src/plugins/ctf/lttng-live/data-stream.cpp

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2019 Francis Deslauriers <francis.deslauriers@efficios.com>
   5  * Copyright 2016 Philippe Proulx <pproulx@efficios.com>
   6  * Copyright 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
   8  */
   9
  10 #include <sstream>
  11
  12 #include <glib.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15
  16 #include <babeltrace2/babeltrace.h>
  17
  18 #include "common/assert.h"
  19 #include "compat/mman.h" /* IWYU pragma: keep  */
  20 #include "cpp-common/bt2s/make-unique.hpp"
  21 #include "cpp-common/vendor/fmt/format.h"
  22
  23 #include "../common/src/msg-iter/msg-iter.hpp"
  24 #include "data-stream.hpp"
  25
  26 #define STREAM_NAME_PREFIX "stream-"
  27
  28 static enum ctf_msg_iter_medium_status medop_request_bytes(size_t request_sz, uint8_t **buffer_addr,
  29                                                            size_t *buffer_sz, void *data)
  30 {
  31     lttng_live_stream_iterator *stream = (lttng_live_stream_iterator *) data;
  32     struct lttng_live_trace *trace = stream->trace;
  33     struct lttng_live_session *session = trace->session;
  34     struct lttng_live_msg_iter *live_msg_iter = session->lttng_live_msg_iter;
  35     uint64_t recv_len = 0;
  36     uint64_t len_left;
  37     uint64_t read_len;
  38
  39     BT_ASSERT(request_sz);
  40
  41     if (stream->has_stream_hung_up) {
  42         return CTF_MSG_ITER_MEDIUM_STATUS_EOF;
  43     }
  44
  45     len_left = stream->base_offset + stream->len - stream->offset;
  46     if (!len_left) {
  47         lttng_live_stream_iterator_set_state(stream, LTTNG_LIVE_STREAM_ACTIVE_NO_DATA);
  48         return CTF_MSG_ITER_MEDIUM_STATUS_AGAIN;
  49     }
  50
  51     read_len = MIN(request_sz, stream->buf.size());
  52     read_len = MIN(read_len, len_left);
  53
  54     const auto status = lttng_live_get_stream_bytes(live_msg_iter, stream, stream->buf.data(),
  55                                                     stream->offset, read_len, &recv_len);
  56
  57     if (status != CTF_MSG_ITER_MEDIUM_STATUS_OK) {
  58         return status;
  59     }
  60
  61     *buffer_addr = stream->buf.data();
  62     *buffer_sz = recv_len;
  63     stream->offset += recv_len;
  64
  65     return CTF_MSG_ITER_MEDIUM_STATUS_OK;
  66 }
  67
  68 static bt_stream *medop_borrow_stream(bt_stream_class *stream_class, int64_t stream_id, void *data)
  69 {
  70     lttng_live_stream_iterator *lttng_live_stream = (lttng_live_stream_iterator *) data;
  71
  72     if (!lttng_live_stream->stream) {
  73         uint64_t stream_class_id = bt_stream_class_get_id(stream_class);
  74
  75         BT_CPPLOGI_SPEC(lttng_live_stream->logger,
  76                         "Creating stream {} (ID: {}) out of stream class {}",
  77                         lttng_live_stream->name, stream_id, stream_class_id);
  78
  79         bt_stream *stream;
  80
  81         if (stream_id < 0) {
  82             /*
  83              * No stream instance ID in the stream. It's possible
  84              * to encounter this situation with older version of
  85              * LTTng. In these cases, use the viewer_stream_id that
  86              * is unique for a live viewer session.
