Add favicon database histograms to UMA.

components/history/core/browser/thumbnail_database.cc

 // Copyright (c) 2012 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 "components/history/core/browser/thumbnail_database.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 595 matching lines @@
     if (status == sql::INIT_OK)
       return status;
 
     meta_table_.Reset();
     db_.Close();
   }
   return status;
 }
 
 void ThumbnailDatabase::ComputeDatabaseMetrics() {
-  sql::Statement favicon_count(
-      db_.GetCachedStatement(SQL_FROM_HERE, "SELECT COUNT(*) FROM favicons"));
-  UMA_HISTOGRAM_COUNTS_10000(
-      "History.NumFaviconsInDB",
-      favicon_count.Step() ? favicon_count.ColumnInt(0) : 0);
+  base::TimeTicks start_time = base::TimeTicks::Now();
+
+  // Calculate the size of the favicon database.
+  {
+    sql::Statement page_count(
+        db_.GetCachedStatement(SQL_FROM_HERE, "PRAGMA page_count"));
+    int64 page_count_bytes = page_count.Step() ? page_count.ColumnInt64(0) : 0;
+    sql::Statement page_size(
+        db_.GetCachedStatement(SQL_FROM_HERE, "PRAGMA page_size"));
+    int64 page_size_bytes = page_size.Step() ? page_size.ColumnInt64(0) : 0;
+    int size_mb = static_cast<int>(
+        (page_count_bytes * page_size_bytes) / (1024 * 1024));
+    UMA_HISTOGRAM_MEMORY_MB("History.FaviconDatabaseSizeMB", size_mb);
+  }
+
+  // Count all icon files referenced by the DB.
+  {
+    sql::Statement favicon_count(
+        db_.GetCachedStatement(SQL_FROM_HERE, "SELECT COUNT(*) FROM favicons"));
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumFaviconsInDB",
+        favicon_count.Step() ? favicon_count.ColumnInt(0) : 0);
+  }
+
+  // Count all bitmap resources cached in the DB.
+  {
+    sql::Statement bitmap_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE, "SELECT COUNT(*) FROM favicon_bitmaps"));
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumFaviconBitmapsInDB",
+        bitmap_count.Step() ? bitmap_count.ColumnInt(0) : 0);
+  }
+
+  // Count the subset of "large" icon files referenced by the DB. We define
+  // "large" icon files all types other than INVALID_ICON and FAVICON, for
+  // which we usually store only small (16x16 or 32x32) bitmaps by default.

[pkotwicz, 2015/03/27 15:45:25]

Can you rename the UMA metric to be "History.NumTouchIconsInDB". This is
representative of what the query does currently. If we end up adding a new icon
type, it would be probably useful to a new histogram to count the number of
icons of that type

[Roger McFarlane (Chromium), 2015/03/30 17:35:48]

Done.

+  {
+    sql::Statement large_favicon_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE,
+            "SELECT COUNT(*) FROM favicons WHERE icon_type not in (?, ?)"));
+    large_favicon_count.BindInt64(0, favicon_base::INVALID_ICON);
+    large_favicon_count.BindInt64(0, favicon_base::FAVICON);
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumLargeFaviconsInDB",
+        large_favicon_count.Step() ? large_favicon_count.ColumnInt(0) : 0);
+  }
+
+  // Count the subset of "large" bitmap resources cached in the DB.
+  {
+    sql::Statement large_bitmap_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE,
+            "SELECT COUNT(*) FROM favicon_bitmaps WHERE width >= 64"));
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumLargeFaviconBitmapsInDB",
+        large_bitmap_count.Step() ? large_bitmap_count.ColumnInt(0) : 0);
+  }
+
+  // Count all icon mappings maintained by the DB.
+  {
+    sql::Statement mapping_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE, "SELECT COUNT(*) FROM icon_mapping"));
+    UMA_HISTOGRAM_COUNTS_10000(

[pkotwicz, 2015/03/27 15:45:25]

I checked the "icon_mapping" table for the instance of Chrome that I run locally
and I have 16501 icon mappings (You should probably use
UMA_HISTOGRAM_CUSTOM_COUNTS)

[Roger McFarlane (Chromium), 2015/03/30 17:35:48]

Done.

+        "History.NumFaviconsMappingsInDB",

[pkotwicz, 2015/03/27 15:45:25]

Nit: History.NumFaviconsMappingsInDB -> History.NumFaviconMappingsInDB

[Roger McFarlane (Chromium), 2015/03/30 17:35:48]

Done.

+        mapping_count.Step() ? mapping_count.ColumnInt(0) : 0);
+  }
+
+  UMA_HISTOGRAM_TIMES("History.FaviconDatabaseAdvancedMetricsTime",
+                      base::TimeTicks::Now() - start_time);
 }
 
 void ThumbnailDatabase::BeginTransaction() {
   db_.BeginTransaction();
 }
 
 void ThumbnailDatabase::CommitTransaction() {
   db_.CommitTransaction();
 }
 
@@ skipping 667 matching lines @@
   meta_table_.SetVersionNumber(7);
   meta_table_.SetCompatibleVersionNumber(std::min(7, kCompatibleVersionNumber));
   return true;
 }
 
 bool ThumbnailDatabase::IsFaviconDBStructureIncorrect() {
   return !db_.IsSQLValid("SELECT id, url, icon_type FROM favicons");
 }
 
 }  // namespace history