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Diffstat (limited to 'third_party/libwebrtc/common_audio/ring_buffer.h')
-rw-r--r-- | third_party/libwebrtc/common_audio/ring_buffer.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/third_party/libwebrtc/common_audio/ring_buffer.h b/third_party/libwebrtc/common_audio/ring_buffer.h new file mode 100644 index 0000000000..de0b4fed80 --- /dev/null +++ b/third_party/libwebrtc/common_audio/ring_buffer.h @@ -0,0 +1,79 @@ +/* + * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +// A ring buffer to hold arbitrary data. Provides no thread safety. Unless +// otherwise specified, functions return 0 on success and -1 on error. + +#ifndef COMMON_AUDIO_RING_BUFFER_H_ +#define COMMON_AUDIO_RING_BUFFER_H_ + +// TODO(alessiob): Used by AEC, AECm and AudioRingBuffer. Remove when possible. + +#ifdef __cplusplus +extern "C" { +#endif + +#include <stddef.h> // size_t + +enum Wrap { SAME_WRAP, DIFF_WRAP }; + +typedef struct RingBuffer { + size_t read_pos; + size_t write_pos; + size_t element_count; + size_t element_size; + enum Wrap rw_wrap; + char* data; +} RingBuffer; + +// Creates and initializes the buffer. Returns null on failure. +RingBuffer* WebRtc_CreateBuffer(size_t element_count, size_t element_size); +void WebRtc_InitBuffer(RingBuffer* handle); +void WebRtc_FreeBuffer(void* handle); + +// Reads data from the buffer. Returns the number of elements that were read. +// The `data_ptr` will point to the address where the read data is located. +// If no data can be read, `data_ptr` is set to `NULL`. If all data can be read +// without buffer wrap around then `data_ptr` will point to the location in the +// buffer. Otherwise, the data will be copied to `data` (memory allocation done +// by the user) and `data_ptr` points to the address of `data`. `data_ptr` is +// only guaranteed to be valid until the next call to WebRtc_WriteBuffer(). +// +// To force a copying to `data`, pass a null `data_ptr`. +// +// Returns number of elements read. +size_t WebRtc_ReadBuffer(RingBuffer* handle, + void** data_ptr, + void* data, + size_t element_count); + +// Writes `data` to buffer and returns the number of elements written. +size_t WebRtc_WriteBuffer(RingBuffer* handle, + const void* data, + size_t element_count); + +// Moves the buffer read position and returns the number of elements moved. +// Positive `element_count` moves the read position towards the write position, +// that is, flushing the buffer. Negative `element_count` moves the read +// position away from the the write position, that is, stuffing the buffer. +// Returns number of elements moved. +int WebRtc_MoveReadPtr(RingBuffer* handle, int element_count); + +// Returns number of available elements to read. +size_t WebRtc_available_read(const RingBuffer* handle); + +// Returns number of available elements for write. +size_t WebRtc_available_write(const RingBuffer* handle); + +#ifdef __cplusplus +} +#endif + +#endif // COMMON_AUDIO_RING_BUFFER_H_ |