net/base/upload_data_stream.h

   1 // Copyright (c) 2011 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_BASE_UPLOAD_DATA_STREAM_H_
   6 #define NET_BASE_UPLOAD_DATA_STREAM_H_
   7 #pragma once
   8
   9 #include "base/memory/scoped_ptr.h"
  10 #include "net/base/net_export.h"
  11 #include "net/base/upload_data.h"
  12
  13 namespace net {
  14
  15 class FileStream;
  16 class IOBuffer;
  17
  18 class NET_EXPORT UploadDataStream {
  19  public:
  20   ~UploadDataStream();
  21
  22   // Returns a new instance of UploadDataStream if it can be created and
  23   // initialized successfully. If not, NULL will be returned and the error
  24   // code will be set if the output parameter error_code is not empty.
  25   static UploadDataStream* Create(UploadData* data, int* error_code);
  26
  27   // Returns the stream's buffer and buffer length.
  28   IOBuffer* buf() const { return buf_; }
  29   size_t buf_len() const { return buf_len_; }
  30
  31   // TODO(satish): We should ideally have UploadDataStream expose a Read()
  32   // method which returns data in a caller provided IOBuffer. That would do away
  33   // with this method and make the interface cleaner as well with less memmove
  34   // calls.
  35   size_t GetMaxBufferSize() const { return kBufSize; }
  36
  37   // Call to indicate that a portion of the stream's buffer was consumed.  This
  38   // call modifies the stream's buffer so that it contains the next segment of
  39   // the upload data to be consumed.
  40   void MarkConsumedAndFillBuffer(size_t num_bytes);
  41
  42   // Sets the callback to be invoked when new chunks are available to upload.
  43   void set_chunk_callback(ChunkCallback* callback) {
  44     data_->set_chunk_callback(callback);
  45   }
  46
  47   // Returns the total size of the data stream and the current position.
  48   // size() is not to be used to determine whether the stream has ended
  49   // because it is possible for the stream to end before its size is reached,
  50   // for example, if the file is truncated.
  51   uint64 size() const { return total_size_; }
  52   uint64 position() const { return current_position_; }
  53
  54   bool is_chunked() const { return data_->is_chunked(); }
  55
  56   // Returns whether there is no more data to read, regardless of whether
  57   // position < size.
  58   bool eof() const { return eof_; }
  59
  60   // Returns whether the data available in buf() includes the last chunk in a
  61   // chunked data stream. This method returns true once the final chunk has been
  62   // placed in the IOBuffer returned by buf(), in contrast to eof() which
  63   // returns true only after the data in buf() has been consumed.
  64   bool IsOnLastChunk() const;
  65
  66   // This method is provided only to be used by unit tests.
  67   static void set_merge_chunks(bool merge) { merge_chunks_ = merge; }
  68
  69  private:
  70   enum { kBufSize = 16384 };
  71
  72   // Protects from public access since now we have a static creator function
  73   // which will do both creation and initialization and might return an error.
  74   explicit UploadDataStream(UploadData* data);
  75
  76   // Fills the buffer with any remaining data and sets eof_ if there was nothing
  77   // left to fill the buffer with.
  78   // Returns OK if the operation succeeds. Otherwise error code is returned.
  79   int FillBuf();
  80
  81   scoped_refptr<UploadData> data_;
  82
  83   // This buffer is filled with data to be uploaded.  The data to be sent is
  84   // always at the front of the buffer.  If we cannot send all of the buffer at
  85   // once, then we memmove the remaining portion and back-fill the buffer for
  86   // the next "write" call.  buf_len_ indicates how much data is in the buffer.
  87   scoped_refptr<IOBuffer> buf_;
  88   size_t buf_len_;
  89
  90   // Index of the upload element to be written to the send buffer next.
  91   size_t next_element_;
  92
  93   // The byte offset into next_element_'s data buffer if the next element is
  94   // a TYPE_BYTES element.
  95   size_t next_element_offset_;
  96
  97   // A stream to the currently open file, for next_element_ if the next element
  98   // is a TYPE_FILE element.
  99   scoped_ptr<FileStream> next_element_stream_;
 100
 101   // The number of bytes remaining to be read from the currently open file
 102   // if the next element is of TYPE_FILE.
 103   uint64 next_element_remaining_;
 104
 105   // Size and current read position within the stream.
 106   uint64 total_size_;
 107   uint64 current_position_;
 108
 109   // Whether there is no data left to read.
 110   bool eof_;
 111
 112   // TODO(satish): Remove this once we have a better way to unit test POST
 113   // requests with chunked uploads.
 114   static bool merge_chunks_;
 115
 116   DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
 117 };
 118
 119 }  // namespace net
 120
 121 #endif  // NET_BASE_UPLOAD_DATA_STREAM_H_