Home | History | Annotate | Download | only in url_request 
      1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
      6 #define NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
      7 #pragma once
      8 
      9 #include <string>
     10 
     11 #include "net/base/completion_callback.h"
     12 #include "net/base/io_buffer.h"
     13 
     14 namespace disk_cache {
     15 class Backend;
     16 class Entry;
     17 }  // namespace disk_cache
     18 
     19 namespace net {
     20 
     21 class URLRequestContext;
     22 
     23 class ViewCacheHelper {
     24  public:
     25   ViewCacheHelper();
     26   ~ViewCacheHelper();
     27 
     28   // Formats the cache information for |key| as HTML. Returns a net error code.
     29   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
     30   // operation completes. |out| must remain valid until this operation completes
     31   // or the object is destroyed.
     32   int GetEntryInfoHTML(const std::string& key,
     33                        URLRequestContext* context,
     34                        std::string* out,
     35                        CompletionCallback* callback);
     36 
     37   // Formats the cache contents as HTML. Returns a net error code.
     38   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
     39   // operation completes. |out| must remain valid until this operation completes
     40   // or the object is destroyed. |url_prefix| will be prepended to each entry
     41   // key as a link to the entry.
     42   int GetContentsHTML(URLRequestContext* context,
     43                       const std::string& url_prefix,
     44                       std::string* out,
     45                       CompletionCallback* callback);
     46 
     47  private:
     48   enum State {
     49     STATE_NONE,
     50     STATE_GET_BACKEND,
     51     STATE_GET_BACKEND_COMPLETE,
     52     STATE_OPEN_NEXT_ENTRY,
     53     STATE_OPEN_NEXT_ENTRY_COMPLETE,
     54     STATE_OPEN_ENTRY,
     55     STATE_OPEN_ENTRY_COMPLETE,
     56     STATE_READ_RESPONSE,
     57     STATE_READ_RESPONSE_COMPLETE,
     58     STATE_READ_DATA,
     59     STATE_READ_DATA_COMPLETE
     60   };
     61 
     62   // Implements GetEntryInfoHTML and GetContentsHTML.
     63   int GetInfoHTML(const std::string& key,
     64                   URLRequestContext* context,
     65                   const std::string& url_prefix,
     66                   std::string* out,
     67                   CompletionCallback* callback);
     68 
     69   // This is a helper function used to trigger a completion callback. It may
     70   // only be called if callback_ is non-null.
     71   void DoCallback(int rv);
     72 
     73   // This will trigger the completion callback if appropriate.
     74   void HandleResult(int rv);
     75 
     76   // Runs the state transition loop.
     77   int DoLoop(int result);
     78 
     79   // Each of these methods corresponds to a State value. If there is an
     80   // argument, the value corresponds to the return of the previous state or
     81   // corresponding callback.
     82   int DoGetBackend();
     83   int DoGetBackendComplete(int result);
     84   int DoOpenNextEntry();
     85   int DoOpenNextEntryComplete(int result);
     86   int DoOpenEntry();
     87   int DoOpenEntryComplete(int result);
     88   int DoReadResponse();
     89   int DoReadResponseComplete(int result);
     90   int DoReadData();
     91   int DoReadDataComplete(int result);
     92 
     93   // Called to signal completion of asynchronous IO.
     94   void OnIOComplete(int result);
     95 
     96   scoped_refptr<URLRequestContext> context_;
     97   disk_cache::Backend* disk_cache_;
     98   disk_cache::Entry* entry_;
     99   void* iter_;
    100   scoped_refptr<IOBuffer> buf_;
    101   int buf_len_;
    102   int index_;
    103 
    104   std::string key_;
    105   std::string url_prefix_;
    106   std::string* data_;
    107   CompletionCallback* callback_;
    108 
    109   State next_state_;
    110 
    111   CompletionCallbackImpl<ViewCacheHelper> cache_callback_;
    112   scoped_refptr<CancelableCompletionCallback<ViewCacheHelper> > entry_callback_;
    113 
    114   DISALLOW_COPY_AND_ASSIGN(ViewCacheHelper);
    115 };
    116 
    117 }  // namespace net.
    118 
    119 #endif  // NET_URL_REQUEST_VIEW_CACHE_HELPER_H_
    120