src/input/stream_memory.c

   1 /*****************************************************************************
   2  * stream_memory.c: stream_t wrapper around memory buffer
   3  *****************************************************************************
   4  * Copyright (C) 1999-2008 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Sigmund Augdal Helberg <dnumgis@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include "stream.h"
  29
  30 struct stream_sys_t
  31 {
  32     bool  i_preserve_memory;
  33     uint64_t    i_pos;      /* Current reading offset */
  34     uint64_t    i_size;
  35     uint8_t    *p_buffer;
  36
  37 };
  38
  39 static int  Read   ( stream_t *, void *p_read, unsigned int i_read );
  40 static int  Peek   ( stream_t *, const uint8_t **pp_peek, unsigned int i_read );
  41 static int  Control( stream_t *, int i_query, va_list );
  42 static void Delete ( stream_t * );
  43
  44 #undef stream_MemoryNew
  45 /**
  46  * Create a stream from a memory buffer
  47  *
  48  * \param p_this the calling vlc_object
  49  * \param p_buffer the memory buffer for the stream
  50  * \param i_buffer the size of the buffer
  51  * \param i_preserve_memory if this is set to false the memory buffer
  52  *        pointed to by p_buffer is freed on stream_Destroy
  53  */
  54 stream_t *stream_MemoryNew( vlc_object_t *p_this, uint8_t *p_buffer,
  55                             uint64_t i_size, bool i_preserve_memory )
  56 {
  57     stream_t *s = stream_CommonNew( p_this );
  58     stream_sys_t *p_sys;
  59
  60     if( !s )
  61         return NULL;
  62
  63     s->psz_path = strdup( "" ); /* N/A */
  64     s->p_sys = p_sys = malloc( sizeof( stream_sys_t ) );
  65     if( !s->psz_path || !s->p_sys )
  66     {
  67         stream_CommonDelete( s );
  68         return NULL;
  69     }
  70     p_sys->i_pos = 0;
  71     p_sys->i_size = i_size;
  72     p_sys->p_buffer = p_buffer;
  73     p_sys->i_preserve_memory = i_preserve_memory;
  74
  75     s->pf_read    = Read;
  76     s->pf_peek    = Peek;
  77     s->pf_control = Control;
  78     s->pf_destroy = Delete;
  79     s->p_input = NULL;
  80
  81     return s;
  82 }
  83
  84 static void Delete( stream_t *s )
  85 {
  86     if( !s->p_sys->i_preserve_memory ) free( s->p_sys->p_buffer );
  87     free( s->p_sys );
  88     stream_CommonDelete( s );
  89 }
  90
  91 /****************************************************************************
  92  * AStreamControl:
  93  ****************************************************************************/
  94 static int Control( stream_t *s, int i_query, va_list args )
  95 {
  96     stream_sys_t *p_sys = s->p_sys;
  97
  98     uint64_t   *pi_64, i_64;
  99
 100     switch( i_query )
 101     {
 102         case STREAM_GET_SIZE:
 103             pi_64 = va_arg( args, uint64_t * );
 104             *pi_64 = p_sys->i_size;
 105             break;
 106
 107         case STREAM_CAN_SEEK:
 108         case STREAM_CAN_FASTSEEK:
 109         case STREAM_CAN_PAUSE:
 110         case STREAM_CAN_CONTROL_PACE:
 111             *va_arg( args, bool * ) = true;
 112             break;
 113
 114         case STREAM_GET_POSITION:
 115             pi_64 = va_arg( args, uint64_t * );
 116             *pi_64 = p_sys->i_pos;
 117             break;
 118
 119         case STREAM_SET_POSITION:
 120             i_64 = va_arg( args, uint64_t );
 121             i_64 = __MIN( i_64, s->p_sys->i_size );
 122             p_sys->i_pos = i_64;
 123             break;
 124
 125         case STREAM_GET_TITLE_INFO:
 126         case STREAM_GET_META:
 127         case STREAM_GET_CONTENT_TYPE:
 128         case STREAM_GET_SIGNAL:
 129         case STREAM_SET_TITLE:
 130         case STREAM_SET_SEEKPOINT:
 131             return VLC_EGENERIC;
 132
 133         case STREAM_SET_PAUSE_STATE:
 134             break; /* nothing to do */
 135
 136         case STREAM_CONTROL_ACCESS:
 137             msg_Err( s, "Hey, what are you thinking ?"
 138                      "DON'T USE STREAM_CONTROL_ACCESS !!!" );
 139             return VLC_EGENERIC;
 140
 141         default:
 142             msg_Err( s, "invalid stream_vaControl query=0x%x", i_query );
 143             return VLC_EGENERIC;
 144     }
 145     return VLC_SUCCESS;
 146 }
 147
 148 static int Read( stream_t *s, void *p_read, unsigned int i_read )
 149 {
 150     stream_sys_t *p_sys = s->p_sys;
 151     int i_res = __MIN( i_read, p_sys->i_size - p_sys->i_pos );
 152     memcpy( p_read, p_sys->p_buffer + p_sys->i_pos, i_res );
 153     p_sys->i_pos += i_res;
 154     return i_res;
 155 }
 156
 157 static int Peek( stream_t *s, const uint8_t **pp_peek, unsigned int i_read )
 158 {
 159     stream_sys_t *p_sys = s->p_sys;
 160     int i_res = __MIN( i_read, p_sys->i_size - p_sys->i_pos );
 161     *pp_peek = p_sys->p_buffer + p_sys->i_pos;
 162     return i_res;
 163 }