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/* -*- c++ -*- */
/*
* Copyright 2005 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 2, 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef INCLUDED_TIME_SERIES_H
#define INCLUDED_TIME_SERIES_H
#include <string>
/*!
* \brief Memory mapped input for complex time series data
*
* Inspired by "iqts" by John Sahr, Univ of Washington
*/
class time_series {
size_t d_itemsize; // user specified item size
std::string d_filename;
int d_fd; // file descriptor
unsigned long long d_filesize; // in bytes
unsigned long long d_start; // in items
unsigned long long d_limit; // in items
void *d_buffer; // points to base of file
public:
/*!
* \brief Create read-only mapped file accessor.
* \param item_size size of item in bytes
* \param filename name of file to open
* \param starting_offset offset in file in item_size units at which to start
* \param nsamples_to_process maximum number of samples to map in starting at \p start. -1 implies no limit.
*
* \throws string on error opening file, etc.
*/
time_series(size_t item_size, const std::string filename,
unsigned long long starting_offset=0,
long long nsamples_to_process=-1);
~time_series();
/*!
* \brief Return a pointer to a buffer of data at file offset pos.
*
* \param pos offset from beginning of file in itemsize units.
* \param blocksize minimum size of returned buffer in itemsize units.
*
* "Seek" to pos in file and return a pointer to the data at that
* location. The returned pointer will have at least blocksize valid
* elements. Return 0 if pos is out of bounds, or if there isn't
* at least blocksize units available in the file.
*/
const void *seek(unsigned long long pos, unsigned long long blocksize) const;
long long nsamples_available(unsigned long long pos) const;
};
#endif /* INCLUDED_TIME_SERIES_H */
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