66 lines
1.9 KiB
C++
66 lines
1.9 KiB
C++
/* -*- c++ -*- */
|
|
/*
|
|
* Copyright 2002,2013 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 <gnuradio/api.h>
|
|
|
|
namespace gr {
|
|
|
|
/*
|
|
* 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 circular_file
|
|
{
|
|
private:
|
|
int d_fd;
|
|
int *d_header;
|
|
unsigned char *d_buffer;
|
|
int d_mapped_size;
|
|
int d_bytes_read;
|
|
|
|
public:
|
|
circular_file(const char *filename, bool writable = false, int size = 0);
|
|
~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();
|
|
};
|
|
|
|
} /* namespace gr */
|
|
|
|
#endif /* GR_CIRCULAR_FILE_H */
|