Cross platform low level file IO wrappers

util/file/fd_io.h

-// Copyright 2014 The Crashpad Authors. All rights reserved.
-//
-// Licensed 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.
-
-#ifndef CRASHPAD_UTIL_FILE_FD_IO_H_
-#define CRASHPAD_UTIL_FILE_FD_IO_H_
-
-#include <sys/types.h>
-
-namespace crashpad {
-
-//! \brief Wraps `read()`, retrying when interrupted or following a short read.
-//!
-//! This function reads into \a buffer, stopping only when \a size bytes have
-//! been read or when `read()` returns 0, indicating that end-of-file has been
-//! reached.
-//!
-//! \return The number of bytes read and placed into \a buffer, or `-1` on
-//!     error, with `errno` set appropriately. On error, a portion of \a fd may
-//!     have been read into \a buffer.
-//!
-//! \sa WriteFD
-//! \sa LoggingReadFD
-//! \sa CheckedReadFD
-//! \sa CheckedReadFDAtEOF
-ssize_t ReadFD(int fd, void* buffer, size_t size);
-
-//! \brief Wraps `write()`, retrying when interrupted or following a short
-//!     write.
-//!
-//! This function writes to \a fd, stopping only when \a size bytes have been
-//! written.
-//!
-//! \return The number of bytes written from \a buffer, or `-1` on error, with
-//!     `errno` set appropriately. On error, a portion of \a buffer may have
-//!     been written to \a fd.
-//!
-//! \sa ReadFD
-//! \sa LoggingWriteFD
-//! \sa CheckedWriteFD
-ssize_t WriteFD(int fd, const void* buffer, size_t size);
-
-//! \brief Wraps ReadFD(), ensuring that exactly \a size bytes are read.
-//!
-//! \return `true` on success. If \a size is out of the range of possible
-//!     `read()` return values, if the underlying ReadFD() fails, or if other
-//!     than \a size bytes were read, this function logs a message and returns
-//!     `false`.
-//!
-//! \sa LoggingWriteFD
-//! \sa ReadFD
-//! \sa CheckedReadFD
-//! \sa CheckedReadFDAtEOF
-bool LoggingReadFD(int fd, void* buffer, size_t size);
-
-//! \brief Wraps WriteFD(), ensuring that exactly \a size bytes are written.
-//!
-//! \return `true` on success. If \a size is out of the range of possible
-//!     `write()` return values, if the underlying WriteFD() fails, or if other
-//!     than \a size bytes were written, this function logs a message and
-//!     returns `false`.
-//!
-//! \sa LoggingReadFD
-//! \sa WriteFD
-//! \sa CheckedWriteFD
-bool LoggingWriteFD(int fd, const void* buffer, size_t size);
-
-//! \brief Wraps ReadFD(), ensuring that exactly \a size bytes are read.
-//!
-//! If \a size is out of the range of possible `read()` return values, if the
-//! underlying ReadFD() fails, or if other than \a size bytes were read, this
-//! function causes execution to terminate without returning.
-//!
-//! \sa CheckedWriteFD
-//! \sa ReadFD
-//! \sa LoggingReadFD
-//! \sa CheckedReadFDAtEOF
-void CheckedReadFD(int fd, void* buffer, size_t size);
-
-//! \brief Wraps WriteFD(), ensuring that exactly \a size bytes are written.
-//!
-//! If \a size is out of the range of possible `write()` return values, if the
-//! underlying WriteFD() fails, or if other than \a size bytes were written,
-//! this function causes execution to terminate without returning.
-//!
-//! \sa CheckedReadFD
-//! \sa WriteFD
-//! \sa LoggingWriteFD
-void CheckedWriteFD(int fd, const void* buffer, size_t size);
-
-//! \brief Wraps ReadFD(), ensuring that it indicates end-of-file.
-//!
-//! Attempts to read a single byte from \a fd, expecting no data to be read. If
-//! the underlying ReadFD() fails, or if a byte actually is read, this function
-//! causes execution to terminate without returning.
-//!
-//! \sa CheckedReadFD
-//! \sa ReadFD
-void CheckedReadFDAtEOF(int fd);
-
-//! \brief Wraps `close()`, logging an error if the operation fails.
-//!
-//! \return On success, `true` is returned. On failure, an error is logged and
-//!     `false` is returned.
-bool LoggingCloseFD(int fd);
-
-//! \brief Wraps `close()`, ensuring that it succeeds.
-//!
-//! If `close()` fails, this function causes execution to terminate without
-//! returning.
-void CheckedCloseFD(int fd);
-
-}  // namespace crashpad
-
-#endif  // CRASHPAD_UTIL_FILE_FD_IO_H_