view-cache: Refactor ViewCacheHelper and ViewHttpCacheJobFactory...

net/url_request/view_cache_helper.h

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2010 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 NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
 #define NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
 
 #include <string>
 
+#include "net/base/completion_callback.h"
+#include "net/base/io_buffer.h"
+
 class URLRequestContext;
 
+namespace disk_cache {
+class Backend;
+class Entry;
+}
+
+namespace net {
+
 class ViewCacheHelper {
  public:
-  // Formats the cache information for |key| as HTML.
-  static void GetEntryInfoHTML(const std::string& key,
-                               URLRequestContext* context,
-                               const std::string& url_prefix,
-                               std::string* out);
+  ViewCacheHelper()
+      : disk_cache_(NULL), entry_(NULL), iter_(NULL), buf_len_(0), index_(0),
+        data_(NULL), callback_(NULL), next_state_(STATE_NONE),
+        ALLOW_THIS_IN_INITIALIZER_LIST(
+            cache_callback_(this, &ViewCacheHelper::OnIOComplete)),
+        ALLOW_THIS_IN_INITIALIZER_LIST(
+            entry_callback_(new CancelableCompletionCallback<ViewCacheHelper>(
+                this, &ViewCacheHelper::OnIOComplete))) {}
+  ~ViewCacheHelper();
 
-  static void GetStatisticsHTML(URLRequestContext* context,
-                                std::string* out);
+  // Formats the cache information for |key| as HTML. Returns a net error code.
+  // If this method returns ERR_IO_PENDING, |callback| will be notified when the
+  // operation completes. |out| must remain valid until this operation completes
+  // or the object is destroyed.
+  int GetEntryInfoHTML(const std::string& key, URLRequestContext* context,
+                       std::string* out, CompletionCallback* callback);
+
+  // Formats the cache contents as HTML. Returns a net error code.
+  // If this method returns ERR_IO_PENDING, |callback| will be notified when the
+  // operation completes. |out| must remain valid until this operation completes
+  // or the object is destroyed. |url_prefix| will be prepended to each entry
+  // key as a link to the entry.
+  int GetContentsHTML(URLRequestContext* context, const std::string& url_prefix,
+                      std::string* out, CompletionCallback* callback);
+
+ private:
+  enum State {
+    STATE_NONE,
+    STATE_GET_BACKEND,
+    STATE_GET_BACKEND_COMPLETE,
+    STATE_OPEN_NEXT_ENTRY,
+    STATE_OPEN_NEXT_ENTRY_COMPLETE,
+    STATE_OPEN_ENTRY,
+    STATE_OPEN_ENTRY_COMPLETE,
+    STATE_READ_RESPONSE,
+    STATE_READ_RESPONSE_COMPLETE,
+    STATE_READ_DATA,
+    STATE_READ_DATA_COMPLETE
+  };
+
+  // Implements GetEntryInfoHTML and GetContentsHTML.
+  int GetInfoHTML(const std::string& key, URLRequestContext* context,
+                  const std::string& url_prefix, std::string* out,
+                  CompletionCallback* callback);
+
+  // This is a helper function used to trigger a completion callback. It may
+  // only be called if callback_ is non-null.
+  void DoCallback(int rv);
+
+  // This will trigger the completion callback if appropriate.
+  void HandleResult(int rv);
+
+  // Runs the state transition loop.
+  int DoLoop(int result);
+
+  // Each of these methods corresponds to a State value. If there is an
+  // argument, the value corresponds to the return of the previous state or
+  // corresponding callback.
+  int DoGetBackend();
+  int DoGetBackendComplete(int result);
+  int DoOpenNextEntry();
+  int DoOpenNextEntryComplete(int result);
+  int DoOpenEntry();
+  int DoOpenEntryComplete(int result);
+  int DoReadResponse();
+  int DoReadResponseComplete(int result);
+  int DoReadData();
+  int DoReadDataComplete(int result);
+
+  // Called to signal completion of asynchronous IO.
+  void OnIOComplete(int result);
+
+  scoped_refptr<URLRequestContext> context_;
+  disk_cache::Backend* disk_cache_;
+  disk_cache::Entry* entry_;
+  void* iter_;
+  scoped_refptr<net::IOBuffer> buf_;
+  int buf_len_;
+  int index_;
+
+  std::string key_;
+  std::string url_prefix_;
+  std::string* data_;
+  CompletionCallback* callback_;
+
+  State next_state_;
+
+  CompletionCallbackImpl<ViewCacheHelper> cache_callback_;
+  scoped_refptr<CancelableCompletionCallback<ViewCacheHelper> > entry_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ViewCacheHelper);
 };
 
+}  // namespace net.
+
 #endif  // NET_URL_REQUEST_VIEW_CACHE_HELPER_H_