src/input/stream_fifo.c

   1 /*****************************************************************************
   2  * stream_fifo.c
   3  *****************************************************************************
   4  * Copyright (C) 2016 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <assert.h>
  26 #include <errno.h>
  27 #include <stdbool.h>
  28 #include <stdlib.h>
  29
  30 #include <vlc_common.h>
  31 #include <vlc_block.h>
  32 #include <vlc_queue.h>
  33 #include <vlc_stream.h>
  34
  35 #include "stream.h"
  36
  37 struct vlc_stream_fifo {
  38     vlc_queue_t queue;
  39     bool eof;
  40 };
  41
  42 struct vlc_stream_fifo_private {
  43     vlc_stream_fifo_t *writer;
  44 };
  45
  46 static vlc_stream_fifo_t *vlc_stream_fifo_Writer(stream_t *s)
  47 {
  48     struct vlc_stream_fifo_private *sys = vlc_stream_Private(s);
  49
  50     return sys->writer;
  51 }
  52
  53 static void vlc_stream_fifo_Destroy(stream_t *s)
  54 {
  55     struct vlc_stream_fifo *writer = vlc_stream_fifo_Writer(s);
  56     block_t *block;
  57     bool closed;
  58
  59     vlc_queue_Lock(&writer->queue);
  60     block = vlc_queue_DequeueAllUnlocked(&writer->queue);
  61     closed = writer->eof;
  62     writer->eof = true;
  63     vlc_queue_Unlock(&writer->queue);
  64
  65     block_ChainRelease(block);
  66
  67     if (closed)
  68         /* Destroy shared state if write end is already closed */
  69         free(writer);
  70 }
  71
  72 static block_t *vlc_stream_fifo_Block(stream_t *s, bool *restrict eof)
  73 {
  74     struct vlc_stream_fifo *sys = vlc_stream_fifo_Writer(s);
  75     block_t *block = vlc_queue_DequeueKillable(&sys->queue, &sys->eof);
  76
  77     if (block == NULL)
  78         *eof = true;
  79
  80     return block;
  81 }
  82
  83 static int vlc_stream_fifo_Control(stream_t *s, int query, va_list ap)
  84 {
  85     (void) s;
  86
  87     switch (query)
  88     {
  89         case STREAM_CAN_SEEK:
  90         case STREAM_CAN_FASTSEEK:
  91         case STREAM_CAN_PAUSE:
  92         case STREAM_CAN_CONTROL_PACE:
  93             *va_arg(ap, bool *) = false;
  94             break;
  95
  96         case STREAM_GET_PTS_DELAY:
  97             *va_arg(ap, vlc_tick_t *) = DEFAULT_PTS_DELAY;
  98             break;
  99
 100         default:
 101             return VLC_EGENERIC;
 102     }
 103     return VLC_SUCCESS;
 104 }
 105
 106 vlc_stream_fifo_t *vlc_stream_fifo_New(vlc_object_t *parent, stream_t **reader)
 107 {
 108     struct vlc_stream_fifo *writer = malloc(sizeof (*writer));
 109     if (unlikely(writer == NULL))
 110         return NULL;
 111
 112     vlc_queue_Init(&writer->queue, offsetof (block_t, p_next));
 113     writer->eof = false;
 114
 115     struct vlc_stream_fifo_private *sys;
 116     stream_t *s = vlc_stream_CustomNew(parent, vlc_stream_fifo_Destroy,
 117                                        sizeof (*sys), "stream");
 118     if (unlikely(s == NULL)) {
 119         free(writer);
 120         return NULL;
 121     }
 122
 123     sys = vlc_stream_Private(s);
 124     sys->writer = writer;
 125     s->pf_block = vlc_stream_fifo_Block;
 126     s->pf_seek = NULL;
 127     s->pf_control = vlc_stream_fifo_Control;
 128     *reader = s;
 129     return writer;
 130 }
 131
 132 int vlc_stream_fifo_Queue(vlc_stream_fifo_t *writer, block_t *block)
 133 {
 134     vlc_queue_Lock(&writer->queue);
 135     if (likely(!writer->eof))
 136     {
 137         vlc_queue_EnqueueUnlocked(&writer->queue, block);
 138         block = NULL;
 139     }
 140     vlc_queue_Unlock(&writer->queue);
 141
 142     if (unlikely(block != NULL))
 143     {
 144         block_Release(block);
 145         errno = EPIPE;
 146         return -1;
 147     }
 148     return 0;
 149 }
 150
 151 ssize_t vlc_stream_fifo_Write(vlc_stream_fifo_t *writer,
 152                               const void *buf, size_t len)
 153 {
 154     block_t *block = block_Alloc(len);
 155     if (unlikely(block == NULL))
 156         return -1;
 157
 158     memcpy(block->p_buffer, buf, len);
 159     return vlc_stream_fifo_Queue(writer, block) ? -1 : (ssize_t)len;
 160 }
 161
 162 void vlc_stream_fifo_Close(vlc_stream_fifo_t *writer)
 163 {
 164     bool closed;
 165
 166     vlc_queue_Lock(&writer->queue);
 167     closed = writer->eof;
 168     writer->eof = true;
 169     vlc_queue_Signal(&writer->queue);
 170     vlc_queue_Unlock(&writer->queue);
 171
 172     if (closed)
 173         /* Destroy shared state if read end is already closed */
 174         free(writer);
 175 }