Disk cache: Use TimeTicks instead of Time for some of the

cache histograms.

BUG=14193
TEST=none

Review URL: http://codereview.chromium.org/650068

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@39654 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 32 insertions, 26 deletions

diff --git a/net/disk_cache/backend_impl.cc b/net/disk_cache/backend_impl.cc
index f233172..194a74e 100644
--- a/net/disk_cache/backend_impl.cc
+++ b/net/disk_cache/backend_impl.cc
@@ -27,6 +27,7 @@
 
 using base::Time;
 using base::TimeDelta;
+using base::TimeTicks;
 
 namespace {
 
@@ -350,7 +351,7 @@ bool BackendImpl::OpenEntry(const std::string& key, Entry** entry) {
   if (disabled_)
     return false;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   uint32 hash = Hash(key);
 
   EntryImpl* cache_entry = MatchEntry(key, hash, false);
@@ -390,7 +391,7 @@ bool BackendImpl::CreateEntry(const std::string& key, Entry** entry) {
   DCHECK(entry);
   *entry = NULL;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   uint32 hash = Hash(key);
 
   scoped_refptr<EntryImpl> parent;
@@ -1160,7 +1161,7 @@ int BackendImpl::NewEntry(Addr address, EntryImpl** entry, bool* dirty) {
     return ERR_INVALID_ADDRESS;
   }
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   if (!cache_entry->entry()->Load())
     return ERR_READ_FAILURE;
 
diff --git a/net/disk_cache/block_files.cc b/net/disk_cache/block_files.cc
index fe02f67..3161317 100644
--- a/net/disk_cache/block_files.cc
+++ b/net/disk_cache/block_files.cc
@@ -12,6 +12,7 @@
 #include "net/disk_cache/file_lock.h"
 
 using base::Time;
+using base::TimeTicks;
 
 namespace {
 
@@ -41,7 +42,7 @@ bool CreateMapBlock(int target, int size, disk_cache::BlockFileHeader* header,
     return false;
   }
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   // We are going to process the map on 32-block chunks (32 bits), and on every
   // chunk, iterate through the 8 nibbles where the new block can be located.
   int current = header->hints[target - 1];
@@ -67,7 +68,7 @@ bool CreateMapBlock(int target, int size, disk_cache::BlockFileHeader* header,
       if (target != size) {
         header->empty[target - size - 1]++;
       }
-      HISTOGRAM_TIMES("DiskCache.CreateBlock", Time::Now() - start);
+      HISTOGRAM_TIMES("DiskCache.CreateBlock", TimeTicks::Now() - start);
       return true;
     }
   }
@@ -86,7 +87,7 @@ void DeleteMapBlock(int index, int size, disk_cache::BlockFileHeader* header) {
     NOTREACHED();
     return;
   }
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   int byte_index = index / 8;
   uint8* byte_map = reinterpret_cast<uint8*>(header->allocation_map);
   uint8 map_block = byte_map[byte_index];
@@ -115,7 +116,7 @@ void DeleteMapBlock(int index, int size, disk_cache::BlockFileHeader* header) {
   }
   header->num_entries--;
   DCHECK(header->num_entries >= 0);
-  HISTOGRAM_TIMES("DiskCache.DeleteBlock", Time::Now() - start);
+  HISTOGRAM_TIMES("DiskCache.DeleteBlock", TimeTicks::Now() - start);
 }
 
 // Restores the "empty counters" and allocation hints.
@@ -314,7 +315,7 @@ MappedFile* BlockFiles::FileForNewBlock(FileType block_type, int block_count) {
   MappedFile* file = block_files_[block_type - 1];
   BlockFileHeader* header = reinterpret_cast<BlockFileHeader*>(file->buffer());
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   while (NeedToGrowBlockFile(header, block_count)) {
     if (kMaxBlocks == header->max_entries) {
       file = NextFile(file);
@@ -328,7 +329,7 @@ MappedFile* BlockFiles::FileForNewBlock(FileType block_type, int block_count) {
       return NULL;
     break;
   }
-  HISTOGRAM_TIMES("DiskCache.GetFileForNewBlock", Time::Now() - start);
+  HISTOGRAM_TIMES("DiskCache.GetFileForNewBlock", TimeTicks::Now() - start);
   return file;
 }
 
