net/url_request/view_cache_helper.h

   1 // Copyright (c) 2012 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
   8 #include <string>
   9
  10 #include "base/memory/weak_ptr.h"
  11 #include "net/base/completion_callback.h"
  12 #include "net/base/io_buffer.h"
  13 #include "net/base/net_export.h"
  14 #include "net/disk_cache/disk_cache.h"
  15
  16 namespace net {
  17
  18 class URLRequestContext;
  19
  20 class NET_EXPORT ViewCacheHelper {
  21  public:
  22   ViewCacheHelper();
  23   ~ViewCacheHelper();
  24
  25   // Formats the cache information for |key| as HTML. Returns a net error code.
  26   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
  27   // operation completes. |out| must remain valid until this operation completes
  28   // or the object is destroyed.
  29   int GetEntryInfoHTML(const std::string& key,
  30                        const URLRequestContext* context,
  31                        std::string* out,
  32                        const CompletionCallback& callback);
  33
  34   // Formats the cache contents as HTML. Returns a net error code.
  35   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
  36   // operation completes. |out| must remain valid until this operation completes
  37   // or the object is destroyed. |url_prefix| will be prepended to each entry
  38   // key as a link to the entry.
  39   int GetContentsHTML(const URLRequestContext* context,
  40                       const std::string& url_prefix,
  41                       std::string* out,
  42                       const CompletionCallback& callback);
  43
  44   // Lower-level helper to produce a textual representation of binary data.
  45   // The results are appended to |result| and can be used in HTML pages
  46   // provided the dump is contained within <pre></pre> tags.
  47   static void HexDump(const char *buf, size_t buf_len, std::string* result);
  48
  49  private:
  50   enum State {
  51     STATE_NONE,
  52     STATE_GET_BACKEND,
  53     STATE_GET_BACKEND_COMPLETE,
  54     STATE_OPEN_NEXT_ENTRY,
  55     STATE_OPEN_NEXT_ENTRY_COMPLETE,
  56     STATE_OPEN_ENTRY,
  57     STATE_OPEN_ENTRY_COMPLETE,
  58     STATE_READ_RESPONSE,
  59     STATE_READ_RESPONSE_COMPLETE,
  60     STATE_READ_DATA,
  61     STATE_READ_DATA_COMPLETE
  62   };
  63
  64   // Implements GetEntryInfoHTML and GetContentsHTML.
  65   int GetInfoHTML(const std::string& key,
  66                   const URLRequestContext* context,
  67                   const std::string& url_prefix,
  68                   std::string* out,
  69                   const CompletionCallback& callback);
  70
  71   // This is a helper function used to trigger a completion callback. It may
  72   // only be called if callback_ is non-null.
  73   void DoCallback(int rv);
  74
  75   // This will trigger the completion callback if appropriate.
  76   void HandleResult(int rv);
  77
  78   // Runs the state transition loop.
  79   int DoLoop(int result);
  80
  81   // Each of these methods corresponds to a State value. If there is an
  82   // argument, the value corresponds to the return of the previous state or
  83   // corresponding callback.
  84   int DoGetBackend();
  85   int DoGetBackendComplete(int result);
  86   int DoOpenNextEntry();
  87   int DoOpenNextEntryComplete(int result);
  88   int DoOpenEntry();
  89   int DoOpenEntryComplete(int result);
  90   int DoReadResponse();
  91   int DoReadResponseComplete(int result);
  92   int DoReadData();
  93   int DoReadDataComplete(int result);
  94
  95   // Called to signal completion of asynchronous IO.
  96   void OnIOComplete(int result);
  97
  98   const URLRequestContext* context_;
  99   disk_cache::Backend* disk_cache_;
 100   disk_cache::Entry* entry_;
 101   scoped_ptr<disk_cache::Backend::Iterator> iter_;
 102   scoped_refptr<IOBuffer> buf_;
 103   int buf_len_;
 104   int index_;
 105
 106   std::string key_;
 107   std::string url_prefix_;
 108   std::string* data_;
 109   CompletionCallback callback_;
 110
 111   State next_state_;
 112
 113   base::WeakPtrFactory<ViewCacheHelper> weak_factory_;
 114
 115   DISALLOW_COPY_AND_ASSIGN(ViewCacheHelper);
 116 };
 117
 118 }  // namespace net.
 119
 120 #endif  // NET_URL_REQUEST_VIEW_CACHE_HELPER_H_