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