        } else {
                fprintf(stderr, "[error] packet_seek function undefined.\n");
                ret = -1;
                goto error_def;
        }

        ret = ctf_init_pos(&file_stream->pos, &td->parent, fd, flags);
        if (ret)
                goto error_def;
        ret = create_trace_definitions(td, &file_stream->parent);
        if (ret)
                goto error_def;
        /*
         * For now, only a single clock per trace is supported.
         */
        file_stream->parent.current_clock = td->single_clock;
        ret = create_stream_packet_index(td, file_stream);
        if (ret)
                goto error_index;
        /* Add stream file to stream class */
        g_ptr_array_add(file_stream->parent.stream_class->streams,
                        &file_stream->parent);
        return 0;

error_index:
        if (file_stream->parent.trace_packet_header)
                bt_definition_unref(&file_stream->parent.trace_packet_header->p);
error_def:
        closeret = ctf_fini_pos(&file_stream->pos);
        if (closeret) {
                fprintf(stderr, "Error on ctf_fini_pos\n");
        }
        g_free(file_stream);
fd_is_dir_ok:
fstat_error:
        closeret = close(fd);
        if (closeret) {
                perror("Error on fd close");
        }
error:
        return ret;
}

static
int ctf_open_trace_read(struct ctf_trace *td,
                const char *path, int flags,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence), FILE *metadata_fp)
{
        int ret, closeret;
        struct dirent *dirent;
        struct dirent *diriter;
        size_t dirent_len;

        td->flags = flags;

        /* Open trace directory */
        td->dir = opendir(path);
        if (!td->dir) {
                fprintf(stderr, "[error] Unable to open trace directory \"%s\".\n", path);
                ret = -ENOENT;
                goto error;
        }

        td->dirfd = open(path, 0);
        if (td->dirfd < 0) {
                fprintf(stderr, "[error] Unable to open trace directory file descriptor for path \"%s\".\n", path);
                perror("Trace directory open");
                ret = -errno;
                goto error_dirfd;
        }
        strncpy(td->path, path, sizeof(td->path));
        td->path[sizeof(td->path) - 1] = '\0';

        /*
         * Keep the metadata file separate.
         */

        ret = ctf_open_trace_metadata_read(td, packet_seek, metadata_fp);
        if (ret) {
                fprintf(stderr, "[warning] Unable to open trace metadata for path \"%s\".\n", path);
                goto error_metadata;
        }

        /*
         * Open each stream: for each file, try to open, check magic
         * number, and get the stream ID to add to the right location in
         * the stream array.
         */

        dirent_len = offsetof(struct dirent, d_name) +
                        fpathconf(td->dirfd, _PC_NAME_MAX) + 1;

        dirent = malloc(dirent_len);

        for (;;) {
                ret = readdir_r(td->dir, dirent, &diriter);
                if (ret) {
                        fprintf(stderr, "[error] Readdir error.\n");
                        goto readdir_error;
                }
                if (!diriter)
                        break;
                /* Ignore hidden files, ., .. and metadata. */
                if (!strncmp(diriter->d_name, ".", 1)
                                || !strcmp(diriter->d_name, "..")
                                || !strcmp(diriter->d_name, "metadata"))
                        continue;
                ret = ctf_open_file_stream_read(td, diriter->d_name,
                                        flags, packet_seek);
                if (ret) {
                        fprintf(stderr, "[error] Open file stream error.\n");
                        goto readdir_error;
                }
        }

        free(dirent);
        return 0;

readdir_error:
        free(dirent);
error_metadata:
        closeret = close(td->dirfd);
        if (closeret) {
                perror("Error on fd close");
        }
error_dirfd:
        closeret = closedir(td->dir);
        if (closeret) {
                perror("Error on closedir");
        }
error:
        return ret;
}

/*
 * ctf_open_trace: Open a CTF trace and index it.
 * Note that the user must seek the trace after the open (using the iterator)
 * since the index creation read it entirely.
 */
static
struct bt_trace_descriptor *ctf_open_trace(const char *path, int flags,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence), FILE *metadata_fp)
{
        struct ctf_trace *td;
        int ret;

