[Downloads] Retry renames after transient failures.

content/browser/download/download_file_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_FILE_IMPL_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_IMPL_H_
 
 #include "content/browser/download/download_file.h"
 
 #include "base/memory/ref_counted.h"
@@ skipping 50 matching lines @@
   virtual int64 CurrentSpeed() const OVERRIDE;
   virtual bool GetHash(std::string* hash) OVERRIDE;
   virtual std::string GetHashState() OVERRIDE;
   virtual void SetClientGuid(const std::string& guid) OVERRIDE;
 
  protected:
   // For test class overrides.
   virtual DownloadInterruptReason AppendDataToFile(
       const char* data, size_t data_len);
 
+  virtual base::TimeDelta GetRetryDelayForFailedRename(int attempt_number);
+
+  virtual bool ShouldRetryFailedRename(DownloadInterruptReason reason);
+
  private:
+  friend class DownloadFileTest;
+
+  // Options for RenameWithRetryInternal.
+  enum RenameOption {
+    UNIQUIFY = 1 << 0,  // If there's already a file on disk that conflicts with
+                        // |new_path|, try to create a unique file by appending
+                        // a uniquifier.
+    ANNOTATE_WITH_SOURCE_INFORMATION = 1 << 1
+  };
+
+  // Rename file_ to |new_path|.
+  // |option| specifies additional operations to be performed during the rename.
+  //     See RenameOptions above.

[Randy Smith (Not in Mondays), 2014/06/11 18:07:29]

nit: No 's'  (IMO).

[asanka, 2014/06/12 20:02:37]

Done.

+  // |retries_left| indicates how many times to retry the operation if the
+  //     rename fails with a transient error.
+  // |time_of_first_failure| should be empty when this method is called for the
+  //     first time.

[Randy Smith (Not in Mondays), 2014/06/11 18:07:29]

If you just read the comment, you're left with the question "and what about when
I'm not calling it for the first time?"  Maybe instead "should be empty (it is
used to propagate time to first failure for internal retries)."?

[asanka, 2014/06/12 20:02:37]

Reworded.

+  void RenameWithRetryInternal(const base::FilePath& new_path,
+                               RenameOption option,
+                               int retries_left,
+                               base::TimeTicks time_of_first_failure,
+                               const RenameCompletionCallback& callback);
+
   // Send an update on our progress.
   void SendUpdate();
 
   // Called when there's some activity on stream_reader_ that needs to be
   // handled.
   void StreamActive();
 
   // The base file instance.
   BaseFile file_;
 
@@ skipping 20 matching lines @@
   base::WeakPtr<DownloadDestinationObserver> observer_;
 
   base::WeakPtrFactory<DownloadFileImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_IMPL_H_