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      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 WEBKIT_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
      6 #define WEBKIT_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
      7 
      8 #include <map>
      9 
     10 #include "base/memory/scoped_ptr.h"
     11 #include "base/memory/weak_ptr.h"
     12 #include "base/platform_file.h"
     13 #include "net/http/http_byte_range.h"
     14 #include "net/http/http_status_code.h"
     15 #include "net/url_request/url_request_job.h"
     16 #include "webkit/browser/webkit_storage_browser_export.h"
     17 #include "webkit/common/blob/blob_data.h"
     18 
     19 namespace base {
     20 class MessageLoopProxy;
     21 struct PlatformFileInfo;
     22 }
     23 
     24 namespace fileapi {
     25 class FileSystemContext;
     26 }
     27 
     28 namespace net {
     29 class DrainableIOBuffer;
     30 class IOBuffer;
     31 }
     32 
     33 namespace webkit_blob {
     34 
     35 class FileStreamReader;
     36 
     37 // A request job that handles reading blob URLs.
     38 class WEBKIT_STORAGE_BROWSER_EXPORT BlobURLRequestJob
     39     : public net::URLRequestJob {
     40  public:
     41   BlobURLRequestJob(net::URLRequest* request,
     42                     net::NetworkDelegate* network_delegate,
     43                     BlobData* blob_data,
     44                     fileapi::FileSystemContext* file_system_context,
     45                     base::MessageLoopProxy* resolving_message_loop_proxy);
     46 
     47   // net::URLRequestJob methods.
     48   virtual void Start() OVERRIDE;
     49   virtual void Kill() OVERRIDE;
     50   virtual bool ReadRawData(net::IOBuffer* buf,
     51                            int buf_size,
     52                            int* bytes_read) OVERRIDE;
     53   virtual bool GetMimeType(std::string* mime_type) const OVERRIDE;
     54   virtual void GetResponseInfo(net::HttpResponseInfo* info) OVERRIDE;
     55   virtual int GetResponseCode() const OVERRIDE;
     56   virtual void SetExtraRequestHeaders(
     57       const net::HttpRequestHeaders& headers) OVERRIDE;
     58 
     59  protected:
     60   virtual ~BlobURLRequestJob();
     61 
     62  private:
     63   typedef std::map<size_t, FileStreamReader*> IndexToReaderMap;
     64 
     65   // For preparing for read: get the size, apply the range and perform seek.
     66   void DidStart();
     67   bool AddItemLength(size_t index, int64 item_length);
     68   void CountSize();
     69   void DidCountSize(int error);
     70   void DidGetFileItemLength(size_t index, int64 result);
     71   void Seek(int64 offset);
     72 
     73   // For reading the blob.
     74   bool ReadLoop(int* bytes_read);
     75   bool ReadItem();
     76   void AdvanceItem();
     77   void AdvanceBytesRead(int result);
     78   bool ReadBytesItem(const BlobData::Item& item, int bytes_to_read);
     79   bool ReadFileItem(FileStreamReader* reader, int bytes_to_read);
     80 
     81   void DidReadFile(int result);
     82   void DeleteCurrentFileReader();
     83 
     84   int ComputeBytesToRead() const;
     85   int BytesReadCompleted();
     86 
     87   // These methods convert the result of blob data reading into response headers
     88   // and pass it to URLRequestJob's NotifyDone() or NotifyHeadersComplete().
     89   void NotifySuccess();
     90   void NotifyFailure(int);
     91   void HeadersCompleted(net::HttpStatusCode status_code);
     92 
     93   // Returns a FileStreamReader for a blob item at |index|.
     94   // If the item at |index| is not of file this returns NULL.
     95   FileStreamReader* GetFileStreamReader(size_t index);
     96 
     97   // Creates a FileStreamReader for the item at |index| with additional_offset.
     98   void CreateFileStreamReader(size_t index, int64 additional_offset);
     99 
    100   base::WeakPtrFactory<BlobURLRequestJob> weak_factory_;
    101 
    102   scoped_refptr<BlobData> blob_data_;
    103 
    104   // Variables for controlling read from |blob_data_|.
    105   scoped_refptr<fileapi::FileSystemContext> file_system_context_;
    106   scoped_refptr<base::MessageLoopProxy> file_thread_proxy_;
    107   std::vector<int64> item_length_list_;
    108   int64 total_size_;
    109   int64 remaining_bytes_;
    110   int pending_get_file_info_count_;
    111   IndexToReaderMap index_to_reader_;
    112   size_t current_item_index_;
    113   int64 current_item_offset_;
    114 
    115   // Holds the buffer for read data with the IOBuffer interface.
    116   scoped_refptr<net::DrainableIOBuffer> read_buf_;
    117 
    118   // Is set when NotifyFailure() is called and reset when DidStart is called.
    119   bool error_;
    120 
    121   bool byte_range_set_;
    122   net::HttpByteRange byte_range_;
    123 
    124   scoped_ptr<net::HttpResponseInfo> response_info_;
    125 
    126   DISALLOW_COPY_AND_ASSIGN(BlobURLRequestJob);
    127 };
    128 
    129 }  // namespace webkit_blob
    130 
    131 #endif  // WEBKIT_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
    132