[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 RenameOption above.
+  // |retries_left| indicates how many times to retry the operation if the
+  //     rename fails with a transient error.
+  // |time_of_first_failure| Set to an empty base::TimeTicks during the first
+  //     call. Once the first failure is seen, subsequent calls of
+  //     RenameWithRetryInternal will have a non-empty value keeping track of
+  //     the time of first observed failure.  Used for UMA.
+  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_