Improve time resolution in PlatformFileInfo.

base/platform_file_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/platform_file.h"
 
 #include <fcntl.h>
 #include <errno.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ skipping 361 matching lines @@
   if (!info)
     return false;
 
   stat_wrapper_t file_info;
   if (CallFstat(file, &file_info))
     return false;
 
   info->is_directory = S_ISDIR(file_info.st_mode);
   info->is_symbolic_link = S_ISLNK(file_info.st_mode);
   info->size = file_info.st_size;
-  info->last_modified = base::Time::FromTimeT(file_info.st_mtime);
-  info->last_accessed = base::Time::FromTimeT(file_info.st_atime);
-  info->creation_time = base::Time::FromTimeT(file_info.st_ctime);
+
+#if defined(OS_LINUX)
+  const time_t last_modified_sec = file_info.st_mtim.tv_sec;
+  const int64 last_modified_nsec = file_info.st_mtim.tv_nsec;
+  const time_t last_accessed_sec = file_info.st_atim.tv_sec;
+  const int64 last_accessed_nsec = file_info.st_atim.tv_nsec;
+  const time_t creation_time_sec = file_info.st_ctim.tv_sec;
+  const int64 creation_time_nsec = file_info.st_ctim.tv_nsec;
+#elif defined(OS_ANDROID)
+  const time_t last_modified_sec = file_info.st_mtime;
+  const int64 last_modified_nsec = file_info.st_mtime_nsec;
+  const time_t last_accessed_sec = file_info.st_atime;
+  const int64 last_accessed_nsec = file_info.st_atime_nsec;
+  const time_t creation_time_sec = file_info.st_ctime;
+  const int64 creation_time_nsec = file_info.st_ctime_nsec;
+#elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
+  const time_t last_modified_sec = file_info.st_mtimespec.tv_sec;
+  const int64 last_modified_nsec = file_info.st_mtimespec.tv_nsec;
+  const time_t last_accessed_sec = file_info.st_atimespec.tv_sec;
+  const int64 last_accessed_nsec = file_info.st_atimespec.tv_nsec;
+  const time_t creation_time_sec = file_info.st_ctimespec.tv_sec;
+  const int64 creation_time_nsec = file_info.st_ctimespec.tv_nsec;
+#else
+  // TODO(gavinp): Investigate a good high resolution option for OS_NACL.
+  const time_t last_modified_sec = file_info.st_mtime;
+  const int64 last_modified_nsec = 0;
+  const time_t last_accessed_sec = file_info.st_atime;
+  const int64 last_accessed_nsec = 0;
+  const time_t creation_time_sec = file_info.st_ctime;
+  const int64 creation_time_nsec = 0;
+#endif
+
+  info->last_modified =
+      base::Time::FromTimeT(last_modified_sec) +
+      base::TimeDelta::FromMicroseconds(last_modified_nsec /
+                                        base::Time::kNanosecondsPerMicrosecond);
+  info->last_accessed =
+      base::Time::FromTimeT(last_accessed_sec) +
+      base::TimeDelta::FromMicroseconds(last_accessed_nsec /
+                                        base::Time::kNanosecondsPerMicrosecond);
+  info->creation_time =
+      base::Time::FromTimeT(creation_time_sec) +
+      base::TimeDelta::FromMicroseconds(creation_time_nsec /
+                                        base::Time::kNanosecondsPerMicrosecond);
   return true;
 }
 
 PlatformFileError ErrnoToPlatformFileError(int saved_errno) {
   switch (saved_errno) {
     case EACCES:
     case EISDIR:
     case EROFS:
     case EPERM:
       return PLATFORM_FILE_ERROR_ACCESS_DENIED;
@@ skipping 16 matching lines @@
     default:
 #if !defined(OS_NACL)  // NaCl build has no metrics code.
       UMA_HISTOGRAM_SPARSE_SLOWLY("PlatformFile.UnknownErrors.Posix",
                                   saved_errno);
 #endif
       return PLATFORM_FILE_ERROR_FAILED;
   }
 }
 
 }  // namespace base