[IndexedDB] Adding txn, value, and key size metrics

content/browser/indexed_db/indexed_db_transaction.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/indexed_db/indexed_db_transaction.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "content/browser/indexed_db/indexed_db_backing_store.h"
 #include "content/browser/indexed_db/indexed_db_cursor.h"
 #include "content/browser/indexed_db/indexed_db_database.h"
 #include "content/browser/indexed_db/indexed_db_database_callbacks.h"
 #include "content/browser/indexed_db/indexed_db_tracing.h"
 #include "content/browser/indexed_db/indexed_db_transaction_coordinator.h"
@@ skipping 313 matching lines @@
 
   DCHECK_EQ(state_, COMMITTING);
 
   state_ = FINISHED;
 
   leveldb::Status s;
   bool committed;
   if (!used_) {
     committed = true;
   } else {
+    const char* time_uma_name = nullptr;
+    const char* size_uma_name = nullptr;
+    switch (mode_) {
+      case blink::kWebIDBTransactionModeReadOnly:
+        time_uma_name = "WebCore.IndexedDB.Transaction.ReadOnly.TimeActive";
+        size_uma_name = "WebCore.IndexedDB.Transaction.ReadOnly.SizeOnCommit";
+        break;
+      case blink::kWebIDBTransactionModeReadWrite:
+        time_uma_name = "WebCore.IndexedDB.Transaction.ReadWrite.TimeActive";
+        size_uma_name = "WebCore.IndexedDB.Transaction.ReadWrite.SizeOnCommit";
+        break;
+      case blink::kWebIDBTransactionModeVersionChange:
+        time_uma_name =
+            "WebCore.IndexedDB.Transaction.VersionChange.TimeActive";
+        size_uma_name =
+            "WebCore.IndexedDB.Transaction.VersionChange.SizeOnCommit";
+        break;
+      default:
+        NOTREACHED();
+    }
+    UMA_HISTOGRAM_MEDIUM_TIMES(time_uma_name,

[Mark P, 2017/05/24 18:57:38]

I don't think these macros will work.  Have you tested this?  I need think you
need to use FactoryGet directly.
(time_uma_name can have different values at different times.  I think the
caching done in the macro will cause an emit to go to the wrong histogram.)

[dmurph, 2017/05/24 19:25:59]

Yep, fixed.

+                               base::Time::Now() - diagnostics_.start_time);
+    UMA_HISTOGRAM_MEMORY_KB(
+        size_uma_name,
+        transaction_->transaction()->GetTransactionSize() / 1024);
+
     s = transaction_->CommitPhaseTwo();
     committed = s.ok();
   }
 
   // Backing store resources (held via cursors) must be released
   // before script callbacks are fired, as the script callbacks may
   // release references and allow the backing store itself to be
   // released, and order is critical.
   CloseOpenCursors();
   transaction_->Reset();
@@ skipping 166 matching lines @@
 
 ::indexed_db::mojom::ObserverChangesPtr*
 IndexedDBTransaction::GetPendingChangesForConnection(int32_t connection_id) {
   auto it = connection_changes_map_.find(connection_id);
   if (it != connection_changes_map_.end())
     return &it->second;
   return nullptr;
 }
 
 }  // namespace content