Download resumption - Preliminary

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 15 matching lines @@
 
 namespace content {
 class DownloadFile;
 class DownloadItemImplDelegate;
 
 // See download_item.h for usage.
 class CONTENT_EXPORT DownloadItemImpl
     : public DownloadItem,
       public DownloadDestinationObserver {
  public:
+  enum ResumeMode {
+    RESUME_MODE_INVALID = 0,
+    RESUME_MODE_IMMEDIATE_CONTINUE,
+    RESUME_MODE_IMMEDIATE_RESTART,
+    RESUME_MODE_USER_CONTINUE,
+    RESUME_MODE_USER_RESTART
+  };
+
+  // The maximum number of attempts we will make to resume automatically.
+  static const int kMaxAutoResumeAttempts;
+
   // Note that it is the responsibility of the caller to ensure that a
   // DownloadItemImplDelegate passed to a DownloadItemImpl constructor
   // outlives the DownloadItemImpl.
 
   // Constructing from persistent store:
   // |bound_net_log| is constructed externally for our use.
   DownloadItemImpl(DownloadItemImplDelegate* delegate,
                    DownloadId download_id,
                    const FilePath& path,
                    const GURL& url,
                    const GURL& referrer_url,
                    const base::Time& start_time,
                    const base::Time& end_time,
                    int64 received_bytes,
                    int64 total_bytes,
                    DownloadItem::DownloadState state,
                    bool opened,
                    const net::BoundNetLog& bound_net_log);
 
   // Constructing for a regular download.
   // |bound_net_log| is constructed externally for our use.
   DownloadItemImpl(DownloadItemImplDelegate* delegate,
                    const DownloadCreateInfo& info,
-                   scoped_ptr<DownloadRequestHandleInterface> request_handle,
                    const net::BoundNetLog& bound_net_log);
 
   // Constructing for the "Save Page As..." feature:
   // |bound_net_log| is constructed externally for our use.
   DownloadItemImpl(DownloadItemImplDelegate* delegate,
                    const FilePath& path,
                    const GURL& url,
                    DownloadId download_id,
                    const std::string& mime_type,
                    const net::BoundNetLog& bound_net_log);
 
   virtual ~DownloadItemImpl();
 
   // DownloadItem
   virtual void AddObserver(DownloadItem::Observer* observer) OVERRIDE;
   virtual void RemoveObserver(DownloadItem::Observer* observer) OVERRIDE;
   virtual void UpdateObservers() OVERRIDE;
   virtual void DangerousDownloadValidated() OVERRIDE;
   virtual void TogglePause() OVERRIDE;
   virtual void Cancel(bool user_cancel) OVERRIDE;
   virtual void Delete(DeleteReason reason) OVERRIDE;
   virtual void Remove() OVERRIDE;
   virtual void OpenDownload() OVERRIDE;
   virtual void ShowDownloadInShell() OVERRIDE;
   virtual int32 GetId() const OVERRIDE;
   virtual DownloadId GetGlobalId() const OVERRIDE;
   virtual DownloadState GetState() const OVERRIDE;
   virtual DownloadInterruptReason GetLastReason() const OVERRIDE;
   virtual bool IsPaused() const OVERRIDE;
+  virtual bool CanResumeInterrupted() const OVERRIDE;
   virtual bool IsTemporary() const OVERRIDE;
   virtual bool IsPartialDownload() const OVERRIDE;
   virtual bool IsInProgress() const OVERRIDE;
   virtual bool IsCancelled() const OVERRIDE;
   virtual bool IsInterrupted() const OVERRIDE;
   virtual bool IsComplete() const OVERRIDE;
   virtual const GURL& GetURL() const OVERRIDE;
   virtual const std::vector<GURL>& GetUrlChain() const OVERRIDE;
   virtual const GURL& GetOriginalUrl() const OVERRIDE;
   virtual const GURL& GetReferrerUrl() const OVERRIDE;
@@ skipping 22 matching lines @@
   virtual bool TimeRemaining(base::TimeDelta* remaining) const OVERRIDE;
   virtual int64 CurrentSpeed() const OVERRIDE;
   virtual int PercentComplete() const OVERRIDE;
   virtual bool AllDataSaved() const OVERRIDE;
   virtual int64 GetTotalBytes() const OVERRIDE;
   virtual int64 GetReceivedBytes() const OVERRIDE;
   virtual base::Time GetStartTime() const OVERRIDE;
   virtual base::Time GetEndTime() const OVERRIDE;
   virtual bool CanShowInFolder() OVERRIDE;
   virtual bool CanOpenDownload() OVERRIDE;
+  virtual bool CanResumeDownload() const OVERRIDE;
   virtual bool ShouldOpenFileBasedOnExtension() OVERRIDE;
   virtual bool GetOpenWhenComplete() const OVERRIDE;
   virtual bool GetAutoOpened() OVERRIDE;
   virtual bool GetOpened() const OVERRIDE;
   virtual BrowserContext* GetBrowserContext() const OVERRIDE;
   virtual WebContents* GetWebContents() const OVERRIDE;
   virtual void OnContentCheckCompleted(DownloadDangerType danger_type) OVERRIDE;
   virtual void SetOpenWhenComplete(bool open) OVERRIDE;
   virtual void SetIsTemporary(bool temporary) OVERRIDE;
   virtual void SetOpened(bool opened) OVERRIDE;
   virtual void SetDisplayName(const FilePath& name) OVERRIDE;
   virtual std::string DebugString(bool verbose) const OVERRIDE;
   virtual void MockDownloadOpenForTesting() OVERRIDE;
+  virtual const net::BoundNetLog& GetBoundNetLog() const OVERRIDE;
 
