[Resumption 6/11] Add a RESUMING_INTERNAL state to DownloadItem.

content/browser/download/download_item_impl.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 CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 192 matching lines @@
                               int64 bytes_per_sec,
                               const std::string& hash_state);
 
   virtual void OnAllDataSaved(const std::string& final_hash);
 
   // Called by SavePackage to display progress when the DownloadItem
   // should be considered complete.
   virtual void MarkAsComplete();
 
  private:
-  // Fine grained states of a download.
+  // Fine grained states of a download. Note that active downloads are created
+  // in IN_PROGRESS_INTERNAL state. However, downloads creates via history can
+  // be created in COMPLETE_INTERNAL, CANCELLED_INTERNAL and
+  // INTERRUPTED_INTERNAL.
+
   enum DownloadInternalState {
-    // Unless otherwise specified, state transitions are linear forward
-    // in this list.
-
-    // Includes both before and after file name determination.
+    // Includes both before and after file name determination, and paused
+    // downloads.
     // TODO(rdsmith): Put in state variable for file name determination.
+    // Transitions from:
+    //   <Initial creation>    Active downloads are created in this state.
+    //   RESUMING_INTERNAL
+    // Transitions to:
+    //   COMPLETING_INTERNAL   On final rename completion.
+    //   CANCELLED_INTERNAL    On cancel.
+    //   INTERRUPTED_INTERNAL  On interrupt.
+    //   COMPLETE_INTERNAL     On SavePackage download completion.
     IN_PROGRESS_INTERNAL,
 
     // Between commit point (dispatch of download file release) and completed.
-    // Embedder may be opening the file in this state.  Note that the
-    // DownloadItem may be deleted (by shutdown) or interrupted (e.g. due to a
-    // failure during AnnotateWithSourceInformation()) in this state.
+    // Embedder may be opening the file in this state.
+    // Transitions from:
+    //   IN_PROGRESS_INTERNAL
+    // Transitions to:
+    //   COMPLETE_INTERNAL     On successful completion.
     COMPLETING_INTERNAL,
 
     // After embedder has had a chance to auto-open.  User may now open
     // or auto-open based on extension.
+    // Transitions from:
+    //   COMPLETING_INTERNAL
+    //   IN_PROGRESS_INTERNAL  SavePackage only.
+    //   <Initial creation>    Completed persisted downloads.
+    // Transitions to:
+    //   <none>                Terminal state.
     COMPLETE_INTERNAL,
 
     // User has cancelled the download.
-    // Only incoming transition IN_PROGRESS->
+    // Transitions from:
+    //   IN_PROGRESS_INTERNAL
+    //   INTERRUPTED_INTERNAL
+    //   RESUMING_INTERNAL
+    //   <Initial creation>    Canceleld persisted downloads.
+    // Transitions to:
+    //   <none>                Terminal state.
     CANCELLED_INTERNAL,
 
     // An error has interrupted the download.
-    // Only incoming transition IN_PROGRESS->
+    // Transitions from:
+    //   IN_PROGRESS_INTERNAL
+    //   RESUMING_INTERNAL
+    //   <Initial creation>    Interrupted persisted downloads.
+    // Transitions to:
+    //   RESUMING_INTERNAL     On resumption.
     INTERRUPTED_INTERNAL,
 
+    // A request to resume this interrupted download is in progress.
+    // Transitions from:
+    //   INTERRUPTED_INTERNAL
+    // Transitions to:
+    //   IN_PROGRESS_INTERNAL  Once a server response is received from a
+    //                         resumption.
+    //   INTERRUPTED_INTERNAL  If the resumption request fails.
+    //   CANCELLED_INTERNAL    On cancel.
+    RESUMING_INTERNAL,
+
     MAX_DOWNLOAD_INTERNAL_STATE,
   };
 
   // DownloadDestinationObserver
   virtual void DestinationUpdate(int64 bytes_so_far,
                                  int64 bytes_per_sec,
                                  const std::string& hash_state) OVERRIDE;
   virtual void DestinationError(DownloadInterruptReason reason) OVERRIDE;
   virtual void DestinationCompleted(const std::string& final_hash) OVERRIDE;
 
@@ skipping 40 matching lines @@
                                     const base::FilePath& full_path);
 
   // Called if the embedder took over opening a download, to indicate that
   // the download has been opened.
   void DelayedDownloadOpened(bool auto_opened);
 
   // Called when the entire download operation (including renaming etc)
   // is completed.
   void Completed();
 
+  // Callback invoked when the URLRequest for a download resumption has started.
+  void OnResumeRequestStarted(DownloadItem* item, net::Error error);
+
   // Helper routines -----------------------------------------------------------
 
   // Indicate that an error has occurred on the download.
   void Interrupt(DownloadInterruptReason reason);
 
   // Destroy the DownloadFile object.  If |destroy_file| is true, the file is
   // destroyed with it.  Otherwise, DownloadFile::Detach() is called before
   // object destruction to prevent file destruction. Destroying the file also
   // resets |current_path_|.
   void ReleaseDownloadFile(bool destroy_file);
@@ skipping 185 matching lines @@
   const net::BoundNetLog bound_net_log_;
 
   base::WeakPtrFactory<DownloadItemImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadItemImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_H_