libcamera: Move file_descriptor.h to base/

The FileDescriptor class is a generic helper that matches the criteria
for the base library. Move it there.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 0 insertions, 272 deletions

diff --git a/src/libcamera/file_descriptor.cpp b/src/libcamera/file_descriptor.cpp
deleted file mode 100644
index 0409c3e1..00000000
--- a/src/libcamera/file_descriptor.cpp
+++ /dev/null
@@ -1,272 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-/*
- * Copyright (C) 2019, Google Inc.
- *
- * file_descriptor.cpp - File descriptor wrapper
- */
-
-#include <libcamera/file_descriptor.h>
-
-#include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <utility>
-
-#include <libcamera/base/log.h>
-
-/**
- * \file file_descriptor.h
- * \brief File descriptor wrapper
- */
-
-namespace libcamera {
-
-LOG_DEFINE_CATEGORY(FileDescriptor)
-
-/**
- * \class FileDescriptor
- * \brief RAII-style wrapper for file descriptors
- *
- * The FileDescriptor class provides RAII-style lifetime management of file
- * descriptors with an efficient mechanism for ownership sharing. At its core,
- * an internal Descriptor object wraps a file descriptor (expressed as a signed
- * integer) with an RAII-style interface. The Descriptor is then implicitly
- * shared with all FileDescriptor instances constructed as copies.
- *
- * When constructed from a numerical file descriptor, the FileDescriptor
- * instance either duplicates or takes over the file descriptor:
- *
- * - The FileDescriptor(const int &) constructor duplicates the numerical file
- *   descriptor and wraps the duplicate in a Descriptor. The caller is
- *   responsible for closing the original file descriptor, and the value
- *   returned by fd() will be different from the value passed to the
- *   constructor.
- *
- * - The FileDescriptor(int &&) constructor takes over the numerical file
- *   descriptor and wraps it in a Descriptor. The caller shall not touch the
- *   original file descriptor once the function returns, and the value returned
- *   by fd() will be identical to the value passed to the constructor.
- *
- * The copy constructor and assignment operator create copies that share the
- * Descriptor, while the move versions of those functions additionally make the
- * other FileDescriptor invalid. When the last FileDescriptor that references a
- * Descriptor is destroyed, the file descriptor is closed.
- *
- * The numerical file descriptor is available through the fd() function. All
- * FileDescriptor instances created as copies of a FileDescriptor will report
- * the same fd() value. Callers can perform operations on the fd(), but shall
- * never close it manually.
- */
-
-/**
- * \brief Create a FileDescriptor copying a given \a fd
- * \param[in] fd File descriptor
- *
- * Construct a FileDescriptor from a numerical file descriptor by duplicating
- * the \a fd, and take ownership of the copy. The original \a fd is left
- * untouched, and the caller is responsible for closing it when appropriate.
- * The duplicated file descriptor will be closed automatically when all
- * FileDescriptor instances that reference it are destroyed.
- *
- * If the \a fd is negative, the FileDescriptor is constructed as invalid and
- * the fd() function will return -1.
- */
-FileDescriptor::FileDescriptor(const int &fd)
-{
-	if (fd < 0)
-		return;
-
-	fd_ = std::make_shared<Descriptor>(fd, true);
-	if (fd_->fd() < 0)
-		fd_.reset();
-}
-
-/**
- * \brief Create a FileDescriptor taking ownership of a given \a fd
- * \param[in] fd File descriptor
- *
- * Construct a FileDescriptor from a numerical file descriptor by taking
- * ownership of the \a fd. The original \a fd is set to -1 and shall not be
- * touched by the caller anymore. In particular, the caller shall not close the
- * original \a fd manually. The duplicated file descriptor will be closed
- * automatically when all FileDescriptor instances that reference it are
- * destroyed.
- *
- * If the \a fd is negative, the FileDescriptor is constructed as invalid and
- * the fd() function will return -1.
- */
-FileDescriptor::FileDescriptor(int &&fd)
-{
-	if (fd < 0)
-		return;
-
-	fd_ = std::make_shared<Descriptor>(fd, false);
-	/*
-	 * The Descriptor constructor can't have failed here, as it took over
-	 * the fd without duplicating it. Just set the original fd to -1 to
-	 * implement move semantics.
-	 */
-	fd = -1;
-}
-
-/**
- * \brief Copy constructor, create a FileDescriptor from a copy of \a other
- * \param[in] other The other FileDescriptor
- *
- * Copying a FileDescriptor implicitly shares ownership of the wrapped file
- * descriptor. The original FileDescriptor is left untouched, and the caller is
- * responsible for destroying it when appropriate. The wrapped file descriptor
- * will be closed automatically when all FileDescriptor instances that
- * reference it are destroyed.
