| Index: net/spdy/spdy_priority_forest.h
|
| diff --git a/net/spdy/spdy_priority_forest.h b/net/spdy/spdy_priority_forest.h
|
| deleted file mode 100644
|
| index 8624bbfe8eeac441b372bb7b2815035c5810a33a..0000000000000000000000000000000000000000
|
| --- a/net/spdy/spdy_priority_forest.h
|
| +++ /dev/null
|
| @@ -1,528 +0,0 @@
|
| -// 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.
|
| -
|
| -#ifndef NET_SPDY_SPDY_PRIORITY_FOREST_H_
|
| -#define NET_SPDY_SPDY_PRIORITY_FOREST_H_
|
| -
|
| -#include <map>
|
| -#include <set>
|
| -#include <vector>
|
| -
|
| -#include "base/basictypes.h"
|
| -#include "base/containers/hash_tables.h"
|
| -#include "base/logging.h"
|
| -#include "base/memory/scoped_ptr.h"
|
| -#include "base/rand_util.h"
|
| -
|
| -namespace net {
|
| -
|
| -// This data structure implements the SPDY prioriziation data structures
|
| -// defined in this document: http://go/spdy4-prioritization
|
| -//
|
| -// Nodes can be added and removed, and dependencies between them defined. Each
|
| -// node can have at most one parent and at most one child (forming a list), but
|
| -// there can be multiple lists, with each list root having its own priority.
|
| -// Individual nodes can also be marked as ready to read/write, and then the
|
| -// whole structure can be queried to pick the next node to read/write out of
|
| -// those ready.
|
| -//
|
| -// The NodeId and Priority types must be POD that support comparison (most
|
| -// likely, they will be numbers).
|
| -template <typename NodeId, typename Priority>
|
| -class SpdyPriorityForest {
|
| - public:
|
| - SpdyPriorityForest();
|
| - ~SpdyPriorityForest();
|
| -
|
| - // Return the number of nodes currently in the forest.
|
| - int num_nodes() const;
|
| -
|
| - // Return true if the forest contains a node with the given ID.
|
| - bool NodeExists(NodeId node_id) const;
|
| -
|
| - // Add a new root node to the forest, with the given priority. Returns true
|
| - // on success, or false if the node_id already exists within the forest.
|
| - bool AddRootNode(NodeId node_id, Priority priority);
|
| -
|
| - // Add a new node to the forest, with the given parent. Returns true on
|
| - // success. Returns false and has no effect if the new node already exists,
|
| - // or if the parent doesn't exist, or if the parent already has a child.
|
| - bool AddNonRootNode(NodeId node_id, NodeId parent_id, bool unordered);
|
| -
|
| - // Remove an existing node from the forest. Returns true on success, or
|
| - // false if the node doesn't exist.
|
| - bool RemoveNode(NodeId node_id);
|
| -
|
| - // Get the priority of the given node. If the node doesn't exist, or is not
|
| - // a root node (and thus has no priority), returns Priority().
|
| - Priority GetPriority(NodeId node_id) const;
|
| -
|
| - // Get the parent of the given node. If the node doesn't exist, or is a root
|
| - // node (and thus has no parent), returns NodeId().
|
| - NodeId GetParent(NodeId node_id) const;
|
| -
|
| - // Determine if the given node is unordered with respect to its parent. If
|
| - // the node doesn't exist, or is a root node (and thus has no parent),
|
| - // returns false.
|
| - bool IsNodeUnordered(NodeId node_id) const;
|
| -
|
| - // Get the child of the given node. If the node doesn't exist, or has no
|
| - // child, returns NodeId().
|
| - NodeId GetChild(NodeId node_id) const;
|
| -
|
| - // Set the priority of the given node. If the node was not already a root
|
| - // node, this makes it a root node. Returns true on success, or false if the
|
| - // node doesn't exist.
|
| - bool SetPriority(NodeId node_id, Priority priority);
|
| -
|
| - // Set the parent of the given node. If the node was a root node, this makes
|
| - // it no longer a root. Returns true on success. Returns false and has no
|
| - // effect if (1) the node and/or the parent doesn't exist, (2) the new parent
|
| - // already has a different child than the node, or (3) if the new parent is a
|
| - // descendant of the node (so this would have created a cycle).
