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

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

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright 2019 Francis Deslauriers <francis.deslauriers@efficios.com>
 * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 * Copyright 2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * BabelTrace - LTTng-live client Component
 */

#ifndef BABELTRACE_PLUGIN_CTF_LTTNG_LIVE_H
#define BABELTRACE_PLUGIN_CTF_LTTNG_LIVE_H

#include <glib.h>
#include <stdint.h>

#include <babeltrace2/babeltrace.h>

#include "cpp-common/bt2/message.hpp"
#include "cpp-common/vendor/fmt/format.h" /* IWYU pragma: keep */

#include "../common/src/metadata/tsdl/decoder.hpp"
#include "../common/src/msg-iter/msg-iter.hpp"
#include "viewer-connection.hpp"

enum lttng_live_stream_state
{
    /* This stream won't have data until some known time in the future. */
    LTTNG_LIVE_STREAM_QUIESCENT,
    /*
     * This stream won't have data until some known time in the future and
     * the message iterator inactivity message was already sent downstream.
     */
    LTTNG_LIVE_STREAM_QUIESCENT_NO_DATA, /* */
    /* This stream has data ready to be consumed. */
    LTTNG_LIVE_STREAM_ACTIVE_DATA,
    /*
     * This stream has no data left to consume. We should asked the relay
     * for more.
     */
    LTTNG_LIVE_STREAM_ACTIVE_NO_DATA,
    /* This stream won't have anymore data, ever. */
    LTTNG_LIVE_STREAM_EOF,
};

inline const char *format_as(const lttng_live_stream_state state) noexcept
{
    switch (state) {
    case LTTNG_LIVE_STREAM_ACTIVE_NO_DATA:
        return "ACTIVE_NO_DATA";

    case LTTNG_LIVE_STREAM_QUIESCENT_NO_DATA:
        return "QUIESCENT_NO_DATA";

    case LTTNG_LIVE_STREAM_QUIESCENT:
        return "QUIESCENT";

    case LTTNG_LIVE_STREAM_ACTIVE_DATA:
        return "ACTIVE_DATA";

    case LTTNG_LIVE_STREAM_EOF:
        return "EOF";
    }

    bt_common_abort();
}

/* Iterator over a live stream. */
struct lttng_live_stream_iterator
{
    using UP = std::unique_ptr<lttng_live_stream_iterator>;

    explicit lttng_live_stream_iterator(const bt2c::Logger& parentLogger) :
        logger {parentLogger, "PLUGIN/SRC.CTF.LTTNG-LIVE/STREAM-ITER"}
    {
    }

    ~lttng_live_stream_iterator();

    bt2c::Logger logger;

    bt2::Stream::Shared stream;

    /* Weak reference. */
    struct lttng_live_trace *trace = nullptr;

    /*
     * Since only a single iterator per viewer connection, we have
     * only a single message iterator per stream.
     */
    ctf_msg_iter_up msg_iter;

    uint64_t viewer_stream_id = 0;

    struct
    {
        bool is_set = false;
        uint64_t value = 0;
    } ctf_stream_class_id;

    /* base offset in current index. */
    uint64_t base_offset = 0;
    /* len to read in current index. */
    uint64_t len = 0;
    /* offset in current index. */
    uint64_t offset = 0;

    /*
     * Clock Snapshot value of the last message iterator inactivity message
     * sent downstream.
     */
    struct
    {
        bool is_set = false;
        uint64_t value = 0;
    } last_inactivity_ts;

    /*
     * Clock Snapshot value of the current message iterator inactivity
     * message we might want to send downstream.
     */
    uint64_t current_inactivity_ts = 0;

    enum lttng_live_stream_state state = LTTNG_LIVE_STREAM_QUIESCENT;

    /* The current message produced by this live stream iterator. */
    bt2::ConstMessage::Shared current_msg;

    /* Timestamp in nanoseconds of the current message (current_msg). */
    int64_t current_msg_ts_ns = 0;

    std::vector<uint8_t> buf;

    std::string name;

    bool has_stream_hung_up = false;
};

struct lttng_live_metadata
{
    using UP = std::unique_ptr<lttng_live_metadata>;

    explicit lttng_live_metadata(const bt2c::Logger& parentLogger) :
        logger {parentLogger, "PLUGIN/SRC.CTF.LTTNG-LIVE/METADATA"}
    {
    }

    bt2c::Logger logger;

    uint64_t stream_id = 0;

