[SPDY] Refactor SpdySession's write queue

net/spdy/spdy_write_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_write_queue.h"
+
+#include <cstddef>
+
+#include "base/logging.h"
+#include "net/spdy/spdy_frame_producer.h"
+#include "net/spdy/spdy_stream.h"
+
+namespace net {
+
+SpdyWriteQueue::PendingWrite::PendingWrite() : frame_producer(NULL) {}
+
+SpdyWriteQueue::PendingWrite::PendingWrite(
+    SpdyFrameProducer* frame_producer,
+    const scoped_refptr<SpdyStream>& stream)
+    : frame_producer(frame_producer),
+      stream(stream) {}
+
+SpdyWriteQueue::PendingWrite::~PendingWrite() {}
+
+SpdyWriteQueue::SpdyWriteQueue() {}
+
+SpdyWriteQueue::~SpdyWriteQueue() {
+  Clear();
+}
+
+void SpdyWriteQueue::Enqueue(RequestPriority priority,
+                             scoped_ptr<SpdyFrameProducer> frame_producer,
+                             const scoped_refptr<SpdyStream>& stream) {
+  if (stream.get()) {
+    DCHECK_EQ(stream->priority(), priority);
+  }
+  queue_[priority].push_back(PendingWrite(frame_producer.release(), stream));
+}
+
+bool SpdyWriteQueue::Dequeue(scoped_ptr<SpdyFrameProducer>* frame_producer,
+                             scoped_refptr<SpdyStream>* stream) {
+  for (int i = NUM_PRIORITIES - 1; i >= 0; --i) {
+    if (!queue_[i].empty()) {
+      PendingWrite pending_write = queue_[i].front();
+      queue_[i].pop_front();
+      frame_producer->reset(pending_write.frame_producer);
+      *stream = pending_write.stream;
+      return true;
+    }
+  }
+  return false;
+}
+
+void SpdyWriteQueue::RemovePendingWritesForStream(
+    const scoped_refptr<SpdyStream>& stream) {
+  DCHECK(stream.get());
+  if (DCHECK_IS_ON()) {
+    // |stream| should not have pending writes in a queue not matching
+    // its priority.
+    for (int i = 0; i < NUM_PRIORITIES; ++i) {
+      if (stream->priority() == i)
+        continue;
+      for (std::deque<PendingWrite>::const_iterator it = queue_[i].begin();
+           it != queue_[i].end(); ++it) {
+        DCHECK_NE(it->stream, stream);
+      }
+    }
+  }
+
+  // Do the actual deletion and removal, preserving FIFO-ness.
+  std::deque<PendingWrite>* queue = &queue_[stream->priority()];
+  std::deque<PendingWrite>::iterator out_it = queue->begin();
+  for (std::deque<PendingWrite>::const_iterator it = queue->begin();
+       it != queue->end(); ++it) {
+    if (it->stream == stream) {
+      delete it->frame_producer;
+    } else {
+      *out_it = *it;
+      ++out_it;
+    }
+  }
+  queue->erase(out_it, queue->end());
+}
+
+void SpdyWriteQueue::Clear() {
+  for (int i = 0; i < NUM_PRIORITIES; ++i) {
+    for (std::deque<PendingWrite>::iterator it = queue_[i].begin();
+         it != queue_[i].end(); ++it) {
+      delete it->frame_producer;
+    }
+    queue_[i].clear();
+  }
+}
+
+}  // namespace net