1 /****************************************************************************** 2 * 3 * Copyright (C) 2015 Google Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 #include <assert.h> 20 #include <stdlib.h> 21 22 #include "osi/include/allocator.h" 23 #include "osi/include/ringbuffer.h" 24 25 struct ringbuffer_t { 26 size_t total; 27 size_t available; 28 uint8_t *base; 29 uint8_t *head; 30 uint8_t *tail; 31 }; 32 33 ringbuffer_t* ringbuffer_init(const size_t size) { 34 ringbuffer_t* p = osi_calloc(sizeof(ringbuffer_t)); 35 36 p->base = osi_calloc(size); 37 p->head = p->tail = p->base; 38 p->total = p->available = size; 39 40 return p; 41 } 42 43 void ringbuffer_free(ringbuffer_t *rb) { 44 if (rb != NULL) 45 osi_free(rb->base); 46 osi_free(rb); 47 } 48 49 size_t ringbuffer_available(const ringbuffer_t *rb) { 50 assert(rb); 51 return rb->available; 52 } 53 54 size_t ringbuffer_size(const ringbuffer_t *rb) { 55 assert(rb); 56 return rb->total - rb->available; 57 } 58 59 size_t ringbuffer_insert(ringbuffer_t *rb, const uint8_t *p, size_t length) { 60 assert(rb); 61 assert(p); 62 63 if (length > ringbuffer_available(rb)) 64 length = ringbuffer_available(rb); 65 66 for (size_t i = 0; i != length; ++i) { 67 *rb->tail++ = *p++; 68 if (rb->tail >= (rb->base + rb->total)) 69 rb->tail = rb->base; 70 } 71 72 rb->available -= length; 73 return length; 74 } 75 76 size_t ringbuffer_delete(ringbuffer_t *rb, size_t length) { 77 assert(rb); 78 79 if (length > ringbuffer_size(rb)) 80 length = ringbuffer_size(rb); 81 82 rb->head += length; 83 if (rb->head >= (rb->base + rb->total)) 84 rb->head -= rb->total; 85 86 rb->available += length; 87 return length; 88 } 89 90 size_t ringbuffer_peek(const ringbuffer_t *rb, off_t offset, uint8_t *p, size_t length) { 91 assert(rb); 92 assert(p); 93 assert(offset >= 0); 94 assert((size_t)offset <= ringbuffer_size(rb)); 95 96 uint8_t *b = ((rb->head - rb->base + offset) % rb->total) + rb->base; 97 const size_t bytes_to_copy = (offset + length > ringbuffer_size(rb)) ? ringbuffer_size(rb) - offset : length; 98 99 for (size_t copied = 0; copied < bytes_to_copy; ++copied) { 100 *p++ = *b++; 101 if (b >= (rb->base + rb->total)) 102 b = rb->base; 103 } 104 105 return bytes_to_copy; 106 } 107 108 size_t ringbuffer_pop(ringbuffer_t *rb, uint8_t *p, size_t length) { 109 assert(rb); 110 assert(p); 111 112 const size_t copied = ringbuffer_peek(rb, 0, p, length); 113 rb->head += copied; 114 if (rb->head >= (rb->base + rb->total)) 115 rb->head -= rb->total; 116 117 rb->available += copied; 118 return copied; 119 } 120