    /* Weak reference. */
    ctf_metadata_decoder_up decoder;
};

enum lttng_live_metadata_stream_state
{
    /*
     * The metadata needs to be updated. This is either because we just
     * created the trace and haven't asked yet, or the relay specifically
     * told us that new metadata is available.
     */
    LTTNG_LIVE_METADATA_STREAM_STATE_NEEDED,
    /*
     * The metadata was updated and the relay has not told us we need to
     * update it yet.
     */
    LTTNG_LIVE_METADATA_STREAM_STATE_NOT_NEEDED,
    /*
     * The relay has closed this metadata stream. We set this in reaction
     * to a LTTNG_VIEWER_METADATA_ERR reply to a LTTNG_VIEWER_GET_METADATA
     * command to the relay. If this field is set, we have received all the
     * metadata that we are ever going to get for that metadata stream.
     */
    LTTNG_LIVE_METADATA_STREAM_STATE_CLOSED,
};

struct lttng_live_trace
{
    explicit lttng_live_trace(const bt2c::Logger& parentLogger) :
        logger {parentLogger, "PLUGIN/SRC.CTF.LTTNG-LIVE/TRACE"}
    {
    }

    bt2c::Logger logger;

    /* Back reference to session. */
    struct lttng_live_session *session = nullptr;

    /* ctf trace ID within the session. */
    uint64_t id = 0;

    bt2::Trace::Shared trace;

    bt2::TraceClass::Shared trace_class;

    lttng_live_metadata::UP metadata;

    const bt_clock_class *clock_class = nullptr;

    /* Array of pointers to struct lttng_live_stream_iterator. */
    /* Owned by this. */
    GPtrArray *stream_iterators = nullptr;

    enum lttng_live_metadata_stream_state metadata_stream_state =
        LTTNG_LIVE_METADATA_STREAM_STATE_NEEDED;
};

struct lttng_live_session
{
    explicit lttng_live_session(const bt2c::Logger& parentLogger) :
        logger {parentLogger, "PLUGIN/SRC.CTF.LTTNG-LIVE/SESSION"}
    {
    }

    bt2c::Logger logger;

    bt_self_component *self_comp = nullptr;

    /* Weak reference. */
    struct lttng_live_msg_iter *lttng_live_msg_iter = nullptr;

    /* Owned by this. */
    GString *hostname = nullptr;

    /* Owned by this. */
    GString *session_name = nullptr;

    uint64_t id = 0;

    /* Array of pointers to struct lttng_live_trace. */
    GPtrArray *traces = nullptr;

    bool attached = false;
    bool new_streams_needed = false;
    bool lazy_stream_msg_init = false;
    bool closed = false;
};

enum session_not_found_action
{
    SESSION_NOT_FOUND_ACTION_CONTINUE,
    SESSION_NOT_FOUND_ACTION_FAIL,
    SESSION_NOT_FOUND_ACTION_END,
};

/*
 * A component instance is an iterator on a single session.
 */
struct lttng_live_component
{
    using UP = std::unique_ptr<lttng_live_component>;

    explicit lttng_live_component(bt2c::Logger loggerParam) noexcept :
        logger {std::move(loggerParam)}
    {
    }

    bt2c::Logger logger;

    /* Weak reference. */
    bt_self_component *self_comp = nullptr;

    struct
    {
        std::string url;
        enum session_not_found_action sess_not_found_act = SESSION_NOT_FOUND_ACTION_CONTINUE;
    } params;

    size_t max_query_size = 0;

    /*
     * Keeps track of whether the downstream component already has a
     * message iterator on this component.
     */
    bool has_msg_iter = false;
};

struct lttng_live_msg_iter
{
    explicit lttng_live_msg_iter(const bt2c::Logger& parentLogger) :
        logger {parentLogger, "PLUGIN/SRC.CTF.LTTNG-LIVE/MSG-ITER"}
    {
    }

    bt2c::Logger logger;

    bt_self_component *self_comp = nullptr;

    /* Weak reference. */
    struct lttng_live_component *lttng_live_comp = nullptr;

    /* Weak reference. */
    bt_self_message_iterator *self_msg_iter = nullptr;

    /* Owned by this. */
    struct live_viewer_connection *viewer_connection = nullptr;

    /* Array of pointers to struct lttng_live_session. */
    GPtrArray *sessions = nullptr;

    /* Number of live stream iterator this message iterator has.*/
    uint64_t active_stream_iter = 0;

    /* Timestamp in nanosecond of the last message sent downstream. */
    int64_t last_msg_ts_ns = 0;

