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_stream.h>
  33
  34 #include "stream.h"
  35
  36 struct stream_sys_t
  37 {
  38     vlc_fifo_t *fifo;
  39     bool eof;
  40 };
  41
  42 static void vlc_stream_fifo_Destroy(stream_t *s)
  43 {
  44     stream_sys_t *sys = s->p_sys;
  45     vlc_fifo_t *fifo = sys->fifo;
  46     block_t *block;
  47     bool closed;
  48
  49     vlc_fifo_Lock(fifo);
  50     block = vlc_fifo_DequeueAllUnlocked(fifo);
  51     closed = sys->eof;
  52     sys->eof = true;
  53     vlc_fifo_Unlock(fifo);
  54
  55     block_ChainRelease(block);
  56
  57     if (closed)
  58     {   /* Destroy shared state if write end is already closed */
  59         block_FifoRelease(fifo);
  60         free(sys);
  61     }
  62 }
  63
  64 static block_t *vlc_stream_fifo_Block(stream_t *s, bool *restrict eof)
  65 {
  66     stream_sys_t *sys = s->p_sys;
  67     vlc_fifo_t *fifo = sys->fifo;
  68     block_t *block;
  69
  70     vlc_fifo_Lock(fifo);
  71     while (vlc_fifo_IsEmpty(fifo))
  72     {
  73         if (sys->eof)
  74         {
  75             *eof = true;
  76             break;
  77         }
  78         vlc_fifo_Wait(fifo);
  79     }
  80
  81     block = vlc_fifo_DequeueUnlocked(fifo);
  82     vlc_fifo_Unlock(fifo);
  83     return block;
  84 }
  85
  86 static int vlc_stream_fifo_Control(stream_t *s, int query, va_list ap)
  87 {
  88     (void) s;
  89
  90     switch (query)
  91     {
  92         case STREAM_CAN_SEEK:
  93         case STREAM_CAN_FASTSEEK:
  94         case STREAM_CAN_PAUSE:
  95         case STREAM_CAN_CONTROL_PACE:
  96             *va_arg(ap, bool *) = false;
  97             break;
  98
  99         case STREAM_GET_PTS_DELAY:
 100             *va_arg(ap, int64_t *) = DEFAULT_PTS_DELAY;
 101             break;
 102
 103         default:
 104             return VLC_EGENERIC;
 105     }
 106     return VLC_SUCCESS;
 107 }
 108
 109 stream_t *vlc_stream_fifo_New(vlc_object_t *parent)
 110 {
 111     stream_sys_t *sys = malloc(sizeof (*sys));
 112     if (unlikely(sys == NULL))
 113         return NULL;
 114
 115     sys->fifo = block_FifoNew();
 116     if (unlikely(sys->fifo == NULL))
 117     {
 118         free(sys);
 119         return NULL;
 120     }
 121
 122     sys->eof = false;
 123
 124     stream_t *s = vlc_stream_CommonNew(parent, vlc_stream_fifo_Destroy);
 125     if (unlikely(s == NULL))
 126     {
 127         block_FifoRelease(sys->fifo);
 128         free(sys);
 129         return NULL;
 130     }
 131
 132     s->pf_block = vlc_stream_fifo_Block;
 133     s->pf_seek = NULL;
 134     s->pf_control = vlc_stream_fifo_Control;
 135     s->p_sys = sys;
 136     return vlc_object_hold(s);
 137 }
 138
 139 int vlc_stream_fifo_Queue(stream_t *s, block_t *block)
 140 {
 141     stream_sys_t *sys = s->p_sys;
 142     vlc_fifo_t *fifo = sys->fifo;
 143
 144     vlc_fifo_Lock(fifo);
 145     if (likely(!sys->eof))
 146     {
 147         vlc_fifo_QueueUnlocked(fifo, block);
 148         block = NULL;
 149     }
 150     vlc_fifo_Unlock(fifo);
 151
 152     if (unlikely(block != NULL))
 153     {
 154         block_Release(block);
 155         errno = EPIPE;
 156         return -1;
 157     }
 158     return 0;
 159 }
 160
 161 ssize_t vlc_stream_fifo_Write(stream_t *s, const void *buf, size_t len)
 162 {
 163     block_t *block = block_Alloc(len);
 164     if (unlikely(block == NULL))
 165         return -1;
 166
 167     memcpy(block->p_buffer, buf, len);
 168     return vlc_stream_fifo_Queue(s, block) ? -1 : (ssize_t)len;
 169 }
 170
 171 void vlc_stream_fifo_Close(stream_t *s)
 172 {
 173     stream_sys_t *sys = s->p_sys;
 174     vlc_fifo_t *fifo = sys->fifo;
 175     bool closed;
 176
 177     vlc_fifo_Lock(fifo);
 178     closed = sys->eof;
 179     sys->eof = true;
 180     vlc_fifo_Signal(fifo);
 181     vlc_fifo_Unlock(fifo);
 182
 183     if (closed)
 184     {   /* Destroy shared state if read end is already closed */
 185         block_FifoRelease(fifo);
 186         free(sys);
 187     }
 188
 189     vlc_object_release(s);
 190 }