lib: make packets and packet messages optional, disabled by default

[babeltrace.git] / src / plugins / utils / trimmer / trimmer.c

/*
 * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 * Copyright 2019 Philippe Proulx <pproulx@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#define BT_COMP_LOG_SELF_COMP (trimmer_comp->self_comp)
#define BT_LOG_OUTPUT_LEVEL (trimmer_comp->log_level)
#define BT_LOG_TAG "PLUGIN/FLT.UTILS.TRIMMER"
#include "plugins/comp-logging.h"

#include "compat/utc.h"
#include "compat/time.h"
#include <babeltrace2/babeltrace.h>
#include "common/common.h"
#include "common/assert.h"
#include <stdint.h>
#include <inttypes.h>
#include <glib.h>
#include "compat/glib.h"

#include "trimmer.h"

#define NS_PER_S        INT64_C(1000000000)

static const char * const in_port_name = "in";

struct trimmer_time {
        unsigned int hour, minute, second, ns;
};

struct trimmer_bound {
        /*
         * Nanoseconds from origin, valid if `is_set` is set and
         * `is_infinite` is false.
         */
        int64_t ns_from_origin;

        /* True if this bound's full time (`ns_from_origin`) is set */
        bool is_set;

        /*
         * True if this bound represents the infinity (negative or
         * positive depending on which bound it is). If this is true,
         * then we don't care about `ns_from_origin` above.
         */
        bool is_infinite;

        /*
         * This bound's time without the date; this time is used to set
         * `ns_from_origin` once we know the date.
         */
        struct trimmer_time time;
};

struct trimmer_comp {
        struct trimmer_bound begin, end;
        bool is_gmt;
        bt_logging_level log_level;
        bt_self_component *self_comp;
};

enum trimmer_iterator_state {
        /*
         * Find the first message's date and set the bounds's times
         * accordingly.
         */
        TRIMMER_ITERATOR_STATE_SET_BOUNDS_NS_FROM_ORIGIN,

        /*
         * Initially seek to the trimming range's beginning time.
         */
        TRIMMER_ITERATOR_STATE_SEEK_INITIALLY,

        /*
         * Fill the output message queue for as long as received input
         * messages are within the trimming time range.
         */
        TRIMMER_ITERATOR_STATE_TRIM,

        /* Flush the remaining messages in the output message queue */
        TRIMMER_ITERATOR_STATE_ENDING,

        /* Trimming operation and message iterator is ended */
        TRIMMER_ITERATOR_STATE_ENDED,
};

struct trimmer_iterator {
        /* Weak */
        struct trimmer_comp *trimmer_comp;

        /* Weak */
        bt_self_message_iterator *self_msg_iter;

        enum trimmer_iterator_state state;

        /* Owned by this */
        bt_self_component_port_input_message_iterator *upstream_iter;
        struct trimmer_bound begin, end;

        /*
         * Queue of `const bt_message *` (owned by the queue).
         *
         * This is where the trimming operation pushes the messages to
         * output by this message iterator.
         */
        GQueue *output_messages;

        /*
         * Hash table of `bt_stream *` (weak) to
         * `struct trimmer_iterator_stream_state *` (owned by the HT).
         */
        GHashTable *stream_states;
};

struct trimmer_iterator_stream_state {
        /* Weak */
        const bt_stream *stream;

        /* Have we seen a message with clock_snapshot going through this stream? */
        bool seen_clock_snapshot;

        /* Owned by this (`NULL` initially and between packets) */
        const bt_packet *cur_packet;
};

static
void destroy_trimmer_comp(struct trimmer_comp *trimmer_comp)
{
        BT_ASSERT(trimmer_comp);
        g_free(trimmer_comp);
}

static
struct trimmer_comp *create_trimmer_comp(void)
{
        return g_new0(struct trimmer_comp, 1);
}

BT_HIDDEN
void trimmer_finalize(bt_self_component_filter *self_comp)
{
        struct trimmer_comp *trimmer_comp =
                bt_self_component_get_data(
                        bt_self_component_filter_as_self_component(self_comp));

        if (trimmer_comp) {
                destroy_trimmer_comp(trimmer_comp);
        }
}

/*
 * Compile regex in `pattern`, and try to match `string`.  If there's a match,
 * return true and set `*match_info` to the list of matches.  The list of
 * matches must be freed by the caller. If there's no match, return false and
 * set `*match_info` to NULL;
 */
static
bool compile_and_match(const char *pattern, const char *string, GMatchInfo **match_info) {
        bool matches = false;
        GError *regex_error = NULL;
        GRegex *regex;

        regex = g_regex_new(pattern, 0, 0, &regex_error);
        if (!regex) {
                goto end;
        }

        matches = g_regex_match(regex, string, 0, match_info);
        if (!matches) {
                /*
                 * g_regex_match allocates `*match_info` even if it returns
                 * FALSE.  If there's no match, we have no use for it, so free
                 * it immediatly and don't return it to the caller.
                 */
                g_match_info_free(*match_info);
                *match_info = NULL;
        }

        g_regex_unref(regex);

end:

        if (regex_error) {
                g_error_free(regex_error);
        }

        return matches;
}

/*
 * Convert the captured text in match number `match_num` in `match_info`
 * to an unsigned integer.
 */
static
guint64 match_to_uint(const GMatchInfo *match_info, gint match_num) {
        gchar *text, *endptr;
        guint64 result;

        text = g_match_info_fetch(match_info, match_num);
        BT_ASSERT(text);

        /*
         * Because the input is carefully sanitized with regexes by the caller,
         * we assume that g_ascii_strtoull cannot fail.
         */
        errno = 0;
        result = g_ascii_strtoull(text, &endptr, 10);
        BT_ASSERT(endptr > text);
        BT_ASSERT(errno == 0);

        g_free(text);

        return result;
}

/*
 * When parsing the nanoseconds part, .512 means .512000000, not .000000512.
 * This function is like match_to_uint, but multiplies the parsed number to get
 * the expected result.
 */
static
guint64 match_to_uint_ns(const GMatchInfo *match_info, gint match_num) {
        guint64 nanoseconds;
        gboolean ret;
        gint start_pos, end_pos, power;
        static int pow10[] = {
                1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
        };

        nanoseconds = match_to_uint(match_info, match_num);

