SimpleCache: correct the time resolution of last modified field

Currently the last modified fields of an entry can end up having a time
resolution of seconds. This patch makes it microseconds all the time.

BUG=230306

Review URL: https://chromiumcodereview.appspot.com/16457002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@204631 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 63 insertions, 42 deletions

diff --git a/net/disk_cache/simple/simple_index_file.cc b/net/disk_cache/simple/simple_index_file.cc
index aa2979d..5316053 100644
--- a/net/disk_cache/simple/simple_index_file.cc
+++ b/net/disk_cache/simple/simple_index_file.cc
@@ -29,45 +29,6 @@ uint32 CalculatePickleCRC(const Pickle& pickle) {
                pickle.payload_size());
 }
 
-bool GetNanoSecsFromStat(const struct stat& st, long* 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;
-}
-
-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;
-  long sec;
-  long nsec;
-  if (GetNanoSecsFromStat(file_stat, &sec, &nsec)) {
-    int64 usec = (nsec / base::Time::kNanosecondsPerMicrosecond);
-    *out_mtime = base::Time::FromTimeT(implicit_cast<time_t>(sec))
-        + base::TimeDelta::FromMicroseconds(usec);
-    return true;
-  }
-#endif
-  base::PlatformFileInfo file_info;
-  if (!file_util::GetFileInfo(path, &file_info))
-    return false;
-  *out_mtime = file_info.last_modified;
-  return true;
-}
-
 void DoomEntrySetReply(scoped_ptr<int> result,
                        const base::Callback<void(int)>& reply_callback) {
   reply_callback.Run(*result.get());
@@ -194,9 +155,9 @@ void SimpleIndexFile::DoomEntrySet(
 bool SimpleIndexFile::IsIndexFileStale(const base::FilePath& index_filename) {
   base::Time index_mtime;
   base::Time dir_mtime;
-  if (!GetMTime(index_filename.DirName(), &dir_mtime))
+  if (!simple_util::GetMTime(index_filename.DirName(), &dir_mtime))
     return true;
-  if (!GetMTime(index_filename, &index_mtime))
+  if (!simple_util::GetMTime(index_filename, &index_mtime))
     return true;
   // Index file last_modified must be equal to the directory last_modified since
   // the last operation we do is ReplaceFile in the
diff --git a/net/disk_cache/simple/simple_synchronous_entry.cc b/net/disk_cache/simple/simple_synchronous_entry.cc
index 8db3d76..d359bed 100644
--- a/net/disk_cache/simple/simple_synchronous_entry.cc
+++ b/net/disk_cache/simple/simple_synchronous_entry.cc
@@ -431,12 +431,17 @@ bool SimpleSynchronousEntry::OpenOrCreateFiles(bool create) {
     for (int i = 0; i < kSimpleEntryFileCount; ++i) {
       PlatformFileInfo file_info;
       bool success = GetPlatformFileInfo(files_[i], &file_info);
+      base::Time file_last_modified;
       if (!success) {
         DLOG(WARNING) << "Could not get platform file info.";
         continue;
       }
       last_used_ = std::max(last_used_, file_info.last_accessed);
-      last_modified_ = std::max(last_modified_, file_info.last_modified);
+      if (simple_util::GetMTime(path_, &file_last_modified))
+        last_modified_ = std::max(last_modified_, file_last_modified);
+      else
+        last_modified_ = std::max(last_modified_, file_info.last_modified);
+
       data_size_[i] = GetDataSizeFromKeyAndFileSize(key_, file_info.size);
       if (data_size_[i] < 0) {
         // This entry can't possibly be valid, as it does not enough space to
diff --git a/net/disk_cache/simple/simple_util.cc b/net/disk_cache/simple/simple_util.cc
index 148a2c2..bb15881 100644
--- a/net/disk_cache/simple/simple_util.cc
+++ b/net/disk_cache/simple/simple_util.cc
@@ -6,11 +6,14 @@
 
 #include <limits>
 
+#include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/sha1.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/threading/thread_restrictions.h"
+#include "base/time.h"
 #include "net/disk_cache/simple/simple_entry_format.h"
 
 namespace {
@@ -18,6 +21,25 @@ 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 {
@@ -82,6 +104,30 @@ int64 GetFileOffsetFromKeyAndDataOffset(const std::string& key,
   return headers_size + data_offset;
 }
 
+// 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;
+  *out_mtime = file_info.last_modified;
+  return true;
+}
+
 }  // namespace simple_backend
 
 }  // namespace disk_cache
diff --git a/net/disk_cache/simple/simple_util.h b/net/disk_cache/simple/simple_util.h
index cb869f8..505501e 100644
--- a/net/disk_cache/simple/simple_util.h
+++ b/net/disk_cache/simple/simple_util.h
@@ -10,6 +10,11 @@
 #include "base/basictypes.h"
 #include "net/base/net_export.h"
 
+namespace base {
+class FilePath;
+class Time;
+}
+
 namespace disk_cache {
 
 namespace simple_util {
@@ -57,6 +62,10 @@ 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.
+NET_EXPORT_PRIVATE bool GetMTime(const base::FilePath& path,
+                                 base::Time* out_mtime);
 }  // namespace simple_backend
 
 }  // namespace disk_cache