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Write accessor for relevant block_fifo_t state
[vlc] / src / misc / block.c
1 /*****************************************************************************
2  * block.c: Data blocks management functions
3  *****************************************************************************
4  * Copyright (C) 2003-2004 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Laurent Aimar <fenrir@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 /*****************************************************************************
25  * Preamble
26  *****************************************************************************/
27 #include <vlc/vlc.h>
28 #include "vlc_block.h"
29
30 /*****************************************************************************
31  * Block functions.
32  *****************************************************************************/
33 /* private */
34 struct block_sys_t
35 {
36     uint8_t     *p_allocated_buffer;
37     int         i_allocated_buffer;
38 };
39
40 #define BLOCK_PADDING_SIZE 32
41 static void BlockRelease( block_t * );
42
43 block_t *__block_New( vlc_object_t *p_obj, int i_size )
44 {
45     /* We do only one malloc
46      * TODO bench if doing 2 malloc but keeping a pool of buffer is better
47      * 16 -> align on 16
48      * 2 * BLOCK_PADDING_SIZE -> pre + post padding
49      */
50     block_sys_t *p_sys;
51     const int i_alloc = i_size + 2 * BLOCK_PADDING_SIZE + 16;
52     block_t *p_block =
53         malloc( sizeof( block_t ) + sizeof( block_sys_t ) + i_alloc );
54
55     if( p_block == NULL )
56         return NULL;
57
58     /* Fill opaque data */
59     p_sys = (block_sys_t*)( (uint8_t*)p_block + sizeof( block_t ) );
60     p_sys->i_allocated_buffer = i_alloc;
61     p_sys->p_allocated_buffer = (uint8_t*)p_block + sizeof( block_t ) +
62         sizeof( block_sys_t );
63
64     /* Fill all fields */
65     p_block->p_next         = NULL;
66     p_block->p_prev         = NULL;
67     p_block->i_flags        = 0;
68     p_block->i_pts          = 0;
69     p_block->i_dts          = 0;
70     p_block->i_length       = 0;
71     p_block->i_rate         = 0;
72     p_block->i_buffer       = i_size;
73     p_block->p_buffer       =
74         &p_sys->p_allocated_buffer[BLOCK_PADDING_SIZE +
75             16 - ((uintptr_t)p_sys->p_allocated_buffer % 16 )];
76     p_block->pf_release     = BlockRelease;
77
78     /* Is ok, as no comunication between p_vlc */
79     p_block->p_manager      = VLC_OBJECT( p_obj->p_libvlc );
80     p_block->p_sys          = p_sys;
81
82     return p_block;
83 }
84
85 block_t *block_Realloc( block_t *p_block, int i_prebody, int i_body )
86 {
87     int i_buffer_size;
88
89     if( p_block->pf_release != BlockRelease )
90     {
91         /* Special case when pf_release if overloaded
92          * TODO if used one day, them implement it in a smarter way */
93         block_t *p_dup = block_Duplicate( p_block );
94         block_Release( p_block );
95         if( !p_dup )
96             return NULL;
97
98         p_block = p_dup;
99     }
100
101     i_buffer_size = i_prebody + i_body;
102
103     if( i_body < 0 || i_buffer_size <= 0 )
104     {
105         block_Release( p_block );
106         return NULL;
107     }
108
109     if( p_block->p_buffer - i_prebody > p_block->p_sys->p_allocated_buffer &&
110         p_block->p_buffer - i_prebody < p_block->p_sys->p_allocated_buffer +
111         p_block->p_sys->i_allocated_buffer )
112     {
113         p_block->p_buffer -= i_prebody;
114         p_block->i_buffer += i_prebody;
115         i_prebody = 0;
116     }
117     if( p_block->p_buffer + i_body < p_block->p_sys->p_allocated_buffer +
118         p_block->p_sys->i_allocated_buffer )
119     {
120         p_block->i_buffer = i_buffer_size;
121         i_body = 0;
122     }
123
124     if( i_body > 0 || i_prebody > 0 )
125     {
126         block_t *p_rea = block_New( p_block->p_manager, i_buffer_size );
127
128         if( p_rea )
129         {
130             p_rea->i_dts     = p_block->i_dts;
131             p_rea->i_pts     = p_block->i_pts;
132             p_rea->i_flags   = p_block->i_flags;
