ceph/src/fmt/src/posix.cc

   1 // A C++ interface to POSIX functions.
   2 //
   3 // Copyright (c) 2012 - 2016, Victor Zverovich
   4 // All rights reserved.
   5 //
   6 // For the license information refer to format.h.
   7
   8 // Disable bogus MSVC warnings.
   9 #if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
  10 #  define _CRT_SECURE_NO_WARNINGS
  11 #endif
  12
  13 #include "fmt/posix.h"
  14
  15 #include <limits.h>
  16 #include <sys/stat.h>
  17 #include <sys/types.h>
  18
  19 #ifndef _WIN32
  20 #  include <unistd.h>
  21 #else
  22 #  ifndef WIN32_LEAN_AND_MEAN
  23 #    define WIN32_LEAN_AND_MEAN
  24 #  endif
  25 #  include <io.h>
  26 #  include <windows.h>
  27
  28 #  define O_CREAT _O_CREAT
  29 #  define O_TRUNC _O_TRUNC
  30
  31 #  ifndef S_IRUSR
  32 #    define S_IRUSR _S_IREAD
  33 #  endif
  34
  35 #  ifndef S_IWUSR
  36 #    define S_IWUSR _S_IWRITE
  37 #  endif
  38
  39 #  ifdef __MINGW32__
  40 #    define _SH_DENYNO 0x40
  41 #  endif
  42
  43 #endif  // _WIN32
  44
  45 #ifdef fileno
  46 #  undef fileno
  47 #endif
  48
  49 namespace {
  50 #ifdef _WIN32
  51 // Return type of read and write functions.
  52 typedef int RWResult;
  53
  54 // On Windows the count argument to read and write is unsigned, so convert
  55 // it from size_t preventing integer overflow.
  56 inline unsigned convert_rwcount(std::size_t count) {
  57   return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
  58 }
  59 #else
  60 // Return type of read and write functions.
  61 typedef ssize_t RWResult;
  62
  63 inline std::size_t convert_rwcount(std::size_t count) { return count; }
  64 #endif
  65 }  // namespace
  66
  67 FMT_BEGIN_NAMESPACE
  68
  69 buffered_file::~buffered_file() FMT_NOEXCEPT {
  70   if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
  71     report_system_error(errno, "cannot close file");
  72 }
  73
  74 buffered_file::buffered_file(cstring_view filename, cstring_view mode) {
  75   FMT_RETRY_VAL(file_, FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())),
  76                 FMT_NULL);
  77   if (!file_)
  78     FMT_THROW(system_error(errno, "cannot open file {}", filename.c_str()));
  79 }
  80
  81 void buffered_file::close() {
  82   if (!file_) return;
  83   int result = FMT_SYSTEM(fclose(file_));
  84   file_ = FMT_NULL;
  85   if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
  86 }
  87
  88 // A macro used to prevent expansion of fileno on broken versions of MinGW.
  89 #define FMT_ARGS
  90
  91 int buffered_file::fileno() const {
  92   int fd = FMT_POSIX_CALL(fileno FMT_ARGS(file_));
  93   if (fd == -1) FMT_THROW(system_error(errno, "cannot get file descriptor"));
  94   return fd;
  95 }
  96
  97 file::file(cstring_view path, int oflag) {
  98   int mode = S_IRUSR | S_IWUSR;
  99 #if defined(_WIN32) && !defined(__MINGW32__)
 100   fd_ = -1;
 101   FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
 102 #else
 103   FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
 104 #endif
 105   if (fd_ == -1)
 106     FMT_THROW(system_error(errno, "cannot open file {}", path.c_str()));
 107 }
 108
 109 file::~file() FMT_NOEXCEPT {
 110   // Don't retry close in case of EINTR!
 111   // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
 112   if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
 113     report_system_error(errno, "cannot close file");
 114 }
 115
 116 void file::close() {
 117   if (fd_ == -1) return;
 118   // Don't retry close in case of EINTR!
 119   // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
 120   int result = FMT_POSIX_CALL(close(fd_));
 121   fd_ = -1;
 122   if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
 123 }
 124
 125 long long file::size() const {
 126 #ifdef _WIN32
 127   // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
 128   // is less than 0x0500 as is the case with some default MinGW builds.
