[SPDY] Replace SpdyIOBuffer with new SpdyBuffer class

net/spdy/spdy_read_queue.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_read_queue.h"
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "net/spdy/spdy_buffer.h"
+
+namespace net {
+
+SpdyReadQueue::SpdyReadQueue() : total_size_(0) {}
+
+SpdyReadQueue::~SpdyReadQueue() {
+  Clear();
+}
+
+bool SpdyReadQueue::IsEmpty() const {
+  DCHECK_EQ(queue_.empty(), total_size_ == 0);
+  return queue_.empty();
+}
+
+size_t SpdyReadQueue::GetTotalSize() const {
+  return total_size_;
+}
+
+void SpdyReadQueue::Enqueue(scoped_ptr<SpdyBuffer> buffer) {
+  DCHECK_GT(buffer->GetRemainingSize(), 0u);
+  total_size_ += buffer->GetRemainingSize();
+  queue_.push_back(buffer.release());
+}
+
+size_t SpdyReadQueue::Dequeue(char* out, size_t len) {
+  DCHECK_GT(len, 0u);
+  size_t bytes_copied = 0;
+  while (!queue_.empty() && bytes_copied < len) {
+    SpdyBuffer* buffer = queue_.front();
+    size_t bytes_to_copy = std::min(len, buffer->GetRemainingSize());
+    memcpy(out + bytes_copied, buffer->GetRemainingData(), bytes_to_copy);
+    bytes_copied += bytes_to_copy;
+    if (bytes_to_copy == buffer->GetRemainingSize()) {
+      delete queue_.front();
+      queue_.pop_front();
+    } else {
+      buffer->Consume(bytes_to_copy);
+    }
+  }
+  total_size_ -= bytes_copied;
+  return bytes_copied;
+}
+
+void SpdyReadQueue::Clear() {
+  STLDeleteElements(&queue_);
+  queue_.clear();
+}
+
+}  // namespace