diff --git a/net/disk_cache/entry_impl.cc b/net/disk_cache/entry_impl.cc
index e3fda2a..67fa32b 100644
--- a/net/disk_cache/entry_impl.cc
+++ b/net/disk_cache/entry_impl.cc
@@ -17,6 +17,7 @@
 
 using base::Time;
 using base::TimeDelta;
+using base::TimeTicks;
 
 namespace {
 
@@ -29,7 +30,8 @@ class SyncCallback: public disk_cache::FileIOCallback {
  public:
   SyncCallback(disk_cache::EntryImpl* entry, net::IOBuffer* buffer,
                net::CompletionCallback* callback )
-      : entry_(entry), callback_(callback), buf_(buffer), start_(Time::Now()) {
+      : entry_(entry), callback_(callback), buf_(buffer),
+        start_(TimeTicks::Now()) {
     entry->AddRef();
     entry->IncrementIoCount();
   }
@@ -41,7 +43,7 @@ class SyncCallback: public disk_cache::FileIOCallback {
   disk_cache::EntryImpl* entry_;
   net::CompletionCallback* callback_;
   scoped_refptr<net::IOBuffer> buf_;
-  Time start_;
+  TimeTicks start_;
 
   DISALLOW_EVIL_CONSTRUCTORS(SyncCallback);
 };
@@ -199,7 +201,7 @@ int EntryImpl::ReadData(int index, int offset, net::IOBuffer* buf, int buf_len,
   if (buf_len < 0)
     return net::ERR_INVALID_ARGUMENT;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
 
   if (offset + buf_len > entry_size)
     buf_len = entry_size - offset;
@@ -270,7 +272,7 @@ int EntryImpl::WriteData(int index, int offset, net::IOBuffer* buf, int buf_len,
     return net::ERR_FAILED;
   }
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
 
   // Read the size at this point (it may change inside prepare).
   int entry_size = entry_.Data()->data_size[index];
@@ -355,7 +357,7 @@ int EntryImpl::ReadSparseData(int64 offset, net::IOBuffer* buf, int buf_len,
   if (net::OK != result)
     return result;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   result = sparse_->StartIO(SparseControl::kReadOperation, offset, buf, buf_len,
                             completion_callback);
   ReportIOTime(kSparseRead, start);
@@ -369,7 +371,7 @@ int EntryImpl::WriteSparseData(int64 offset, net::IOBuffer* buf, int buf_len,
   if (net::OK != result)
     return result;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   result = sparse_->StartIO(SparseControl::kWriteOperation, offset, buf,
                             buf_len, completion_callback);
   ReportIOTime(kSparseWrite, start);
@@ -596,7 +598,7 @@ void EntryImpl::SetTimes(base::Time last_used, base::Time last_modified) {
   node_.set_modified();
 }
 
-void EntryImpl::ReportIOTime(Operation op, const base::Time& start) {
+void EntryImpl::ReportIOTime(Operation op, const base::TimeTicks& start) {
   int group = backend_->GetSizeGroup();
   switch (op) {
     case kRead:
diff --git a/net/disk_cache/entry_impl.h b/net/disk_cache/entry_impl.h
index 76e4965..1cc0b84 100644
--- a/net/disk_cache/entry_impl.h
+++ b/net/disk_cache/entry_impl.h
@@ -112,7 +112,7 @@ class EntryImpl : public Entry, public base::RefCounted<EntryImpl> {
   void SetTimes(base::Time last_used, base::Time last_modified);
 
   // Generates a histogram for the time spent working on this operation.
-  void ReportIOTime(Operation op, const base::Time& start);
+  void ReportIOTime(Operation op, const base::TimeTicks& start);
 
  private:
   enum {
diff --git a/net/disk_cache/eviction.cc b/net/disk_cache/eviction.cc
index fd5bd2e..0d92935 100644
--- a/net/disk_cache/eviction.cc
+++ b/net/disk_cache/eviction.cc
@@ -38,6 +38,7 @@
 #include "net/disk_cache/trace.h"
 
 using base::Time;
+using base::TimeTicks;
 
 namespace {
 
@@ -83,7 +84,7 @@ void Eviction::TrimCache(bool empty) {
 
   Trace("*** Trim Cache ***");
   trimming_ = true;
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   Rankings::ScopedRankingsBlock node(rankings_);
   Rankings::ScopedRankingsBlock next(rankings_,
       rankings_->GetPrev(node.get(), Rankings::NO_USE));
@@ -104,7 +105,7 @@ void Eviction::TrimCache(bool empty) {
       if (!empty) {
         backend_->OnEvent(Stats::TRIM_ENTRY);
 
