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/* aKode: ByteBuffer
Copyright (C) 2004 Allan Sandfeld Jensen <kde@carewolf.com>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef _AKODE_BYTEBUFFER_H
#define _AKODE_BYTEBUFFER_H
#include <pthread.h>
#include "akode_export.h"
namespace aKode {
//! A reentrant circular buffer of bytes
/*!
* A buffer of bytes to synchronize I/O between two threads, one reading and one writing.
*/
class AKODE_EXPORT ByteBuffer {
const unsigned int length;
char* buffer;
volatile unsigned int readPos;
volatile unsigned int writePos;
pthread_cond_t not_empty;
pthread_cond_t not_full;
pthread_mutex_t mutex;
volatile bool flushed, released, closed;
public:
/*!
* Constructs a buffer with \a len bytes.
*/
ByteBuffer(unsigned int len);
~ByteBuffer();
/*!
* Write \a len bytes from \a buf into the buffer. If blocking is set to true,
* write will block until all bytes have been writen or release() or flush()
* is called.
* Returns the number of bytes writen.
*/
int write(char* buf, unsigned int len, bool blocking = false);
/*!
* Read \a len bytes from the buffer into \a buf. If blocking is set to true,
* read will block until \a len bytes have been read or release()
* is called.
* Returns the number of bytes read.
*/
int read(char* buf, unsigned int len, bool blocking = false);
/*!
* Called by the writing thread to denote EOF
*/
void close();
/*!
* Returns true if the stream is empty and closed
*/
bool eof();
/*!
* Returns true if the buffer is empty
*/
bool empty();
/*!
* Returns true if the buffer is full
*/
bool full();
/*!
* Returns the number of bytes that can be read without blocking
*/
unsigned int content();
/*!
* Returns the number of bytes that can be writen without blocking
*/
unsigned int space();
/*!
* Flushes the buffer and releases any blocking write-calls.
*/
void flush() ;
/*!
* Releases all blocking threads and prepares the buffer for deletion.
* Use reset to make the buffer usable again.
*/
void release();
/*!
* Resets the buffer to be as good as new. Assumes all threads are released.
*/
void reset();
};
} // namespace
#endif
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