src/bin/lttng-relayd/viewer-stream.h

   1 #ifndef _VIEWER_STREAM_H
   2 #define _VIEWER_STREAM_H
   3
   4 /*
   5  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   6  *                      David Goulet <dgoulet@efficios.com>
   7  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License, version 2 only, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program; if not, write to the Free Software Foundation, Inc., 51
  20  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include <limits.h>
  24 #include <inttypes.h>
  25 #include <pthread.h>
  26
  27 #include <common/hashtable/hashtable.h>
  28
  29 #include "ctf-trace.h"
  30 #include "lttng-viewer-abi.h"
  31 #include "stream.h"
  32
  33 struct relay_stream;
  34
  35 /*
  36  * The viewer stream's lifetime is the intersection of their viewer connection's
  37  * lifetime and the duration during which at least:
  38  * a) their input source is still active
  39  * b) they still have data left to send to the client.
  40  *
  41  * This means that both the sessiond/consumerd connection or the viewer
  42  * connection may tear down (and unpublish) a relay_viewer_stream.
  43  *
  44  * Viewer stream updates are protected by their associated stream's lock.
  45  */
  46 struct relay_viewer_stream {
  47         struct urcu_ref ref;
  48         pthread_mutex_t reflock;
  49
  50         /* Back ref to stream. */
  51         struct relay_stream *stream;
  52
  53         /* FD from which to read the stream data. */
  54         struct stream_fd *stream_fd;
  55         /* index file from which to read the index data. */
  56         struct lttng_index_file *index_file;
  57
  58         char *path_name;
  59         char *channel_name;
  60
  61         uint64_t current_tracefile_id;
  62
  63         /*
  64          * Counts the number of sent indexes. The "tag" associated
  65          * with an index to send is the current index_received_seqcount,
  66          * because we increment index_received_seqcount after sending
  67          * each index. This index_received_seqcount counter can also be
  68          * updated when catching up with the producer.
  69          */
  70         uint64_t index_sent_seqcount;
  71
  72         /* Indicates if this stream has been sent to a viewer client. */
  73         bool sent_flag;
  74         /* For metadata stream, how much metadata has been sent. */
  75         uint64_t metadata_sent;
  76
  77         struct lttng_ht_node_u64 stream_n;
  78         struct rcu_head rcu_node;
  79 };
  80
  81 struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
  82                 enum lttng_viewer_seek seek_t);
  83
  84 struct relay_viewer_stream *viewer_stream_get_by_id(uint64_t id);
  85 bool viewer_stream_get(struct relay_viewer_stream *vstream);
  86 void viewer_stream_put(struct relay_viewer_stream *vstream);
  87 int viewer_stream_rotate(struct relay_viewer_stream *vstream);
  88 bool viewer_stream_is_tracefile_seq_readable(struct relay_viewer_stream *vstream,
  89                 uint64_t seq);
  90 void print_viewer_streams(void);
  91
  92 #endif /* _VIEWER_STREAM_H */