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 #pragma once 20 21 #include <stdint.h> 22 23 typedef struct ringbuffer_t ringbuffer_t; 24 25 // NOTE: 26 // None of the functions below are thread safe when it comes to accessing the 27 // *rb pointer. It is *NOT* possible to insert and pop/delete at the same time. 28 // Callers must protect the *rb pointer separately. 29 30 // Create a ringbuffer with the specified size 31 // Returns NULL if memory allocation failed. Resulting pointer must be freed 32 // using |ringbuffer_free|. 33 ringbuffer_t* ringbuffer_init(const size_t size); 34 35 // Frees the ringbuffer structure and buffer 36 // Save to call with NULL. 37 void ringbuffer_free(ringbuffer_t *rb); 38 39 // Returns remaining buffer size 40 size_t ringbuffer_available(const ringbuffer_t *rb); 41 42 // Returns size of data in buffer 43 size_t ringbuffer_size(const ringbuffer_t *rb); 44 45 // Attempts to insert up to |length| bytes of data at |p| into the buffer 46 // Return actual number of bytes added. Can be less than |length| if buffer 47 // is full. 48 size_t ringbuffer_insert(ringbuffer_t *rb, const uint8_t *p, size_t length); 49 50 // Peek |length| number of bytes from the ringbuffer, starting at |offset|, 51 // into the buffer |p|. Return the actual number of bytes peeked. Can be less 52 // than |length| if there is less than |length| data available. |offset| must 53 // be non-negative. 54 size_t ringbuffer_peek(const ringbuffer_t *rb, off_t offset, uint8_t *p, size_t length); 55 56 // Does the same as |ringbuffer_peek|, but also advances the ring buffer head 57 size_t ringbuffer_pop(ringbuffer_t *rb, uint8_t *p, size_t length); 58 59 // Deletes |length| bytes from the ringbuffer starting from the head 60 // Return actual number of bytes deleted. 61 size_t ringbuffer_delete(ringbuffer_t *rb, size_t length); 62
