Simple Cache: Add two optional stream 2 histograms

Add two histograms to see how often we remove old empty stream 2 files
and how often we omit new empty stream 2 files.

BUG=280592

Review URL: https://codereview.chromium.org/24400004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225571 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 35 insertions, 16 deletions

diff --git a/net/disk_cache/simple/simple_entry_impl.cc b/net/disk_cache/simple/simple_entry_impl.cc
index 3d2bc22..be7788b 100644
--- a/net/disk_cache/simple/simple_entry_impl.cc
+++ b/net/disk_cache/simple/simple_entry_impl.cc
@@ -1296,8 +1296,8 @@ int SimpleEntryImpl::SetStream0Data(net::IOBuffer* buf,
                                     int buf_len,
                                     bool truncate) {
   // Currently, stream 0 is only used for HTTP headers, and always writes them
-  // with a single, truncating write.  Detect these writes and record the size
-  // changes of the headers.  Also, support writes to stream 0 that have
+  // with a single, truncating write. Detect these writes and record the size
+  // changes of the headers. Also, support writes to stream 0 that have
   // different access patterns, as required by the API contract.
   // All other clients of the Simple Cache are encouraged to use stream 1.
   have_written_[0] = true;
diff --git a/net/disk_cache/simple/simple_index_file.h b/net/disk_cache/simple/simple_index_file.h
index ce19e2b..7562941 100644
--- a/net/disk_cache/simple/simple_index_file.h
+++ b/net/disk_cache/simple/simple_index_file.h
@@ -40,15 +40,15 @@ struct NET_EXPORT_PRIVATE SimpleIndexLoadResult {
 };
 
 // Simple Index File format is a pickle serialized data of IndexMetadata and
-// EntryMetadata objects.  The file format is as follows: one instance of
+// EntryMetadata objects. The file format is as follows: one instance of
 // serialized |IndexMetadata| followed serialized |EntryMetadata| entries
-// repeated |number_of_entries| amount of times.  To know more about the format,
+// repeated |number_of_entries| amount of times. To know more about the format,
 // see SimpleIndexFile::Serialize() and SeeSimpleIndexFile::LoadFromDisk()
 // methods.
 //
-// The non-static methods must run on the IO thread.  All the real
+// The non-static methods must run on the IO thread. All the real
 // work is done in the static methods, which are run on the cache thread
-// or in worker threads.  Synchronization between methods is the
+// or in worker threads. Synchronization between methods is the
 // responsibility of the caller.
 class NET_EXPORT_PRIVATE SimpleIndexFile {
  public:
diff --git a/net/disk_cache/simple/simple_index_unittest.cc b/net/disk_cache/simple/simple_index_unittest.cc
index 47ae24f..cee7bf3 100644
--- a/net/disk_cache/simple/simple_index_unittest.cc
+++ b/net/disk_cache/simple/simple_index_unittest.cc
@@ -538,7 +538,7 @@ TEST_F(SimpleIndexTest, BasicEviction) {
 
   // Trigger an eviction, and make sure the right things are tossed.
   // TODO(rdsmith): This is dependent on the innards of the implementation
-  // as to at exactly what point we trigger eviction.  Not sure how to fix
+  // as to at exactly what point we trigger eviction. Not sure how to fix
   // that.
   index()->UpdateEntrySize(hashes_.at<3>(), 475);
   EXPECT_EQ(1, doom_entries_calls());
diff --git a/net/disk_cache/simple/simple_net_log_parameters.h b/net/disk_cache/simple/simple_net_log_parameters.h
index b6f386f..41ea9a2 100644
--- a/net/disk_cache/simple/simple_net_log_parameters.h
+++ b/net/disk_cache/simple/simple_net_log_parameters.h
@@ -14,14 +14,14 @@ namespace disk_cache {
 class SimpleEntryImpl;
 
 // Creates a NetLog callback that returns parameters for the construction of a
-// SimpleEntryImpl.  Contains the entry's hash.  |entry| can't be NULL and must
+// SimpleEntryImpl. Contains the entry's hash. |entry| can't be NULL and must
 // outlive the returned callback.
 net::NetLog::ParametersCallback CreateNetLogSimpleEntryConstructionCallback(
     const SimpleEntryImpl* entry);
 
 // Creates a NetLog callback that returns parameters for the result of calling
-// |CreateEntry| or |OpenEntry| on a SimpleEntryImpl.  Contains the |net_error|
-// and, if successful, the entry's key.  |entry| can't be NULL and must outlive
+// |CreateEntry| or |OpenEntry| on a SimpleEntryImpl. Contains the |net_error|
+// and, if successful, the entry's key. |entry| can't be NULL and must outlive
 // the returned callback.
 net::NetLog::ParametersCallback CreateNetLogSimpleEntryCreationCallback(
     const SimpleEntryImpl* entry,
diff --git a/net/disk_cache/simple/simple_synchronous_entry.cc b/net/disk_cache/simple/simple_synchronous_entry.cc
index 13fd531..659d1c1 100644
--- a/net/disk_cache/simple/simple_synchronous_entry.cc
+++ b/net/disk_cache/simple/simple_synchronous_entry.cc
@@ -482,6 +482,12 @@ void SimpleSynchronousEntry::Close(
                      cluster_loss * 100 / (cluster_loss + file_size));
   }
 