|
| - bool SetParent(NodeId node_id, NodeId parent_id, bool unordered);
|
| -
|
| - // Check if a node is marked as ready to read. Returns false if the node
|
| - // doesn't exist.
|
| - bool IsMarkedReadyToRead(NodeId node_id) const;
|
| - // Mark the node as ready or not ready to read. Returns true on success, or
|
| - // false if the node doesn't exist.
|
| - bool MarkReadyToRead(NodeId node_id);
|
| - bool MarkNoLongerReadyToRead(NodeId node_id);
|
| - // Return the ID of the next node that we should read, or return NodeId() if
|
| - // no node in the forest is ready to read.
|
| - NodeId NextNodeToRead();
|
| -
|
| - // Check if a node is marked as ready to write. Returns false if the node
|
| - // doesn't exist.
|
| - bool IsMarkedReadyToWrite(NodeId node_id) const;
|
| - // Mark the node as ready or not ready to write. Returns true on success, or
|
| - // false if the node doesn't exist.
|
| - bool MarkReadyToWrite(NodeId node_id);
|
| - bool MarkNoLongerReadyToWrite(NodeId node_id);
|
| - // Return the ID of the next node that we should write, or return NodeId() if
|
| - // no node in the forest is ready to write.
|
| - NodeId NextNodeToWrite();
|
| -
|
| - // Return true if all internal invariants hold (useful for unit tests).
|
| - // Unless there are bugs, this should always return true.
|
| - bool ValidateInvariantsForTests() const;
|
| -
|
| - private:
|
| - enum NodeType { ROOT_NODE, NONROOT_ORDERED, NONROOT_UNORDERED };
|
| - struct Node {
|
| - Node() : type(ROOT_NODE), flags(0), child() {
|
| - depends_on.priority = Priority();
|
| - }
|
| - NodeType type;
|
| - unsigned int flags; // bitfield of flags
|
| - union {
|
| - Priority priority; // used for root nodes
|
| - NodeId parent_id; // used for non-root nodes
|
| - } depends_on;
|
| - NodeId child; // node ID of child (or NodeId() for no child)
|
| - };
|
| -
|
| - typedef base::hash_map<NodeId, Node> NodeMap;
|
| -
|
| - // Constants for the Node.flags bitset:
|
| - // kReadToRead: set for nodes that are ready for reading
|
| - static const unsigned int kReadyToRead = (1 << 0);
|
| - // kReadToWrite: set for nodes that are ready for writing
|
| - static const unsigned int kReadyToWrite = (1 << 1);
|
| -
|
| - // Common code for IsMarkedReadyToRead and IsMarkedReadyToWrite.
|
| - bool IsMarked(NodeId node_id, unsigned int flag) const;
|
| - // Common code for MarkReadyToRead and MarkReadyToWrite.
|
| - bool Mark(NodeId node_id, unsigned int flag);
|
| - // Common code for MarkNoLongerReadyToRead and MarkNoLongerReadyToWrite.
|
| - bool Unmark(NodeId node_id, unsigned int flag);
|
| - // Common code for NextNodeToRead and NextNodeToWrite;
|
| - NodeId FirstMarkedNode(unsigned int flag);
|
| - // Get the given node, or return NULL if it doesn't exist.