        /* Multiply by 10 as many times as there are omitted digits. */
        ret = g_match_info_fetch_pos(match_info, match_num, &start_pos, &end_pos);
        BT_ASSERT(ret);

        power = 9 - (end_pos - start_pos);
        BT_ASSERT(power >= 0 && power <= 8);

        nanoseconds *= pow10[power];

        return nanoseconds;
}

/*
 * Sets the time (in ns from origin) of a trimmer bound from date and
 * time components.
 *
 * Returns a negative value if anything goes wrong.
 */
static
int set_bound_ns_from_origin(struct trimmer_bound *bound,
                unsigned int year, unsigned int month, unsigned int day,
                unsigned int hour, unsigned int minute, unsigned int second,
                unsigned int ns, bool is_gmt)
{
        int ret = 0;
        time_t result;
        struct tm tm = {
                .tm_sec = second,
                .tm_min = minute,
                .tm_hour = hour,
                .tm_mday = day,
                .tm_mon = month - 1,
                .tm_year = year - 1900,
                .tm_isdst = -1,
        };

        if (is_gmt) {
                result = bt_timegm(&tm);
        } else {
                result = mktime(&tm);
        }

        if (result < 0) {
                ret = -1;
                goto end;
        }

        BT_ASSERT(bound);
        bound->ns_from_origin = (int64_t) result;
        bound->ns_from_origin *= NS_PER_S;
        bound->ns_from_origin += ns;
        bound->is_set = true;

end:
        return ret;
}

/*
 * Parses a timestamp, figuring out its format.
 *
 * Returns a negative value if anything goes wrong.
 *
 * Expected formats:
 *
 *     YYYY-MM-DD hh:mm[:ss[.ns]]
 *     [hh:mm:]ss[.ns]
 *     [-]s[.ns]
 *
 * TODO: Check overflows.
 */
static
int set_bound_from_str(struct trimmer_comp *trimmer_comp,
                const char *str, struct trimmer_bound *bound, bool is_gmt)
{
/* Matches YYYY-MM-DD */
#define DATE_RE "([0-9]{4})-([0-9]{2})-([0-9]{2})"

/* Matches HH:MM[:SS[.NS]] */
#define TIME_RE "([0-9]{2}):([0-9]{2})(?::([0-9]{2})(?:\\.([0-9]{1,9}))?)?"

/* Matches [-]SS[.NS] */
#define S_NS_RE "^(-?)([0-9]+)(?:\\.([0-9]{1,9}))?$"

        GMatchInfo *match_info;
        int ret = 0;

        /* Try `YYYY-MM-DD hh:mm[:ss[.ns]]` format */
        if (compile_and_match("^" DATE_RE " " TIME_RE "$", str, &match_info)) {
                unsigned int year = 0, month = 0, day = 0, hours = 0, minutes = 0, seconds = 0, nanoseconds = 0;
                gint match_count = g_match_info_get_match_count(match_info);

                BT_ASSERT(match_count >= 6 && match_count <= 8);

                year = match_to_uint(match_info, 1);
                month = match_to_uint(match_info, 2);
                day = match_to_uint(match_info, 3);
                hours = match_to_uint(match_info, 4);
                minutes = match_to_uint(match_info, 5);

                if (match_count >= 7) {
                        seconds = match_to_uint(match_info, 6);
                }

                if (match_count >= 8) {
                        nanoseconds = match_to_uint_ns(match_info, 7);
                }

                set_bound_ns_from_origin(bound, year, month, day, hours, minutes, seconds, nanoseconds, is_gmt);

                goto end;
        }

        if (compile_and_match("^" DATE_RE "$", str, &match_info)) {
                unsigned int year = 0, month = 0, day = 0;

                BT_ASSERT(g_match_info_get_match_count(match_info) == 4);

                year = match_to_uint(match_info, 1);
                month = match_to_uint(match_info, 2);
                day = match_to_uint(match_info, 3);

                set_bound_ns_from_origin(bound, year, month, day, 0, 0, 0, 0, is_gmt);

                goto end;
        }

        /* Try `hh:mm[:ss[.ns]]` format */
        if (compile_and_match("^" TIME_RE "$", str, &match_info)) {
                gint match_count = g_match_info_get_match_count(match_info);
                BT_ASSERT(match_count >= 3 && match_count <= 5);
                bound->time.hour = match_to_uint(match_info, 1);
                bound->time.minute = match_to_uint(match_info, 2);

                if (match_count >= 4) {
                        bound->time.second = match_to_uint(match_info, 3);
                }

                if (match_count >= 5) {
                        bound->time.ns = match_to_uint_ns(match_info, 4);
                }

                goto end;
        }

        /* Try `[-]s[.ns]` format */
        if (compile_and_match("^" S_NS_RE "$", str, &match_info)) {
                gboolean is_neg, fetch_pos_ret;
                gint start_pos, end_pos, match_count;
                guint64 seconds, nanoseconds = 0;

                match_count = g_match_info_get_match_count(match_info);
                BT_ASSERT(match_count >= 3 && match_count <= 4);

                /* Check for presence of negation sign. */
                fetch_pos_ret = g_match_info_fetch_pos(match_info, 1, &start_pos, &end_pos);
                BT_ASSERT(fetch_pos_ret);
                is_neg = (end_pos - start_pos) > 0;

                seconds = match_to_uint(match_info, 2);

                if (match_count >= 4) {
                        nanoseconds = match_to_uint_ns(match_info, 3);
                }

                bound->ns_from_origin = seconds * NS_PER_S + nanoseconds;

                if (is_neg) {
                        bound->ns_from_origin = -bound->ns_from_origin;
                }

                bound->is_set = true;

                goto end;
        }

        BT_COMP_LOGE("Invalid date/time format: param=\"%s\"", str);
        ret = -1;

end:
        return ret;
}

/*
 * Sets a trimmer bound's properties from a parameter string/integer
 * value.
 *
 * Returns a negative value if anything goes wrong.
 */
static
int set_bound_from_param(struct trimmer_comp *trimmer_comp,
                const char *param_name, const bt_value *param,
                struct trimmer_bound *bound, bool is_gmt)
{
        int ret;
        const char *arg;
        char tmp_arg[64];

        if (bt_value_is_signed_integer(param)) {
                int64_t value = bt_value_signed_integer_get(param);

                /*
                 * Just convert it to a temporary string to handle
                 * everything the same way.
                 */
                sprintf(tmp_arg, "%" PRId64, value);
                arg = tmp_arg;
        } else if (bt_value_is_string(param)) {
                arg = bt_value_string_get(param);
        } else {
                BT_COMP_LOGE("`%s` parameter must be an integer or a string value.",
                        param_name);
                ret = -1;
                goto end;
        }

        ret = set_bound_from_str(trimmer_comp, arg, bound, is_gmt);

end:
        return ret;
}

static
int validate_trimmer_bounds(struct trimmer_comp *trimmer_comp,
                struct trimmer_bound *begin, struct trimmer_bound *end)
{
        int ret = 0;

        BT_ASSERT(begin->is_set);
        BT_ASSERT(end->is_set);

        if (!begin->is_infinite && !end->is_infinite &&
                        begin->ns_from_origin > end->ns_from_origin) {
                BT_COMP_LOGE("Trimming time range's beginning time is greater than end time: "
                        "begin-ns-from-origin=%" PRId64 ", "
                        "end-ns-from-origin=%" PRId64,
                        begin->ns_from_origin,
                        end->ns_from_origin);
                ret = -1;
                goto end;
        }

        if (!begin->is_infinite && begin->ns_from_origin == INT64_MIN) {
                BT_COMP_LOGE("Invalid trimming time range's beginning time: "
                        "ns-from-origin=%" PRId64,
                        begin->ns_from_origin);
                ret = -1;
                goto end;
        }

        if (!end->is_infinite && end->ns_from_origin == INT64_MIN) {
                BT_COMP_LOGE("Invalid trimming time range's end time: "
                        "ns-from-origin=%" PRId64,
                        end->ns_from_origin);
                ret = -1;
                goto end;
        }

end:
        return ret;
}

static
int init_trimmer_comp_from_params(struct trimmer_comp *trimmer_comp,
                const bt_value *params)
{
        const bt_value *value;
        int ret = 0;

