pdf/document_loader.h

   1 // Copyright (c) 2010 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 PDF_DOCUMENT_LOADER_H_
   6 #define PDF_DOCUMENT_LOADER_H_
   7
   8 #include <list>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "pdf/chunk_stream.h"
  14 #include "ppapi/cpp/url_loader.h"
  15 #include "ppapi/utility/completion_callback_factory.h"
  16
  17 #define kDefaultRequestSize 32768u
  18
  19 namespace chrome_pdf {
  20
  21 class DocumentLoader {
  22  public:
  23   class Client {
  24   public:
  25     // Gets the pp::Instance object.
  26     virtual pp::Instance* GetPluginInstance() = 0;
  27     // Creates new URLLoader based on client settings.
  28     virtual pp::URLLoader CreateURLLoader() = 0;
  29     // Notification called when partial information about document is available.
  30     // Only called for urls that returns full content size and supports byte
  31     // range requests.
  32     virtual void OnPartialDocumentLoaded() = 0;
  33     // Notification called when all outstanding pending requests are complete.
  34     virtual void OnPendingRequestComplete() = 0;
  35     // Notification called when new data is available.
  36     virtual void OnNewDataAvailable() = 0;
  37     // Notification called when document is fully loaded.
  38     virtual void OnDocumentComplete() = 0;
  39   };
  40
  41   explicit DocumentLoader(Client* client);
  42   virtual ~DocumentLoader();
  43
  44   bool Init(const pp::URLLoader& loader,
  45             const std::string& url,
  46             const std::string& headers);
  47
  48   // Data access interface. Return true is sucessful.
  49   bool GetBlock(uint32 position, uint32 size, void* buf) const;
  50
  51   // Data availability interface. Return true data avaialble.
  52   bool IsDataAvailable(uint32 position, uint32 size) const;
  53
  54   // Data availability interface. Return true data avaialble.
  55   void RequestData(uint32 position, uint32 size);
  56
  57   bool IsDocumentComplete() const;
  58   uint32 document_size() const { return document_size_; }
  59
  60   // Return number of bytes available.
  61   uint32 GetAvailableData() const;
  62
  63   // Clear pending requests from the queue.
  64   void ClearPendingRequests();
  65
  66   bool is_partial_document() { return partial_document_; }
  67
  68  private:
  69   // Called by the completion callback of the document's URLLoader.
  70   void DidOpen(int32_t result);
  71   // Call to read data from the document's URLLoader.
  72   void ReadMore();
  73   // Called by the completion callback of the document's URLLoader.
  74   void DidRead(int32_t result);
  75
  76   // If the headers have a byte-range response, writes the start and end
  77   // positions and returns true if at least the start position was parsed.
  78   // The end position will be set to 0 if it was not found or parsed from the
  79   // response.
  80   // Returns false if not even a start position could be parsed.
  81   static bool GetByteRange(const std::string& headers, uint32* start,
  82                            uint32* end);
  83
  84   // If the headers have a multi-part response, returns the boundary name.
  85   // Otherwise returns an empty string.
  86   static std::string GetMultiPartBoundary(const std::string& headers);
  87
  88   // Called when we detect that partial document load is possible.
  89   void LoadPartialDocument();
  90   // Called when we have to load full document.
  91   void LoadFullDocument();
  92   // Download pending requests.
  93   void DownloadPendingRequests();
  94   // Called when we complete server request and read all data from it.
  95   void ReadComplete();
  96   // Creates request to download size byte of data data starting from position.
  97   pp::URLRequestInfo GetRequest(uint32 position, uint32 size) const;
  98   // Returns current request size in bytes.
  99   uint32 GetRequestSize() const;
 100
 101   Client* client_;
 102   std::string url_;
 103   pp::URLLoader loader_;
 104   pp::CompletionCallbackFactory<DocumentLoader> loader_factory_;
 105   ChunkStream chunk_stream_;
 106   bool partial_document_;
 107   bool request_pending_;
 108   typedef std::list<std::pair<size_t, size_t> > PendingRequests;
 109   PendingRequests pending_requests_;
 110   char buffer_[kDefaultRequestSize];
 111   uint32 current_pos_;
 112   uint32 current_chunk_size_;
 113   uint32 current_chunk_read_;
 114   uint32 document_size_;
 115   bool header_request_;
 116   bool is_multipart_;
 117   std::string multipart_boundary_;
 118   uint32 requests_count_;
 119   std::list<std::vector<unsigned char> > chunk_buffer_;
 120 };
 121
 122 }  // namespace chrome_pdf
 123
 124 #endif  // PDF_DOCUMENT_LOADER_H_