src.ctf.lttng-live: viewer-connection.cpp: remove goto error-handling

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

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

#include "compat/memstream.h"
#include "cpp-common/bt2c/libc-up.hpp"
#include "cpp-common/bt2s/make-unique.hpp"

#include "../common/src/metadata/tsdl/ctf-meta-configure-ir-trace.hpp"
#include "../common/src/metadata/tsdl/decoder.hpp"
#include "lttng-live.hpp"
#include "metadata.hpp"

#define TSDL_MAGIC 0x75d11d57

struct packet_header
{
    uint32_t magic;
    uint8_t uuid[16];
    uint32_t checksum;
    uint32_t content_size;
    uint32_t packet_size;
    uint8_t compression_scheme;
    uint8_t encryption_scheme;
    uint8_t checksum_scheme;
    uint8_t major;
    uint8_t minor;
} __attribute__((__packed__));

static bool stream_classes_all_have_default_clock_class(bt_trace_class *tc,
                                                        const bt2c::Logger& logger)
{
    uint64_t i, sc_count;
    const bt_clock_class *cc = NULL;
    const bt_stream_class *sc;
    bool ret = true;

    sc_count = bt_trace_class_get_stream_class_count(tc);
    for (i = 0; i < sc_count; i++) {
        sc = bt_trace_class_borrow_stream_class_by_index_const(tc, i);

        BT_ASSERT(sc);

        cc = bt_stream_class_borrow_default_clock_class_const(sc);
        if (!cc) {
            ret = false;
            BT_CPPLOGE_APPEND_CAUSE_SPEC(logger,
                                         "Stream class doesn't have a default clock class: "
                                         "sc-id={}, sc-name=\"{}\"",
                                         bt_stream_class_get_id(sc), bt_stream_class_get_name(sc));
            goto end;
        }
    }

end:
    return ret;
}
/*
 * Iterate over the stream classes and returns the first clock class
 * encountered. This is useful to create message iterator inactivity message as
 * we don't need a particular clock class.
 */
static const bt_clock_class *borrow_any_clock_class(bt_trace_class *tc)
{
    uint64_t i, sc_count;
    const bt_clock_class *cc = NULL;
    const bt_stream_class *sc;

    sc_count = bt_trace_class_get_stream_class_count(tc);
    for (i = 0; i < sc_count; i++) {
        sc = bt_trace_class_borrow_stream_class_by_index_const(tc, i);
        BT_ASSERT_DBG(sc);

        cc = bt_stream_class_borrow_default_clock_class_const(sc);
        if (cc) {
            goto end;
        }
    }
end:
    BT_ASSERT_DBG(cc);
    return cc;
}

enum lttng_live_iterator_status lttng_live_metadata_update(struct lttng_live_trace *trace)
{
    struct lttng_live_session *session = trace->session;
    struct lttng_live_metadata *metadata = trace->metadata.get();
    std::vector<char> metadataBuf;
    bool keep_receiving;
    bt2c::FileUP fp;
    enum ctf_metadata_decoder_status decoder_status;
    enum lttng_live_iterator_status status = LTTNG_LIVE_ITERATOR_STATUS_OK;
    enum lttng_live_get_one_metadata_status metadata_status;

    BT_CPPLOGD_SPEC(metadata->logger, "Updating metadata for trace: session-id={}, trace-id={}",
                    session->id, trace->id);

    /* No metadata stream yet. */
    if (!metadata) {
        if (session->closed) {
            /*
             * The session is closed AND we never received any
             * metadata this indicates that we will never receive
             * any metadata.
             */
            status = LTTNG_LIVE_ITERATOR_STATUS_END;
        } else if (session->new_streams_needed) {
            status = LTTNG_LIVE_ITERATOR_STATUS_AGAIN;
        } else {
            session->new_streams_needed = true;
            status = LTTNG_LIVE_ITERATOR_STATUS_CONTINUE;
        }
        goto end;
    }

    if (trace->metadata_stream_state != LTTNG_LIVE_METADATA_STREAM_STATE_NEEDED) {
        goto end;
    }

    keep_receiving = true;
    /* Grab all available metadata. */
    while (keep_receiving) {
        /*
         * lttng_live_get_one_metadata_packet() asks the Relay Daemon
         * for new metadata. If new metadata is received, the function
         * writes it to the provided file handle and updates the
         * reply_len output parameter. We call this function in loop
         * until it returns _END meaning that no new metadata is
         * available.
         * We may receive a _CLOSED status if the metadata stream we
         * are requesting is no longer available on the relay.
         * If we receive an _ERROR status, it means there was a
         * networking, allocating, or some other unrecoverable error.
         */
        metadata_status = lttng_live_get_one_metadata_packet(trace, metadataBuf);

