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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#include <sal/config.h>
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <limits>
#include "readwrite_helper.hxx"
#include "system.hxx"
namespace {
std::size_t cap_ssize_t(std::size_t value) {
return std::min(value, std::size_t(std::numeric_limits<ssize_t>::max()));
}
}
bool safeWrite(int fd, void* data, std::size_t dataSize)
{
auto nToWrite = dataSize;
unsigned char* dataToWrite = static_cast<unsigned char *>(data);
while ( nToWrite ) {
auto nWritten = write(fd, dataToWrite, cap_ssize_t(nToWrite));
if ( nWritten < 0 ) {
if ( errno == EINTR )
continue;
return false;
}
assert(nWritten > 0);
nToWrite -= nWritten;
dataToWrite += nWritten;
}
return true;
}
bool safeRead( int fd, void* buffer, std::size_t count )
{
auto nToRead = count;
unsigned char* bufferForReading = static_cast<unsigned char *>(buffer);
while ( nToRead ) {
auto nRead = read(fd, bufferForReading, cap_ssize_t(nToRead));
if ( nRead < 0 ) {
// We were interrupted before reading, retry.
if (errno == EINTR)
continue;
return false;
}
// If we reach the EOF, we consider this a partial transfer and thus
// an error.
if ( nRead == 0 )
return false;
nToRead -= nRead;
bufferForReading += nRead;
}
return true;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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