Kévin Redon | ccbed0b | 2019-01-24 18:30:26 +0100 | [diff] [blame] | 1 | /** |
| 2 | * \file |
| 3 | * |
| 4 | * \brief Ringbuffer functionality implementation. |
| 5 | * |
| 6 | * Copyright (c) 2014-2018 Microchip Technology Inc. and its subsidiaries. |
| 7 | * |
| 8 | * \asf_license_start |
| 9 | * |
| 10 | * \page License |
| 11 | * |
| 12 | * Subject to your compliance with these terms, you may use Microchip |
| 13 | * software and any derivatives exclusively with Microchip products. |
| 14 | * It is your responsibility to comply with third party license terms applicable |
| 15 | * to your use of third party software (including open source software) that |
| 16 | * may accompany Microchip software. |
| 17 | * |
| 18 | * THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES, |
| 19 | * WHETHER EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE, |
| 20 | * INCLUDING ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY, |
| 21 | * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL MICROCHIP BE |
| 22 | * LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, INCIDENTAL OR CONSEQUENTIAL |
| 23 | * LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND WHATSOEVER RELATED TO THE |
| 24 | * SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS BEEN ADVISED OF THE |
| 25 | * POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO THE FULLEST EXTENT |
| 26 | * ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY |
| 27 | * RELATED TO THIS SOFTWARE WILL NOT EXCEED THE AMOUNT OF FEES, IF ANY, |
| 28 | * THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE. |
| 29 | * |
| 30 | * \asf_license_stop |
| 31 | * |
| 32 | */ |
| 33 | #include "utils_ringbuffer.h" |
| 34 | |
| 35 | /** |
| 36 | * \brief Ringbuffer init |
| 37 | */ |
| 38 | int32_t ringbuffer_init(struct ringbuffer *const rb, void *buf, uint32_t size) |
| 39 | { |
| 40 | ASSERT(rb && buf && size); |
| 41 | |
| 42 | /* |
| 43 | * buf size must be aligned to power of 2 |
| 44 | */ |
| 45 | if ((size & (size - 1)) != 0) { |
| 46 | return ERR_INVALID_ARG; |
| 47 | } |
| 48 | |
| 49 | /* size - 1 is faster in calculation */ |
| 50 | rb->size = size - 1; |
| 51 | rb->read_index = 0; |
| 52 | rb->write_index = rb->read_index; |
| 53 | rb->buf = (uint8_t *)buf; |
| 54 | |
| 55 | return ERR_NONE; |
| 56 | } |
| 57 | |
| 58 | /** |
| 59 | * \brief Get one byte from ringbuffer |
| 60 | * |
| 61 | */ |
| 62 | int32_t ringbuffer_get(struct ringbuffer *const rb, uint8_t *data) |
| 63 | { |
| 64 | ASSERT(rb && data); |
| 65 | |
| 66 | if (rb->write_index != rb->read_index) { |
| 67 | *data = rb->buf[rb->read_index & rb->size]; |
| 68 | rb->read_index++; |
| 69 | return ERR_NONE; |
| 70 | } |
| 71 | |
| 72 | return ERR_NOT_FOUND; |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * \brief Put one byte to ringbuffer |
| 77 | * |
| 78 | */ |
| 79 | int32_t ringbuffer_put(struct ringbuffer *const rb, uint8_t data) |
| 80 | { |
| 81 | ASSERT(rb); |
| 82 | |
| 83 | rb->buf[rb->write_index & rb->size] = data; |
| 84 | |
| 85 | /* |
| 86 | * buffer full strategy: new data will overwrite the oldest data in |
| 87 | * the buffer |
| 88 | */ |
| 89 | if ((rb->write_index - rb->read_index) > rb->size) { |
| 90 | rb->read_index = rb->write_index - rb->size; |
| 91 | } |
| 92 | |
| 93 | rb->write_index++; |
| 94 | |
| 95 | return ERR_NONE; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * \brief Return the element number of ringbuffer |
| 100 | */ |
| 101 | uint32_t ringbuffer_num(const struct ringbuffer *const rb) |
| 102 | { |
| 103 | ASSERT(rb); |
| 104 | |
| 105 | return rb->write_index - rb->read_index; |
| 106 | } |
| 107 | |
| 108 | /** |
| 109 | * \brief Flush ringbuffer |
| 110 | */ |
| 111 | uint32_t ringbuffer_flush(struct ringbuffer *const rb) |
| 112 | { |
| 113 | ASSERT(rb); |
| 114 | |
| 115 | rb->read_index = rb->write_index; |
| 116 | |
| 117 | return ERR_NONE; |
| 118 | } |