        switch (metadata_status) {
        case LTTNG_LIVE_GET_ONE_METADATA_STATUS_OK:
            break;
        case LTTNG_LIVE_GET_ONE_METADATA_STATUS_END:
            keep_receiving = false;
            break;
        case LTTNG_LIVE_GET_ONE_METADATA_STATUS_CLOSED:
            BT_CPPLOGD_SPEC(
                metadata->logger,
                "Metadata stream was closed by the Relay, the trace is no longer active: "
                "trace-id={}, metadata-stream-id={}",
                trace->id, metadata->stream_id);
            /*
             * The stream was closed and we received everything
             * there was to receive for this metadata stream.
             * We go on with the decoding of what we received. So
             * that data stream can be decoded.
             */
            keep_receiving = false;
            trace->metadata_stream_state = LTTNG_LIVE_METADATA_STREAM_STATE_CLOSED;
            break;
        case LTTNG_LIVE_GET_ONE_METADATA_STATUS_ERROR:
            BT_CPPLOGE_APPEND_CAUSE_SPEC(metadata->logger,
                                         "Error getting one trace metadata packet: trace-id={}",
                                         trace->id);
            goto error;
        default:
            bt_common_abort();
        }
    }

    if (metadataBuf.empty()) {
        if (!trace->trace) {
            status = LTTNG_LIVE_ITERATOR_STATUS_AGAIN;
            goto end;
        }

        /* The relay sent zero bytes of metadata. */
        trace->metadata_stream_state = LTTNG_LIVE_METADATA_STREAM_STATE_NOT_NEEDED;
        goto end;
    }

    /*
     * Open a new reading file handle on the `metadata_buf` and pass it to
     * the metadata decoder.
     */
    fp.reset(bt_fmemopen(metadataBuf.data(), metadataBuf.size(), "rb"));
    if (!fp) {
        if (errno == EINTR && lttng_live_graph_is_canceled(session->lttng_live_msg_iter)) {
            session->lttng_live_msg_iter->was_interrupted = true;
            status = LTTNG_LIVE_ITERATOR_STATUS_AGAIN;
        } else {
            BT_CPPLOGE_ERRNO_APPEND_CAUSE_SPEC(metadata->logger,
                                               "Cannot memory-open metadata buffer", ".");
            status = LTTNG_LIVE_ITERATOR_STATUS_ERROR;
        }
        goto end;
    }

    /*
     * The call to ctf_metadata_decoder_append_content() will append
     * new metadata to our current trace class.
     */
    BT_CPPLOGD_SPEC(metadata->logger, "Appending new metadata to the ctf_trace class");
    decoder_status = ctf_metadata_decoder_append_content(metadata->decoder.get(), fp.get());
    switch (decoder_status) {
    case CTF_METADATA_DECODER_STATUS_OK:
        if (!trace->trace_class) {
            struct ctf_trace_class *tc =
                ctf_metadata_decoder_borrow_ctf_trace_class(metadata->decoder.get());

            trace->trace_class = ctf_metadata_decoder_get_ir_trace_class(metadata->decoder.get());
            trace->trace = trace->trace_class->instantiate();
            if (!trace->trace) {
                BT_CPPLOGE_APPEND_CAUSE_SPEC(metadata->logger, "Failed to create bt_trace");
                goto error;
            }

            ctf_trace_class_configure_ir_trace(tc, *trace->trace);

            if (!stream_classes_all_have_default_clock_class(trace->trace_class->libObjPtr(),
                                                             metadata->logger)) {
                /* Error logged in function. */
                goto error;
            }
            trace->clock_class = borrow_any_clock_class(trace->trace_class->libObjPtr());
        }

        /* The metadata was updated successfully. */
        trace->metadata_stream_state = LTTNG_LIVE_METADATA_STREAM_STATE_NOT_NEEDED;

        break;
    default:
        goto error;
    }

    goto end;

error:
    status = LTTNG_LIVE_ITERATOR_STATUS_ERROR;
end:
    return status;
}

int lttng_live_metadata_create_stream(struct lttng_live_session *session, uint64_t ctf_trace_id,
                                      uint64_t stream_id)
{
    struct lttng_live_trace *trace;

    ctf_metadata_decoder_config cfg {session->logger};
    cfg.self_comp = session->self_comp;
    cfg.create_trace_class = true;

    auto metadata = bt2s::make_unique<lttng_live_metadata>(session->logger);
    metadata->stream_id = stream_id;

    metadata->decoder = ctf_metadata_decoder_create(&cfg);
    if (!metadata->decoder) {
        BT_CPPLOGE_APPEND_CAUSE_SPEC(session->logger, "Failed to create CTF metadata decoder");
        return -1;
    }

    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 trace");
        return -1;
    }

    trace->metadata = std::move(metadata);
    return 0;
}