        /*
         * If packet_seek is NULL, we provide our default version.
         */
        if (!packet_seek)
                packet_seek = ctf_packet_seek;

        td = g_new0(struct ctf_trace, 1);

        switch (flags & O_ACCMODE) {
        case O_RDONLY:
                if (!path) {
                        fprintf(stderr, "[error] Path missing for input CTF trace.\n");
                        goto error;
                }
                ret = ctf_open_trace_read(td, path, flags, packet_seek, metadata_fp);
                if (ret)
                        goto error;
                break;
        case O_RDWR:
                fprintf(stderr, "[error] Opening CTF traces for output is not supported yet.\n");
                goto error;
        default:
                fprintf(stderr, "[error] Incorrect open flags.\n");
                goto error;
        }

        return &td->parent;
error:
        g_free(td);
        return NULL;
}

static
void ctf_init_mmap_pos(struct ctf_stream_pos *pos,
                struct bt_mmap_stream *mmap_info)
{
        pos->mmap_offset = 0;
        pos->packet_size = 0;
        pos->content_size = 0;
        pos->content_size_loc = NULL;
        pos->fd = mmap_info->fd;
        pos->base_mma = NULL;
        pos->offset = 0;
        pos->dummy = false;
        pos->cur_index = 0;
        pos->packet_cycles_index = NULL;
        pos->packet_real_index = NULL;
        pos->prot = PROT_READ;
        pos->flags = MAP_PRIVATE;
        pos->parent.rw_table = read_dispatch_table;
        pos->parent.event_cb = ctf_read_event;
}

static
int prepare_mmap_stream_definition(struct ctf_trace *td,
                struct ctf_file_stream *file_stream)
{
        struct ctf_stream_declaration *stream;
        uint64_t stream_id = 0;
        int ret;

        file_stream->parent.stream_id = stream_id;
        if (stream_id >= td->streams->len) {
                fprintf(stderr, "[error] Stream %" PRIu64 " is not declared "
                                "in metadata.\n", stream_id);
                ret = -EINVAL;
                goto end;
        }
        stream = g_ptr_array_index(td->streams, stream_id);
        if (!stream) {
                fprintf(stderr, "[error] Stream %" PRIu64 " is not declared "
                                "in metadata.\n", stream_id);
                ret = -EINVAL;
                goto end;
        }
        file_stream->parent.stream_class = stream;
        ret = create_stream_definitions(td, &file_stream->parent);
end:
        return ret;
}

static
int ctf_open_mmap_stream_read(struct ctf_trace *td,
                struct bt_mmap_stream *mmap_info,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence))
{
        int ret;
        struct ctf_file_stream *file_stream;

        file_stream = g_new0(struct ctf_file_stream, 1);
        file_stream->pos.last_offset = LAST_OFFSET_POISON;
        ctf_init_mmap_pos(&file_stream->pos, mmap_info);

        file_stream->pos.packet_seek = packet_seek;

        ret = create_trace_definitions(td, &file_stream->parent);
        if (ret) {
                goto error_def;
        }

        ret = prepare_mmap_stream_definition(td, file_stream);
        if (ret)
                goto error_index;

        /*
         * For now, only a single clock per trace is supported.
         */
        file_stream->parent.current_clock = td->single_clock;

        /* Add stream file to stream class */
        g_ptr_array_add(file_stream->parent.stream_class->streams,
                        &file_stream->parent);
        return 0;

error_index:
        if (file_stream->parent.trace_packet_header)
                bt_definition_unref(&file_stream->parent.trace_packet_header->p);
error_def:
        g_free(file_stream);
        return ret;
}

static
int ctf_open_mmap_trace_read(struct ctf_trace *td,
                struct bt_mmap_stream_list *mmap_list,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence),
                FILE *metadata_fp)
{
        int ret;
        struct bt_mmap_stream *mmap_info;

        ret = ctf_open_trace_metadata_read(td, ctf_packet_seek, metadata_fp);
        if (ret) {
                goto error;
        }

        /*
         * for each stream, try to open, check magic number, and get the
         * stream ID to add to the right location in the stream array.
         */
        bt_list_for_each_entry(mmap_info, &mmap_list->head, list) {
                ret = ctf_open_mmap_stream_read(td, mmap_info, packet_seek);
                if (ret) {
                        fprintf(stderr, "[error] Open file mmap stream error.\n");
                        goto error;
                }
        }

        return 0;

error:
        return ret;
}

static
struct bt_trace_descriptor *ctf_open_mmap_trace(
                struct bt_mmap_stream_list *mmap_list,
                void (*packet_seek)(struct bt_stream_pos *pos, size_t index,
                        int whence),
                FILE *metadata_fp)
{
        struct ctf_trace *td;
        int ret;