  87              */
  88             stream =
  89                 bt_stream_create_with_id(stream_class, lttng_live_stream->trace->trace->libObjPtr(),
  90                                          lttng_live_stream->viewer_stream_id);
  91         } else {
  92             stream = bt_stream_create_with_id(
  93                 stream_class, lttng_live_stream->trace->trace->libObjPtr(), (uint64_t) stream_id);
  94         }
  95
  96         if (!stream) {
  97             BT_CPPLOGE_APPEND_CAUSE_SPEC(
  98                 lttng_live_stream->logger,
  99                 "Cannot create stream {} (stream class ID {}, stream ID {})",
 100                 lttng_live_stream->name, stream_class_id, stream_id);
 101             return nullptr;
 102         }
 103
 104         lttng_live_stream->stream = bt2::Stream::Shared::createWithoutRef(stream);
 105
 106         lttng_live_stream->stream->name(lttng_live_stream->name);
 107     }
 108
 109     return lttng_live_stream->stream->libObjPtr();
 110 }
 111
 112 static struct ctf_msg_iter_medium_ops medops = {
 113     medop_request_bytes,
 114     nullptr,
 115     nullptr,
 116     medop_borrow_stream,
 117 };
 118
 119 enum lttng_live_iterator_status lttng_live_lazy_msg_init(struct lttng_live_session *session,
 120                                                          bt_self_message_iterator *self_msg_iter)
 121 {
 122     struct lttng_live_component *lttng_live = session->lttng_live_msg_iter->lttng_live_comp;
 123
 124     if (!session->lazy_stream_msg_init) {
 125         return LTTNG_LIVE_ITERATOR_STATUS_OK;
 126     }
 127
 128     BT_CPPLOGD_SPEC(session->logger,
 129                     "Lazily initializing self message iterator for live session: "
 130                     "session-id={}, self-msg-iter-addr={}",
 131                     session->id, fmt::ptr(self_msg_iter));
 132
 133     for (lttng_live_trace::UP& trace : session->traces) {
 134         for (lttng_live_stream_iterator::UP& stream_iter : trace->stream_iterators) {
 135             struct ctf_trace_class *ctf_tc;
 136
 137             if (stream_iter->msg_iter) {
 138                 continue;
 139             }
 140
 141             ctf_tc = ctf_metadata_decoder_borrow_ctf_trace_class(trace->metadata->decoder.get());
 142             BT_CPPLOGD_SPEC(stream_iter->logger,
 143                             "Creating CTF message iterator: session-id={}, ctf-tc-addr={}, "
 144                             "stream-iter-name={}, self-msg-iter-addr={}",
 145                             session->id, fmt::ptr(ctf_tc), stream_iter->name,
 146                             fmt::ptr(self_msg_iter));
 147             stream_iter->msg_iter =
 148                 ctf_msg_iter_create(ctf_tc, lttng_live->max_query_size, medops, stream_iter.get(),
 149                                     self_msg_iter, stream_iter->logger);
 150             if (!stream_iter->msg_iter) {
 151                 BT_CPPLOGE_APPEND_CAUSE_SPEC(stream_iter->logger,
 152                                              "Failed to create CTF message iterator");
 153                 return LTTNG_LIVE_ITERATOR_STATUS_ERROR;
 154             }
 155         }
 156     }
 157
 158     session->lazy_stream_msg_init = false;
 159
 160     return LTTNG_LIVE_ITERATOR_STATUS_OK;
 161 }
 162
 163 struct lttng_live_stream_iterator *
 164 lttng_live_stream_iterator_create(struct lttng_live_session *session, uint64_t ctf_trace_id,
 165                                   uint64_t stream_id, bt_self_message_iterator *self_msg_iter)
 166 {
 167     std::stringstream nameSs;
 168
 169     BT_ASSERT(session);
 170     BT_ASSERT(session->lttng_live_msg_iter);
 171     BT_ASSERT(session->lttng_live_msg_iter->lttng_live_comp);
 172
 173     lttng_live_component *lttng_live = session->lttng_live_msg_iter->lttng_live_comp;
 174     lttng_live_trace *trace =
 175         lttng_live_session_borrow_or_create_trace_by_id(session, ctf_trace_id);
 176     if (!trace) {
 177         BT_CPPLOGE_APPEND_CAUSE_SPEC(session->logger, "Failed to borrow CTF trace.");
 178         return nullptr;
 179     }
 180
 181     auto stream_iter = bt2s::make_unique<lttng_live_stream_iterator>(session->logger);
 182
 183     stream_iter->trace = trace;
 184     stream_iter->state = LTTNG_LIVE_STREAM_ACTIVE_NO_DATA;
 185     stream_iter->viewer_stream_id = stream_id;
 186
 187     stream_iter->ctf_stream_class_id.is_set = false;
 188     stream_iter->ctf_stream_class_id.value = UINT64_MAX;
 189
 190     stream_iter->last_inactivity_ts.is_set = false;
 191     stream_iter->last_inactivity_ts.value = 0;
 192
 193     if (trace->trace) {
 194         struct ctf_trace_class *ctf_tc =
 195             ctf_metadata_decoder_borrow_ctf_trace_class(trace->metadata->decoder.get());
 196         BT_ASSERT(!stream_iter->msg_iter);
 197         stream_iter->msg_iter =
 198             ctf_msg_iter_create(ctf_tc, lttng_live->max_query_size, medops, stream_iter.get(),
 199                                 self_msg_iter, stream_iter->logger);
 200         if (!stream_iter->msg_iter) {
 201             BT_CPPLOGE_APPEND_CAUSE_SPEC(stream_iter->logger,
 202                                          "Failed to create CTF message iterator");
 203             return nullptr;
 204         }
 205     }
 206     stream_iter->buf.resize(lttng_live->max_query_size);
 207
 208     nameSs << STREAM_NAME_PREFIX << stream_iter->viewer_stream_id;
 209     stream_iter->name = nameSs.str();
 210
 211     const auto ret = stream_iter.get();
 212     trace->stream_iterators.emplace_back(std::move(stream_iter));
 213
 214     /* Track the number of active stream iterator. */
 215     session->lttng_live_msg_iter->active_stream_iter++;
 216
 217     return ret;
 218 }
 219
 220 lttng_live_stream_iterator::~lttng_live_stream_iterator()
 221 {
 222     /* Track the number of active stream iterator. */
 223     this->trace->session->lttng_live_msg_iter->active_stream_iter--;
 224 }