[SPDY] Replace SpdyIOBuffer with new SpdyBuffer class

net/spdy/spdy_buffer.cc

+// Copyright (c) 2013 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.
+
+#include "net/spdy/spdy_buffer.h"
+
+#include <cstring>
+
+#include "base/logging.h"
+#include "net/base/io_buffer.h"
+#include "net/spdy/spdy_protocol.h"
+
+namespace net {
+
+namespace {
+
+// Makes a SpdyFrame with |size| bytes of data copied from
+// |data|. |data| must be non-NULL and |size| must be positive.
+scoped_ptr<SpdyFrame> MakeSpdyFrame(const char* data, size_t size) {
+  DCHECK(data);
+  DCHECK_GT(size, 0u);
+  scoped_array<char> frame_data(new char[size]);
+  std::memcpy(frame_data.get(), data, size);
+  scoped_ptr<SpdyFrame> frame(
+      new SpdyFrame(frame_data.release(), size, true /* owns_buffer */));
+  return frame.Pass();
+}
+
+}  // namespace
+
+SpdyBuffer::SpdyBuffer(scoped_ptr<SpdyFrame> frame)
+    : frame_(frame.Pass()),
+      offset_(0) {}
+
+// The given data may not be strictly a SPDY frame; we (ab)use
+// |frame_| just as a container.
+SpdyBuffer::SpdyBuffer(const char* data, size_t size) :
+    frame_(MakeSpdyFrame(data, size)),
+    offset_(0) {}
+
+SpdyBuffer::~SpdyBuffer() {}
+
+const char* SpdyBuffer::GetRemainingData() const {
+  return frame_->data() + offset_;
+}
+
+size_t SpdyBuffer::GetRemainingSize() const {
+  return frame_->size() - offset_;
+}
+
+void SpdyBuffer::Consume(size_t consume_size) {
+  DCHECK_GE(consume_size, 1u);
+  DCHECK_LE(consume_size, GetRemainingSize());
+  offset_ += consume_size;
+};
+
+IOBuffer* SpdyBuffer::GetIOBufferForRemainingData() {
+  return new WrappedIOBuffer(GetRemainingData());
+}
+
+}  // namespace net