src/input/stream_memory.c

   1 /*****************************************************************************
   2  * stream_memory.c: stream_t wrapper around memory buffer
   3  *****************************************************************************
   4  * Copyright (C) 1999-2008 the VideoLAN team
   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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 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
  80     vlc_object_attach( s, p_this );
  81
  82     /* Get a weak link to the parent input */
  83     /* FIXME: The usage of vlc_object_find has to be removed. */
  84     s->p_input = (input_thread_t *)vlc_object_find( p_this, VLC_OBJECT_INPUT, FIND_PARENT );
  85     if(s->p_input)
  86         vlc_object_release((vlc_object_t*)s->p_input);
  87
  88     return s;
  89 }
  90
  91 static void Delete( stream_t *s )
  92 {
  93     if( !s->p_sys->i_preserve_memory ) free( s->p_sys->p_buffer );
  94     free( s->p_sys );
  95     stream_CommonDelete( s );
  96 }
  97
  98 /****************************************************************************
  99  * AStreamControl:
 100  ****************************************************************************/
 101 static int Control( stream_t *s, int i_query, va_list args )
 102 {
 103     stream_sys_t *p_sys = s->p_sys;
 104
 105     bool *p_bool;
 106     uint64_t   *pi_64, i_64;
 107     int        i_int;
 108
 109     switch( i_query )
 110     {
 111         case STREAM_GET_SIZE:
 112             pi_64 = va_arg( args, uint64_t * );
 113             *pi_64 = p_sys->i_size;
 114             break;
 115
 116         case STREAM_CAN_SEEK:
 117             p_bool = (bool*)va_arg( args, bool * );
 118             *p_bool = true;
 119             break;
 120
 121         case STREAM_CAN_FASTSEEK:
 122             p_bool = (bool*)va_arg( args, bool * );
 123             *p_bool = true;
 124             break;
 125
 126         case STREAM_GET_POSITION:
 127             pi_64 = va_arg( args, uint64_t * );
 128             *pi_64 = p_sys->i_pos;
 129             break;
 130
 131         case STREAM_SET_POSITION:
 132             i_64 = va_arg( args, uint64_t );
 133             i_64 = __MIN( i_64, s->p_sys->i_size );
 134             p_sys->i_pos = i_64;
 135             break;
 136
 137         case STREAM_GET_CONTENT_TYPE:
 138             return VLC_EGENERIC;
 139
 140         case STREAM_CONTROL_ACCESS:
 141             i_int = (int) va_arg( args, int );
 142             msg_Err( s, "Hey, what are you thinking ?"
 143                      "DON'T USE STREAM_CONTROL_ACCESS !!!" );
 144             return VLC_EGENERIC;
 145
 146         default:
 147             msg_Err( s, "invalid stream_vaControl query=0x%x", i_query );
 148             return VLC_EGENERIC;
 149     }
 150     return VLC_SUCCESS;
 151 }
 152
 153 static int Read( stream_t *s, void *p_read, unsigned int i_read )
 154 {
 155     stream_sys_t *p_sys = s->p_sys;
 156     int i_res = __MIN( i_read, p_sys->i_size - p_sys->i_pos );
 157     memcpy( p_read, p_sys->p_buffer + p_sys->i_pos, i_res );
 158     p_sys->i_pos += i_res;
 159     return i_res;
 160 }
 161
 162 static int Peek( stream_t *s, const uint8_t **pp_peek, unsigned int i_read )
 163 {
 164     stream_sys_t *p_sys = s->p_sys;
 165     int i_res = __MIN( i_read, p_sys->i_size - p_sys->i_pos );
 166     *pp_peek = p_sys->p_buffer + p_sys->i_pos;
 167     return i_res;
 168 }