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/*
* Copyright (C) 2015, Mike Walters <mike@flomp.net>
*
* This file is part of inspectrum.
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "inputsource.h"
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <stdexcept>
InputSource::InputSource(const char *filename) {
m_file = fopen(filename, "rb");
if (m_file == nullptr)
throw std::runtime_error("Error opening file");
struct stat sb;
if (fstat(fileno(m_file), &sb) != 0)
throw std::runtime_error("Error fstating file");
m_file_size = sb.st_size;
sampleCount = m_file_size / sizeof(fftwf_complex);
m_data = (fftwf_complex*)mmap(NULL, m_file_size, PROT_READ, MAP_SHARED, fileno(m_file), 0);
if (m_data == 0)
throw std::runtime_error("Error mmapping file");
}
InputSource::~InputSource() {
munmap(m_data, m_file_size);
fclose(m_file);
}
bool InputSource::getSamples(fftwf_complex *dest, off_t start, int length)
{
if(start < 0 || length < 0)
return false;
if (start + length >= sampleCount)
return false;
memcpy(dest, &m_data[start], length * sizeof(fftwf_complex));
return true;
}
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