Introduce ERR_NETWORK_CHANGED and allow URLFetcher to automatically retry on that error.

net/url_request/url_fetcher_core.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 NET_URL_REQUEST_URL_FETCHER_CORE_H_
 #define NET_URL_REQUEST_URL_FETCHER_CORE_H_
 
 #include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/debug/stack_trace.h"
 #include "base/file_path.h"
 #include "base/lazy_instance.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"
 #include "base/timer.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/host_port_pair.h"
+#include "net/base/network_change_notifier.h"
 #include "net/http/http_request_headers.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_status.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace net {
 class HttpResponseHeaders;
 class IOBuffer;
 class URLFetcherDelegate;
 class URLRequestContextGetter;
 class URLRequestThrottlerEntryInterface;
 
 class URLFetcherCore
     : public base::RefCountedThreadSafe<URLFetcherCore>,
-      public URLRequest::Delegate {
+      public URLRequest::Delegate,
+      public NetworkChangeNotifier::ConnectionTypeObserver {
  public:
   URLFetcherCore(URLFetcher* fetcher,
                  const GURL& original_url,
                  URLFetcher::RequestType request_type,
                  URLFetcherDelegate* d);
 
   // Starts the load.  It's important that this not happen in the constructor
   // because it causes the IO thread to begin AddRef()ing and Release()ing
   // us.  If our caller hasn't had time to fully construct us and take a
   // reference, the IO thread could interrupt things, run a task, Release()
@@ skipping 30 matching lines @@
   // Set the key and data callback that is used when setting the user
   // data on any URLRequest objects this object creates.
   void SetURLRequestUserData(
       const void* key,
       const URLFetcher::CreateDataCallback& create_data_callback);
   void SetStopOnRedirect(bool stop_on_redirect);
   void SetAutomaticallyRetryOn5xx(bool retry);
   void SetMaxRetries(int max_retries);
   int GetMaxRetries() const;
   base::TimeDelta GetBackoffDelay() const;
+  void SetAutomaticallyRetryOnNetworkChanges(int max_retries);
   void SaveResponseToFileAtPath(
       const FilePath& file_path,
       scoped_refptr<base::TaskRunner> file_task_runner);
   void SaveResponseToTemporaryFile(
       scoped_refptr<base::TaskRunner> file_task_runner);
   HttpResponseHeaders* GetResponseHeaders() const;
   HostPortPair GetSocketAddress() const;
   bool WasFetchedViaProxy() const;
   const GURL& GetOriginalURL() const;
   const GURL& GetURL() const;
@@ skipping 13 matching lines @@
                              FilePath* out_response_path);
 
   // Overridden from URLRequest::Delegate:
   virtual void OnReceivedRedirect(URLRequest* request,
                                   const GURL& new_url,
                                   bool* defer_redirect) OVERRIDE;
   virtual void OnResponseStarted(URLRequest* request) OVERRIDE;
   virtual void OnReadCompleted(URLRequest* request,
                                int bytes_read) OVERRIDE;
 
+  // Overridden from NetworkChangeNotifier::ConnectionTypeObserver:
+  virtual void OnConnectionTypeChanged(
+      NetworkChangeNotifier::ConnectionType type) OVERRIDE;
+
   URLFetcherDelegate* delegate() const { return delegate_; }
   static void CancelAll();
   static int GetNumFetcherCores();
   static void SetEnableInterceptionForTests(bool enabled);
 
  private:
   friend class base::RefCountedThreadSafe<URLFetcherCore>;
 
   // How should the response be stored?
   enum ResponseDestinationType {
@@ skipping 243 matching lines @@
   // use this to ensure that |url_| is set to the redirect destination rather
   // than the originally-fetched URL.
   bool stopped_on_redirect_;
 
   // If |automatically_retry_on_5xx_| is false, 5xx responses will be
   // propagated to the observer, if it is true URLFetcher will automatically
   // re-execute the request, after the back-off delay has expired.
   // true by default.
   bool automatically_retry_on_5xx_;
   // Maximum retries allowed.
   int max_retries_;

[pauljensen, 2012/12/07 23:00:05]

Might be nice to comment this more explicitly, ditto with SetMaxRetries() which
doesn't have any comment.  Just so it doesn't get confused with your retry
counter.

[Joao da Silva, 2012/12/10 15:32:42]

Done. Also renamed these fields and the setter/getter to make them clearer.

   // Back-off time delay. 0 by default.
   base::TimeDelta backoff_delay_;
 
+  // Number of times to retry when the request fails with ERR_NETWORK_CHANGED.
+  // Defaults to 0.

[pauljensen, 2012/12/07 23:00:05]

nit: Maybe change to "0 by default." to match two lines above.

[Joao da Silva, 2012/12/10 15:32:42]

Done.

+  int max_retries_on_network_changes_;
+
   // Timer to poll the progress of uploading for POST and PUT requests.
   // When crbug.com/119629 is fixed, scoped_ptr is not necessary here.
   scoped_ptr<base::RepeatingTimer<URLFetcherCore> >
       upload_progress_checker_timer_;
   // Number of bytes sent so far.
   int64 current_upload_bytes_;
   // Number of bytes received so far.
   int64 current_response_bytes_;
   // Total expected bytes to receive (-1 if it cannot be determined).
   int64 total_response_bytes_;
 
   // TODO(willchan): Get rid of this after debugging crbug.com/90971.
   base::debug::StackTrace stack_trace_;
 
   static base::LazyInstance<Registry> g_registry;
 
   DISALLOW_COPY_AND_ASSIGN(URLFetcherCore);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_FETCHER_CORE_H_