1c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi/****************************************************************************** 2c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * 3c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * Copyright (C) 2017 Google Inc. 4c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * 5c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * Licensed under the Apache License, Version 2.0 (the "License"); 6c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * you may not use this file except in compliance with the License. 7c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * You may obtain a copy of the License at: 8c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * 9c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * http://www.apache.org/licenses/LICENSE-2.0 10c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * 11c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * Unless required by applicable law or agreed to in writing, software 12c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * distributed under the License is distributed on an "AS IS" BASIS, 13c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * See the License for the specific language governing permissions and 15c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * limitations under the License. 16c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi * 17c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi ******************************************************************************/ 18c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 19c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi#include <assert.h> 20c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi#include <stdlib.h> 21c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 22c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi#include "ringbuffer.h" 23c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 24c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoistruct ringbuffer_t { 25c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi size_t total; 26c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi size_t available; 27c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi uint8_t* base; 28c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi uint8_t* head; 29c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi uint8_t* tail; 30c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi}; 31c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 32c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoiringbuffer_t* ringbuffer_init(const size_t size) { 33c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi ringbuffer_t* p = static_cast<ringbuffer_t*>(calloc(1, sizeof(ringbuffer_t))); 34c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 35c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (p == NULL) return p; 36c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 37c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi p->base = static_cast<uint8_t*>(calloc(size, sizeof(uint8_t))); 38c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi p->head = p->tail = p->base; 39c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi p->total = p->available = size; 40c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 41c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return p; 42c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 43c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 44c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoivoid ringbuffer_free(ringbuffer_t* rb) { 45c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (rb != NULL) free(rb->base); 46c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi free(rb); 47c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 48c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 49c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoisize_t ringbuffer_available(const ringbuffer_t* rb) { 50c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(rb); 51c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return rb->available; 52c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 53c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 54c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoisize_t ringbuffer_size(const ringbuffer_t* rb) { 55c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(rb); 56c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return rb->total - rb->available; 57c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 58c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 59c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoisize_t ringbuffer_insert(ringbuffer_t* rb, const uint8_t* p, size_t length) { 60c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(rb); 61c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(p); 62c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 63c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (length > ringbuffer_available(rb)) length = ringbuffer_available(rb); 64c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 65c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi for (size_t i = 0; i != length; ++i) { 66c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi *rb->tail++ = *p++; 67c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (rb->tail >= (rb->base + rb->total)) rb->tail = rb->base; 68c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi } 69c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 70c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi rb->available -= length; 71c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return length; 72c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 73c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 74c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoisize_t ringbuffer_delete(ringbuffer_t* rb, size_t length) { 75c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(rb); 76c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 77c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (length > ringbuffer_size(rb)) length = ringbuffer_size(rb); 78c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 79c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi rb->head += length; 80c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (rb->head >= (rb->base + rb->total)) rb->head -= rb->total; 81c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 82c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi rb->available += length; 83c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return length; 84c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 85c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 86c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoisize_t ringbuffer_peek(const ringbuffer_t* rb, off_t offset, uint8_t* p, 87c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi size_t length) { 88c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(rb); 89c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(p); 90c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(offset >= 0); 91c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert((size_t)offset <= ringbuffer_size(rb)); 92c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 93c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi uint8_t* b = ((rb->head - rb->base + offset) % rb->total) + rb->base; 94c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi const size_t bytes_to_copy = (offset + length > ringbuffer_size(rb)) 95c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi ? ringbuffer_size(rb) - offset 96c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi : length; 97c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 98c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi for (size_t copied = 0; copied < bytes_to_copy; ++copied) { 99c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi *p++ = *b++; 100c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (b >= (rb->base + rb->total)) b = rb->base; 101c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi } 102c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 103c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return bytes_to_copy; 104c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 105c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 106c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoisize_t ringbuffer_pop(ringbuffer_t* rb, uint8_t* p, size_t length) { 107c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(rb); 108c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi assert(p); 109c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 110c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi const size_t copied = ringbuffer_peek(rb, 0, p, length); 111c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi rb->head += copied; 112c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi if (rb->head >= (rb->base + rb->total)) rb->head -= rb->total; 113c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi 114c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi rb->available += copied; 115c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi return copied; 116c0cd1abf314c381ad47114d08a4a3d0750d7a797Ruchi Kandoi} 117