-        if ((Time::Now() - start).InMilliseconds() > 20) {
+        if ((TimeTicks::Now() - start).InMilliseconds() > 20) {
           MessageLoop::current()->PostTask(FROM_HERE,
               factory_.NewRunnableMethod(&Eviction::TrimCache, false));
           break;
@@ -245,7 +246,7 @@ bool Eviction::EvictEntry(CacheRankingsBlock* node, bool empty) {
 void Eviction::TrimCacheV2(bool empty) {
   Trace("*** Trim Cache ***");
   trimming_ = true;
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
 
   const int kListsToSearch = 3;
   Rankings::ScopedRankingsBlock next[kListsToSearch];
@@ -296,7 +297,7 @@ void Eviction::TrimCacheV2(bool empty) {
         if (!EvictEntry(node.get(), empty))
           continue;
 
-        if (!empty && (Time::Now() - start).InMilliseconds() > 20) {
+        if (!empty && (TimeTicks::Now() - start).InMilliseconds() > 20) {
           MessageLoop::current()->PostTask(FROM_HERE,
               factory_.NewRunnableMethod(&Eviction::TrimCache, false));
           break;
@@ -415,7 +416,7 @@ void Eviction::TrimDeleted(bool empty) {
   if (backend_->disabled_)
     return;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   Rankings::ScopedRankingsBlock node(rankings_);
   Rankings::ScopedRankingsBlock next(rankings_,
     rankings_->GetPrev(node.get(), Rankings::DELETED));
diff --git a/net/disk_cache/histogram_macros.h b/net/disk_cache/histogram_macros.h
index 17cd345..27610f5 100644
--- a/net/disk_cache/histogram_macros.h
+++ b/net/disk_cache/histogram_macros.h
@@ -17,13 +17,13 @@
 
 // HISTOGRAM_AGE will collect time elapsed since |initial_time|, with a
 // granularity of hours and normal values of a few months.
-#define UMA_HISTOGRAM_AGE(name, initial_time)\
+#define UMA_HISTOGRAM_AGE(name, initial_time) \
     UMA_HISTOGRAM_COUNTS_10000(name, (Time::Now() - initial_time).InHours())
 
 // HISTOGRAM_AGE_MS will collect time elapsed since |initial_time|, with the
 // normal resolution of the UMA_HISTOGRAM_TIMES.
 #define UMA_HISTOGRAM_AGE_MS(name, initial_time)\
-    UMA_HISTOGRAM_TIMES(name, Time::Now() - initial_time)
+    UMA_HISTOGRAM_TIMES(name, TimeTicks::Now() - initial_time)
 
 #define UMA_HISTOGRAM_CACHE_ERROR(name, sample) \
     UMA_HISTOGRAM_ENUMERATION(name, sample, 50)
diff --git a/net/disk_cache/rankings.cc b/net/disk_cache/rankings.cc
index d2250df..34c002b 100644
--- a/net/disk_cache/rankings.cc
+++ b/net/disk_cache/rankings.cc
@@ -11,6 +11,7 @@
 #include "net/disk_cache/histogram_macros.h"
 
 using base::Time;
+using base::TimeTicks;
 
 // This is used by crash_cache.exe to generate unit test files.
 disk_cache::RankCrashes g_rankings_crash = disk_cache::NO_CRASH;
@@ -207,7 +208,7 @@ bool Rankings::GetRanking(CacheRankingsBlock* rankings) {
   if (!rankings->address().is_initialized())
     return false;
 
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   if (!rankings->Load())
     return false;
 
@@ -406,7 +407,7 @@ void Rankings::Remove(CacheRankingsBlock* node, List list) {
 // but the net effect is just an assert on debug when attempting to remove the
 // entry. Otherwise we'll need reentrant transactions, which is an overkill.
 void Rankings::UpdateRank(CacheRankingsBlock* node, bool modified, List list) {
-  Time start = Time::Now();
+  TimeTicks start = TimeTicks::Now();
   Remove(node, list);
   Insert(node, modified, list);
   CACHE_UMA(AGE_MS, "UpdateRank", 0, start);