        BT_ASSERT(params);
        value = bt_value_map_borrow_entry_value_const(params, "gmt");
        if (value) {
                trimmer_comp->is_gmt = (bool) bt_value_bool_get(value);
        }

        value = bt_value_map_borrow_entry_value_const(params, "begin");
        if (value) {
                if (set_bound_from_param(trimmer_comp, "begin", value,
                                &trimmer_comp->begin, trimmer_comp->is_gmt)) {
                        /* set_bound_from_param() logs errors */
                        ret = -1;
                        goto end;
                }
        } else {
                trimmer_comp->begin.is_infinite = true;
                trimmer_comp->begin.is_set = true;
        }

        value = bt_value_map_borrow_entry_value_const(params, "end");
        if (value) {
                if (set_bound_from_param(trimmer_comp, "end", value,
                                &trimmer_comp->end, trimmer_comp->is_gmt)) {
                        /* set_bound_from_param() logs errors */
                        ret = -1;
                        goto end;
                }
        } else {
                trimmer_comp->end.is_infinite = true;
                trimmer_comp->end.is_set = true;
        }

end:
        if (trimmer_comp->begin.is_set && trimmer_comp->end.is_set) {
                /* validate_trimmer_bounds() logs errors */
                ret = validate_trimmer_bounds(trimmer_comp,
                        &trimmer_comp->begin, &trimmer_comp->end);
        }

        return ret;
}

bt_component_class_init_method_status trimmer_init(
                bt_self_component_filter *self_comp_flt,
                const bt_value *params, void *init_data)
{
        int ret;
        bt_component_class_init_method_status status =
                BT_COMPONENT_CLASS_INIT_METHOD_STATUS_OK;
        bt_self_component_add_port_status add_port_status;
        struct trimmer_comp *trimmer_comp = create_trimmer_comp();
        bt_self_component *self_comp =
                bt_self_component_filter_as_self_component(self_comp_flt);
        if (!trimmer_comp) {
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_MEMORY_ERROR;
                goto error;
        }

        trimmer_comp->log_level = bt_component_get_logging_level(
                bt_self_component_as_component(self_comp));
        trimmer_comp->self_comp = self_comp;
        add_port_status = bt_self_component_filter_add_input_port(
                self_comp_flt, in_port_name, NULL, NULL);
        switch (add_port_status) {
        case BT_SELF_COMPONENT_ADD_PORT_STATUS_ERROR:
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_ERROR;
                goto error;
        case BT_SELF_COMPONENT_ADD_PORT_STATUS_MEMORY_ERROR:
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_MEMORY_ERROR;
                goto error;
        default:
                break;
        }

        add_port_status = bt_self_component_filter_add_output_port(
                self_comp_flt, "out", NULL, NULL);
        switch (add_port_status) {
        case BT_SELF_COMPONENT_ADD_PORT_STATUS_ERROR:
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_ERROR;
                goto error;
        case BT_SELF_COMPONENT_ADD_PORT_STATUS_MEMORY_ERROR:
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_MEMORY_ERROR;
                goto error;
        default:
                break;
        }

        ret = init_trimmer_comp_from_params(trimmer_comp, params);
        if (ret) {
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_ERROR;
                goto error;
        }

        bt_self_component_set_data(self_comp, trimmer_comp);
        goto end;

error:
        if (status == BT_COMPONENT_CLASS_INIT_METHOD_STATUS_OK) {
                status = BT_COMPONENT_CLASS_INIT_METHOD_STATUS_ERROR;
        }

        if (trimmer_comp) {
                destroy_trimmer_comp(trimmer_comp);
        }

end:
        return status;
}

static
void destroy_trimmer_iterator(struct trimmer_iterator *trimmer_it)
{
        BT_ASSERT(trimmer_it);
        bt_self_component_port_input_message_iterator_put_ref(
                trimmer_it->upstream_iter);

        if (trimmer_it->output_messages) {
                g_queue_free(trimmer_it->output_messages);
        }

        if (trimmer_it->stream_states) {
                g_hash_table_destroy(trimmer_it->stream_states);
        }

        g_free(trimmer_it);
}

static
void destroy_trimmer_iterator_stream_state(
                struct trimmer_iterator_stream_state *sstate)
{
        BT_ASSERT(sstate);
        BT_PACKET_PUT_REF_AND_RESET(sstate->cur_packet);
        g_free(sstate);
}

BT_HIDDEN
bt_component_class_message_iterator_init_method_status trimmer_msg_iter_init(
                bt_self_message_iterator *self_msg_iter,
                bt_self_component_filter *self_comp,
                bt_self_component_port_output *port)
{
        bt_component_class_message_iterator_init_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_OK;
        struct trimmer_iterator *trimmer_it;

        trimmer_it = g_new0(struct trimmer_iterator, 1);
        if (!trimmer_it) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_MEMORY_ERROR;
                goto end;
        }

        trimmer_it->trimmer_comp = bt_self_component_get_data(
                bt_self_component_filter_as_self_component(self_comp));
        BT_ASSERT(trimmer_it->trimmer_comp);

        if (trimmer_it->trimmer_comp->begin.is_set &&
                        trimmer_it->trimmer_comp->end.is_set) {
                /*
                 * Both trimming time range's bounds are set, so skip
                 * the
                 * `TRIMMER_ITERATOR_STATE_SET_BOUNDS_NS_FROM_ORIGIN`
                 * phase.
                 */
                trimmer_it->state = TRIMMER_ITERATOR_STATE_SEEK_INITIALLY;
        }

        trimmer_it->begin = trimmer_it->trimmer_comp->begin;
        trimmer_it->end = trimmer_it->trimmer_comp->end;
        trimmer_it->upstream_iter =
                bt_self_component_port_input_message_iterator_create(
                        bt_self_component_filter_borrow_input_port_by_name(
                                self_comp, in_port_name));
        if (!trimmer_it->upstream_iter) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_ERROR;
                goto end;
        }

        trimmer_it->output_messages = g_queue_new();
        if (!trimmer_it->output_messages) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_MEMORY_ERROR;
                goto end;
        }

        trimmer_it->stream_states = g_hash_table_new_full(g_direct_hash,
                g_direct_equal, NULL,
                (GDestroyNotify) destroy_trimmer_iterator_stream_state);
        if (!trimmer_it->stream_states) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_MEMORY_ERROR;
                goto end;
        }

        trimmer_it->self_msg_iter = self_msg_iter;
        bt_self_message_iterator_set_data(self_msg_iter, trimmer_it);

end:
        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_INIT_METHOD_STATUS_OK && trimmer_it) {
                destroy_trimmer_iterator(trimmer_it);
        }

        return status;
}

static inline
int get_msg_ns_from_origin(const bt_message *msg, int64_t *ns_from_origin,
                bool *has_clock_snapshot)
{
        const bt_clock_class *clock_class = NULL;
        const bt_clock_snapshot *clock_snapshot = NULL;
        int ret = 0;