    /* True if the iterator was interrupted. */
    bool was_interrupted = false;
};

enum lttng_live_iterator_status
{
    /** Iterator state has progressed. Continue iteration immediately. */
    LTTNG_LIVE_ITERATOR_STATUS_CONTINUE = 3,
    /** No message available for now. Try again later. */
    LTTNG_LIVE_ITERATOR_STATUS_AGAIN = 2,
    /** No more CTF_LTTNG_LIVEs to be delivered. */
    LTTNG_LIVE_ITERATOR_STATUS_END = 1,
    /** No error, okay. */
    LTTNG_LIVE_ITERATOR_STATUS_OK = 0,
    /** Invalid arguments. */
    LTTNG_LIVE_ITERATOR_STATUS_INVAL = -1,
    /** General error. */
    LTTNG_LIVE_ITERATOR_STATUS_ERROR = -2,
    /** Out of memory. */
    LTTNG_LIVE_ITERATOR_STATUS_NOMEM = -3,
    /** Unsupported iterator feature. */
    LTTNG_LIVE_ITERATOR_STATUS_UNSUPPORTED = -4,
};

inline const char *format_as(const lttng_live_iterator_status status) noexcept
{
    switch (status) {
    case LTTNG_LIVE_ITERATOR_STATUS_CONTINUE:
        return "LTTNG_LIVE_ITERATOR_STATUS_CONTINUE";

    case LTTNG_LIVE_ITERATOR_STATUS_AGAIN:
        return "LTTNG_LIVE_ITERATOR_STATUS_AGAIN";

    case LTTNG_LIVE_ITERATOR_STATUS_END:
        return "LTTNG_LIVE_ITERATOR_STATUS_END";

    case LTTNG_LIVE_ITERATOR_STATUS_OK:
        return "LTTNG_LIVE_ITERATOR_STATUS_OK";

    case LTTNG_LIVE_ITERATOR_STATUS_INVAL:
        return "LTTNG_LIVE_ITERATOR_STATUS_INVAL";

    case LTTNG_LIVE_ITERATOR_STATUS_ERROR:
        return "LTTNG_LIVE_ITERATOR_STATUS_ERROR";

    case LTTNG_LIVE_ITERATOR_STATUS_NOMEM:
        return "LTTNG_LIVE_ITERATOR_STATUS_NOMEM";

    case LTTNG_LIVE_ITERATOR_STATUS_UNSUPPORTED:
        return "LTTNG_LIVE_ITERATOR_STATUS_UNSUPPORTED";
    }

    bt_common_abort();
}

bt_component_class_initialize_method_status
lttng_live_component_init(bt_self_component_source *self_comp,
                          bt_self_component_source_configuration *config, const bt_value *params,
                          void *init_method_data);

bt_component_class_query_method_status lttng_live_query(bt_self_component_class_source *comp_class,
                                                        bt_private_query_executor *priv_query_exec,
                                                        const char *object, const bt_value *params,
                                                        void *method_data, const bt_value **result);

void lttng_live_component_finalize(bt_self_component_source *component);

bt_message_iterator_class_next_method_status
lttng_live_msg_iter_next(bt_self_message_iterator *iterator, bt_message_array_const msgs,
                         uint64_t capacity, uint64_t *count);

bt_message_iterator_class_initialize_method_status
lttng_live_msg_iter_init(bt_self_message_iterator *self_msg_it,
                         bt_self_message_iterator_configuration *config,
                         bt_self_component_port_output *self_port);

void lttng_live_msg_iter_finalize(bt_self_message_iterator *it);

enum lttng_live_viewer_status lttng_live_session_attach(struct lttng_live_session *session,
                                                        bt_self_message_iterator *self_msg_iter);

enum lttng_live_viewer_status lttng_live_session_detach(struct lttng_live_session *session);

enum lttng_live_iterator_status
lttng_live_session_get_new_streams(struct lttng_live_session *session,
                                   bt_self_message_iterator *self_msg_iter);

struct lttng_live_trace *
lttng_live_session_borrow_or_create_trace_by_id(struct lttng_live_session *session,
                                                uint64_t trace_id);

int lttng_live_add_session(struct lttng_live_msg_iter *lttng_live_msg_iter, uint64_t session_id,
                           const char *hostname, const char *session_name);

/*
 * 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. This function should be
 * called in loop until _END status is received to ensure all metadata is
 * written to the file.
 */
enum lttng_live_get_one_metadata_status
lttng_live_get_one_metadata_packet(struct lttng_live_trace *trace, std::vector<char>& buf);

enum lttng_live_iterator_status
lttng_live_get_next_index(struct lttng_live_msg_iter *lttng_live_msg_iter,
                          struct lttng_live_stream_iterator *stream, struct packet_index *index);

enum ctf_msg_iter_medium_status
lttng_live_get_stream_bytes(struct lttng_live_msg_iter *lttng_live_msg_iter,
                            struct lttng_live_stream_iterator *stream, uint8_t *buf,
                            uint64_t offset, uint64_t req_len, uint64_t *recv_len);

bool lttng_live_graph_is_canceled(struct lttng_live_msg_iter *msg_iter);

void lttng_live_stream_iterator_set_state(struct lttng_live_stream_iterator *stream_iter,
                                          enum lttng_live_stream_state new_state);

#endif /* BABELTRACE_PLUGIN_CTF_LTTNG_LIVE_H */