Support both preconnection, and pre-resolution for subresources...

chrome/browser/net/url_info.h

 // Copyright (c) 2006-2010 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.
 
 // A UrlInfo object is used to store prediction related information about a host
 // port and scheme triplet.  When performing DNS pre-resolution of the host/port
 // pair, its state is monitored as it is resolved.
 // It includes progress, from placement in the Predictor's queue, to resolution
 // by the DNS service as either FOUND or NO_SUCH_NAME.  Each instance may also
 // hold records of previous resolution times, which might later be shown to be
@@ skipping 11 matching lines @@
 
 #include "base/time.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/host_port_pair.h"
 
 namespace chrome_browser_net {
 
 // Use command line switch to enable detailed logging.
 void EnablePredictorDetailedLog(bool enable);
 
-enum DnsBenefit {
-  PREFETCH_NO_BENEFIT,  // Prefetch never hit the network. Name was pre-cached.
-  PREFETCH_CACHE_EVICTION,  // Prefetch used network, but so did HTTP stack.
-  PREFETCH_NAME_NONEXISTANT,  // Valuable prefetch of "name not found" was used.
-  PREFETCH_NAME_FOUND,  // Valuable prefetch was used.
-  PREFETCH_OBLIVIOUS  // No prefetch attempt was even made.
-};
-
 class UrlInfo {
  public:
   // Reasons for a domain to be resolved.
   enum ResolutionMotivation {
     MOUSE_OVER_MOTIVATED,  // Mouse-over link induced resolution.
     PAGE_SCAN_MOTIVATED,   // Scan of rendered page induced resolution.
     UNIT_TEST_MOTIVATED,
     LINKED_MAX_MOTIVATED,    // enum demarkation above motivation from links.
     OMNIBOX_MOTIVATED,       // Omni-box suggested resolving this.
     STARTUP_LIST_MOTIVATED,  // Startup list caused this resolution.
 
     NO_PREFETCH_MOTIVATION,  // Browser navigation info (not prefetch related).
 
     // The following involve predictive prefetching, triggered by a navigation.
     // The referrinrg_url_ is also set when these are used.
     // TODO(jar): Support STATIC_REFERAL_MOTIVATED API and integration.
     STATIC_REFERAL_MOTIVATED,  // External database suggested this resolution.
     LEARNED_REFERAL_MOTIVATED,  // Prior navigation taught us this resolution.
+
+    MAX_MOTIVATED  // Beyond all enums, for use in histogram bounding.
   };
 
   enum DnsProcessingState {
       // When processed by our prefetching system, the states are:
       PENDING,       // Constructor has completed.
       QUEUED,        // In name queue but not yet being resolved.
       ASSIGNED,      // Being resolved (or being reset to earlier state)
       ASSIGNED_BUT_MARKED,  // Needs to be deleted as soon as it's resolved.
       FOUND,         // DNS resolution completed.
       NO_SUCH_NAME,  // DNS resolution completed.
-      // When processed by the network stack during navigation, the states are:
-      STARTED,               // Resolution has begun for a navigation.
-      FINISHED,              // Resolution has completed for a navigation.
-      FINISHED_UNRESOLVED};  // No resolution found, so navigation will fail.
+  };
   static const base::TimeDelta kMaxNonNetworkDnsLookupDuration;
   // The number of OS cache entries we can guarantee(?) before cache eviction
   // might likely take place.
   static const int kMaxGuaranteedDnsCacheSize = 50;
 
-  typedef std::vector<UrlInfo> DnsInfoTable;
+  typedef std::vector<UrlInfo> UrlInfoTable;
 
   static const base::TimeDelta kNullDuration;
 
   // UrlInfo are usually made by the default constructor during
   // initializing of the Predictor's map (of info for Hostnames).
   UrlInfo()
       : state_(PENDING),
         old_prequeue_state_(state_),
         resolve_duration_(kNullDuration),
         queue_duration_(kNullDuration),
-        benefits_remaining_(),
         sequence_number_(0),
         motivation_(NO_PREFETCH_MOTIVATION),
         was_linked_(false) {
   }
 
   ~UrlInfo() {}
 
   // NeedDnsUpdate decides, based on our internal info,
   // if it would be valuable to attempt to update (prefectch)
   // DNS data for hostname.  This decision is based
   // on how recently we've done DNS prefetching for hostname.
   bool NeedsDnsUpdate();
 
   static void set_cache_expiration(base::TimeDelta time);
 
   // The prefetching lifecycle.
   void SetQueuedState(ResolutionMotivation motivation);
   void SetAssignedState();
   void RemoveFromQueue();
   void SetPendingDeleteState();
   void SetFoundState();
   void SetNoSuchNameState();
-  // The actual browsing resolution lifecycle.
-  void SetStartedState();
-  void SetFinishedState(bool was_resolved);
 
   // Finish initialization. Must only be called once.
   void SetUrl(const GURL& url);
 
   bool was_linked() const { return was_linked_; }
 
   GURL referring_url() const { return referring_url_; }
   void SetReferringHostname(const GURL& url) {
     referring_url_ = url;
   }
 
   bool was_found() const { return FOUND == state_; }
   bool was_nonexistant() const { return NO_SUCH_NAME == state_; }
   bool is_assigned() const {
     return ASSIGNED == state_ || ASSIGNED_BUT_MARKED == state_;
   }
   bool is_marked_to_delete() const { return ASSIGNED_BUT_MARKED == state_; }
   const GURL url() const { return url_; }
 
   bool HasUrl(const GURL& url) const {
     return url_ == url;
   }
 
   base::TimeDelta resolve_duration() const { return resolve_duration_;}
   base::TimeDelta queue_duration() const { return queue_duration_;}
-  base::TimeDelta benefits_remaining() const { return benefits_remaining_; }
-
-  DnsBenefit AccruePrefetchBenefits(UrlInfo* navigation_info);
 
   void DLogResultsStats(const char* message) const;
 
-  static void GetHtmlTable(const DnsInfoTable host_infos,
+  static void GetHtmlTable(const UrlInfoTable host_infos,
                            const char* description,
                            const bool brief,
                            std::string* output);
 
  private:
   base::TimeDelta GetDuration() {
     base::TimeTicks old_time = time_;
     time_ = base::TimeTicks::Now();
     return time_ - old_time;
   }
@@ skipping 19 matching lines @@
   DnsProcessingState old_prequeue_state_;
 
   GURL url_;  // Host, port and scheme for this info.
 
   // When was last state changed (usually lookup completed).
   base::TimeTicks time_;
   // Time needed for DNS to resolve.
   base::TimeDelta resolve_duration_;
   // Time spent in queue.
   base::TimeDelta queue_duration_;
-  // Unused potential benefits of a prefetch.
-  base::TimeDelta benefits_remaining_;
 
   int sequence_number_;  // Used to calculate potential of cache eviction.
   static int sequence_counter;  // Used to allocate sequence_number_'s.
 
   // Motivation for creation of this instance.
   ResolutionMotivation motivation_;
 
   // Record if the motivation for prefetching was ever a page-link-scan.
   bool was_linked_;
 
   // If this instance holds data about a navigation, we store the referrer.
   // If this instance hold data about a prefetch, and the prefetch was
   // instigated by a referrer, we store it here (for use in about:dns).
   GURL referring_url_;
 
   // We put these objects into a std::map, and hence we
   // need some "evil" constructors.
   // DISALLOW_COPY_AND_ASSIGN(UrlInfo);
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_URL_INFO_H_