        BT_ASSERT(msg);
        BT_ASSERT(ns_from_origin);
        BT_ASSERT(has_clock_snapshot);

        switch (bt_message_get_type(msg)) {
        case BT_MESSAGE_TYPE_EVENT:
                clock_class =
                        bt_message_event_borrow_stream_class_default_clock_class_const(
                                msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                clock_snapshot = bt_message_event_borrow_default_clock_snapshot_const(
                        msg);
                break;
        case BT_MESSAGE_TYPE_PACKET_BEGINNING:
                clock_class =
                        bt_message_packet_beginning_borrow_stream_class_default_clock_class_const(
                                msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                clock_snapshot = bt_message_packet_beginning_borrow_default_clock_snapshot_const(
                        msg);
                break;
        case BT_MESSAGE_TYPE_PACKET_END:
                clock_class =
                        bt_message_packet_end_borrow_stream_class_default_clock_class_const(
                                msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                clock_snapshot = bt_message_packet_end_borrow_default_clock_snapshot_const(
                        msg);
                break;
        case BT_MESSAGE_TYPE_STREAM_BEGINNING:
        {
                enum bt_message_stream_clock_snapshot_state cs_state;

                clock_class =
                        bt_message_stream_beginning_borrow_stream_class_default_clock_class_const(msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                cs_state = bt_message_stream_beginning_borrow_default_clock_snapshot_const(msg, &clock_snapshot);
                if (cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
                        goto no_clock_snapshot;
                }

                break;
        }
        case BT_MESSAGE_TYPE_STREAM_END:
        {
                enum bt_message_stream_clock_snapshot_state cs_state;

                clock_class =
                        bt_message_stream_end_borrow_stream_class_default_clock_class_const(msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                cs_state = bt_message_stream_end_borrow_default_clock_snapshot_const(msg, &clock_snapshot);
                if (cs_state != BT_MESSAGE_STREAM_CLOCK_SNAPSHOT_STATE_KNOWN) {
                        goto no_clock_snapshot;
                }

                break;
        }
        case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
                clock_class =
                        bt_message_discarded_events_borrow_stream_class_default_clock_class_const(
                                msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                clock_snapshot = bt_message_discarded_events_borrow_beginning_default_clock_snapshot_const(
                        msg);
                break;
        case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
                clock_class =
                        bt_message_discarded_packets_borrow_stream_class_default_clock_class_const(
                                msg);
                if (G_UNLIKELY(!clock_class)) {
                        goto error;
                }

                clock_snapshot = bt_message_discarded_packets_borrow_beginning_default_clock_snapshot_const(
                        msg);
                break;
        case BT_MESSAGE_TYPE_MESSAGE_ITERATOR_INACTIVITY:
                clock_snapshot =
                        bt_message_message_iterator_inactivity_borrow_default_clock_snapshot_const(
                                msg);
                break;
        default:
                goto no_clock_snapshot;
        }

        ret = bt_clock_snapshot_get_ns_from_origin(clock_snapshot,
                ns_from_origin);
        if (G_UNLIKELY(ret)) {
                goto error;
        }

        *has_clock_snapshot = true;
        goto end;

no_clock_snapshot:
        *has_clock_snapshot = false;
        goto end;

error:
        ret = -1;

end:
        return ret;
}

static inline
void put_messages(bt_message_array_const msgs, uint64_t count)
{
        uint64_t i;

        for (i = 0; i < count; i++) {
                BT_MESSAGE_PUT_REF_AND_RESET(msgs[i]);
        }
}

static inline
int set_trimmer_iterator_bound(struct trimmer_iterator *trimmer_it,
                struct trimmer_bound *bound, int64_t ns_from_origin,
                bool is_gmt)
{
        struct trimmer_comp *trimmer_comp = trimmer_it->trimmer_comp;
        struct tm tm;
        time_t time_seconds = (time_t) (ns_from_origin / NS_PER_S);
        int ret = 0;

        BT_ASSERT(!bound->is_set);
        errno = 0;

        /* We only need to extract the date from this time */
        if (is_gmt) {
                bt_gmtime_r(&time_seconds, &tm);
        } else {
                bt_localtime_r(&time_seconds, &tm);
        }

        if (errno) {
                BT_COMP_LOGE_ERRNO("Cannot convert timestamp to date and time",
                        "ts=%" PRId64, (int64_t) time_seconds);
                ret = -1;
                goto end;
        }

        ret = set_bound_ns_from_origin(bound, tm.tm_year + 1900, tm.tm_mon + 1,
                tm.tm_mday, bound->time.hour, bound->time.minute,
                bound->time.second, bound->time.ns, is_gmt);

end:
        return ret;
}

static
bt_component_class_message_iterator_next_method_status
state_set_trimmer_iterator_bounds(
                struct trimmer_iterator *trimmer_it)
{
        bt_message_iterator_next_status upstream_iter_status =
                BT_MESSAGE_ITERATOR_NEXT_STATUS_OK;
        struct trimmer_comp *trimmer_comp = trimmer_it->trimmer_comp;
        bt_message_array_const msgs;
        uint64_t count = 0;
        int64_t ns_from_origin = INT64_MIN;
        uint64_t i;
        int ret;

        BT_ASSERT(!trimmer_it->begin.is_set ||
                !trimmer_it->end.is_set);

        while (true) {
                upstream_iter_status =
                        bt_self_component_port_input_message_iterator_next(
                                trimmer_it->upstream_iter, &msgs, &count);
                if (upstream_iter_status != BT_MESSAGE_ITERATOR_NEXT_STATUS_OK) {
                        goto end;
                }

                for (i = 0; i < count; i++) {
                        const bt_message *msg = msgs[i];
                        bool has_ns_from_origin;
                        int ret;

                        ret = get_msg_ns_from_origin(msg, &ns_from_origin,
                                &has_ns_from_origin);
                        if (ret) {
                                goto error;
                        }

                        if (!has_ns_from_origin) {
                                continue;
                        }

