/*
* Copyright (C) 2012-2015 Max Kellermann <max@duempel.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef FILE_DESCRIPTOR_HXX
#define FILE_DESCRIPTOR_HXX
#include "check.h"
#include "Compiler.h"
#include <assert.h>
#include <unistd.h>
#include <sys/types.h>
#ifdef USE_SIGNALFD
#include <signal.h>
#endif
/**
* An OO wrapper for a UNIX file descriptor.
*
* This class is unmanaged and trivial.
*/
class FileDescriptor {
protected:
int fd;
public:
FileDescriptor() = default;
explicit constexpr FileDescriptor(int _fd):fd(_fd) {}
constexpr bool operator==(FileDescriptor other) const {
return fd == other.fd;
}
constexpr bool IsDefined() const {
return fd >= 0;
}
/**
* Returns the file descriptor. This may only be called if
* IsDefined() returns true.
*/
constexpr int Get() const {
return fd;
}
void Set(int _fd) {
fd = _fd;
}
int Steal() {
assert(IsDefined());
int _fd = fd;
fd = -1;
return _fd;
}
void SetUndefined() {
fd = -1;
}
static constexpr FileDescriptor Undefined() {
return FileDescriptor(-1);
}
bool Open(const char *pathname, int flags, mode_t mode=0666);
bool OpenReadOnly(const char *pathname);
#ifndef WIN32
bool OpenNonBlocking(const char *pathname);
static bool CreatePipe(FileDescriptor &r, FileDescriptor &w);
/**
* Enable non-blocking mode on this file descriptor.
*/
void SetNonBlocking();
/**
* Enable blocking mode on this file descriptor.
*/
void SetBlocking();
/**
* Duplicate the file descriptor onto the given file descriptor.
*/
bool Duplicate(int new_fd) const {
return ::dup2(Get(), new_fd) == 0;
}
#endif
#ifdef USE_EVENTFD
bool CreateEventFD(unsigned initval=0);
#endif
#ifdef USE_SIGNALFD
bool CreateSignalFD(const sigset_t *mask);
#endif
#ifdef HAVE_INOTIFY_INIT
bool CreateInotify();
#endif
/**
* Close the file descriptor. It is legal to call it on an
* "undefined" object. After this call, IsDefined() is guaranteed
* to return false, and this object may be reused.
*/
bool Close() {
return ::close(Steal()) == 0;
}
/**
* Rewind the pointer to the beginning of the file.
*/
bool Rewind();
off_t Seek(off_t offset) {
return lseek(Get(), offset, SEEK_SET);
}
gcc_pure
off_t Tell() const {
return lseek(Get(), 0, SEEK_CUR);
}
/**
* Returns the size of the file in bytes, or -1 on error.
*/
gcc_pure
off_t GetSize() const;
ssize_t Read(void *buffer, size_t length) {
return ::read(fd, buffer, length);
}
ssize_t Write(const void *buffer, size_t length) {
return ::write(fd, buffer, length);
}
#ifndef WIN32
int Poll(short events, int timeout) const;
int WaitReadable(int timeout) const;
int WaitWritable(int timeout) const;
#endif
};
#endif
