Copy the (early prototype of) remoting in Chrome into the public tree....

remoting/base/multiple_array_input_stream.h

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_BASE_MULTIPLE_ARRAY_INPUT_STREAM_H_
+#define REMOTING_BASE_MULTIPLE_ARRAY_INPUT_STREAM_H_
+
+#include "base/basictypes.h"
+#include "base/scoped_ptr.h"
+#include "google/protobuf/io/zero_copy_stream.h"
+
+namespace remoting {
+
+// A MultipleArrayInputStream provides a ZeroCopyInputStream with multiple
+// backing arrays.
+class MultipleArrayInputStream :
+      public google::protobuf::io::ZeroCopyInputStream {
+ public:
+  // Construct a MultipleArrayInputStream with |count| backing arrays.
+  // TODO(hclam): Consider adding block size to see if it has a performance
+  // gain.
+  explicit MultipleArrayInputStream(int count);
+  virtual ~MultipleArrayInputStream();
+
+  virtual bool Next(const void** data, int* size);
+  virtual void BackUp(int count);
+  virtual bool Skip(int count);
+  virtual int64 ByteCount() const;
+
+  // Set the n-th buffer to be |buffer|.
+  void SetBuffer(int n, const uint8* buffer, int size);
+
+ private:
+  scoped_array<const uint8*> buffers_;
+  scoped_array<int> buffer_sizes_;
+
+  const int buffer_count_;
+
+  int current_buffer_;
+  int current_buffer_offset_;
+  int position_;
+  int last_returned_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(MultipleArrayInputStream);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_BASE_MULTIPLE_ARRAY_INPUT_STREAM_H_