                        BT_ASSERT(ns_from_origin != INT64_MIN &&
                                ns_from_origin != INT64_MAX);
                        put_messages(msgs, count);
                        goto found;
                }

                put_messages(msgs, count);
        }

found:
        if (!trimmer_it->begin.is_set) {
                BT_ASSERT(!trimmer_it->begin.is_infinite);
                ret = set_trimmer_iterator_bound(trimmer_it, &trimmer_it->begin,
                        ns_from_origin, trimmer_comp->is_gmt);
                if (ret) {
                        goto error;
                }
        }

        if (!trimmer_it->end.is_set) {
                BT_ASSERT(!trimmer_it->end.is_infinite);
                ret = set_trimmer_iterator_bound(trimmer_it, &trimmer_it->end,
                        ns_from_origin, trimmer_comp->is_gmt);
                if (ret) {
                        goto error;
                }
        }

        ret = validate_trimmer_bounds(trimmer_it->trimmer_comp,
                &trimmer_it->begin, &trimmer_it->end);
        if (ret) {
                goto error;
        }

        goto end;

error:
        put_messages(msgs, count);
        upstream_iter_status = BT_MESSAGE_ITERATOR_NEXT_STATUS_ERROR;

end:
        return (int) upstream_iter_status;
}

static
bt_component_class_message_iterator_next_method_status state_seek_initially(
                struct trimmer_iterator *trimmer_it)
{
        struct trimmer_comp *trimmer_comp = trimmer_it->trimmer_comp;
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;

        BT_ASSERT(trimmer_it->begin.is_set);

        if (trimmer_it->begin.is_infinite) {
                if (!bt_self_component_port_input_message_iterator_can_seek_beginning(
                                trimmer_it->upstream_iter)) {
                        BT_COMP_LOGE_STR("Cannot make upstream message iterator initially seek its beginning.");
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                        goto end;
                }

                status = (int) bt_self_component_port_input_message_iterator_seek_beginning(
                        trimmer_it->upstream_iter);
        } else {
                if (!bt_self_component_port_input_message_iterator_can_seek_ns_from_origin(
                                trimmer_it->upstream_iter,
                                trimmer_it->begin.ns_from_origin)) {
                        BT_COMP_LOGE("Cannot make upstream message iterator initially seek: "
                                "seek-ns-from-origin=%" PRId64,
                                trimmer_it->begin.ns_from_origin);
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                        goto end;
                }

                status = (int) bt_self_component_port_input_message_iterator_seek_ns_from_origin(
                        trimmer_it->upstream_iter, trimmer_it->begin.ns_from_origin);
        }

        if (status == BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                trimmer_it->state = TRIMMER_ITERATOR_STATE_TRIM;
        }

end:
        return status;
}

static inline
void push_message(struct trimmer_iterator *trimmer_it, const bt_message *msg)
{
        g_queue_push_head(trimmer_it->output_messages, (void *) msg);
}

static inline
const bt_message *pop_message(struct trimmer_iterator *trimmer_it)
{
        return g_queue_pop_tail(trimmer_it->output_messages);
}

static inline
int clock_raw_value_from_ns_from_origin(const bt_clock_class *clock_class,
                int64_t ns_from_origin, uint64_t *raw_value)
{

        int64_t cc_offset_s;
        uint64_t cc_offset_cycles;
        uint64_t cc_freq;

        bt_clock_class_get_offset(clock_class, &cc_offset_s, &cc_offset_cycles);
        cc_freq = bt_clock_class_get_frequency(clock_class);
        return bt_common_clock_value_from_ns_from_origin(cc_offset_s,
                cc_offset_cycles, cc_freq, ns_from_origin, raw_value);
}

static inline
bt_component_class_message_iterator_next_method_status
end_stream(struct trimmer_iterator *trimmer_it,
                struct trimmer_iterator_stream_state *sstate)
{
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
        /* Initialize to silence maybe-uninitialized warning. */
        uint64_t raw_value = 0;
        bt_message *msg = NULL;

        BT_ASSERT(!trimmer_it->end.is_infinite);
        BT_ASSERT(sstate->stream);

        /*
         * If we haven't seen a message with a clock snapshot, we don't know if the trimmer's end bound is within
         * the clock's range, so it wouldn't be safe to try to convert ns_from_origin to a clock value.
         *
         * Also, it would be a bit of a lie to generate a stream end message with the end bound as its
         * clock snapshot, because we don't really know if the stream existed at that time.  If we have
         * seen a message with a clock snapshot and the stream is cut short by another message with a
         * clock snapshot, then we are sure that the the end bound time is not below the clock range,
         * and we know the stream was active at that time (and that we cut it short).
         */
        if (sstate->seen_clock_snapshot) {
                const bt_clock_class *clock_class;
                int ret;

                clock_class = bt_stream_class_borrow_default_clock_class_const(
                        bt_stream_borrow_class_const(sstate->stream));
                BT_ASSERT(clock_class);
                ret = clock_raw_value_from_ns_from_origin(clock_class,
                        trimmer_it->end.ns_from_origin, &raw_value);
                if (ret) {
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                        goto end;
                }
        }

        if (sstate->cur_packet) {
                /*
                 * Create and push a packet end message, making its time
                 * the trimming range's end time.
                 *
                 * We know that we must have seen a clock snapshot, the one in
                 * the packet beginning message, since trimmer currently
                 * requires packet messages to have clock snapshots (see comment
                 * in create_stream_state_entry).
                 */
                BT_ASSERT(sstate->seen_clock_snapshot);

                msg = bt_message_packet_end_create_with_default_clock_snapshot(
                        trimmer_it->self_msg_iter, sstate->cur_packet,
                        raw_value);
                if (!msg) {
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_MEMORY_ERROR;
                        goto end;
                }

                push_message(trimmer_it, msg);
                msg = NULL;
                BT_PACKET_PUT_REF_AND_RESET(sstate->cur_packet);
        }

        /* Create and push a stream end message. */
        msg = bt_message_stream_end_create(trimmer_it->self_msg_iter,
                sstate->stream);
        if (!msg) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_MEMORY_ERROR;
                goto end;
        }

        if (sstate->seen_clock_snapshot) {
                bt_message_stream_end_set_default_clock_snapshot(msg, raw_value);
        }

        push_message(trimmer_it, msg);
        msg = NULL;

        /*
         * Just to make sure that we don't use this stream state again
         * in the future without an obvious error.
         */
        sstate->stream = NULL;

end:
        bt_message_put_ref(msg);
        return status;
}

static inline
bt_component_class_message_iterator_next_method_status end_iterator_streams(
                struct trimmer_iterator *trimmer_it)
{
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
        GHashTableIter iter;
        gpointer key, sstate;

        if (trimmer_it->end.is_infinite) {
                /*
                 * An infinite trimming range's end time guarantees that
                 * we received (and pushed) all the appropriate end
                 * messages.
                 */
                goto remove_all;
        }

        /*
         * End each stream and then remove them from the hash table of
         * stream states to release unneeded references.
         */
        g_hash_table_iter_init(&iter, trimmer_it->stream_states);

        while (g_hash_table_iter_next(&iter, &key, &sstate)) {
                status = end_stream(trimmer_it, sstate);
                if (status) {
                        goto end;
                }
        }

remove_all:
        g_hash_table_remove_all(trimmer_it->stream_states);

end:
        return status;
}

static
bt_component_class_message_iterator_next_method_status
create_stream_state_entry(
                struct trimmer_iterator *trimmer_it,
                const struct bt_stream *stream,
                struct trimmer_iterator_stream_state **stream_state)
{
        struct trimmer_comp *trimmer_comp = trimmer_it->trimmer_comp;
        bt_component_class_message_iterator_next_method_status status;
        struct trimmer_iterator_stream_state *sstate;
        const bt_stream_class *sc;

