net/base/upload_data_stream.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_BASE_UPLOAD_DATA_STREAM_H_
   6 #define NET_BASE_UPLOAD_DATA_STREAM_H_
   7 #pragma once
   8
   9 #include "base/memory/ref_counted.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   explicit UploadDataStream(UploadData* upload_data);
  21   ~UploadDataStream();
  22
  23   // Initializes the stream. This function must be called exactly once,
  24   // before calling any other method. It is not valid to call any method
  25   // (other than the destructor) if Init() returns a failure.
  26   //
  27   // Returns OK on success. Returns ERR_UPLOAD_FILE_CHANGED if the expected
  28   // file modification time is set (usually not set, but set for sliced
  29   // files) and the target file is changed.
  30   int Init();
  31
  32   // Reads up to |buf_len| bytes from the upload data stream to |buf|. The
  33   // number of bytes read is returned. Partial reads are allowed.  Zero is
  34   // returned on a call to Read when there are no remaining bytes in the
  35   // stream, and IsEof() will return true hereafter.
  36   //
  37   // If there's less data to read than we initially observed (i.e. the actual
  38   // upload data is smaller than size()), zeros are padded to ensure that
  39   // size() bytes can be read, which can happen for TYPE_FILE payloads.
  40   //
  41   // If the upload data stream is chunked (i.e. is_chunked() is true),
  42   // ERR_IO_PENDING is returned to indicate there is nothing to read at the
  43   // moment, but more data to come at a later time. If not chunked, reads
  44   // won't fail.
  45   int Read(IOBuffer* buf, int buf_len);
  46
  47   // Sets the callback to be invoked when new chunks are available to upload.
  48   void set_chunk_callback(ChunkCallback* callback) {
  49     upload_data_->set_chunk_callback(callback);
  50   }
  51
  52   // Returns the total size of the data stream and the current position.
  53   // size() is not to be used to determine whether the stream has ended
  54   // because it is possible for the stream to end before its size is reached,
  55   // for example, if the file is truncated.
  56   uint64 size() const { return total_size_; }
  57   uint64 position() const { return current_position_; }
  58
  59   bool is_chunked() const { return upload_data_->is_chunked(); }
  60
  61   // Returns true if all data has been consumed from this upload data
  62   // stream.
  63   bool IsEOF() const;
  64
  65   // Returns true if the upload data in the stream is entirely in memory.
  66   bool IsInMemory() const;
  67
  68   // This method is provided only to be used by unit tests.
  69   static void set_merge_chunks(bool merge) { merge_chunks_ = merge; }
  70
  71  private:
  72   scoped_refptr<UploadData> upload_data_;
  73
  74   // Index of the current upload element (i.e. the element currently being
  75   // read). The index is used as a cursor to iterate over elements in
  76   // |upload_data_|.
  77   size_t element_index_;
  78
  79   // Size and current read position within the upload data stream.
  80   uint64 total_size_;
  81   uint64 current_position_;
  82
  83   // True if the initialization was successful.
  84   bool initialized_successfully_;
  85
  86   // TODO(satish): Remove this once we have a better way to unit test POST
  87   // requests with chunked uploads.
  88   static bool merge_chunks_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
  91 };
  92
  93 }  // namespace net
  94
  95 #endif  // NET_BASE_UPLOAD_DATA_STREAM_H_