76 lines
2.7 KiB
C
76 lines
2.7 KiB
C
|
/*
|
||
|
|
* 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 WEBRTC_COMMON_AUDIO_RING_BUFFER_H_
|
||
|
|
#define WEBRTC_COMMON_AUDIO_RING_BUFFER_H_
|
||
|
|
|
||
|
|
#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. The |data_ptr| will point to the address where
|
||
|
|
// it is located. If all |element_count| data are feasible to read without
|
||
|
|
// buffer wrap around |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 // WEBRTC_COMMON_AUDIO_RING_BUFFER_H_
|