        BT_ASSERT(!bt_g_hash_table_contains(trimmer_it->stream_states, stream));

        /*
         * Validate right now that the stream's class
         * has a registered default clock class so that
         * an existing stream state guarantees existing
         * default clock snapshots for its associated
         * messages.
         *
         * Also check that clock snapshots are always
         * known.
         */
        sc = bt_stream_borrow_class_const(stream);
        if (!bt_stream_class_borrow_default_clock_class_const(sc)) {
                BT_COMP_LOGE("Unsupported stream: stream class does "
                        "not have a default clock class: "
                        "stream-addr=%p, "
                        "stream-id=%" PRIu64 ", "
                        "stream-name=\"%s\"",
                        stream, bt_stream_get_id(stream),
                        bt_stream_get_name(stream));
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                goto end;
        }

        /*
         * Temporary: make sure packet beginning, packet
         * end, discarded events, and discarded packets
         * messages have default clock snapshots until
         * the support for not having them is
         * implemented.
         */
        if (!bt_stream_class_packets_have_beginning_default_clock_snapshot(
                        sc)) {
                BT_COMP_LOGE("Unsupported stream: packets have "
                        "no beginning clock snapshot: "
                        "stream-addr=%p, "
                        "stream-id=%" PRIu64 ", "
                        "stream-name=\"%s\"",
                        stream, bt_stream_get_id(stream),
                        bt_stream_get_name(stream));
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                goto end;
        }

        if (!bt_stream_class_packets_have_end_default_clock_snapshot(
                        sc)) {
                BT_COMP_LOGE("Unsupported stream: packets have "
                        "no end clock snapshot: "
                        "stream-addr=%p, "
                        "stream-id=%" PRIu64 ", "
                        "stream-name=\"%s\"",
                        stream, bt_stream_get_id(stream),
                        bt_stream_get_name(stream));
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                goto end;
        }

        if (bt_stream_class_supports_discarded_events(sc) &&
                        !bt_stream_class_discarded_events_have_default_clock_snapshots(sc)) {
                BT_COMP_LOGE("Unsupported stream: discarded events "
                        "have no clock snapshots: "
                        "stream-addr=%p, "
                        "stream-id=%" PRIu64 ", "
                        "stream-name=\"%s\"",
                        stream, bt_stream_get_id(stream),
                        bt_stream_get_name(stream));
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                goto end;
        }

        if (bt_stream_class_supports_discarded_packets(sc) &&
                        !bt_stream_class_discarded_packets_have_default_clock_snapshots(sc)) {
                BT_COMP_LOGE("Unsupported stream: discarded packets "
                        "have no clock snapshots: "
                        "stream-addr=%p, "
                        "stream-id=%" PRIu64 ", "
                        "stream-name=\"%s\"",
                        stream, bt_stream_get_id(stream),
                        bt_stream_get_name(stream));
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                goto end;
        }

        sstate = g_new0(struct trimmer_iterator_stream_state, 1);
        if (!sstate) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_MEMORY_ERROR;
                goto end;
        }

        sstate->stream = stream;

        g_hash_table_insert(trimmer_it->stream_states, (void *) stream, sstate);

        *stream_state = sstate;

        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;

end:
        return status;
}

static
struct trimmer_iterator_stream_state *get_stream_state_entry(
                struct trimmer_iterator *trimmer_it,
                const struct bt_stream *stream)
{
        struct trimmer_iterator_stream_state *sstate;

        BT_ASSERT(stream);
        sstate = g_hash_table_lookup(trimmer_it->stream_states, stream);
        BT_ASSERT(sstate);

        return sstate;
}

/*
 * Handles a message which is associated to a given stream state. This
 * _could_ make the iterator's output message queue grow; this could
 * also consume the message without pushing anything to this queue, only
 * modifying the stream state.
 *
 * This function consumes the `msg` reference, _whatever the outcome_.
 *
 * If non-NULL, `ns_from_origin` is the message's time, as given by
 * get_msg_ns_from_origin().  If NULL, the message doesn't have a time.
 *
 * This function sets `reached_end` if handling this message made the
 * iterator reach the end of the trimming range. Note that the output
 * message queue could contain messages even if this function sets
 * `reached_end`.
 */
static
bt_component_class_message_iterator_next_method_status
handle_message_with_stream(
                struct trimmer_iterator *trimmer_it, const bt_message *msg,
                const struct bt_stream *stream, const int64_t *ns_from_origin,
                bool *reached_end)
{
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
        bt_message_type msg_type = bt_message_get_type(msg);
        int ret;
        struct trimmer_iterator_stream_state *sstate = NULL;

        /*
         * Retrieve the stream's state - except if the message is stream
         * beginning, in which case we don't know about about this stream yet.
         */
        if (msg_type != BT_MESSAGE_TYPE_STREAM_BEGINNING) {
                sstate = get_stream_state_entry(trimmer_it, stream);
        }

        switch (msg_type) {
        case BT_MESSAGE_TYPE_EVENT:
                /*
                 * Event messages always have a clock snapshot if the stream
                 * class has a clock class. And we know it has, otherwise we
                 * couldn't be using the trimmer component.
                 */
                BT_ASSERT(ns_from_origin);

                if (G_UNLIKELY(!trimmer_it->end.is_infinite &&
                                *ns_from_origin > trimmer_it->end.ns_from_origin)) {
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                        break;
                }

                sstate->seen_clock_snapshot = true;

                push_message(trimmer_it, msg);
                msg = NULL;
                break;

        case BT_MESSAGE_TYPE_PACKET_BEGINNING:
                /*
                 * Packet beginning messages won't have a clock snapshot if
                 * stream_class->packets_have_beginning_default_clock_snapshot
                 * is false.  But for now, assume they always do.
                 */
                BT_ASSERT(ns_from_origin);
                BT_ASSERT(!sstate->cur_packet);

                if (G_UNLIKELY(!trimmer_it->end.is_infinite &&
                                *ns_from_origin > trimmer_it->end.ns_from_origin)) {
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                        break;
                }

                sstate->cur_packet =
                        bt_message_packet_beginning_borrow_packet_const(msg);
                bt_packet_get_ref(sstate->cur_packet);

                sstate->seen_clock_snapshot = true;

                push_message(trimmer_it, msg);
                msg = NULL;
                break;

        case BT_MESSAGE_TYPE_PACKET_END:
                /*
                 * Packet end messages won't have a clock snapshot if
                 * stream_class->packets_have_end_default_clock_snapshot
                 * is false.  But for now, assume they always do.
                 */
                BT_ASSERT(ns_from_origin);
                BT_ASSERT(sstate->cur_packet);

                if (G_UNLIKELY(!trimmer_it->end.is_infinite &&
                                *ns_from_origin > trimmer_it->end.ns_from_origin)) {
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                        break;
                }