+  if (files_created_) {
+    const int stream2_file_index = GetFileIndexFromStreamIndex(2);
+    SIMPLE_CACHE_UMA(BOOLEAN, "EntryCreatedAndStream2Omitted", cache_type_,
+                     empty_file_omitted_[stream2_file_index]);
+  }
+
   RecordCloseResult(cache_type_, CLOSE_RESULT_SUCCESS);
   have_open_files_ = false;
   delete this;
@@ -622,6 +628,8 @@ bool SimpleSynchronousEntry::OpenFiles(
                    "SyncOpenEntryAge", cache_type_,
                    entry_age.InHours(), 1, 1000, 50);
 
+  files_created_ = false;
+
   return true;
 }
 
@@ -661,6 +669,8 @@ bool SimpleSynchronousEntry::CreateFiles(
   for (int i = 0; i < kSimpleEntryStreamCount; ++i)
       out_entry_stat->set_data_size(i, 0);
 
+  files_created_ = true;
+
   return true;
 }
 
@@ -754,6 +764,7 @@ int SimpleSynchronousEntry::InitializeForOpen(
     }
   }
 
+  bool removed_stream2 = false;
   const int stream2_file_index = GetFileIndexFromStreamIndex(2);
   DCHECK(CanOmitEmptyFile(stream2_file_index));
   if (!empty_file_omitted_[stream2_file_index] &&
@@ -762,8 +773,12 @@ int SimpleSynchronousEntry::InitializeForOpen(
     CloseFile(stream2_file_index);
     DeleteFileForEntryHash(path_, entry_hash_, stream2_file_index);
     empty_file_omitted_[stream2_file_index] = true;
+    removed_stream2 = true;
   }
 
+  SIMPLE_CACHE_UMA(BOOLEAN, "EntryOpenedAndStream2Removed", cache_type_,
+                   removed_stream2);
+
   RecordSyncOpenResult(cache_type_, OPEN_ENTRY_SUCCESS, had_index);
   initialized_ = true;
   return net::OK;
diff --git a/net/disk_cache/simple/simple_synchronous_entry.h b/net/disk_cache/simple/simple_synchronous_entry.h
index 470e8e2..74823a2 100644
--- a/net/disk_cache/simple/simple_synchronous_entry.h
+++ b/net/disk_cache/simple/simple_synchronous_entry.h
@@ -175,12 +175,12 @@ class SimpleSynchronousEntry {
   // called.
   ~SimpleSynchronousEntry();
 
-  // Tries to open one of the cache entry files.  Succeeds if the open succeeds
+  // Tries to open one of the cache entry files. Succeeds if the open succeeds
   // or if the file was not found and is allowed to be omitted if the
   // corresponding stream is empty.
   bool MaybeOpenFile(int file_index,
                      base::PlatformFileError* out_error);
-  // Creates one of the cache entry files if necessary.  If the file is allowed
+  // Creates one of the cache entry files if necessary. If the file is allowed
   // to be omitted if the corresponding stream is empty, and if |file_required|
   // is FILE_NOT_REQUIRED, then the file is not created; otherwise, it is.
   bool MaybeCreateFile(int file_index,
@@ -193,7 +193,7 @@ class SimpleSynchronousEntry {
   void CloseFile(int index);
   void CloseFiles();
 
-  // Returns a net error, i.e. net::OK on success.  |had_index| is passed
+  // Returns a net error, i.e. net::OK on success. |had_index| is passed
   // from the main entry for metrics purposes, and is true if the index was
   // initialized when the open operation began.
   int InitializeForOpen(bool had_index,
@@ -201,13 +201,13 @@ class SimpleSynchronousEntry {
                         scoped_refptr<net::GrowableIOBuffer>* stream_0_data,
                         uint32* out_stream_0_crc32);
 
-  // Writes the header and key to a newly-created stream file.  |index| is the
-  // index of the stream.  Returns true on success; returns false and sets
+  // Writes the header and key to a newly-created stream file. |index| is the
+  // index of the stream. Returns true on success; returns false and sets
   // |*out_result| on failure.
   bool InitializeCreatedFile(int index, CreateEntryResult* out_result);
 
   // Returns a net error, including net::OK on success and net::FILE_EXISTS
-  // when the entry already exists.  |had_index| is passed from the main entry
+  // when the entry already exists. |had_index| is passed from the main entry
   // for metrics purposes, and is true if the index was initialized when the
   // create operation began.
   int InitializeForCreate(bool had_index, SimpleEntryStat* out_entry_stat);
@@ -250,6 +250,10 @@ class SimpleSynchronousEntry {
   // True if the corresponding stream is empty and therefore no on-disk file
   // was created to store it.
   bool empty_file_omitted_[kSimpleEntryFileCount];
+
+  // True if the entry was created, or false if it was opened. Used to log
+  // SimpleCache.*.EntryCreatedWithStream2Omitted only for created entries.
+  bool files_created_;
 };
 
 }  // namespace disk_cache