Simple Cache: Add two optional stream 2 histograms

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
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=225571

[Deprecated (see juliatuttle), 2013-09-23 23:22:24]

PTAL, gavinp and pasko (everything) and isherman (histograms.xml).

[Ilya Sherman, 2013-09-24 00:16:35]

histograms.xml lgtm.

Btw, it looks like there are *a lot* of Simple Cache histograms around.  That's
perfectly fine if they are still relevant and useful; but if any are obsolete,
it would be helpful to go through and deprecate them when you have a chance. 
Thanks :)

[gavinp, 2013-09-24 21:15:42]

lgtm with or without nits.

https://codereview.chromium.org/24400004/diff/1/net/disk_cache/simple/simple_...
File net/disk_cache/simple/simple_synchronous_entry.h (right):

https://codereview.chromium.org/24400004/diff/1/net/disk_cache/simple/simple_...
net/disk_cache/simple/simple_synchronous_entry.h:254: // True if the entry was
created, or false if it was opened.  (Used to log
Nit: no need for the parens, and only one space after a period please.

[Deprecated (see juliatuttle), 2013-09-24 23:28:53]

https://chromiumcodereview.appspot.com/24400004/diff/1/net/disk_cache/simple/...
File net/disk_cache/simple/simple_synchronous_entry.h (right):

https://chromiumcodereview.appspot.com/24400004/diff/1/net/disk_cache/simple/...
net/disk_cache/simple/simple_synchronous_entry.h:254: // True if the entry was
created, or false if it was opened.  (Used to log
On 2013/09/24 21:15:42, gavinp wrote:
> Nit: no need for the parens, and only one space after a period please.

Done.  Everywhere in net/disk_cache/simple.

[commit-bot: I haz the power, 2013-09-25 16:07:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ttuttle@chromium.org/24400004/7001

[commit-bot: I haz the power, 2013-09-25 17:29:47]

Retried try job too often on linux_rel for step(s) unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2013-09-25 19:36:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ttuttle@chromium.org/24400004/7001

[commit-bot: I haz the power, 2013-09-25 21:44:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ttuttle@chromium.org/24400004/7001

[commit-bot: I haz the power, 2013-09-26 09:20:30]

Failed to apply patch for net/disk_cache/simple/simple_synchronous_entry.cc:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file net/disk_cache/simple/simple_synchronous_entry.cc
  Hunk #4 FAILED at 764.
  Hunk #5 FAILED at 772.
  2 out of 5 hunks FAILED -- saving rejects to file
net/disk_cache/simple/simple_synchronous_entry.cc.rej

Patch:       net/disk_cache/simple/simple_synchronous_entry.cc
Index: net/disk_cache/simple/simple_synchronous_entry.cc
diff --git a/net/disk_cache/simple/simple_synchronous_entry.cc
b/net/disk_cache/simple/simple_synchronous_entry.cc
index
38e8a3cae995175df0a71e7c34d4ce6190fc8cab..7b4d1a9dd83ec64b0891d49cef61018441b64f78
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 third_stream_file_index = GetFileIndexFromStreamIndex(2);
   DCHECK(CanOmitEmptyFile(third_stream_file_index));
   if (!empty_file_omitted_[third_stream_file_index] &&
@@ -762,8 +773,12 @@ int SimpleSynchronousEntry::InitializeForOpen(
     CloseFile(third_stream_file_index);
     DeleteFileForEntryHash(path_, entry_hash_, third_stream_file_index);
     empty_file_omitted_[third_stream_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;

[commit-bot: I haz the power, 2013-09-26 18:28:04]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ttuttle@chromium.org/24400004/42001

[commit-bot: I haz the power, 2013-09-26 21:25:21]

Change committed as 225571