Test file errors in downloads.

content/test/test_file_error_injector.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_TEST_TEST_FILE_ERROR_INJECTOR_H_
+#define CONTENT_TEST_TEST_FILE_ERROR_INJECTOR_H_
+#pragma once
+
+#include <string>
+
+#include "base/memory/ref_counted.h"
+#include "net/base/net_errors.h"
+
+class GURL;
+
+namespace content {
+
+class DownloadId;
+
+// Test helper for injecting errors into download file operations.
+// All errors for a download must be injected before it starts.

[cbentzel, 2012/03/08 20:02:55]

Good comment.

+// This class needs to be |RefCountedThreadSafe| because the implementation
+// is referenced by other classes that live past the time when the user is
+// nominally done with it.  These classes are internal to content/.
+//
+// NOTE: No more than one download with the same URL can be in progress at
+// the same time.  You can have multiple simultaneous downloads as long as the
+// URLs are different, as the URLs are used as keys to get information about
+// the download.
+//
+// Example:
+//
+// FileErrorInfo a = { url1, ... };
+// FileErrorInfo b = { url2, ... };
+//
+// scoped_refptr<TestFileErrorInjector> injector =
+//     TestFileErrorInjector::Create();
+//
+// injector->AddError(a);
+// injector->AddError(b);
+// injector->InjectErrors();
+//
+// download_manager->DownloadUrl(url1, ...);
+// download_manager->DownloadUrl(url2, ...);
+// ... wait for downloads to finish or get an injected error ...
+//
+class TestFileErrorInjector
+    : public base::RefCountedThreadSafe<TestFileErrorInjector> {
+ public:
+  enum FileOperationCode {
+    FILE_OPERATION_INITIALIZE,
+    FILE_OPERATION_WRITE,
+    FILE_OPERATION_RENAME
+  };
+
+  // Structure that encapsulates the information needed to inject a file error.
+  struct FileErrorInfo {
+    std::string url;  // Full URL of the download.  Identifies the download.
+    FileOperationCode code;  // Operation to affect.
+    int operation_instance;  // 0-based count of operation calls, for each code.
+    net::Error net_error;  // Error to inject.
+  };
+
+  // Creates an instance.  May only be called once.
+  // Lives until all callbacks (in the implementation) are complete and the
+  // creator goes out of scope.
+  static scoped_refptr<TestFileErrorInjector> Create();
+
+  // Adds an error.
+  // Must be called before |InjectErrors()| for a particular download file.
+  // It is an error to call |AddError()| more than once for the same file
+  // (URL), unless you call |ClearErrors()| in between them.
+  virtual bool AddError(const FileErrorInfo& error_info) = 0;
+
+  // Clears all errors.
+  // Only affects files created after the next call to InjectErrors().
+  virtual void ClearErrors() = 0;
+
+  // Injects the errors such that new download files will be affected.
+  // The download system must already be initialized before calling this.
+  // Multiple calls are allowed, but only useful if the errors have changed.
+  // Replaces the injected error list.
+  virtual bool InjectErrors() = 0;
+
+  // Tells how many files are currently open.
+  virtual size_t CurrentFileCount() const = 0;
+
+  // Tells how many files have ever been open (since construction or the
+  // last call to |ClearFoundFiles()|).
+  virtual size_t TotalFileCount() const = 0;
+
+  // Returns whether or not a file matching |url| has been created.
+  virtual bool HadFile(const GURL& url) const = 0;
+
+  // Gets the download ID associated with the file matching |url|.
+  virtual const content::DownloadId GetId(const GURL& url) const = 0;
+
+  // Resets the found file list.
+  virtual void ClearFoundFiles() = 0;
+
+  static std::string DebugString(FileOperationCode code);
+
+ protected:
+  TestFileErrorInjector() {}
+
+  virtual ~TestFileErrorInjector();
+
+ private:
+  friend class base::RefCountedThreadSafe<TestFileErrorInjector>;
+
+  DISALLOW_COPY_AND_ASSIGN(TestFileErrorInjector);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_TEST_TEST_FILE_ERROR_INJECTOR_H_