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// Copyright (C) 2011-2015 Internet Systems Consortium, Inc. ("ISC")
//
// 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 <config.h>
#include <util/io/fd.h>
#include <unistd.h>
#include <cerrno>
namespace isc {
namespace util {
namespace io {
bool
write_data(const int fd, const void *buffer_v, const size_t length) {
const unsigned char* buffer(static_cast<const unsigned char*>(buffer_v));
size_t remaining = length; // Amount remaining to be written
// Just keep writing until all is written
while (remaining > 0) {
const int written = write(fd, buffer, remaining);
if (written == -1) {
if (errno == EINTR) { // Just keep going
continue;
} else {
return (false);
}
} else if (written > 0) {
// Wrote "written" bytes from the buffer
remaining -= written;
buffer += written;
} else {
// Wrote zero bytes from the buffer. We should not get here as any
// error that causes zero bytes to be written should have returned
// -1. However, write(2) can return 0, and in this case we
// interpret it as an error.
return (false);
}
}
return (true);
}
ssize_t
read_data(const int fd, void *buffer_v, const size_t length) {
unsigned char* buffer(static_cast<unsigned char*>(buffer_v));
size_t remaining = length; // Amount remaining to be read
while (remaining > 0) {
const int amount = read(fd, buffer, remaining);
if (amount == -1) {
if (errno == EINTR) { // Continue on interrupted call
continue;
} else {
return (-1);
}
} else if (amount > 0) {
// Read "amount" bytes into the buffer
remaining -= amount;
buffer += amount;
} else {
// EOF - end the read
break;
}
}
// Return total number of bytes read
return (static_cast<ssize_t>(length - remaining));
}
}
}
}
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