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  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   7  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-only
  10  *
  11  */
  12
  13 #include <limits.h>
  14 #include <inttypes.h>
  15 #include <pthread.h>
  16
  17 #include <common/hashtable/hashtable.h>
  18
  19 #include "ctf-trace.h"
  20 #include "lttng-viewer-abi.h"
  21 #include "stream.h"
  22
  23 struct relay_stream;
  24
  25 /*
  26  * The viewer stream's lifetime is the intersection of their viewer connection's
  27  * lifetime and the duration during which at least:
  28  * a) their input source is still active
  29  * b) they still have data left to send to the client.
  30  *
  31  * This means that both the sessiond/consumerd connection or the viewer
  32  * connection may tear down (and unpublish) a relay_viewer_stream.
  33  *
  34  * Viewer stream updates are protected by their associated stream's lock.
  35  */
  36 struct relay_viewer_stream {
  37         struct urcu_ref ref;
  38
  39         /* Back ref to stream. */
  40         struct relay_stream *stream;
  41
  42         struct {
  43                 struct fs_handle *handle;
  44                 struct lttng_trace_chunk *trace_chunk;
  45         } stream_file;
  46         /* index file from which to read the index data. */
  47         struct lttng_index_file *index_file;
  48         /*
  49          * Last seen rotation count in stream.
  50          *
  51          * Sampled on every change to the viewer stream trace chunk,
  52          * this allows the live server to determine if it saw the latest
  53          * rotation that occurred on the receiving end.
  54          */
  55         uint64_t last_seen_rotation_count;
  56
  57         char *path_name;
  58         char *channel_name;
  59
  60         uint64_t current_tracefile_id;
  61
  62         /*
  63          * Counts the number of sent indexes. The "tag" associated
  64          * with an index to send is the current index_received_seqcount,
  65          * because we increment index_received_seqcount after sending
  66          * each index. This index_received_seqcount counter can also be
  67          * updated when catching up with the producer.
  68          */
  69         uint64_t index_sent_seqcount;
  70
  71         /* Indicates if this stream has been sent to a viewer client. */
  72         bool sent_flag;
  73         /* For metadata stream, how much metadata has been sent. */
  74         uint64_t metadata_sent;
  75
  76         struct lttng_ht_node_u64 stream_n;
  77         struct rcu_head rcu_node;
  78 };
  79
  80 struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
  81                 struct lttng_trace_chunk *viewer_trace_chunk,
  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 void viewer_stream_close_files(struct relay_viewer_stream *vstream);
  92 void viewer_stream_sync_tracefile_array_tail(struct relay_viewer_stream *vstream);
  93
  94 #endif /* _VIEWER_STREAM_H */