1 /*
2 * Copyright (C) 2016 BlueKitchen GmbH
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the copyright holders nor the names of
14 * contributors may be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * 4. Any redistribution, use, or modification is done solely for
17 * personal benefit and not for any commercial purpose or for
18 * monetary gain.
19 *
20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
24 * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * Please inquire about commercial licensing options at
34 * [email protected]
35 *
36 */
37
38 #define BTSTACK_FILE__ "btstack_ring_buffer.c"
39
40 /*
41 * btstack_ring_buffer.c
42 *
43 */
44
45 #include <string.h>
46
47 #include "bluetooth.h"
48 #include "btstack_ring_buffer.h"
49 #include "btstack_util.h"
50
51
52 // init ring buffer
btstack_ring_buffer_init(btstack_ring_buffer_t * ring_buffer,uint8_t * storage,uint32_t storage_size)53 void btstack_ring_buffer_init(btstack_ring_buffer_t * ring_buffer, uint8_t * storage, uint32_t storage_size){
54 ring_buffer->storage = storage;
55 ring_buffer->size = storage_size;
56 btstack_ring_buffer_reset(ring_buffer);
57 }
58
btstack_ring_buffer_reset(btstack_ring_buffer_t * ring_buffer)59 void btstack_ring_buffer_reset(btstack_ring_buffer_t * ring_buffer){
60 ring_buffer->last_read_index = 0;
61 ring_buffer->last_written_index = 0;
62 ring_buffer->full = 0;
63 }
64
btstack_ring_buffer_bytes_available(btstack_ring_buffer_t * ring_buffer)65 uint32_t btstack_ring_buffer_bytes_available(btstack_ring_buffer_t * ring_buffer){
66 if (ring_buffer->full) return ring_buffer->size;
67 int diff = ring_buffer->last_written_index - ring_buffer->last_read_index;
68 if (diff >= 0) return diff;
69 return diff + ring_buffer->size;
70 }
71
72 // test if ring buffer is empty
btstack_ring_buffer_empty(btstack_ring_buffer_t * ring_buffer)73 int btstack_ring_buffer_empty(btstack_ring_buffer_t * ring_buffer){
74 return btstack_ring_buffer_bytes_available(ring_buffer) == 0u;
75 }
76
77 //
btstack_ring_buffer_bytes_free(btstack_ring_buffer_t * ring_buffer)78 uint32_t btstack_ring_buffer_bytes_free(btstack_ring_buffer_t * ring_buffer){
79 return ring_buffer->size - btstack_ring_buffer_bytes_available(ring_buffer);
80 }
81
82 // add byte block to ring buffer,
btstack_ring_buffer_write(btstack_ring_buffer_t * ring_buffer,uint8_t * data,uint32_t data_length)83 int btstack_ring_buffer_write(btstack_ring_buffer_t * ring_buffer, uint8_t * data, uint32_t data_length){
84 if (btstack_ring_buffer_bytes_free(ring_buffer) < data_length){
85 return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED;
86 }
87
88 // simplify logic below by asserting data_length > 0
89 if (data_length == 0u) return 0u;
90
91 uint32_t remaining_data_length = data_length;
92 const uint8_t * remaining_data = data;
93
94 // copy first chunk
95 unsigned int bytes_until_end = ring_buffer->size - ring_buffer->last_written_index;
96 unsigned int bytes_to_copy = btstack_min(bytes_until_end, remaining_data_length);
97 (void)memcpy(&ring_buffer->storage[ring_buffer->last_written_index], remaining_data, bytes_to_copy);
98 remaining_data_length -= bytes_to_copy;
99 remaining_data += bytes_to_copy;
100
101 // update last written index
102 ring_buffer->last_written_index += bytes_to_copy;
103 if (ring_buffer->last_written_index == ring_buffer->size){
104 ring_buffer->last_written_index = 0;
105 }
106
107 // copy second chunk
108 if (remaining_data_length != 0) {
109 (void)memcpy(&ring_buffer->storage[0], remaining_data, remaining_data_length);
110 ring_buffer->last_written_index += remaining_data_length;
111 }
112
113 // mark buffer as full
114 if (ring_buffer->last_written_index == ring_buffer->last_read_index){
115 ring_buffer->full = 1;
116 }
117 return ERROR_CODE_SUCCESS;
118 }
119
120 // fetch data_length bytes from ring buffer
btstack_ring_buffer_read(btstack_ring_buffer_t * ring_buffer,uint8_t * data,uint32_t data_length,uint32_t * number_of_bytes_read)121 void btstack_ring_buffer_read(btstack_ring_buffer_t * ring_buffer, uint8_t * data, uint32_t data_length, uint32_t * number_of_bytes_read){
122 // limit data to get and report
123 uint32_t remaining_data_length = btstack_min(data_length, btstack_ring_buffer_bytes_available(ring_buffer));
124 *number_of_bytes_read = remaining_data_length;
125
126 // simplify logic below by asserting remaining_data_length > 0
127 if (remaining_data_length == 0u) return;
128
129 uint8_t * remaining_data = data;
130
131 // copy first chunk
132 unsigned int bytes_until_end = ring_buffer->size - ring_buffer->last_read_index;
133 unsigned int bytes_to_copy = btstack_min(bytes_until_end, remaining_data_length);
134 (void)memcpy(remaining_data, &ring_buffer->storage[ring_buffer->last_read_index],
135 bytes_to_copy);
136 remaining_data_length -= bytes_to_copy;
137 remaining_data += bytes_to_copy;
138
139 // update last read index
140 ring_buffer->last_read_index += bytes_to_copy;
141 if (ring_buffer->last_read_index == ring_buffer->size){
142 ring_buffer->last_read_index = 0;
143 }
144
145 // copy second chunk
146 if (remaining_data_length != 0) {
147 (void)memcpy(remaining_data, &ring_buffer->storage[0], remaining_data_length);
148 ring_buffer->last_read_index += remaining_data_length;
149 }
150
151 // clear full flag
152 ring_buffer->full = 0;
153 }
154
155