Split net/spdy into core and chromium subdirectories.

net/spdy/http2_priority_dependencies.h

-// Copyright 2016 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 NET_SPDY_HTTP2_PRIORITY_DEPENDENCIES_H_
-#define NET_SPDY_HTTP2_PRIORITY_DEPENDENCIES_H_
-
-#include <list>
-#include <map>
-
-#include "net/base/net_export.h"
-#include "net/spdy/spdy_protocol.h"
-
-namespace net {
-
-// A helper class encapsulating the state and logic to set dependencies of
-// HTTP2 streams based on their SpdyPriority and the ordering
-// of creation and deletion of the streams.
-class NET_EXPORT_PRIVATE Http2PriorityDependencies {
- public:
-  Http2PriorityDependencies();
-  ~Http2PriorityDependencies();
-
-  // Called when a stream is created. This is used for both client-initiated
-  // and server-initiated (pushed) streams.
-  // On return, |*dependent_stream_id| is set to the stream id that
-  // this stream should be made dependent on, and |*exclusive| set to
-  // whether that dependency should be exclusive.
-  void OnStreamCreation(SpdyStreamId id,
-                        SpdyPriority priority,
-                        SpdyStreamId* dependent_stream_id,
-                        bool* exclusive);
-
-  // Called when a stream is destroyed.
-  void OnStreamDestruction(SpdyStreamId id);
-
-  struct DependencyUpdate {
-    SpdyStreamId id;
-    SpdyStreamId dependent_stream_id;
-    bool exclusive;
-  };
-
-  // Called when a stream's priority has changed. Returns a list of
-  // dependency updates that should be sent to the server to describe
-  // the requested priority change. The updates should be sent in the
-  // given order.
-  std::vector<DependencyUpdate> OnStreamUpdate(SpdyStreamId id,
-                                               SpdyPriority new_priority);
-
-  // Returns the estimate of dynamically allocated memory in bytes.
-  size_t EstimateMemoryUsage() const;
-
- private:
-  // The requirements for the internal data structure for this class are:
-  //     a) Constant time insertion of entries at the end of the list,
-  //     b) Fast removal of any entry based on its id.
-  //     c) Constant time lookup of the entry at the end of the list.
-  // std::list would satisfy (a) & (c), but some form of map is
-  // needed for (b).  The priority must be included in the map
-  // entries so that deletion can determine which list in id_priority_lists_
-  // to erase from.
-  using IdList = std::list<std::pair<SpdyStreamId, SpdyPriority>>;
-  using EntryMap = std::map<SpdyStreamId, IdList::iterator>;
-
-  IdList id_priority_lists_[kV3LowestPriority + 1];
-
-  // Tracks the location of an id anywhere in the above vector of lists.
-  // Iterators to list elements remain valid until those particular elements
-  // are erased.
-  EntryMap entry_by_stream_id_;
-
-  // Finds the lowest-priority stream that has a priority >= |priority|.
-  // Returns false if there are no such streams.
-  // Otherwise, returns true and sets |*bound|.
-  bool PriorityLowerBound(SpdyPriority priority, IdList::iterator* bound);
-
-  // Finds the stream just above |id| in the total order.
-  // Returns false if there are no streams with a higher priority.
-  // Otherwise, returns true and sets |*parent|.
-  bool ParentOfStream(SpdyStreamId id, IdList::iterator* parent);
-
-  // Finds the stream just below |id| in the total order.
-  // Returns false if there are no streams with a lower priority.
-  // Otherwise, returns true and sets |*child|.
-  bool ChildOfStream(SpdyStreamId id, IdList::iterator* child);
-};
-
-}  // namespace net
-
-#endif  // NET_SPDY_HTTP2_PRIORITY_DEPENDENCIES_H_