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/* -*- c++ -*- */
/*
* Copyright 2002 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef _GR_CIRCULAR_FILE_H_
#define _GR_CIRCULAR_FILE_H_
#include <gr_runtime_api.h>
/*
* writes input data into a circular buffer on disk.
*
* the file contains a fixed header:
* 0x0000: int32 magic (0xEB021026)
* 0x0004: int32 size in bytes of header (constant 4096)
* 0x0008: int32 size in bytes of circular buffer (not including header)
* 0x000C: int32 file offset to beginning of circular buffer
* 0x0010: int32 byte offset from beginning of circular buffer to
* current start of data
*
*/
class GR_RUNTIME_API gr_circular_file {
int d_fd;
int *d_header;
unsigned char *d_buffer;
int d_mapped_size;
int d_bytes_read;
public:
gr_circular_file (const char *filename, bool writable = false, int size = 0);
~gr_circular_file ();
bool write (void *data, int nbytes);
// returns # of bytes actually read or 0 if end of buffer, or -1 on error.
int read (void *data, int nbytes);
// reset read pointer to beginning of buffer.
void reset_read_pointer ();
};
#endif /* _GR_CIRCULAR_FILE_H_ */
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