src.ctf.lttng-live: introduce and use lttng_live_stream_iterator::UP

[babeltrace.git] / src / plugins / ctf / lttng-live / data-stream.cpp

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright 2019 Francis Deslauriers <francis.deslauriers@efficios.com>
 * Copyright 2016 Philippe Proulx <pproulx@efficios.com>
 * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
 */

#include <sstream>

#include <glib.h>
#include <stdio.h>
#include <stdlib.h>

#include <babeltrace2/babeltrace.h>

#include "common/assert.h"
#include "compat/mman.h" /* IWYU pragma: keep  */
#include "cpp-common/bt2s/make-unique.hpp"
#include "cpp-common/vendor/fmt/format.h"

#include "../common/src/msg-iter/msg-iter.hpp"
#include "data-stream.hpp"

#define STREAM_NAME_PREFIX "stream-"

static enum ctf_msg_iter_medium_status medop_request_bytes(size_t request_sz, uint8_t **buffer_addr,
                                                           size_t *buffer_sz, void *data)
{
    enum ctf_msg_iter_medium_status status = CTF_MSG_ITER_MEDIUM_STATUS_OK;
    lttng_live_stream_iterator *stream = (lttng_live_stream_iterator *) data;
    struct lttng_live_trace *trace = stream->trace;
    struct lttng_live_session *session = trace->session;
    struct lttng_live_msg_iter *live_msg_iter = session->lttng_live_msg_iter;
    uint64_t recv_len = 0;
    uint64_t len_left;
    uint64_t read_len;

    BT_ASSERT(request_sz);

    if (stream->has_stream_hung_up) {
        status = CTF_MSG_ITER_MEDIUM_STATUS_EOF;
        goto end;
    }

    len_left = stream->base_offset + stream->len - stream->offset;
    if (!len_left) {
        lttng_live_stream_iterator_set_state(stream, LTTNG_LIVE_STREAM_ACTIVE_NO_DATA);
        status = CTF_MSG_ITER_MEDIUM_STATUS_AGAIN;
        goto end;
    }

    read_len = MIN(request_sz, stream->buf.size());
    read_len = MIN(read_len, len_left);
    status = lttng_live_get_stream_bytes(live_msg_iter, stream, stream->buf.data(), stream->offset,
                                         read_len, &recv_len);
    *buffer_addr = stream->buf.data();
    *buffer_sz = recv_len;
    stream->offset += recv_len;
end:
    return status;
}

static bt_stream *medop_borrow_stream(bt_stream_class *stream_class, int64_t stream_id, void *data)
{
    lttng_live_stream_iterator *lttng_live_stream = (lttng_live_stream_iterator *) data;

    if (!lttng_live_stream->stream) {
        uint64_t stream_class_id = bt_stream_class_get_id(stream_class);

        BT_CPPLOGI_SPEC(lttng_live_stream->logger,
                        "Creating stream {} (ID: {}) out of stream class {}",
                        lttng_live_stream->name, stream_id, stream_class_id);

        bt_stream *stream;

        if (stream_id < 0) {
            /*
             * No stream instance ID in the stream. It's possible
             * to encounter this situation with older version of
             * LTTng. In these cases, use the viewer_stream_id that
             * is unique for a live viewer session.
             */
            stream =
                bt_stream_create_with_id(stream_class, lttng_live_stream->trace->trace->libObjPtr(),
                                         lttng_live_stream->viewer_stream_id);
        } else {
            stream = bt_stream_create_with_id(
                stream_class, lttng_live_stream->trace->trace->libObjPtr(), (uint64_t) stream_id);
        }

        if (!stream) {
            BT_CPPLOGE_APPEND_CAUSE_SPEC(
                lttng_live_stream->logger,
                "Cannot create stream {} (stream class ID {}, stream ID {})",
                lttng_live_stream->name, stream_class_id, stream_id);
            return nullptr;
        }

        lttng_live_stream->stream = bt2::Stream::Shared::createWithoutRef(stream);

        lttng_live_stream->stream->name(lttng_live_stream->name);
    }

    return lttng_live_stream->stream->libObjPtr();
}

static struct ctf_msg_iter_medium_ops medops = {
    medop_request_bytes,
    nullptr,
    nullptr,
    medop_borrow_stream,
};

enum lttng_live_iterator_status lttng_live_lazy_msg_init(struct lttng_live_session *session,
                                                         bt_self_message_iterator *self_msg_iter)
{
    struct lttng_live_component *lttng_live = session->lttng_live_msg_iter->lttng_live_comp;
    uint64_t trace_idx, stream_iter_idx;

    if (!session->lazy_stream_msg_init) {
        return LTTNG_LIVE_ITERATOR_STATUS_OK;
    }