        if (!metadata_fp) {
                fprintf(stderr, "[error] No metadata file pointer associated, "
                                "required for mmap parsing\n");
                goto error;
        }
        if (!packet_seek) {
                fprintf(stderr, "[error] packet_seek function undefined.\n");
                goto error;
        }
        td = g_new0(struct ctf_trace, 1);
        ret = ctf_open_mmap_trace_read(td, mmap_list, packet_seek, metadata_fp);
        if (ret)
                goto error_free;

        return &td->parent;

error_free:
        g_free(td);
error:
        return NULL;
}

static
int ctf_convert_index_timestamp(struct bt_trace_descriptor *tdp)
{
        int i, j, k;
        struct ctf_trace *td = container_of(tdp, struct ctf_trace, parent);

        /* for each stream_class */
        for (i = 0; i < td->streams->len; i++) {
                struct ctf_stream_declaration *stream_class;

                stream_class = g_ptr_array_index(td->streams, i);
                if (!stream_class)
                        continue;
                /* for each file_stream */
                for (j = 0; j < stream_class->streams->len; j++) {
                        struct ctf_stream_definition *stream;
                        struct ctf_stream_pos *stream_pos;
                        struct ctf_file_stream *cfs;

                        stream = g_ptr_array_index(stream_class->streams, j);
                        if (!stream)
                                continue;
                        cfs = container_of(stream, struct ctf_file_stream,
                                        parent);
                        stream_pos = &cfs->pos;
                        if (!stream_pos->packet_cycles_index)
                                continue;

                        for (k = 0; k < stream_pos->packet_cycles_index->len; k++) {
                                struct packet_index *index;
                                struct packet_index new_index;

                                index = &g_array_index(stream_pos->packet_cycles_index,
                                                struct packet_index, k);
                                memcpy(&new_index, index,
                                                sizeof(struct packet_index));
                                new_index.timestamp_begin =
                                        ctf_get_real_timestamp(stream,
                                                        index->timestamp_begin);
                                new_index.timestamp_end =
                                        ctf_get_real_timestamp(stream,
                                                        index->timestamp_end);
                                g_array_append_val(stream_pos->packet_real_index,
                                                new_index);
                        }
                }
        }
        return 0;
}

static
int ctf_close_file_stream(struct ctf_file_stream *file_stream)
{
        int ret;

        ret = ctf_fini_pos(&file_stream->pos);
        if (ret) {
                fprintf(stderr, "Error on ctf_fini_pos\n");
                return -1;
        }
        ret = close(file_stream->pos.fd);
        if (ret) {
                perror("Error closing file fd");
                return -1;
        }
        return 0;
}

static
int ctf_close_trace(struct bt_trace_descriptor *tdp)
{
        struct ctf_trace *td = container_of(tdp, struct ctf_trace, parent);
        int ret;

        if (td->streams) {
                int i;

                for (i = 0; i < td->streams->len; i++) {
                        struct ctf_stream_declaration *stream;
                        int j;

                        stream = g_ptr_array_index(td->streams, i);
                        if (!stream)
                                continue;
                        for (j = 0; j < stream->streams->len; j++) {
                                struct ctf_file_stream *file_stream;
                                file_stream = container_of(g_ptr_array_index(stream->streams, j),
                                                struct ctf_file_stream, parent);
                                ret = ctf_close_file_stream(file_stream);
                                if (ret)
                                        return ret;
                        }
                }
        }
        ctf_destroy_metadata(td);
        ret = close(td->dirfd);
        if (ret) {
                perror("Error closing dirfd");
                return ret;
        }
        ret = closedir(td->dir);
        if (ret) {
                perror("Error closedir");
                return ret;
        }
        free(td->metadata_string);
        g_free(td);
        return 0;
}

static
void ctf_set_context(struct bt_trace_descriptor *descriptor,
                struct bt_context *ctx)
{
        struct ctf_trace *td = container_of(descriptor, struct ctf_trace,
                        parent);

        td->ctx = ctx;
}

static
void ctf_set_handle(struct bt_trace_descriptor *descriptor,
                struct bt_trace_handle *handle)
{
        struct ctf_trace *td = container_of(descriptor, struct ctf_trace,
                        parent);

        td->handle = handle;
}

static
void __attribute__((constructor)) ctf_init(void)
{
        int ret;

        ctf_format.name = g_quark_from_static_string("ctf");
        ret = bt_register_format(&ctf_format);
        assert(!ret);
}

static
void __attribute__((destructor)) ctf_exit(void)
{
        bt_unregister_format(&ctf_format);
}