Create a browser feature extractor that runs after the renderer has

chrome/browser/safe_browsing/browser_feature_extractor.h

+// Copyright (c) 2011 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.
+//
+// BrowserFeatureExtractor computes various browser features for client-side
+// phishing detection.  For now it does a bunch of lookups in the history
+// service to see whether a particular URL has been visited before by the
+// user.
+
+#ifndef CHROME_BROWSER_SAFE_BROWSING_BROWSER_FEATURE_EXTRACTOR_H_
+#define CHROME_BROWSER_SAFE_BROWSING_BROWSER_FEATURE_EXTRACTOR_H_
+#pragma once
+
+#include <map>
+#include <set>
+#include <utility>
+
+#include "base/basictypes.h"
+#include "base/callback_old.h"
+#include "base/task.h"
+#include "base/time.h"
+#include "chrome/browser/history/history_types.h"
+#include "content/browser/cancelable_request.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
+
+class HistoryService;
+class TabContents;
+
+namespace safe_browsing {
+class ClientPhishingRequest;
+
+namespace features {
+
+// TODO(noelutz): move renderer/safe_browsing/features.h to common.
+////////////////////////////////////////////////////
+// History features.
+////////////////////////////////////////////////////
+
+// Number of visits to that URL stored in the browser history.
+// Should always be an integer larger than 1 because by the time
+// we lookup the history the current URL should already be stored there.
+extern const char kUrlHistoryVisitCount[];
+
+// Number of times the URL was typed in the Omnibox.
+extern const char kUrlHistoryTypedCount[];
+
+// Number of times the URL was reached by clicking a link.
+extern const char kUrlHistoryLinkCount[];
+
+// Number of times URL was visited more than 24h ago.
+extern const char kUrlHistoryVisitCountMoreThan24hAgo[];
+
+// Number of user-visible visits to all URLs on the same host/port as
+// the URL for HTTP and HTTPs.
+extern const char kHttpHostVisitCount[];
+extern const char kHttpsHostVisitCount[];
+
+// Boolean feature which is true if the host was visited for the first
+// time more than 24h ago (only considers user-visible visits like above).
+extern const char kFirstHttpHostVisitMoreThan24hAgo[];
+extern const char kFirstHttpsHostVisitMoreThan24hAgo[];
+}  // namespace features
+
+// All methods of this class must be called on the UI thread (including
+// the constructor).
+class BrowserFeatureExtractor : public NotificationObserver {
+ public:
+  // Called when feature extraction is done.  The first argument will be
+  // true iff feature extraction succeeded.  The second argument is the
+  // phishing request which was modified by the feature extractor.  The
+  // DoneCallback takes ownership of the request object.
+  typedef Callback2<bool, ClientPhishingRequest*>::Type DoneCallback;
+
+  // The caller keeps ownership of the tab object and is responsible for
+  // ensuring that it stays valid for the entire lifetime of this object.
+  explicit BrowserFeatureExtractor(TabContents* tab);
+
+  // The destructor will cancel any pending requests.
+  ~BrowserFeatureExtractor();
+
+  // Begins extraction of the browser features.  We take ownership
+  // of the request object until |callback| is called (see DoneCallback above)
+  // and will write the extracted features to the feature map.  Once the
+  // feature extraction is complete, |callback| is run on the UI thread.  We
+  // take ownership of the |callback| object.  This method must run on the UI
+  // thread.
+  void ExtractFeatures(ClientPhishingRequest* request,
+                       DoneCallback* callback);
+
+ private:
+  friend class DeleteTask<BrowserFeatureExtractor>;
+  typedef std::pair<ClientPhishingRequest*, DoneCallback*> ExtractionData;
+  typedef std::map<CancelableRequestProvider::Handle,
+                   ExtractionData> PendingQueriesMap;
+
+  // Actually starts feature extraction (does the real work).
+  void StartExtractFeatures(ClientPhishingRequest* request,
+                            DoneCallback* callback);
+
+  // HistoryService callback which is called when we're done querying URL visits
+  // in the history.
+  void QueryUrlHistoryDone(CancelableRequestProvider::Handle handle,
+                           bool success,
+                           const history::URLRow* row,
+                           history::VisitVector* visits);
+
+  // HistoryService callback which is called when we're done querying HTTP host
+  // visits in the history.
+  void QueryHttpHostVisitsDone(CancelableRequestProvider::Handle handle,
+                               bool success,
+                               int num_visits,
+                               base::Time first_visit);
+
+  // HistoryService callback which is called when we're done querying HTTPS host
+  // visits in the history.
+  void QueryHttpsHostVisitsDone(CancelableRequestProvider::Handle handle,
+                                bool success,
+                                int num_visits,
+                                base::Time first_visit);
+
+  // Helper function which sets the host history features given the
+  // number of host visits and the time of the fist host visit.  Set
+  // |is_http_query| to true if the URL scheme is HTTP and to false if
+  // the scheme is HTTPS.
+  void SetHostVisitsFeatures(int num_visits,
+                             base::Time first_visit,
+                             bool is_http_query,
+                             ClientPhishingRequest* request);
+
+  // Helper function which stores the request and callback while the history
+  // query is being processed.
+  void StorePendingQuery(CancelableRequestProvider::Handle handle,
+                         ClientPhishingRequest* request,
+                         DoneCallback* callback);
+
+  // Helper function which is the counterpart of StorePendingQuery.  If there
+  // is a pending query for the given handle it will return false and set both
+  // the request and cb pointers.  Otherwise, it will return false.
+  bool GetPendingQuery(CancelableRequestProvider::Handle handle,
+                       ClientPhishingRequest** request,
+                       DoneCallback** callback);
+
+  // Helper function which gets the history server if possible.  If the pointer
+  // is set it will return true and false otherwise.
+  bool GetHistoryService(HistoryService** history);
+
+  // Called when the tab goes away (in which case we cancel everything).
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
+  void Cancel();
+
+  TabContents* tab_;
+  CancelableRequestConsumer request_consumer_;
+  ScopedRunnableMethodFactory<BrowserFeatureExtractor> method_factory_;
+  bool cancelled_;
+  NotificationRegistrar registrar_;
+
+  // Set of pending extractions (i.e. extractions for which ExtractFeatures was
+  // called but not StartExtractFeatures).
+  std::set<ExtractionData> pending_extractions_;
+
+  // Set of pending queries (i.e., where history->Query...() was called but
+  // the history callback hasn't been invoked yet).
+  PendingQueriesMap pending_queries_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserFeatureExtractor);
+};
+}  // namespace safe_browsing
+#endif  // CHROME_BROWSER_SAFE_BROWSING_BROWSER_FEATURE_EXTRACTOR_H_