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