|
| - const Node* FindNode(NodeId node_id) const;
|
| -
|
| - NodeMap all_nodes_; // maps from node IDs to Node objects
|
| -
|
| - DISALLOW_COPY_AND_ASSIGN(SpdyPriorityForest);
|
| -};
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -SpdyPriorityForest<NodeId, Priority>::SpdyPriorityForest() {}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -SpdyPriorityForest<NodeId, Priority>::~SpdyPriorityForest() {}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -int SpdyPriorityForest<NodeId, Priority>::num_nodes() const {
|
| - return all_nodes_.size();
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::NodeExists(NodeId node_id) const {
|
| - return all_nodes_.count(node_id) != 0;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::AddRootNode(
|
| - NodeId node_id, Priority priority) {
|
| - if (NodeExists(node_id)) {
|
| - return false;
|
| - }
|
| - Node* new_node = &all_nodes_[node_id];
|
| - new_node->type = ROOT_NODE;
|
| - new_node->depends_on.priority = priority;
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::AddNonRootNode(
|
| - NodeId node_id, NodeId parent_id, bool unordered) {
|
| - if (NodeExists(node_id) || !NodeExists(parent_id)) {
|
| - return false;
|
| - }
|
| -
|
| - Node* parent = &all_nodes_[parent_id];
|
| - if (parent->child != NodeId()) {
|
| - return false;
|
| - }
|
| -
|
| - Node* new_node = &all_nodes_[node_id];
|
| - new_node->type = (unordered ? NONROOT_UNORDERED : NONROOT_ORDERED);
|
| - new_node->depends_on.parent_id = parent_id;
|
| - parent->child = node_id;
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::RemoveNode(NodeId node_id) {
|
| - if (!NodeExists(node_id)) {
|
| - return false;
|
| - }
|
| - const Node& node = all_nodes_[node_id];
|
| -
|
| - // If the node to be removed is not a root node, we need to change its
|
| - // parent's child ID.
|
| - if (node.type != ROOT_NODE) {
|
| - DCHECK(NodeExists(node.depends_on.parent_id));
|
| - Node* parent = &all_nodes_[node.depends_on.parent_id];
|
| - DCHECK_EQ(node_id, parent->child);
|
| - parent->child = node.child;
|
| - }
|
| -
|
| - // If the node has a child, we need to change the child's priority or parent.
|
| - if (node.child != NodeId()) {
|
| - DCHECK(NodeExists(node.child));
|
| - Node* child = &all_nodes_[node.child];
|
| - DCHECK_NE(ROOT_NODE, child->type);
|
| - DCHECK_EQ(node_id, child->depends_on.parent_id);
|
| - // Make the child's new depends_on be the node's depends_on (whether that
|
| - // be a priority or a parent node ID).
|
| - child->depends_on = node.depends_on;
|
| - // If the removed node was a root, its child is now a root. Otherwise, the
|
| - // child will be be unordered if and only if it was already unordered and
|
| - // the removed not is also not ordered.
|
| - if (node.type == ROOT_NODE) {
|
| - child->type = ROOT_NODE;
|
| - } else if (node.type == NONROOT_ORDERED) {
|
| - child->type = NONROOT_ORDERED;
|
| - }
|
| - }
|
| -
|
| - // Delete the node.
|
| - all_nodes_.erase(node_id);
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -Priority SpdyPriorityForest<NodeId, Priority>::GetPriority(
|
| - NodeId node_id) const {
|
| - const Node* node = FindNode(node_id);
|
| - if (node != NULL && node->type == ROOT_NODE) {
|
| - return node->depends_on.priority;
|
| - } else {
|
| - return Priority();
|
| - }
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -NodeId SpdyPriorityForest<NodeId, Priority>::GetParent(NodeId node_id) const {
|
| - const Node* node = FindNode(node_id);
|
| - if (node != NULL && node->type != ROOT_NODE) {
|
| - return node->depends_on.parent_id;
|
| - } else {
|
| - return NodeId();
|
| - }
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::IsNodeUnordered(
|
| - NodeId node_id) const {
|
| - const Node* node = FindNode(node_id);
|
| - return node != NULL && node->type == NONROOT_UNORDERED;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -NodeId SpdyPriorityForest<NodeId, Priority>::GetChild(NodeId node_id) const {
|
| - const Node* node = FindNode(node_id);
|
| - if (node != NULL) {
|
| - return node->child;
|
| - } else {
|
| - return NodeId();
|
| - }
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::SetPriority(
|
| - NodeId node_id, Priority priority) {
|
| - if (!NodeExists(node_id)) {
|
| - return false;
|
| - }
|
| -
|
| - Node* node = &all_nodes_[node_id];
|
| - // If this is not already a root node, we need to make it be a root node.
