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
  15 namespace disk_cache {
  16 class Backend;
  17 class Entry;
  18 }  // namespace disk_cache
  19
  20 namespace net {
  21
  22 class URLRequestContext;
  23
  24 class NET_EXPORT ViewCacheHelper {
  25  public:
  26   ViewCacheHelper();
  27   ~ViewCacheHelper();
  28
  29   // Formats the cache information for |key| as HTML. Returns a net error code.
  30   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
  31   // operation completes. |out| must remain valid until this operation completes
  32   // or the object is destroyed.
  33   int GetEntryInfoHTML(const std::string& key,
  34                        const URLRequestContext* context,
  35                        std::string* out,
  36                        const CompletionCallback& callback);
  37
  38   // Formats the cache contents as HTML. Returns a net error code.
  39   // If this method returns ERR_IO_PENDING, |callback| will be notified when the
  40   // operation completes. |out| must remain valid until this operation completes
  41   // or the object is destroyed. |url_prefix| will be prepended to each entry
  42   // key as a link to the entry.
  43   int GetContentsHTML(const URLRequestContext* context,
  44                       const std::string& url_prefix,
  45                       std::string* out,
  46                       const CompletionCallback& callback);
  47
  48   // Lower-level helper to produce a textual representation of binary data.
  49   // The results are appended to |result| and can be used in HTML pages
  50   // provided the dump is contained within <pre></pre> tags.
  51   static void HexDump(const char *buf, size_t buf_len, std::string* result);
  52
  53  private:
  54   enum State {
  55     STATE_NONE,
  56     STATE_GET_BACKEND,
  57     STATE_GET_BACKEND_COMPLETE,
  58     STATE_OPEN_NEXT_ENTRY,
  59     STATE_OPEN_NEXT_ENTRY_COMPLETE,
  60     STATE_OPEN_ENTRY,
  61     STATE_OPEN_ENTRY_COMPLETE,
  62     STATE_READ_RESPONSE,
  63     STATE_READ_RESPONSE_COMPLETE,
  64     STATE_READ_DATA,
  65     STATE_READ_DATA_COMPLETE
  66   };
  67
  68   // Implements GetEntryInfoHTML and GetContentsHTML.
  69   int GetInfoHTML(const std::string& key,
  70                   const URLRequestContext* context,
  71                   const std::string& url_prefix,
  72                   std::string* out,
  73                   const CompletionCallback& callback);
  74
  75   // This is a helper function used to trigger a completion callback. It may
  76   // only be called if callback_ is non-null.
  77   void DoCallback(int rv);
  78
  79   // This will trigger the completion callback if appropriate.
  80   void HandleResult(int rv);
  81
  82   // Runs the state transition loop.
  83   int DoLoop(int result);
  84
  85   // Each of these methods corresponds to a State value. If there is an
  86   // argument, the value corresponds to the return of the previous state or
  87   // corresponding callback.
  88   int DoGetBackend();
  89   int DoGetBackendComplete(int result);
  90   int DoOpenNextEntry();
  91   int DoOpenNextEntryComplete(int result);
  92   int DoOpenEntry();
  93   int DoOpenEntryComplete(int result);
  94   int DoReadResponse();
  95   int DoReadResponseComplete(int result);
  96   int DoReadData();
  97   int DoReadDataComplete(int result);
  98
  99   // Called to signal completion of asynchronous IO.
 100   void OnIOComplete(int result);
 101
 102   const URLRequestContext* context_;
 103   disk_cache::Backend* disk_cache_;
 104   disk_cache::Entry* entry_;
 105   void* iter_;
 106   scoped_refptr<IOBuffer> buf_;
 107   int buf_len_;
 108   int index_;
 109
 110   std::string key_;
 111   std::string url_prefix_;
 112   std::string* data_;
 113   CompletionCallback callback_;
 114
 115   State next_state_;
 116
 117   base::WeakPtrFactory<ViewCacheHelper> weak_factory_;
 118
 119   DISALLOW_COPY_AND_ASSIGN(ViewCacheHelper);
 120 };
 121
 122 }  // namespace net.
 123
 124 #endif  // NET_URL_REQUEST_VIEW_CACHE_HELPER_H_