                BT_PACKET_PUT_REF_AND_RESET(sstate->cur_packet);

                sstate->seen_clock_snapshot = true;

                push_message(trimmer_it, msg);
                msg = NULL;
                break;

        case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
        case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
        {
                /*
                 * `ns_from_origin` is the message's time range's
                 * beginning time here.
                 */
                int64_t end_ns_from_origin;
                const bt_clock_snapshot *end_cs;

                BT_ASSERT(ns_from_origin);

                sstate->seen_clock_snapshot = true;

                if (bt_message_get_type(msg) ==
                                BT_MESSAGE_TYPE_DISCARDED_EVENTS) {
                        /*
                         * Safe to ignore the return value because we
                         * know there's a default clock and it's always
                         * known.
                         */
                        end_cs = bt_message_discarded_events_borrow_end_default_clock_snapshot_const(
                                msg);
                } else {
                        /*
                         * Safe to ignore the return value because we
                         * know there's a default clock and it's always
                         * known.
                         */
                        end_cs = bt_message_discarded_packets_borrow_end_default_clock_snapshot_const(
                                msg);
                }

                if (bt_clock_snapshot_get_ns_from_origin(end_cs,
                                &end_ns_from_origin)) {
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                        goto end;
                }

                if (!trimmer_it->end.is_infinite &&
                                *ns_from_origin > trimmer_it->end.ns_from_origin) {
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                        break;
                }

                if (!trimmer_it->end.is_infinite &&
                                end_ns_from_origin > trimmer_it->end.ns_from_origin) {
                        /*
                         * This message's end time is outside the
                         * trimming time range: replace it with a new
                         * message having an end time equal to the
                         * trimming time range's end and without a
                         * count.
                         */
                        const bt_clock_class *clock_class =
                                bt_clock_snapshot_borrow_clock_class_const(
                                        end_cs);
                        const bt_clock_snapshot *begin_cs;
                        bt_message *new_msg;
                        uint64_t end_raw_value;

                        ret = clock_raw_value_from_ns_from_origin(clock_class,
                                trimmer_it->end.ns_from_origin, &end_raw_value);
                        if (ret) {
                                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                                goto end;
                        }

                        if (msg_type == BT_MESSAGE_TYPE_DISCARDED_EVENTS) {
                                begin_cs = bt_message_discarded_events_borrow_beginning_default_clock_snapshot_const(
                                        msg);
                                new_msg = bt_message_discarded_events_create_with_default_clock_snapshots(
                                        trimmer_it->self_msg_iter,
                                        sstate->stream,
                                        bt_clock_snapshot_get_value(begin_cs),
                                        end_raw_value);
                        } else {
                                begin_cs = bt_message_discarded_packets_borrow_beginning_default_clock_snapshot_const(
                                        msg);
                                new_msg = bt_message_discarded_packets_create_with_default_clock_snapshots(
                                        trimmer_it->self_msg_iter,
                                        sstate->stream,
                                        bt_clock_snapshot_get_value(begin_cs),
                                        end_raw_value);
                        }

                        if (!new_msg) {
                                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_MEMORY_ERROR;
                                goto end;
                        }

                        /* Replace the original message */
                        BT_MESSAGE_MOVE_REF(msg, new_msg);
                }

                push_message(trimmer_it, msg);
                msg = NULL;
                break;
        }

        case BT_MESSAGE_TYPE_STREAM_BEGINNING:
                /*
                 * If this message has a time and this time is greater than the
                 * trimmer's end bound, it triggers the end of the trim window.
                 */
                if (G_UNLIKELY(ns_from_origin && !trimmer_it->end.is_infinite &&
                                *ns_from_origin > trimmer_it->end.ns_from_origin)) {
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                        break;
                }

                /* Learn about this stream. */
                status = create_stream_state_entry(trimmer_it, stream, &sstate);
                if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                        goto end;
                }

                if (ns_from_origin) {
                        sstate->seen_clock_snapshot = true;
                }

                push_message(trimmer_it,  msg);
                msg = NULL;
                break;
        case BT_MESSAGE_TYPE_STREAM_END:
        {
                gboolean removed;

                /*
                 * If this message has a time and this time is greater than the
                 * trimmer's end bound, it triggers the end of the trim window.
                 */
                if (G_UNLIKELY(ns_from_origin && !trimmer_it->end.is_infinite &&
                                *ns_from_origin > trimmer_it->end.ns_from_origin)) {
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                        break;
                }

                /*
                 * Either the stream end message's time is within the trimmer's
                 * bounds, or it doesn't have a time.  In both cases, pass
                 * the message unmodified.
                 */
                push_message(trimmer_it, msg);
                msg = NULL;

                /* Forget about this stream. */
                removed = g_hash_table_remove(trimmer_it->stream_states, sstate->stream);
                BT_ASSERT(removed);
                break;
        }
        default:
                break;
        }

end:
        /* We release the message's reference whatever the outcome */
        bt_message_put_ref(msg);
        return status;
}

/*
 * Handles an input message. This _could_ make the iterator's output
 * message queue grow; this could also consume the message without
 * pushing anything to this queue, only modifying the stream state.
 *
 * This function consumes the `msg` reference, _whatever the outcome_.
 *
 * This function sets `reached_end` if handling this message made the
 * iterator reach the end of the trimming range. Note that the output
 * message queue could contain messages even if this function sets
 * `reached_end`.
 */
static inline
bt_component_class_message_iterator_next_method_status handle_message(
                struct trimmer_iterator *trimmer_it, const bt_message *msg,
                bool *reached_end)
{
        bt_component_class_message_iterator_next_method_status status;
        const bt_stream *stream = NULL;
        int64_t ns_from_origin = INT64_MIN;
        bool has_ns_from_origin;
        int ret;

        /* Find message's associated stream */
        switch (bt_message_get_type(msg)) {
        case BT_MESSAGE_TYPE_EVENT:
                stream = bt_event_borrow_stream_const(
                        bt_message_event_borrow_event_const(msg));
                break;
        case BT_MESSAGE_TYPE_PACKET_BEGINNING:
                stream = bt_packet_borrow_stream_const(
                        bt_message_packet_beginning_borrow_packet_const(msg));
                break;
        case BT_MESSAGE_TYPE_PACKET_END:
                stream = bt_packet_borrow_stream_const(
                        bt_message_packet_end_borrow_packet_const(msg));
                break;
        case BT_MESSAGE_TYPE_DISCARDED_EVENTS:
                stream = bt_message_discarded_events_borrow_stream_const(msg);
                break;
        case BT_MESSAGE_TYPE_DISCARDED_PACKETS:
                stream = bt_message_discarded_packets_borrow_stream_const(msg);
                break;
        case BT_MESSAGE_TYPE_STREAM_BEGINNING:
                stream = bt_message_stream_beginning_borrow_stream_const(msg);
                break;
        case BT_MESSAGE_TYPE_STREAM_END:
                stream = bt_message_stream_end_borrow_stream_const(msg);
                break;
        default:
                break;
        }

