1/* Copyright (C) 2007 Jean-Marc Valin
2
3   File: buffer.c
4   This is a very simple ring buffer implementation. It is not thread-safe
5   so you need to do your own locking.
6
7   Redistribution and use in source and binary forms, with or without
8   modification, are permitted provided that the following conditions are
9   met:
10
11   1. Redistributions of source code must retain the above copyright notice,
12   this list of conditions and the following disclaimer.
13
14   2. Redistributions in binary form must reproduce the above copyright
15   notice, this list of conditions and the following disclaimer in the
16   documentation and/or other materials provided with the distribution.
17
18   3. The name of the author may not be used to endorse or promote products
19   derived from this software without specific prior written permission.
20
21   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24   DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
25   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26   (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
29   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
30   ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31   POSSIBILITY OF SUCH DAMAGE.
32*/
33
34#ifdef HAVE_CONFIG_H
35#include "config.h"
36#endif
37
38
39#include "os_support.h"
40#include "arch.h"
41#include <speex/speex_buffer.h>
42
43struct SpeexBuffer_ {
44   char *data;
45   int   size;
46   int   read_ptr;
47   int   write_ptr;
48   int   available;
49};
50
51EXPORT SpeexBuffer *speex_buffer_init(int size)
52{
53   SpeexBuffer *st = speex_alloc(sizeof(SpeexBuffer));
54   st->data = speex_alloc(size);
55   st->size = size;
56   st->read_ptr = 0;
57   st->write_ptr = 0;
58   st->available = 0;
59   return st;
60}
61
62EXPORT void speex_buffer_destroy(SpeexBuffer *st)
63{
64   speex_free(st->data);
65   speex_free(st);
66}
67
68EXPORT int speex_buffer_write(SpeexBuffer *st, void *_data, int len)
69{
70   int end;
71   int end1;
72   char *data = _data;
73   if (len > st->size)
74   {
75      data += len-st->size;
76      len = st->size;
77   }
78   end = st->write_ptr + len;
79   end1 = end;
80   if (end1 > st->size)
81      end1 = st->size;
82   SPEEX_COPY(st->data + st->write_ptr, data, end1 - st->write_ptr);
83   if (end > st->size)
84   {
85      end -= st->size;
86      SPEEX_COPY(st->data, data+end1 - st->write_ptr, end);
87   }
88   st->available += len;
89   if (st->available > st->size)
90   {
91      st->available = st->size;
92      st->read_ptr = st->write_ptr;
93   }
94   st->write_ptr += len;
95   if (st->write_ptr > st->size)
96      st->write_ptr -= st->size;
97   return len;
98}
99
100EXPORT int speex_buffer_writezeros(SpeexBuffer *st, int len)
101{
102   /* This is almost the same as for speex_buffer_write() but using
103   SPEEX_MEMSET() instead of SPEEX_COPY(). Update accordingly. */
104   int end;
105   int end1;
106   if (len > st->size)
107   {
108      len = st->size;
109   }
110   end = st->write_ptr + len;
111   end1 = end;
112   if (end1 > st->size)
113      end1 = st->size;
114   SPEEX_MEMSET(st->data + st->write_ptr, 0, end1 - st->write_ptr);
115   if (end > st->size)
116   {
117      end -= st->size;
118      SPEEX_MEMSET(st->data, 0, end);
119   }
120   st->available += len;
121   if (st->available > st->size)
122   {
123      st->available = st->size;
124      st->read_ptr = st->write_ptr;
125   }
126   st->write_ptr += len;
127   if (st->write_ptr > st->size)
128      st->write_ptr -= st->size;
129   return len;
130}
131
132EXPORT int speex_buffer_read(SpeexBuffer *st, void *_data, int len)
133{
134   int end, end1;
135   char *data = _data;
136   if (len > st->available)
137   {
138      SPEEX_MEMSET(data+st->available, 0, st->size-st->available);
139      len = st->available;
140   }
141   end = st->read_ptr + len;
142   end1 = end;
143   if (end1 > st->size)
144      end1 = st->size;
145   SPEEX_COPY(data, st->data + st->read_ptr, end1 - st->read_ptr);
146
147   if (end > st->size)
148   {
149      end -= st->size;
150      SPEEX_COPY(data+end1 - st->read_ptr, st->data, end);
151   }
152   st->available -= len;
153   st->read_ptr += len;
154   if (st->read_ptr > st->size)
155      st->read_ptr -= st->size;
156   return len;
157}
158
159EXPORT int speex_buffer_get_available(SpeexBuffer *st)
160{
161   return st->available;
162}
163
164EXPORT int speex_buffer_resize(SpeexBuffer *st, int len)
165{
166   int old_len = st->size;
167   if (len > old_len)
168   {
169      st->data = speex_realloc(st->data, len);
170      /* FIXME: move data/pointers properly for growing the buffer */
171   } else {
172      /* FIXME: move data/pointers properly for shrinking the buffer */
173      st->data = speex_realloc(st->data, len);
174   }
175   return len;
176}
177