1 /* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 // A ring buffer to hold arbitrary data. Provides no thread safety. Unless 12 // otherwise specified, functions return 0 on success and -1 on error. 13 14 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_RING_BUFFER_H_ 15 #define WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_RING_BUFFER_H_ 16 17 #include <stddef.h> // size_t 18 19 int WebRtc_CreateBuffer(void** handle, 20 size_t element_count, 21 size_t element_size); 22 int WebRtc_InitBuffer(void* handle); 23 int WebRtc_FreeBuffer(void* handle); 24 25 // Reads data from the buffer. The |data_ptr| will point to the address where 26 // it is located. If all |element_count| data are feasible to read without 27 // buffer wrap around |data_ptr| will point to the location in the buffer. 28 // Otherwise, the data will be copied to |data| (memory allocation done by the 29 // user) and |data_ptr| points to the address of |data|. |data_ptr| is only 30 // guaranteed to be valid until the next call to WebRtc_WriteBuffer(). 31 // Returns number of elements read. 32 size_t WebRtc_ReadBuffer(void* handle, 33 void** data_ptr, 34 void* data, 35 size_t element_count); 36 37 // Writes |data| to buffer and returns the number of elements written. 38 size_t WebRtc_WriteBuffer(void* handle, const void* data, size_t element_count); 39 40 // Moves the buffer read position and returns the number of elements moved. 41 // Positive |element_count| moves the read position towards the write position, 42 // that is, flushing the buffer. Negative |element_count| moves the read 43 // position away from the the write position, that is, stuffing the buffer. 44 // Returns number of elements moved. 45 int WebRtc_MoveReadPtr(void* handle, int element_count); 46 47 // Returns number of available elements to read. 48 size_t WebRtc_available_read(const void* handle); 49 50 // Returns number of available elements for write. 51 size_t WebRtc_available_write(const void* handle); 52 53 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_RING_BUFFER_H_ 54
