ResourcePrefetchPredictor: Storing last_visit time instead of looking it up at

startup to avoid startup latency.

BUG=149743

Review URL: https://chromiumcodereview.appspot.com/11275015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@164761 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 36 insertions, 23 deletions

diff --git a/chrome/browser/predictors/resource_prefetch_predictor_tables.h b/chrome/browser/predictors/resource_prefetch_predictor_tables.h
index 51ddf11..7d6f8e0 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor_tables.h
+++ b/chrome/browser/predictors/resource_prefetch_predictor_tables.h
@@ -10,6 +10,7 @@
 #include <string>
 #include <vector>
 
+#include "base/time.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/glue/resource_type.h"
 
@@ -18,23 +19,24 @@ namespace predictors {
 // Interface for database tables used by the ResourcePrefetchPredictor.
 // All methods except the constructor and destructor need to be called on the DB
 // thread.
-// NOTE: This class is named in plural as it will hold other tables shortly.
 //
-// TODO(shishir): Move to composition model instead of implemented inheritance.
+// Currently manages two tables:
+//  - UrlResourceTable - Keeps track of resources per Urls.
+//  - UrlMetadataTable - Keeps misc data for Urls (like last visit time).
 class ResourcePrefetchPredictorTables : public PredictorTableBase {
  public:
-  struct UrlTableRow {
-    UrlTableRow();
-    UrlTableRow(const UrlTableRow& other);
-    UrlTableRow(const std::string& main_frame_url,
-                const std::string& resource_url,
-                ResourceType::Type resource_type,
-                int number_of_hits,
-                int number_of_misses,
-                int consecutive_misses,
-                double average_position);
+  struct UrlResourceRow {
+    UrlResourceRow();
+    UrlResourceRow(const UrlResourceRow& other);
+    UrlResourceRow(const std::string& main_frame_url,
+                   const std::string& resource_url,
+                   ResourceType::Type resource_type,
+                   int number_of_hits,
+                   int number_of_misses,
+                   int consecutive_misses,
+                   double average_position);
     void UpdateScore();
-    bool operator==(const UrlTableRow& rhs) const;
+    bool operator==(const UrlResourceRow& rhs) const;
 
     GURL main_frame_url;
     GURL resource_url;
@@ -47,19 +49,30 @@ class ResourcePrefetchPredictorTables : public PredictorTableBase {
     // Not stored.
     float score;
   };
-  typedef std::vector<UrlTableRow> UrlTableRows;
+  typedef std::vector<UrlResourceRow> UrlResourceRows;
 
-  // Sorts the UrlTableRows by score, descending.
-  struct UrlTableRowSorter {
-    bool operator()(const UrlTableRow& x, const UrlTableRow& y) const;
+  // Sorts the UrlResourceRows by score, descending.
+  struct UrlResourceRowSorter {
+    bool operator()(const UrlResourceRow& x, const UrlResourceRow& y) const;
   };
 
-  // |url_row_buffer| should be empty for GetAllRows.
-  virtual void GetAllRows(UrlTableRows* url_row_buffer);
-  virtual void UpdateRowsForUrl(const GURL& main_page_url,
-                                const UrlTableRows& row_buffer);
-  virtual void DeleteRowsForUrls(const std::vector<GURL>& urls);
-  virtual void DeleteAllRows();
+  // Data from both the tables for a particular main frame url.
+  struct UrlData {
+    explicit UrlData(const GURL& main_frame_url);
+    UrlData(const UrlData& other);
+    ~UrlData();
+    bool operator==(const UrlData& rhs) const;
+
+    GURL main_frame_url;
+    base::Time last_visit;
+    UrlResourceRows resources;
+  };
+
+  // |url_data_buffer| should be empty for GetAllRows.
+  virtual void GetAllUrlData(std::vector<UrlData>* url_data_buffer);
+  virtual void UpdateDataForUrl(const UrlData& url_data);
+  virtual void DeleteDataForUrls(const std::vector<GURL>& urls);
+  virtual void DeleteAllUrlData();
 
  private:
   friend class PredictorDatabaseInternal;