80 lines
2.0 KiB
C++
80 lines
2.0 KiB
C++
// Licensed to the Apache Software Foundation (ASF) under one
|
|
// or more contributor license agreements. See the NOTICE file
|
|
// distributed with this work for additional information
|
|
// regarding copyright ownership. The ASF licenses this file
|
|
// to you under the Apache License, Version 2.0 (the
|
|
// "License"); you may not use this file except in compliance
|
|
// with the License. You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing,
|
|
// software distributed under the License is distributed on an
|
|
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
|
|
// KIND, either express or implied. See the License for the
|
|
// specific language governing permissions and limitations
|
|
// under the License.
|
|
|
|
// Date: Mon. Nov 7 14:47:36 CST 2011
|
|
|
|
#ifndef BUTIL_FD_GUARD_H
|
|
#define BUTIL_FD_GUARD_H
|
|
|
|
#include <unistd.h> // close()
|
|
|
|
namespace butil {
|
|
|
|
// RAII file descriptor.
|
|
//
|
|
// Example:
|
|
// fd_guard fd1(open(...));
|
|
// if (fd1 < 0) {
|
|
// printf("Fail to open\n");
|
|
// return -1;
|
|
// }
|
|
// if (another-error-happened) {
|
|
// printf("Fail to do sth\n");
|
|
// return -1; // *** closing fd1 automatically ***
|
|
// }
|
|
class fd_guard {
|
|
public:
|
|
fd_guard() : _fd(-1) {}
|
|
explicit fd_guard(int fd) : _fd(fd) {}
|
|
|
|
~fd_guard() {
|
|
if (_fd >= 0) {
|
|
::close(_fd);
|
|
_fd = -1;
|
|
}
|
|
}
|
|
|
|
// Close current fd and replace with another fd
|
|
void reset(int fd) {
|
|
if (_fd >= 0) {
|
|
::close(_fd);
|
|
_fd = -1;
|
|
}
|
|
_fd = fd;
|
|
}
|
|
|
|
// Set internal fd to -1 and return the value before set.
|
|
int release() {
|
|
const int prev_fd = _fd;
|
|
_fd = -1;
|
|
return prev_fd;
|
|
}
|
|
|
|
operator int() const { return _fd; }
|
|
|
|
private:
|
|
// Copying this makes no sense.
|
|
fd_guard(const fd_guard&);
|
|
void operator=(const fd_guard&);
|
|
|
|
int _fd;
|
|
};
|
|
|
|
} // namespace butil
|
|
|
|
#endif // BUTIL_FD_GUARD_H
|