|
| - if (node->type != ROOT_NODE) {
|
| - DCHECK(NodeExists(node->depends_on.parent_id));
|
| - Node* parent = &all_nodes_[node->depends_on.parent_id];
|
| - parent->child = NodeId();
|
| - node->type = ROOT_NODE;
|
| - }
|
| -
|
| - node->depends_on.priority = priority;
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::SetParent(
|
| - NodeId node_id, NodeId parent_id, bool unordered) {
|
| - if (!NodeExists(node_id) || !NodeExists(parent_id)) {
|
| - return false;
|
| - }
|
| -
|
| - Node* node = &all_nodes_[node_id];
|
| - Node* new_parent = &all_nodes_[parent_id];
|
| - // If the new parent is already the node's parent, all we have to do is
|
| - // update the node type and we're done.
|
| - if (new_parent->child == node_id) {
|
| - node->type = (unordered ? NONROOT_UNORDERED : NONROOT_ORDERED);
|
| - return true;
|
| - }
|
| - // Otherwise, if the new parent already has a child, we fail.
|
| - if (new_parent->child != NodeId()) {
|
| - return false;
|
| - }
|
| -
|
| - // Next, make sure we won't create a cycle.
|
| - if (node_id == parent_id) return false;
|
| - Node* last = node;
|
| - NodeId last_id = node_id;
|
| - while (last->child != NodeId()) {
|
| - if (last->child == parent_id) return false;
|
| - last_id = last->child;
|
| - DCHECK(NodeExists(last_id));
|
| - last = &all_nodes_[last_id];
|
| - }
|
| -
|
| - // If the node is not a root, we need clear its old parent's child field
|
| - // (unless the old parent is the same as the new parent).
|
| - if (node->type != ROOT_NODE) {
|
| - const NodeId old_parent_id = node->depends_on.parent_id;
|
| - DCHECK(NodeExists(old_parent_id));
|
| - DCHECK(old_parent_id != parent_id);
|
| - Node* old_parent = &all_nodes_[old_parent_id];
|
| - DCHECK_EQ(node_id, old_parent->child);
|
| - old_parent->child = NodeId();
|
| - }
|
| -
|
| - // Make the change.
|
| - node->type = (unordered ? NONROOT_UNORDERED : NONROOT_ORDERED);
|
| - node->depends_on.parent_id = parent_id;
|
| - new_parent->child = node_id;
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::IsMarkedReadyToRead(
|
| - NodeId node_id) const {
|
| - return IsMarked(node_id, kReadyToRead);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::MarkReadyToRead(NodeId node_id) {
|
| - return Mark(node_id, kReadyToRead);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::MarkNoLongerReadyToRead(
|
| - NodeId node_id) {
|
| - return Unmark(node_id, kReadyToRead);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -NodeId SpdyPriorityForest<NodeId, Priority>::NextNodeToRead() {
|
| - return FirstMarkedNode(kReadyToRead);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::IsMarkedReadyToWrite(
|
| - NodeId node_id) const {
|
| - return IsMarked(node_id, kReadyToWrite);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::MarkReadyToWrite(NodeId node_id) {
|
| - return Mark(node_id, kReadyToWrite);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::MarkNoLongerReadyToWrite(
|
| - NodeId node_id) {
|
| - return Unmark(node_id, kReadyToWrite);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -NodeId SpdyPriorityForest<NodeId, Priority>::NextNodeToWrite() {
|
| - return FirstMarkedNode(kReadyToWrite);
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::IsMarked(
|
| - NodeId node_id, unsigned int flag) const {
|
| - const Node* node = FindNode(node_id);
|
| - return node != NULL && (node->flags & flag) != 0;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::Mark(
|
| - NodeId node_id, unsigned int flag) {
|
| - if (!NodeExists(node_id)) {
|
| - return false;
|
| - }
|
| - all_nodes_[node_id].flags |= flag;
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::Unmark(
|
| - NodeId node_id, unsigned int flag) {
|
| - if (!NodeExists(node_id)) {
|
| - return false;
|
| - }
|
| - all_nodes_[node_id].flags &= ~flag;
|
| - return true;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -NodeId SpdyPriorityForest<NodeId, Priority>::FirstMarkedNode(
|
| - unsigned int flag) {
|
| - // TODO(mdsteele): This is an *incredibly* stupid brute force solution.
