Current File : //data/old/usr/local/include/gpac/ringbuffer.h
/*
* GPAC - Multimedia Framework C SDK
*
* Authors: Pierre Souchay
* Copyright (c) Telecom ParisTech 2010-2012
* All rights reserved
*
* This file is part of GPAC / common tools sub-project
*
* GPAC is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* GPAC is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#ifndef _GF_RINGBUFFER_H
#define _GF_RINGBUFFER_H
#include <gpac/tools.h>
#include <gpac/thread.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef struct
{
u8 *buf;
volatile u32 write_ptr;
volatile u32 read_ptr;
u32 size;
u32 size_mask;
GF_Mutex * mx;
}
GF_Ringbuffer ;
/*!
* Creates a new ringbuffer with specified size. The caller has the
* reponsability to free the ringbuffer using gf_ringbuffer_del()
*
* \param sz the ringbuffer size in bytes
*
* \return a pointer to a new ringbuffer if successful, NULL otherwise.
*/
GF_Ringbuffer * gf_ringbuffer_new(u32 sz);
/*!
* Frees a previously allocated ringbuffer
* \param ringbuffer The ringbuffer to free
*/
void gf_ringbuffer_del(GF_Ringbuffer * ringbuffer);
/*!
* Reads bytes from ringbuffer
* \param rb The ringbuffer to read from
* \param dest The destination
* \param szDest Size of destination
* \return the number of bytes readen
*/
u32 gf_ringbuffer_read(GF_Ringbuffer *rb, u8 *dest, u32 szDest);
/*!
* Return the number of bytes available for reading. This is the
* number of bytes in front of the read pointer and behind the write
* pointer.
* \param rb The ringbuffer
* \return the number of bytes available for reading
*/
u32 gf_ringbuffer_available_for_read (GF_Ringbuffer * rb);
/*!
* Copy at most sz bytes to rb from src.
* \param rb The ringbuffer to write to
* \param src The source buffer
* \param sz the size of source
* \return Returns the actual number of bytes copied, may be lower than sz if ringbuffer is already full
*/
u32 gf_ringbuffer_write (GF_Ringbuffer * rb, const u8 * src, u32 sz);
#ifdef __cplusplus
}
#endif
#endif /* _GF_RINGBUFFER_H */
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