- */
-FileDescriptor::FileDescriptor(const FileDescriptor &other)
-	: fd_(other.fd_)
-{
-}
-
-/**
- * \brief Move constructor, create a FileDescriptor by taking over \a other
- * \param[in] other The other FileDescriptor
- *
- * Moving a FileDescriptor moves the reference to the wrapped descriptor owned
- * by \a other to the new FileDescriptor. The \a other FileDescriptor is
- * invalidated and its fd() function will return -1. The wrapped file descriptor
- * will be closed automatically when all FileDescriptor instances that
- * reference it are destroyed.
- */
-FileDescriptor::FileDescriptor(FileDescriptor &&other)
-	: fd_(std::move(other.fd_))
-{
-}
-
-/**
- * \brief Destroy the FileDescriptor instance
- *
- * Destroying a FileDescriptor instance releases its reference to the wrapped
- * descriptor, if any. When the last instance that references a wrapped
- * descriptor is destroyed, the file descriptor is automatically closed.
- */
-FileDescriptor::~FileDescriptor()
-{
-}
-
-/**
- * \brief Copy assignment operator, replace the wrapped file descriptor with a
- * copy of \a other
- * \param[in] other The other FileDescriptor
- *
- * Copying a FileDescriptor creates a new reference to the wrapped file
- * descriptor owner by \a other. If \a other is invalid, *this will also be
- * invalid. The original FileDescriptor is left untouched, and the caller is
- * responsible for destroying it when appropriate. The wrapped file descriptor
- * will be closed automatically when all FileDescriptor instances that
- * reference it are destroyed.
- *
- * \return A reference to this FileDescriptor
- */
-FileDescriptor &FileDescriptor::operator=(const FileDescriptor &other)
-{
-	fd_ = other.fd_;
-
-	return *this;
-}
-
-/**
- * \brief Move assignment operator, replace the wrapped file descriptor by
- * taking over \a other
- * \param[in] other The other FileDescriptor
- *
- * Moving a FileDescriptor moves the reference to the wrapped descriptor owned
- * by \a other to the new FileDescriptor. If \a other is invalid, *this will
- * also be invalid. The \a other FileDescriptor is invalidated and its fd()
- * function will return -1. The wrapped file descriptor will be closed
- * automatically when all FileDescriptor instances that reference it are
- * destroyed.
- *
- * \return A reference to this FileDescriptor
- */
-FileDescriptor &FileDescriptor::operator=(FileDescriptor &&other)
-{
-	fd_ = std::move(other.fd_);
-
-	return *this;
-}
-
-/**
- * \fn FileDescriptor::isValid()
- * \brief Check if the FileDescriptor instance is valid
- * \return True if the FileDescriptor is valid, false otherwise
- */
-
-/**
- * \fn FileDescriptor::fd()
- * \brief Retrieve the numerical file descriptor
- * \return The numerical file descriptor, which may be -1 if the FileDescriptor
- * instance is invalid
- */
-
-/**
- * \brief Duplicate a FileDescriptor
- *
- * Duplicating a FileDescriptor creates a duplicate of the wrapped file
- * descriptor and returns a new FileDescriptor instance that wraps the
- * duplicate. The fd() function of the original and duplicate instances will
- * return different values. The duplicate instance will not be affected by
- * destruction of the original instance or its copies.
- *
- * \return A new FileDescriptor instance wrapping a duplicate of the original
- * file descriptor
- */
-FileDescriptor FileDescriptor::dup() const
-{
-	return FileDescriptor(fd());
-}
-
-/**
- * \brief Retrieve the file descriptor inode
- *
- * \todo Should this move to the File class ?
- *
- * \return The file descriptor inode on success, or 0 on error
- */
-ino_t FileDescriptor::inode() const
-{
-	if (!isValid())
-		return 0;
-
-	struct stat st;
-	int ret = fstat(fd_->fd(), &st);
-	if (ret < 0) {
-		ret = -errno;
-		LOG(FileDescriptor, Fatal)
-			<< "Failed to fstat() fd: " << strerror(-ret);
-		return 0;
-	}
-
-	return st.st_ino;
-}
-
-FileDescriptor::Descriptor::Descriptor(int fd, bool duplicate)
-{
-	if (!duplicate) {
-		fd_ = fd;
-		return;
-	}
-
-	/* Failing to dup() a fd should not happen and is fatal. */
-	fd_ = ::dup(fd);
-	if (fd_ == -1) {
-		int ret = -errno;
-		LOG(FileDescriptor, Fatal)
-			<< "Failed to dup() fd: " << strerror(-ret);
-	}
-}
-
-FileDescriptor::Descriptor::~Descriptor()
-{
-	if (fd_ != -1)
-		close(fd_);
-}
-
-} /* namespace libcamera */