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 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 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 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 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 // 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, 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 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