1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/* 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org */ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// A ring buffer to hold arbitrary data. Provides no thread safety. Unless 12b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// otherwise specified, functions return 0 on success and -1 on error. 13b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 14b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_RING_BUFFER_H_ 15b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#define WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_RING_BUFFER_H_ 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org#include <stddef.h> // size_t 18b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 19b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgtypedef struct RingBuffer RingBuffer; 20b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org 21db32d60125dfe78a1eb475f39672484c63b034b1andrew@webrtc.org// Returns NULL on failure. 22db32d60125dfe78a1eb475f39672484c63b034b1andrew@webrtc.orgRingBuffer* WebRtc_CreateBuffer(size_t element_count, size_t element_size); 23b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgint WebRtc_InitBuffer(RingBuffer* handle); 24b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgvoid WebRtc_FreeBuffer(void* handle); 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 26b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Reads data from the buffer. The |data_ptr| will point to the address where 27b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// it is located. If all |element_count| data are feasible to read without 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// buffer wrap around |data_ptr| will point to the location in the buffer. 29b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Otherwise, the data will be copied to |data| (memory allocation done by the 30b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// user) and |data_ptr| points to the address of |data|. |data_ptr| is only 31b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// guaranteed to be valid until the next call to WebRtc_WriteBuffer(). 32b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org// 33b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org// To force a copying to |data|, pass a NULL |data_ptr|. 34b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org// 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Returns number of elements read. 36b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgsize_t WebRtc_ReadBuffer(RingBuffer* handle, 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org void** data_ptr, 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org void* data, 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org size_t element_count); 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Writes |data| to buffer and returns the number of elements written. 42b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgsize_t WebRtc_WriteBuffer(RingBuffer* handle, const void* data, 43b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org size_t element_count); 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Moves the buffer read position and returns the number of elements moved. 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Positive |element_count| moves the read position towards the write position, 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// that is, flushing the buffer. Negative |element_count| moves the read 48b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// position away from the the write position, that is, stuffing the buffer. 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Returns number of elements moved. 50b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgint WebRtc_MoveReadPtr(RingBuffer* handle, int element_count); 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 52b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Returns number of available elements to read. 53b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgsize_t WebRtc_available_read(const RingBuffer* handle); 54b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 55b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Returns number of available elements for write. 56b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.orgsize_t WebRtc_available_write(const RingBuffer* handle); 57b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 58b3e5a623285b082a23655cdc02f35a40f652acdfandrew@webrtc.org#endif // WEBRTC_MODULES_AUDIO_PROCESSING_UTILITY_RING_BUFFER_H_ 59