133             p_rea->i_length  = p_block->i_length;
134             p_rea->i_rate    = p_block->i_rate;
135             p_rea->i_samples = p_block->i_samples;
136
137             memcpy( p_rea->p_buffer + i_prebody, p_block->p_buffer,
138                     __MIN( p_block->i_buffer, p_rea->i_buffer - i_prebody ) );
139         }
140
141         block_Release( p_block );
142
143         return p_rea;
144     }
145
146     return p_block;
147 }
148
149 static void BlockRelease( block_t *p_block )
150 {
151     free( p_block );
152 }
153
154
155 /*****************************************************************************
156  * block_fifo_t management
157  *****************************************************************************/
158 #if 0
159 struct block_fifo_t
160 {
161     vlc_mutex_t         lock;                         /* fifo data lock */
162     vlc_cond_t          wait;         /* fifo data conditional variable */
163
164     int                 i_depth;
165     block_t             *p_first;
166     block_t             **pp_last;
167     int                 i_size;
168 };
169 #endif
170
171 block_fifo_t *__block_FifoNew( vlc_object_t *p_obj )
172 {
173     block_fifo_t *p_fifo;
174
175     p_fifo = malloc( sizeof( block_fifo_t ) );
176     vlc_mutex_init( p_obj, &p_fifo->lock );
177     vlc_cond_init( p_obj, &p_fifo->wait );
178     p_fifo->i_depth = p_fifo->i_size = 0;
179     p_fifo->p_first = NULL;
180     p_fifo->pp_last = &p_fifo->p_first;
181
182     return p_fifo;
183 }
184
185 void block_FifoRelease( block_fifo_t *p_fifo )
186 {
187     block_FifoEmpty( p_fifo );
188     vlc_cond_destroy( &p_fifo->wait );
189     vlc_mutex_destroy( &p_fifo->lock );
190     free( p_fifo );
191 }
192
193 void block_FifoEmpty( block_fifo_t *p_fifo )
194 {
195     block_t *b;
196
197     vlc_mutex_lock( &p_fifo->lock );
198     for( b = p_fifo->p_first; b != NULL; )
199     {
200         block_t *p_next;
201
202         p_next = b->p_next;
203         block_Release( b );
204         b = p_next;
205     }
206
207     p_fifo->i_depth = p_fifo->i_size = 0;
208     p_fifo->p_first = NULL;
209     p_fifo->pp_last = &p_fifo->p_first;
210     vlc_mutex_unlock( &p_fifo->lock );
211 }
212
213 int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
214 {
215     int i_size = 0;
216     vlc_mutex_lock( &p_fifo->lock );
217
218     do
219     {
220         i_size += p_block->i_buffer;
221
222         *p_fifo->pp_last = p_block;
223         p_fifo->pp_last = &p_block->p_next;
224         p_fifo->i_depth++;
225         p_fifo->i_size += p_block->i_buffer;
226
227         p_block = p_block->p_next;
228
229     } while( p_block );
230
231     /* warn there is data in this fifo */
232     vlc_cond_signal( &p_fifo->wait );
233     vlc_mutex_unlock( &p_fifo->lock );
234
235     return i_size;
236 }
237
238 block_t *block_FifoGet( block_fifo_t *p_fifo )
239 {
240     block_t *b;
241
242     vlc_mutex_lock( &p_fifo->lock );
243
244     /* We do a while here because there is a race condition in the
245      * win32 implementation of vlc_cond_wait() (We can't be sure the fifo
246      * hasn't been emptied again since we were signaled). */
247     while( p_fifo->p_first == NULL )
248     {
249         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
250     }
251
252     b = p_fifo->p_first;
253
254     p_fifo->p_first = b->p_next;
255     p_fifo->i_depth--;
256     p_fifo->i_size -= b->i_buffer;
257
258     if( p_fifo->p_first == NULL )
259     {
260         p_fifo->pp_last = &p_fifo->p_first;
261     }
262
263     vlc_mutex_unlock( &p_fifo->lock );
264
265     b->p_next = NULL;
266     return b;
267 }
268
269 block_t *block_FifoShow( block_fifo_t *p_fifo )
270 {
271     block_t *b;
272
273     vlc_mutex_lock( &p_fifo->lock );
274
275     if( p_fifo->p_first == NULL )
276     {
277         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
278     }
279
280     b = p_fifo->p_first;
281
282     vlc_mutex_unlock( &p_fifo->lock );
283
284     return( b );
285 }
286
287 size_t block_FifoSize( const block_fifo_t *p_fifo )
288 {
289     return p_fifo->i_size;
290 }
291
292 size_t block_FifoCount( const block_fifo_t *p_fifo )
293 {
294     return p_fifo->i_depth;
295 }