1/*
2 A C++ interface to POSIX functions.
3
4 Copyright (c) 2012 - 2016, Victor Zverovich
5 All rights reserved.
6
7 For the license information refer to format.h.
8 */
9
10// Disable bogus MSVC warnings.
11#ifndef _CRT_SECURE_NO_WARNINGS
12# define _CRT_SECURE_NO_WARNINGS
13#endif
14
15#include "posix.h"
16
17#include <limits.h>
18#include <sys/types.h>
19#include <sys/stat.h>
20
21#ifndef _WIN32
22# include <unistd.h>
23#else
24# include <windows.h>
25# include <io.h>
26
27# define O_CREAT _O_CREAT
28# define O_TRUNC _O_TRUNC
29
30# ifndef S_IRUSR
31#  define S_IRUSR _S_IREAD
32# endif
33
34# ifndef S_IWUSR
35#  define S_IWUSR _S_IWRITE
36# endif
37
38# ifdef __MINGW32__
39#  define _SH_DENYNO 0x40
40# endif
41
42#endif  // _WIN32
43
44#ifdef fileno
45# undef fileno
46#endif
47
48namespace {
49#ifdef _WIN32
50// Return type of read and write functions.
51typedef int RWResult;
52
53// On Windows the count argument to read and write is unsigned, so convert
54// it from size_t preventing integer overflow.
55inline unsigned convert_rwcount(std::size_t count) {
56  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
57}
58#else
59// Return type of read and write functions.
60typedef ssize_t RWResult;
61
62inline std::size_t convert_rwcount(std::size_t count) { return count; }
63#endif
64}
65
66fmt::BufferedFile::~BufferedFile() FMT_NOEXCEPT {
67  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
68    fmt::report_system_error(errno, "cannot close file");
69}
70
71fmt::BufferedFile::BufferedFile(
72    fmt::CStringRef filename, fmt::CStringRef mode) {
73  FMT_RETRY_VAL(file_, FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())), 0);
74  if (!file_)
75    FMT_THROW(SystemError(errno, "cannot open file {}", filename));
76}
77
78void fmt::BufferedFile::close() {
79  if (!file_)
80    return;
81  int result = FMT_SYSTEM(fclose(file_));
82  file_ = FMT_NULL;
83  if (result != 0)
84    FMT_THROW(SystemError(errno, "cannot close file"));
85}
86
87// A macro used to prevent expansion of fileno on broken versions of MinGW.
88#define FMT_ARGS
89
90int fmt::BufferedFile::fileno() const {
91  int fd = FMT_POSIX_CALL(fileno FMT_ARGS(file_));
92  if (fd == -1)
93    FMT_THROW(SystemError(errno, "cannot get file descriptor"));
94  return fd;
95}
96
97fmt::File::File(fmt::CStringRef 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(SystemError(errno, "cannot open file {}", path));
107}
108
109fmt::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    fmt::report_system_error(errno, "cannot close file");
114}
115
116void fmt::File::close() {
117  if (fd_ == -1)
118    return;
119  // Don't retry close in case of EINTR!
120  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
121  int result = FMT_POSIX_CALL(close(fd_));
122  fd_ = -1;
123  if (result != 0)
124    FMT_THROW(SystemError(errno, "cannot close file"));
125}
126
127fmt::LongLong fmt::File::size() const {
128#ifdef _WIN32
129  // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
130  // is less than 0x0500 as is the case with some default MinGW builds.
131  // Both functions support large file sizes.
132  DWORD size_upper = 0;
133  HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
134  DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
135  if (size_lower == INVALID_FILE_SIZE) {
136    DWORD error = GetLastError();
137    if (error != NO_ERROR)
138      FMT_THROW(WindowsError(GetLastError(), "cannot get file size"));
139  }
140  fmt::ULongLong long_size = size_upper;
141  return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
142#else
143  typedef struct stat Stat;
144  Stat file_stat = Stat();
145  if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
146    FMT_THROW(SystemError(errno, "cannot get file attributes"));
147  FMT_STATIC_ASSERT(sizeof(fmt::LongLong) >= sizeof(file_stat.st_size),
148      "return type of File::size is not large enough");
149  return file_stat.st_size;
150#endif
151}
152
153std::size_t fmt::File::read(void *buffer, std::size_t count) {
154  RWResult result = 0;
155  FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, convert_rwcount(count))));
156  if (result < 0)
157    FMT_THROW(SystemError(errno, "cannot read from file"));
158  return internal::to_unsigned(result);
159}
160
161std::size_t fmt::File::write(const void *buffer, std::size_t count) {
162  RWResult result = 0;
163  FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, convert_rwcount(count))));
164  if (result < 0)
165    FMT_THROW(SystemError(errno, "cannot write to file"));
166  return internal::to_unsigned(result);
167}
168
169fmt::File fmt::File::dup(int fd) {
170  // Don't retry as dup doesn't return EINTR.
171  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
172  int new_fd = FMT_POSIX_CALL(dup(fd));
173  if (new_fd == -1)
174    FMT_THROW(SystemError(errno, "cannot duplicate file descriptor {}", fd));
175  return File(new_fd);
176}
177
178void fmt::File::dup2(int fd) {
179  int result = 0;
180  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
181  if (result == -1) {
182    FMT_THROW(SystemError(errno,
183      "cannot duplicate file descriptor {} to {}", fd_, fd));
184  }
185}
186
187void fmt::File::dup2(int fd, ErrorCode &ec) FMT_NOEXCEPT {
188  int result = 0;
189  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
190  if (result == -1)
191    ec = ErrorCode(errno);
192}
193
194void fmt::File::pipe(File &read_end, File &write_end) {
195  // Close the descriptors first to make sure that assignments don't throw
196  // and there are no leaks.
197  read_end.close();
198  write_end.close();
199  int fds[2] = {};
200#ifdef _WIN32
201  // Make the default pipe capacity same as on Linux 2.6.11+.
202  enum { DEFAULT_CAPACITY = 65536 };
203  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
204#else
205  // Don't retry as the pipe function doesn't return EINTR.
206  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
207  int result = FMT_POSIX_CALL(pipe(fds));
208#endif
209  if (result != 0)
210    FMT_THROW(SystemError(errno, "cannot create pipe"));
211  // The following assignments don't throw because read_fd and write_fd
212  // are closed.
213  read_end = File(fds[0]);
214  write_end = File(fds[1]);
215}
216
217fmt::BufferedFile fmt::File::fdopen(const char *mode) {
218  // Don't retry as fdopen doesn't return EINTR.
219  FILE *f = FMT_POSIX_CALL(fdopen(fd_, mode));
220  if (!f)
221    FMT_THROW(SystemError(errno, "cannot associate stream with file descriptor"));
222  BufferedFile file(f);
223  fd_ = -1;
224  return file;
225}
226
227long fmt::getpagesize() {
228#ifdef _WIN32
229  SYSTEM_INFO si;
230  GetSystemInfo(&si);
231  return si.dwPageSize;
232#else
233  long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
234  if (size < 0)
235    FMT_THROW(SystemError(errno, "cannot get memory page size"));
236  return size;
237#endif
238}
239