boost/beast/core/impl/file_posix.ipp
// // Copyright (c) 2015-2016 Vinnie Falco (vinnie dot falco at gmail dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // // Official repository: https://github.com/boostorg/beast // #ifndef BOOST_BEAST_CORE_IMPL_FILE_POSIX_IPP #define BOOST_BEAST_CORE_IMPL_FILE_POSIX_IPP #if ! defined(BOOST_BEAST_NO_POSIX_FADVISE) # if defined(__APPLE__) || (defined(ANDROID) && (__ANDROID_API__ < 21)) # define BOOST_BEAST_NO_POSIX_FADVISE # endif #endif #if ! defined(BOOST_BEAST_USE_POSIX_FADVISE) # if ! defined(BOOST_BEAST_NO_POSIX_FADVISE) # define BOOST_BEAST_USE_POSIX_FADVISE 1 # else # define BOOST_BEAST_USE_POSIX_FADVISE 0 # endif #endif #include <limits> #include <fcntl.h> #include <sys/types.h> #include <sys/uio.h> #include <sys/stat.h> #include <unistd.h> #include <limits.h> namespace boost { namespace beast { namespace detail { inline int file_posix_close(int fd) { for(;;) { if(! ::close(fd)) break; int const ev = errno; if(errno != EINTR) return ev; } return 0; } } // detail inline file_posix:: ~file_posix() { if(fd_ != -1) detail::file_posix_close(fd_); } inline file_posix:: file_posix(file_posix&& other) : fd_(other.fd_) { other.fd_ = -1; } inline file_posix& file_posix:: operator=(file_posix&& other) { if(&other == this) return *this; if(fd_ != -1) detail::file_posix_close(fd_); fd_ = other.fd_; other.fd_ = -1; return *this; } inline void file_posix:: native_handle(native_handle_type fd) { if(fd_ != -1) detail::file_posix_close(fd_); fd_ = fd; } inline void file_posix:: close(error_code& ec) { if(fd_ != -1) { auto const ev = detail::file_posix_close(fd_); if(ev) ec.assign(ev, generic_category()); else ec.assign(0, ec.category()); fd_ = -1; } else { ec.assign(0, ec.category()); } } inline void file_posix:: open(char const* path, file_mode mode, error_code& ec) { if(fd_ != -1) { auto const ev = detail::file_posix_close(fd_); if(ev) ec.assign(ev, generic_category()); else ec.assign(0, ec.category()); fd_ = -1; } int f = 0; #if BOOST_BEAST_USE_POSIX_FADVISE int advise = 0; #endif switch(mode) { default: case file_mode::read: f = O_RDONLY; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_RANDOM; #endif break; case file_mode::scan: f = O_RDONLY; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_SEQUENTIAL; #endif break; case file_mode::write: f = O_RDWR | O_CREAT | O_TRUNC; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_RANDOM; #endif break; case file_mode::write_new: f = O_RDWR | O_CREAT | O_EXCL; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_RANDOM; #endif break; case file_mode::write_existing: f = O_RDWR | O_EXCL; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_RANDOM; #endif break; case file_mode::append: f = O_RDWR | O_CREAT | O_TRUNC; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_SEQUENTIAL; #endif break; case file_mode::append_new: f = O_RDWR | O_CREAT | O_EXCL; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_SEQUENTIAL; #endif break; case file_mode::append_existing: f = O_RDWR | O_EXCL; #if BOOST_BEAST_USE_POSIX_FADVISE advise = POSIX_FADV_SEQUENTIAL; #endif break; } for(;;) { fd_ = ::open(path, f, 0644); if(fd_ != -1) break; auto const ev = errno; if(ev != EINTR) { ec.assign(ev, generic_category()); return; } } #if BOOST_BEAST_USE_POSIX_FADVISE if(::posix_fadvise(fd_, 0, 0, advise)) { auto const ev = errno; detail::file_posix_close(fd_); fd_ = -1; ec.assign(ev, generic_category()); return; } #endif ec.assign(0, ec.category()); } inline std::uint64_t file_posix:: size(error_code& ec) const { if(fd_ == -1) { ec = make_error_code(errc::invalid_argument); return 0; } struct stat st; if(::fstat(fd_, &st) != 0) { ec.assign(errno, generic_category()); return 0; } ec.assign(0, ec.category()); return st.st_size; } inline std::uint64_t file_posix:: pos(error_code& ec) const { if(fd_ == -1) { ec = make_error_code(errc::invalid_argument); return 0; } auto const result = ::lseek(fd_, 0, SEEK_CUR); if(result == (off_t)-1) { ec.assign(errno, generic_category()); return 0; } ec.assign(0, ec.category()); return result; } inline void file_posix:: seek(std::uint64_t offset, error_code& ec) { if(fd_ == -1) { ec = make_error_code(errc::invalid_argument); return; } auto const result = ::lseek(fd_, offset, SEEK_SET); if(result == static_cast<off_t>(-1)) { ec.assign(errno, generic_category()); return; } ec.assign(0, ec.category()); } inline std::size_t file_posix:: read(void* buffer, std::size_t n, error_code& ec) const { if(fd_ == -1) { ec = make_error_code(errc::invalid_argument); return 0; } std::size_t nread = 0; while(n > 0) { auto const amount = static_cast<ssize_t>((std::min)( n, static_cast<std::size_t>(SSIZE_MAX))); auto const result = ::read(fd_, buffer, amount); if(result == -1) { auto const ev = errno; if(ev == EINTR) continue; ec.assign(ev, generic_category()); return nread; } if(result == 0) { // short read return nread; } n -= result; nread += result; buffer = reinterpret_cast<char*>(buffer) + result; } return nread; } inline std::size_t file_posix:: write(void const* buffer, std::size_t n, error_code& ec) { if(fd_ == -1) { ec = make_error_code(errc::invalid_argument); return 0; } std::size_t nwritten = 0; while(n > 0) { auto const amount = static_cast<ssize_t>((std::min)( n, static_cast<std::size_t>(SSIZE_MAX))); auto const result = ::write(fd_, buffer, amount); if(result == -1) { auto const ev = errno; if(ev == EINTR) continue; ec.assign(ev, generic_category()); return nwritten; } n -= result; nwritten += result; buffer = reinterpret_cast<char const*>(buffer) + result; } return nwritten; } } // beast } // boost #endif