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nix/src/libutil/file-descriptor.cc
Sergei Zimmerman 95d9c13716
Apply clang-format universally.
* It is tough to contribute to a project that doesn't use a formatter,
* It is extra hard to contribute to a project which has configured the formatter, but ignores it for some files
* Code formatting makes it harder to hide obscure / weird bugs by accident or on purpose,

Let's rip the bandaid off?

Note that PRs currently in flight should be able to be merged relatively easily by applying `clang-format` to their tip prior to merge.

Co-authored-by: Graham Christensen <graham@grahamc.com>
2025-07-18 22:26:03 +03:00

141 lines
2.7 KiB
C++

#include "nix/util/serialise.hh"
#include "nix/util/util.hh"
#include <fcntl.h>
#include <unistd.h>
#ifdef _WIN32
# include <winnt.h>
# include <fileapi.h>
# include "nix/util/windows-error.hh"
#endif
namespace nix {
void writeLine(Descriptor fd, std::string s)
{
s += '\n';
writeFull(fd, s);
}
std::string drainFD(Descriptor fd, bool block, const size_t reserveSize)
{
// the parser needs two extra bytes to append terminating characters, other users will
// not care very much about the extra memory.
StringSink sink(reserveSize + 2);
#ifdef _WIN32
// non-blocking is not supported this way on Windows
assert(block);
drainFD(fd, sink);
#else
drainFD(fd, sink, block);
#endif
return std::move(sink.s);
}
//////////////////////////////////////////////////////////////////////
AutoCloseFD::AutoCloseFD()
: fd{INVALID_DESCRIPTOR}
{
}
AutoCloseFD::AutoCloseFD(Descriptor fd)
: fd{fd}
{
}
// NOTE: This can be noexcept since we are just copying a value and resetting
// the file descriptor in the rhs.
AutoCloseFD::AutoCloseFD(AutoCloseFD && that) noexcept
: fd{that.fd}
{
that.fd = INVALID_DESCRIPTOR;
}
AutoCloseFD & AutoCloseFD::operator=(AutoCloseFD && that)
{
close();
fd = that.fd;
that.fd = INVALID_DESCRIPTOR;
return *this;
}
AutoCloseFD::~AutoCloseFD()
{
try {
close();
} catch (...) {
ignoreExceptionInDestructor();
}
}
Descriptor AutoCloseFD::get() const
{
return fd;
}
void AutoCloseFD::close()
{
if (fd != INVALID_DESCRIPTOR) {
if (
#ifdef _WIN32
::CloseHandle(fd)
#else
::close(fd)
#endif
== -1)
/* This should never happen. */
throw NativeSysError("closing file descriptor %1%", fd);
fd = INVALID_DESCRIPTOR;
}
}
void AutoCloseFD::fsync() const
{
if (fd != INVALID_DESCRIPTOR) {
int result;
result =
#ifdef _WIN32
::FlushFileBuffers(fd)
#elif defined(__APPLE__)
::fcntl(fd, F_FULLFSYNC)
#else
::fsync(fd)
#endif
;
if (result == -1)
throw NativeSysError("fsync file descriptor %1%", fd);
}
}
void AutoCloseFD::startFsync() const
{
#ifdef __linux__
if (fd != -1) {
/* Ignore failure, since fsync must be run later anyway. This is just a performance optimization. */
::sync_file_range(fd, 0, 0, SYNC_FILE_RANGE_WRITE);
}
#endif
}
AutoCloseFD::operator bool() const
{
return fd != INVALID_DESCRIPTOR;
}
Descriptor AutoCloseFD::release()
{
Descriptor oldFD = fd;
fd = INVALID_DESCRIPTOR;
return oldFD;
}
//////////////////////////////////////////////////////////////////////
void Pipe::close()
{
readSide.close();
writeSide.close();
}
} // namespace nix