Seculative resource prefetching for URLs CL.

chrome/browser/predictors/resource_prefetch_predictor_tables.h

+// 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.
+
+#ifndef CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_TABLES_H_
+#define CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_TABLES_H_
+#pragma once
+
+#include "chrome/browser/predictors/predictor_table_base.h"
+
+#include <string>
+#include <vector>
+
+#include "googleurl/src/gurl.h"
+#include "webkit/glue/resource_type.h"
+
+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.
+class ResourcePrefetchPredictorTables : public PredictorTableBase {

[willchan no longer on Chromium, 2012/05/24 22:28:52]

Why is PredictorTableBase inherited? The Google style guide recommends
composition over implementation inheritance.

Then for the virtuals, just pass in a base::Callback to the constructor or
something instead.

If this is non-trivial extra work for you, don't let this block you. But in
general, I like to encourage composition over implementation inheritance.

[Shishir, 2012/05/30 01:07:51]

I added a todo for this. I would like to do that in another CL as this will
touch other files outside the scope of this CL.

+ public:
+  struct UrlTableRow {
+    UrlTableRow();
+    UrlTableRow(const UrlTableRow& other);
+    void UpdateScore();
+
+    GURL main_frame_url_;
+    GURL resource_url_;
+    ResourceType::Type resource_type_;
+    int number_of_hits_;
+    int number_of_misses_;
+    int consecutive_misses_;
+    double average_position_;
+
+    // Not stored.
+    float score_;
+  };
+
+  // Sorts the UrlTableRows by score, descending.
+  struct UrlTableRowSorter {
+    bool operator()(const UrlTableRow& x, const UrlTableRow& y) const;
+  };
+
+  void GetAllRows(std::vector<UrlTableRow>* url_row_buffer);
+  void UpdateRowsForUrl(const GURL& main_page_url,
+                        const std::vector<UrlTableRow>& row_buffer);
+  void DeleteUrlRows(const std::vector<GURL>& urls);
+
+ private:
+  friend class PredictorDatabaseInternal;
+
+  ResourcePrefetchPredictorTables();
+  virtual ~ResourcePrefetchPredictorTables();
+
+  // PredictorTableBase methods.
+  virtual void CreateTableIfNonExistent() OVERRIDE;
+  virtual void LogDatabaseStats() OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(ResourcePrefetchPredictorTables);
+};
+
+}  // namespace predictors
+
+#endif  // CHROME_BROWSER_PREDICTORS_RESOURCE_PREFETCH_PREDICTOR_TABLES_H_