 129   // Both functions support large file sizes.
 130   DWORD size_upper = 0;
 131   HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
 132   DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
 133   if (size_lower == INVALID_FILE_SIZE) {
 134     DWORD error = GetLastError();
 135     if (error != NO_ERROR)
 136       FMT_THROW(windows_error(GetLastError(), "cannot get file size"));
 137   }
 138   unsigned long long long_size = size_upper;
 139   return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
 140 #else
 141   typedef struct stat Stat;
 142   Stat file_stat = Stat();
 143   if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
 144     FMT_THROW(system_error(errno, "cannot get file attributes"));
 145   static_assert(sizeof(long long) >= sizeof(file_stat.st_size),
 146                 "return type of file::size is not large enough");
 147   return file_stat.st_size;
 148 #endif
 149 }
 150
 151 std::size_t file::read(void* buffer, std::size_t count) {
 152   RWResult result = 0;
 153   FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, convert_rwcount(count))));
 154   if (result < 0) FMT_THROW(system_error(errno, "cannot read from file"));
 155   return internal::to_unsigned(result);
 156 }
 157
 158 std::size_t file::write(const void* buffer, std::size_t count) {
 159   RWResult result = 0;
 160   FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, convert_rwcount(count))));
 161   if (result < 0) FMT_THROW(system_error(errno, "cannot write to file"));
 162   return internal::to_unsigned(result);
 163 }
 164
 165 file file::dup(int fd) {
 166   // Don't retry as dup doesn't return EINTR.
 167   // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
 168   int new_fd = FMT_POSIX_CALL(dup(fd));
 169   if (new_fd == -1)
 170     FMT_THROW(system_error(errno, "cannot duplicate file descriptor {}", fd));
 171   return file(new_fd);
 172 }
 173
 174 void file::dup2(int fd) {
 175   int result = 0;
 176   FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
 177   if (result == -1) {
 178     FMT_THROW(system_error(errno, "cannot duplicate file descriptor {} to {}",
 179                            fd_, fd));
 180   }
 181 }
 182
 183 void file::dup2(int fd, error_code& ec) FMT_NOEXCEPT {
 184   int result = 0;
 185   FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
 186   if (result == -1) ec = error_code(errno);
 187 }
 188
 189 void file::pipe(file& read_end, file& write_end) {
 190   // Close the descriptors first to make sure that assignments don't throw
 191   // and there are no leaks.
 192   read_end.close();
 193   write_end.close();
 194   int fds[2] = {};
 195 #ifdef _WIN32
 196   // Make the default pipe capacity same as on Linux 2.6.11+.
 197   enum { DEFAULT_CAPACITY = 65536 };
 198   int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
 199 #else
 200   // Don't retry as the pipe function doesn't return EINTR.
 201   // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
 202   int result = FMT_POSIX_CALL(pipe(fds));
 203 #endif
 204   if (result != 0) FMT_THROW(system_error(errno, "cannot create pipe"));
 205   // The following assignments don't throw because read_fd and write_fd
 206   // are closed.
 207   read_end = file(fds[0]);
 208   write_end = file(fds[1]);
 209 }
 210
 211 buffered_file file::fdopen(const char* mode) {
 212   // Don't retry as fdopen doesn't return EINTR.
 213   FILE* f = FMT_POSIX_CALL(fdopen(fd_, mode));
 214   if (!f)
 215     FMT_THROW(
 216         system_error(errno, "cannot associate stream with file descriptor"));
 217   buffered_file bf(f);
 218   fd_ = -1;
 219   return bf;
 220 }
 221
 222 long getpagesize() {
 223 #ifdef _WIN32
 224   SYSTEM_INFO si;
 225   GetSystemInfo(&si);
 226   return si.dwPageSize;
 227 #else
 228   long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
 229   if (size < 0) FMT_THROW(system_error(errno, "cannot get memory page size"));
 230   return size;
 231 #endif
 232 }
 233 FMT_END_NAMESPACE