Make conditional requests when updating the appcache....

webkit/appcache/appcache_update_job.h

 // Copyright (c) 2009 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 WEBKIT_APPCACHE_APPCACHE_UPDATE_JOB_H_
 #define WEBKIT_APPCACHE_APPCACHE_UPDATE_JOB_H_
 
 #include <deque>
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/ref_counted.h"
 #include "base/task.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/completion_callback.h"
 #include "net/url_request/url_request.h"
 #include "testing/gtest/include/gtest/gtest_prod.h"
 #include "webkit/appcache/appcache.h"
 #include "webkit/appcache/appcache_host.h"
 #include "webkit/appcache/appcache_interfaces.h"
+#include "webkit/appcache/appcache_response.h"
 #include "webkit/appcache/appcache_storage.h"
 
 namespace appcache {
 
 class UpdateJobInfo;
 class HostNotifier;
 
 // Application cache Update algorithm and state.
 class AppCacheUpdateJob : public URLRequest::Delegate,
                           public AppCacheStorage::Delegate,
                           public AppCacheHost::Observer {
  public:
   AppCacheUpdateJob(AppCacheService* service, AppCacheGroup* group);
   ~AppCacheUpdateJob();
 
   // Triggers the update process or adds more info if this update is already
   // in progress.
   void StartUpdate(AppCacheHost* host, const GURL& new_master_resource);
 
  private:
   friend class ScopedRunnableMethodFactory<AppCacheUpdateJob>;
   friend class AppCacheUpdateJobTest;
   friend class UpdateJobInfo;
 
   // Master entries have multiple hosts, for example, the same page is opened
   // in different tabs.
   typedef std::vector<AppCacheHost*> PendingHosts;
   typedef std::map<GURL, PendingHosts> PendingMasters;
   typedef std::map<GURL, URLRequest*> PendingUrlFetches;
-  typedef std::pair<GURL, bool> UrlsToFetch;  // flag TRUE if storage checked
   typedef std::map<int64, GURL> LoadingResponses;
 
   static const int kRerunDelayMs = 1000;
 
   // TODO(michaeln): Rework the set of states vs update types vs stored states.
   // The NO_UPDATE state is really more of an update type. For all update types
   // storing the results is relevant.
 
   enum UpdateType {
     UNKNOWN_TYPE,
@@ skipping 12 matching lines @@
     CANCELLED,
     COMPLETED,
   };
 
   enum StoredState {
     UNSTORED,
     STORING,
     STORED,
   };
 
+  struct UrlToFetch {
+    GURL url;
+    bool storage_checked;
+    scoped_refptr<AppCacheResponseInfo> existing_response_info;
+    UrlToFetch(const GURL& url, bool checked, AppCacheResponseInfo* info)
+        : url(url), storage_checked(checked), existing_response_info(info) {}
+  };
+
+  UpdateJobInfo* GetUpdateJobInfo(URLRequest* request);
+
   // Methods for URLRequest::Delegate.
   void OnResponseStarted(URLRequest* request);
   void OnReadCompleted(URLRequest* request, int bytes_read);
   void OnReceivedRedirect(URLRequest* request,
                           const GURL& new_url,
                           bool* defer_redirect);
   // TODO(jennb): any other delegate callbacks to handle? certificate?
 
   // Methods for AppCacheStorage::Delegate.
   void OnResponseInfoLoaded(AppCacheResponseInfo* response_info,
                             int64 response_id);
   void OnGroupAndNewestCacheStored(AppCacheGroup* group, AppCache* newest_cache,
                                    bool success);
   void OnGroupMadeObsolete(AppCacheGroup* group, bool success);
 
   // Methods for AppCacheHost::Observer.
   void OnCacheSelectionComplete(AppCacheHost* host) {}  // N/A
   void OnDestructionImminent(AppCacheHost* host);
 
   void CheckPolicy();
   void OnPolicyCheckComplete(int rv);
 
   void HandleCacheFailure(const std::string& error_message);
 
   void FetchManifest(bool is_first_fetch);
 
-  // Add extra HTTP headers to the request based on the response info and
-  // start the URL request.
-  void AddHttpHeadersAndFetch(URLRequest* request,
-                              const net::HttpResponseInfo* info);
+  // Add extra conditional HTTP headers to the request based on the
+  // currently cached response headers.
+  void AddConditionalHeaders(URLRequest* request,
+                             const net::HttpResponseInfo* info);
 
   void OnResponseCompleted(URLRequest* request);
 
   // Retries a 503 request with retry-after header of 0.
   // Returns true if request should be retried and deletes original request.
   bool RetryRequest(URLRequest* request);
 
   void ReadResponseData(URLRequest* request);
 
   // Returns false if response data is processed asynchronously, in which
@@ skipping 48 matching lines @@
   void AddMasterEntryToFetchList(AppCacheHost* host, const GURL& url,
                                  bool is_new);
   void FetchMasterEntries();
   void CancelAllMasterEntryFetches(const std::string& error_message);
 
   // Asynchronously loads the entry from the newest complete cache if the
   // HTTP caching semantics allow.
   // Returns false if immediately obvious that data cannot be loaded from
   // newest complete cache.
   bool MaybeLoadFromNewestCache(const GURL& url, AppCacheEntry& entry);
-  void LoadFromNewestCacheFailed(const GURL& url);
+  void LoadFromNewestCacheFailed(const GURL& url,
+                                 AppCacheResponseInfo* newest_response_info);
 
   // Does nothing if update process is still waiting for pending master
   // entries or URL fetches to complete downloading. Otherwise, completes
   // the update process.
   void MaybeCompleteUpdate();
 
   // Schedules a rerun of the entire update with the same parameters as
   // this update job after a short delay.
   void ScheduleUpdateRetry(int delay_ms);
 
@@ skipping 32 matching lines @@
   std::set<GURL> master_entries_to_fetch_;
   PendingUrlFetches master_entry_fetches_;
 
   // URLs of files to fetch along with their flags.
   AppCache::EntryMap url_file_list_;
   size_t url_fetches_completed_;
 
   // Helper container to track which urls have not been fetched yet. URLs are
   // removed when the fetch is initiated. Flag indicates whether an attempt
   // to load the URL from storage has already been tried and failed.
-  std::deque<UrlsToFetch> urls_to_fetch_;
+  std::deque<UrlToFetch> urls_to_fetch_;
 
   // Helper container to track which urls are being loaded from response
   // storage.
   LoadingResponses loading_responses_;
 
   // Keep track of pending URL requests so we can cancel them if necessary.
   URLRequest* manifest_url_request_;
   PendingUrlFetches pending_url_fetches_;
 
   // Temporary storage of manifest response data for parsing and comparison.
@@ skipping 26 matching lines @@
   scoped_refptr<net::CancelableCompletionCallback<AppCacheUpdateJob> >
       policy_callback_;
 
   FRIEND_TEST(AppCacheGroupTest, QueueUpdate);
   DISALLOW_COPY_AND_ASSIGN(AppCacheUpdateJob);
 };
 
 }  // namespace appcache
 
 #endif  // WEBKIT_APPCACHE_APPCACHE_UPDATE_JOB_H_