    BT_CPPLOGD_SPEC(session->logger,
                    "Lazily initializing self message iterator for live session: "
                    "session-id={}, self-msg-iter-addr={}",
                    session->id, fmt::ptr(self_msg_iter));

    for (trace_idx = 0; trace_idx < session->traces->len; trace_idx++) {
        struct lttng_live_trace *trace =
            (lttng_live_trace *) g_ptr_array_index(session->traces, trace_idx);

        for (stream_iter_idx = 0; stream_iter_idx < trace->stream_iterators->len;
             stream_iter_idx++) {
            struct ctf_trace_class *ctf_tc;
            struct lttng_live_stream_iterator *stream_iter =
                (lttng_live_stream_iterator *) g_ptr_array_index(trace->stream_iterators,
                                                                 stream_iter_idx);

            if (stream_iter->msg_iter) {
                continue;
            }
            ctf_tc = ctf_metadata_decoder_borrow_ctf_trace_class(trace->metadata->decoder.get());
            BT_CPPLOGD_SPEC(stream_iter->logger,
                            "Creating CTF message iterator: session-id={}, ctf-tc-addr={}, "
                            "stream-iter-name={}, self-msg-iter-addr={}",
                            session->id, fmt::ptr(ctf_tc), stream_iter->name,
                            fmt::ptr(self_msg_iter));
            stream_iter->msg_iter =
                ctf_msg_iter_create(ctf_tc, lttng_live->max_query_size, medops, stream_iter,
                                    self_msg_iter, stream_iter->logger);
            if (!stream_iter->msg_iter) {
                BT_CPPLOGE_APPEND_CAUSE_SPEC(stream_iter->logger,
                                             "Failed to create CTF message iterator");
                goto error;
            }
        }
    }

    session->lazy_stream_msg_init = false;

    return LTTNG_LIVE_ITERATOR_STATUS_OK;

error:
    return LTTNG_LIVE_ITERATOR_STATUS_ERROR;
}

struct lttng_live_stream_iterator *
lttng_live_stream_iterator_create(struct lttng_live_session *session, uint64_t ctf_trace_id,
                                  uint64_t stream_id, bt_self_message_iterator *self_msg_iter)
{
    std::stringstream nameSs;

    BT_ASSERT(session);
    BT_ASSERT(session->lttng_live_msg_iter);
    BT_ASSERT(session->lttng_live_msg_iter->lttng_live_comp);

    lttng_live_component *lttng_live = session->lttng_live_msg_iter->lttng_live_comp;
    lttng_live_trace *trace =
        lttng_live_session_borrow_or_create_trace_by_id(session, ctf_trace_id);
    if (!trace) {
        BT_CPPLOGE_APPEND_CAUSE_SPEC(session->logger, "Failed to borrow CTF trace.");
        return nullptr;
    }

    auto stream_iter = bt2s::make_unique<lttng_live_stream_iterator>(session->logger);

    stream_iter->trace = trace;
    stream_iter->state = LTTNG_LIVE_STREAM_ACTIVE_NO_DATA;
    stream_iter->viewer_stream_id = stream_id;

    stream_iter->ctf_stream_class_id.is_set = false;
    stream_iter->ctf_stream_class_id.value = UINT64_MAX;

    stream_iter->last_inactivity_ts.is_set = false;
    stream_iter->last_inactivity_ts.value = 0;

    if (trace->trace) {
        struct ctf_trace_class *ctf_tc =
            ctf_metadata_decoder_borrow_ctf_trace_class(trace->metadata->decoder.get());
        BT_ASSERT(!stream_iter->msg_iter);
        stream_iter->msg_iter =
            ctf_msg_iter_create(ctf_tc, lttng_live->max_query_size, medops, stream_iter.get(),
                                self_msg_iter, stream_iter->logger);
        if (!stream_iter->msg_iter) {
            BT_CPPLOGE_APPEND_CAUSE_SPEC(stream_iter->logger,
                                         "Failed to create CTF message iterator");
            return nullptr;
        }
    }
    stream_iter->buf.resize(lttng_live->max_query_size);

    nameSs << STREAM_NAME_PREFIX << stream_iter->viewer_stream_id;
    stream_iter->name = nameSs.str();

    const auto ret = stream_iter.get();
    g_ptr_array_add(trace->stream_iterators, stream_iter.release());

    /* Track the number of active stream iterator. */
    session->lttng_live_msg_iter->active_stream_iter++;

    return ret;
}

lttng_live_stream_iterator::~lttng_live_stream_iterator()
{
    /* Track the number of active stream iterator. */
    this->trace->session->lttng_live_msg_iter->active_stream_iter--;
}

void lttng_live_stream_iterator_destroy(struct lttng_live_stream_iterator *stream_iter)
{
    delete stream_iter;
}