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

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License, version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 51
  16  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #ifndef _VIEWER_STREAM_H
  20 #define _VIEWER_STREAM_H
  21
  22 #include <limits.h>
  23 #include <inttypes.h>
  24 #include <pthread.h>
  25
  26 #include <common/hashtable/hashtable.h>
  27
  28 #include "ctf-trace.h"
  29 #include "lttng-viewer-abi.h"
  30 #include "stream.h"
  31
  32 /* Stub */
  33 struct relay_stream;
  34
  35 /*
  36  * Shadow copy of the relay_stream structure for the viewer side.  The only
  37  * fields updated by the writer (streaming side) after allocation are :
  38  * total_index_received and close_flag. Everything else is updated by the
  39  * reader (viewer side).
  40  */
  41 struct relay_viewer_stream {
  42         uint64_t stream_handle;
  43         uint64_t session_id;
  44         int read_fd;
  45         int index_read_fd;
  46         char *path_name;
  47         char *channel_name;
  48         uint64_t last_sent_index;
  49         uint64_t total_index_received;
  50         uint64_t tracefile_count;
  51         uint64_t tracefile_count_current;
  52         /* Stop after reading this tracefile. */
  53         uint64_t tracefile_count_last;
  54         struct lttng_ht_node_u64 stream_n;
  55         struct rcu_head rcu_node;
  56         struct ctf_trace *ctf_trace;
  57         /*
  58          * This lock blocks only when the writer is about to start overwriting
  59          * a file currently read by the reader.
  60          *
  61          * This is nested INSIDE the viewer_stream_rotation_lock.
  62          */
  63         pthread_mutex_t overwrite_lock;
  64         /* Information telling us if the stream is a metadata stream. */
  65         unsigned int metadata_flag:1;
  66         /*
  67          * Information telling us that the stream is closed in write, so
  68          * we don't expect new indexes and we can read up to EOF.
  69          */
  70         unsigned int close_write_flag:1;
  71         /*
  72          * If the streaming side closes a FD in use in the viewer side,
  73          * it sets this flag to inform that it is a normal error.
  74          */
  75         unsigned int abort_flag:1;
  76         /* Indicates if this stream has been sent to a viewer client. */
  77         unsigned int sent_flag:1;
  78 };
  79
  80 struct relay_viewer_stream *viewer_stream_create(struct relay_stream *stream,
  81                 enum lttng_viewer_seek seek_t, struct ctf_trace *ctf_trace);
  82 struct relay_viewer_stream *viewer_stream_find_by_id(uint64_t id);
  83 void viewer_stream_destroy(struct ctf_trace *ctf_trace,
  84                 struct relay_viewer_stream *stream);
  85 void viewer_stream_delete(struct relay_viewer_stream *stream);
  86 int viewer_stream_rotate(struct relay_viewer_stream *vstream,
  87                 struct relay_stream *stream);
  88
  89 #endif /* _VIEWER_STREAM_H */