   // All remaining public interfaces virtual to allow for DownloadItemImpl
   // mocks.
 
+  virtual bool IsResuming() const;
+  virtual ResumeMode GetResumeMode() const;
+
   // Main entry points for regular downloads, in order -------------------------
 
   // TODO(rdsmith): Fold the process that uses these fully into
   // DownloadItemImpl and pass callbacks to the delegate so that all of
   // these other than Start() can be made private.
 
-  // Start the download
-  virtual void Start(scoped_ptr<DownloadFile> download_file);
+  // Start the download.
+  // |download_file| is the associated file on the storage medium.
+  // |req_handle| is the new request handle associated with the download.
+  virtual void Start(scoped_ptr<DownloadFile> download_file,
+                     scoped_ptr<DownloadRequestHandleInterface> req_handle);
 
   // If all pre-requisites have been met, complete download processing, i.e. do
   // internal cleanup, file rename, and potentially auto-open.  (Dangerous
   // downloads still may block on user acceptance after this point.)
   virtual void MaybeCompleteDownload();
 
-  // Needed because of interwining with DownloadManagerImpl --------------------
+  // Needed because of intertwining with DownloadManagerImpl -------------------
 
   // TODO(rdsmith): Unwind DownloadManagerImpl and DownloadItemImpl,
   // removing these from the public interface.
 
   // Notify observers that this item is being removed by the user.
   virtual void NotifyRemoved();
 
   virtual void OnDownloadedFileRemoved();
 
   // Provide a weak pointer reference to a DownloadDestinationObserver
@@ skipping 100 matching lines @@
                                     const FilePath& full_path);
 
   // Called if the embedder took over opening a download, to indicate that
   // the download has been opened.
   virtual void DelayedDownloadOpened(bool auto_opened);
 
   // Called when the entire download operation (including renaming etc)
   // is completed.
   void Completed();
 
+  // Initiates a resume operation on an interrupted download.
+  void ResumeInterruptedDownload();
+
   // Helper routines -----------------------------------------------------------
 
   // Indicate that an error has occurred on the download.
   virtual void Interrupt(DownloadInterruptReason reason);
 
   // Cancel the DownloadFile if we have it.
   void CancelDownloadFile();
 
   // Check if a download is ready for completion.
   bool IsDownloadReadyForCompletion();
 
   // Call to transition state; all state transitions should go through this.
   void TransitionTo(DownloadInternalState new_state);
 
   // Set the |danger_type_| and invoke obserers if necessary.
   void SetDangerType(DownloadDangerType danger_type);
 
   void SetFullPath(const FilePath& new_path);
 
-  // Mapping between internal and external states.
+  void AutoResumeIfValid();
+
   static DownloadState InternalToExternalState(
       DownloadInternalState internal_state);
   static DownloadInternalState ExternalToInternalState(
       DownloadState external_state);
 
   // Debugging routines --------------------------------------------------------
   static const char* DebugDownloadStateString(DownloadInternalState state);
+  static const char* DebugResumeModeString(ResumeMode mode);
 
   // Will be false for save package downloads retrieved from the history.
   // TODO(rdsmith): Replace with a generalized enum for "download source".
   const bool is_save_package_download_;
 
   // The handle to the request information.  Used for operations outside the
   // download system.
   scoped_ptr<DownloadRequestHandleInterface> request_handle_;
 
   // Download ID assigned by DownloadResourceHandler.
@@ skipping 98 matching lines @@
 
   // Time the download completed.
   base::Time end_time_;
 
   // Our delegate.
   DownloadItemImplDelegate* delegate_;
 
   // In progress downloads may be paused by the user, we note it here.
   bool is_paused_;
 
+  // A download has been resumed.
+  bool is_resuming_;
+
+  // The number of times this download has been resumed automatically.
+  int auto_resume_count_;
+
   // A flag for indicating if the download should be opened at completion.
   bool open_when_complete_;
 
   // A flag for indicating if the downloaded file is externally removed.
   bool file_externally_removed_;
 
   // Indicates if the download is considered potentially safe or dangerous
   // (executable files are typically considered dangerous).
   SafetyState safety_state_;
 
@@ skipping 30 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_