        /* Retrieve the message's time */
        ret = get_msg_ns_from_origin(msg, &ns_from_origin, &has_ns_from_origin);
        if (G_UNLIKELY(ret)) {
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_ERROR;
                goto end;
        }

        if (G_LIKELY(stream)) {
                /* Message associated to a stream */
                status = handle_message_with_stream(trimmer_it, msg,
                        stream, has_ns_from_origin ? &ns_from_origin : NULL, reached_end);

                /*
                 * handle_message_with_stream_state() unconditionally
                 * consumes `msg`.
                 */
                msg = NULL;
        } else {
                /*
                 * Message not associated to a stream (message iterator
                 * inactivity).
                 */
                if (G_UNLIKELY(ns_from_origin > trimmer_it->end.ns_from_origin)) {
                        BT_MESSAGE_PUT_REF_AND_RESET(msg);
                        status = end_iterator_streams(trimmer_it);
                        *reached_end = true;
                } else {
                        push_message(trimmer_it, msg);
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
                        msg = NULL;
                }
        }

end:
        /* We release the message's reference whatever the outcome */
        bt_message_put_ref(msg);
        return status;
}

static inline
void fill_message_array_from_output_messages(
                struct trimmer_iterator *trimmer_it,
                bt_message_array_const msgs, uint64_t capacity, uint64_t *count)
{
        *count = 0;

        /*
         * Move auto-seek messages to the output array (which is this
         * iterator's base message array).
         */
        while (capacity > 0 && !g_queue_is_empty(trimmer_it->output_messages)) {
                msgs[*count] = pop_message(trimmer_it);
                capacity--;
                (*count)++;
        }

        BT_ASSERT(*count > 0);
}

static inline
bt_component_class_message_iterator_next_method_status state_ending(
                struct trimmer_iterator *trimmer_it,
                bt_message_array_const msgs, uint64_t capacity,
                uint64_t *count)
{
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;

        if (g_queue_is_empty(trimmer_it->output_messages)) {
                trimmer_it->state = TRIMMER_ITERATOR_STATE_ENDED;
                status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END;
                goto end;
        }

        fill_message_array_from_output_messages(trimmer_it, msgs,
                capacity, count);

end:
        return status;
}

static inline
bt_component_class_message_iterator_next_method_status
state_trim(struct trimmer_iterator *trimmer_it,
                bt_message_array_const msgs, uint64_t capacity,
                uint64_t *count)
{
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;
        bt_message_array_const my_msgs;
        uint64_t my_count;
        uint64_t i;
        bool reached_end = false;

        while (g_queue_is_empty(trimmer_it->output_messages)) {
                status = (int) bt_self_component_port_input_message_iterator_next(
                        trimmer_it->upstream_iter, &my_msgs, &my_count);
                if (G_UNLIKELY(status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK)) {
                        if (status == BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END) {
                                status = end_iterator_streams(trimmer_it);
                                if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                        goto end;
                                }

                                trimmer_it->state =
                                        TRIMMER_ITERATOR_STATE_ENDING;
                                status = state_ending(trimmer_it, msgs,
                                        capacity, count);
                        }

                        goto end;
                }

                BT_ASSERT(my_count > 0);

                for (i = 0; i < my_count; i++) {
                        status = handle_message(trimmer_it, my_msgs[i],
                                &reached_end);

                        /*
                         * handle_message() unconditionally consumes the
                         * message reference.
                         */
                        my_msgs[i] = NULL;

                        if (G_UNLIKELY(status !=
                                        BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK)) {
                                put_messages(my_msgs, my_count);
                                goto end;
                        }

                        if (G_UNLIKELY(reached_end)) {
                                /*
                                 * This message's time was passed the
                                 * trimming time range's end time: we
                                 * are done. Their might still be
                                 * messages in the output message queue,
                                 * so move to the "ending" state and
                                 * apply it immediately since
                                 * state_trim() is called within the
                                 * "next" method.
                                 */
                                put_messages(my_msgs, my_count);
                                trimmer_it->state =
                                        TRIMMER_ITERATOR_STATE_ENDING;
                                status = state_ending(trimmer_it, msgs,
                                        capacity, count);
                                goto end;
                        }
                }
        }

        /*
         * There's at least one message in the output message queue:
         * move the messages to the output message array.
         */
        BT_ASSERT(!g_queue_is_empty(trimmer_it->output_messages));
        fill_message_array_from_output_messages(trimmer_it, msgs,
                capacity, count);

end:
        return status;
}

BT_HIDDEN
bt_component_class_message_iterator_next_method_status trimmer_msg_iter_next(
                bt_self_message_iterator *self_msg_iter,
                bt_message_array_const msgs, uint64_t capacity,
                uint64_t *count)
{
        struct trimmer_iterator *trimmer_it =
                bt_self_message_iterator_get_data(self_msg_iter);
        bt_component_class_message_iterator_next_method_status status =
                BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK;

        BT_ASSERT(trimmer_it);

        if (G_LIKELY(trimmer_it->state == TRIMMER_ITERATOR_STATE_TRIM)) {
                status = state_trim(trimmer_it, msgs, capacity, count);
                if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                        goto end;
                }
        } else {
                switch (trimmer_it->state) {
                case TRIMMER_ITERATOR_STATE_SET_BOUNDS_NS_FROM_ORIGIN:
                        status = state_set_trimmer_iterator_bounds(trimmer_it);
                        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                goto end;
                        }

                        status = state_seek_initially(trimmer_it);
                        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                goto end;
                        }

                        status = state_trim(trimmer_it, msgs, capacity, count);
                        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                goto end;
                        }

                        break;
                case TRIMMER_ITERATOR_STATE_SEEK_INITIALLY:
                        status = state_seek_initially(trimmer_it);
                        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                goto end;
                        }

                        status = state_trim(trimmer_it, msgs, capacity, count);
                        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                goto end;
                        }

                        break;
                case TRIMMER_ITERATOR_STATE_ENDING:
                        status = state_ending(trimmer_it, msgs, capacity,
                                count);
                        if (status != BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_OK) {
                                goto end;
                        }

                        break;
                case TRIMMER_ITERATOR_STATE_ENDED:
                        status = BT_COMPONENT_CLASS_MESSAGE_ITERATOR_NEXT_METHOD_STATUS_END;
                        break;
                default:
                        abort();
                }
        }

end:
        return status;
}

BT_HIDDEN
void trimmer_msg_iter_finalize(bt_self_message_iterator *self_msg_iter)
{
        struct trimmer_iterator *trimmer_it =
                bt_self_message_iterator_get_data(self_msg_iter);

        BT_ASSERT(trimmer_it);
        destroy_trimmer_iterator(trimmer_it);
}