Improve time resolution in PlatformFileInfo.

The Simple Cache uses directory and file mtimes at high granularity to
determine index freshness. As well, for linux process creation times,
a high resolution ctime from /proc is useful; so high resolution ctime
makes process creation times accurate.

R=darin

Review URL: https://chromiumcodereview.appspot.com/22582009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@216478 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 2 insertions, 35 deletions

diff --git a/net/disk_cache/simple/simple_util.cc b/net/disk_cache/simple/simple_util.cc
index 40d3894..72a4612 100644
--- a/net/disk_cache/simple/simple_util.cc
+++ b/net/disk_cache/simple/simple_util.cc
@@ -21,25 +21,6 @@ namespace {
 // Size of the uint64 hash_key number in Hex format in a string.
 const size_t kEntryHashKeyAsHexStringSize = 2 * sizeof(uint64);
 
-// TODO(clamy, gavinp): this should go in base
-bool GetNanoSecsFromStat(const struct stat& st,
-                         time_t* out_sec,
-                         long* out_nsec) {
-#if defined(OS_ANDROID)
-  *out_sec = st.st_mtime;
-  *out_nsec = st.st_mtime_nsec;
-#elif defined(OS_LINUX)
-  *out_sec = st.st_mtim.tv_sec;
-  *out_nsec = st.st_mtim.tv_nsec;
-#elif defined(OS_MACOSX) || defined(OS_IOS) || defined(OS_BSD)
-  *out_sec = st.st_mtimespec.tv_sec;
-  *out_nsec = st.st_mtimespec.tv_nsec;
-#else
-  return false;
-#endif
-  return true;
-}
-
 }  // namespace
 
 namespace disk_cache {
@@ -107,20 +88,6 @@ int64 GetFileOffsetFromKeyAndDataOffset(const std::string& key,
 // TODO(clamy, gavinp): this should go in base
 bool GetMTime(const base::FilePath& path, base::Time* out_mtime) {
   DCHECK(out_mtime);
-#if defined(OS_POSIX)
-  base::ThreadRestrictions::AssertIOAllowed();
-  struct stat file_stat;
-  if (stat(path.value().c_str(), &file_stat) != 0)
-    return false;
-  time_t sec;
-  long nsec;
-  if (GetNanoSecsFromStat(file_stat, &sec, &nsec)) {
-    int64 usec = (nsec / base::Time::kNanosecondsPerMicrosecond);
-    *out_mtime = base::Time::FromTimeT(sec)
-        + base::TimeDelta::FromMicroseconds(usec);
-    return true;
-  }
-#endif
   base::PlatformFileInfo file_info;
   if (!file_util::GetFileInfo(path, &file_info))
     return false;
diff --git a/net/disk_cache/simple/simple_util.h b/net/disk_cache/simple/simple_util.h
index 505501e..2e92b4a 100644
--- a/net/disk_cache/simple/simple_util.h
+++ b/net/disk_cache/simple/simple_util.h
@@ -62,8 +62,8 @@ NET_EXPORT_PRIVATE int64 GetFileOffsetFromKeyAndDataOffset(
     const std::string& key,
     int data_offset);
 
-// Fills |out_time| with the time the file last modified time. Unlike the
-// functions in platform_file.h, the time resolution is milliseconds.
+// Fills |out_time| with the time the file last modified time.
+// TODO(gavinp): Remove this function.
 NET_EXPORT_PRIVATE bool GetMTime(const base::FilePath& path,
                                  base::Time* out_mtime);
 }  // namespace simple_backend