1 /*****************************************************************************
2 * vlc_block_helper.h: Helper functions for data blocks management.
3 *****************************************************************************
4 * Copyright (C) 2003 VideoLAN
5 * $Id: vlc_block_helper.h,v 1.4 2003/10/23 20:51:20 gbazin Exp $
7 * Authors: Gildas Bazin <gbazin@netcourrier.com>
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.
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.
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., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
24 #ifndef _VLC_BLOCK_HELPER_H
25 #define _VLC_BLOCK_HELPER_H 1
27 typedef struct block_bytestream_t
34 #define block_BytestreamInit( a, b, c ) __block_BytestreamInit( VLC_OBJECT(a), b, c )
36 /*****************************************************************************
37 * block_bytestream_t management
38 *****************************************************************************/
39 static inline block_bytestream_t __block_BytestreamInit( vlc_object_t *p_obj,
40 block_t *p_block, int i_offset )
42 block_bytestream_t bytestream;
44 bytestream.i_offset = i_offset;
45 bytestream.p_block = p_block;
46 bytestream.p_chain = p_block;
51 static inline block_t *block_BytestreamFlush( block_bytestream_t *p_bytestream)
53 while( p_bytestream->p_chain != p_bytestream->p_block )
56 p_next = p_bytestream->p_chain->p_next;
57 p_bytestream->p_chain->pf_release( p_bytestream->p_chain );
58 p_bytestream->p_chain = p_next;
61 return p_bytestream->p_chain;
64 static inline int block_SkipByte( block_bytestream_t *p_bytestream )
66 /* Most common case first */
67 if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )
69 p_bytestream->i_offset++;
76 /* Less common case which is also slower */
77 for( p_block = p_bytestream->p_block->p_next;
78 p_block != NULL; p_block = p_block->p_next )
80 if( p_block->i_buffer )
82 p_bytestream->i_offset = 1;
83 p_bytestream->p_block = p_block;
89 /* Not enough data, bail out */
93 static inline int block_PeekByte( block_bytestream_t *p_bytestream,
96 /* Most common case first */
97 if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )
99 *p_data = p_bytestream->p_block->p_buffer[p_bytestream->i_offset];
106 /* Less common case which is also slower */
107 for( p_block = p_bytestream->p_block->p_next;
108 p_block != NULL; p_block = p_block->p_next )
110 if( p_block->i_buffer )
112 *p_data = p_block->p_buffer[0];
118 /* Not enough data, bail out */
122 static inline int block_GetByte( block_bytestream_t *p_bytestream,
125 /* Most common case first */
126 if( p_bytestream->p_block->i_buffer - p_bytestream->i_offset )
128 *p_data = p_bytestream->p_block->p_buffer[p_bytestream->i_offset];
129 p_bytestream->i_offset++;
136 /* Less common case which is also slower */
137 for( p_block = p_bytestream->p_block->p_next;
138 p_block != NULL; p_block = p_block->p_next )
140 if( p_block->i_buffer )
142 *p_data = p_block->p_buffer[0];
143 p_bytestream->i_offset = 1;
144 p_bytestream->p_block = p_block;
150 /* Not enough data, bail out */
154 static inline int block_SkipBytes( block_bytestream_t *p_bytestream,
158 int i_offset, i_copy;
160 /* Check we have that much data */
161 i_offset = p_bytestream->i_offset;
163 for( p_block = p_bytestream->p_block;
164 p_block != NULL; p_block = p_block->p_next )
166 i_copy = __MIN( i_data, p_block->i_buffer - i_offset );
176 /* Not enough data, bail out */
180 p_bytestream->p_block = p_block;
181 p_bytestream->i_offset = i_offset + i_copy;
185 static inline int block_PeekBytes( block_bytestream_t *p_bytestream,
186 uint8_t *p_data, int i_data )
189 int i_offset, i_copy, i_size;
191 /* Check we have that much data */
192 i_offset = p_bytestream->i_offset;
195 for( p_block = p_bytestream->p_block;
196 p_block != NULL; p_block = p_block->p_next )
198 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
207 /* Not enough data, bail out */
212 i_offset = p_bytestream->i_offset;
215 for( p_block = p_bytestream->p_block;
216 p_block != NULL; p_block = p_block->p_next )
218 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
223 memcpy( p_data, p_block->p_buffer + i_offset, i_copy );
235 static inline int block_GetBytes( block_bytestream_t *p_bytestream,
236 uint8_t *p_data, int i_data )
239 int i_offset, i_copy, i_size;
241 /* Check we have that much data */
242 i_offset = p_bytestream->i_offset;
245 for( p_block = p_bytestream->p_block;
246 p_block != NULL; p_block = p_block->p_next )
248 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
257 /* Not enough data, bail out */
262 i_offset = p_bytestream->i_offset;
265 for( p_block = p_bytestream->p_block;
266 p_block != NULL; p_block = p_block->p_next )
268 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
273 memcpy( p_data, p_block->p_buffer + i_offset, i_copy );
282 /* No buffer given, just skip the data */
283 p_bytestream->p_block = p_block;
284 p_bytestream->i_offset = i_offset + i_copy;
289 static inline int block_PeekOffsetBytes( block_bytestream_t *p_bytestream,
290 int i_peek_offset, uint8_t *p_data, int i_data )
293 int i_offset, i_copy, i_size;
295 /* Check we have that much data */
296 i_offset = p_bytestream->i_offset;
297 i_size = i_data + i_peek_offset;
299 for( p_block = p_bytestream->p_block;
300 p_block != NULL; p_block = p_block->p_next )
302 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
311 /* Not enough data, bail out */
315 /* Find the right place */
316 i_offset = p_bytestream->i_offset;
317 i_size = i_peek_offset;
319 for( p_block = p_bytestream->p_block;
320 p_block != NULL; p_block = p_block->p_next )
322 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
334 for( ; p_block != NULL; p_block = p_block->p_next )
336 i_copy = __MIN( i_size, p_block->i_buffer - i_offset );
341 memcpy( p_data, p_block->p_buffer + i_offset, i_copy );
353 #endif /* VLC_BLOCK_HELPER_H */