|
| -
|
| - // Get all root nodes that have at least one marked child.
|
| - uint64 total_weight = 0;
|
| - std::map<uint64, NodeId> roots; // maps cumulative weight to root node ID
|
| - for (typename NodeMap::const_iterator iter = all_nodes_.begin();
|
| - iter != all_nodes_.end(); ++iter) {
|
| - const NodeId root_id = iter->first;
|
| - const Node& root = iter->second;
|
| - if (root.type == ROOT_NODE) {
|
| - // See if there is at least one marked node in this root's chain.
|
| - for (const Node* node = &root; ; node = &all_nodes_[node->child]) {
|
| - if ((node->flags & flag) != 0) {
|
| - total_weight += static_cast<uint64>(root.depends_on.priority);
|
| - roots[total_weight] = root_id;
|
| - break;
|
| - }
|
| - if (node->child == NodeId()) {
|
| - break;
|
| - }
|
| - DCHECK(NodeExists(node->child));
|
| - }
|
| - }
|
| - }
|
| -
|
| - // If there are no ready nodes, then return NodeId().
|
| - if (total_weight == 0) {
|
| - DCHECK(roots.empty());
|
| - return NodeId();
|
| - } else {
|
| - DCHECK(!roots.empty());
|
| - }
|
| -
|
| - // Randomly select a tree to use.
|
| - typename std::map<uint64, NodeId>::const_iterator root_iter =
|
| - roots.upper_bound(base::RandGenerator(total_weight));
|
| - DCHECK(root_iter != roots.end());
|
| - const NodeId root_id = root_iter->second;
|
| -
|
| - // Find the first node in the chain that is ready.
|
| - NodeId node_id = root_id;
|
| - while (true) {
|
| - DCHECK(NodeExists(node_id));
|
| - Node* node = &all_nodes_[node_id];
|
| - if ((node->flags & flag) != 0) {
|
| - // There might be more nodes that are ready and that are linked to this
|
| - // one in an unordered chain. Find all of them, then pick one randomly.
|
| - std::vector<NodeId> group;
|
| - group.push_back(node_id);
|
| - for (Node* next = node; next->child != NodeId();) {
|
| - DCHECK(NodeExists(next->child));
|
| - Node *child = &all_nodes_[next->child];
|
| - DCHECK_NE(ROOT_NODE, child->type);
|
| - if (child->type != NONROOT_UNORDERED) {
|
| - break;
|
| - }
|
| - if ((child->flags & flag) != 0) {
|
| - group.push_back(next->child);
|
| - }
|
| - next = child;
|
| - }
|
| - return group[base::RandGenerator(group.size())];
|
| - }
|
| - node_id = node->child;
|
| - }
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -const typename SpdyPriorityForest<NodeId, Priority>::Node*
|
| -SpdyPriorityForest<NodeId, Priority>::FindNode(NodeId node_id) const {
|
| - typename NodeMap::const_iterator iter = all_nodes_.find(node_id);
|
| - if (iter == all_nodes_.end()) {
|
| - return NULL;
|
| - }
|
| - return &iter->second;
|
| -}
|
| -
|
| -template <typename NodeId, typename Priority>
|
| -bool SpdyPriorityForest<NodeId, Priority>::ValidateInvariantsForTests() const {
|
| - for (typename NodeMap::const_iterator iter = all_nodes_.begin();
|
| - iter != all_nodes_.end(); ++iter) {
|
| - const NodeId node_id = iter->first;
|
| - const Node& node = iter->second;
|
| - if (node.type != ROOT_NODE &&
|
| - (!NodeExists(node.depends_on.parent_id) ||
|
| - GetChild(node.depends_on.parent_id) != node_id)) {
|
| - return false;
|
| - }
|
| - if (node.child != NodeId()) {
|
| - if (!NodeExists(node.child) || node_id != GetParent(node.child)) {
|
| - return false;
|
| - }
|
| - }
|
| -
|
| - NodeId child_id = node.child;
|
| - int count = 0;
|
| - while (child_id != NodeId()) {
|
| - if (count > num_nodes() || node_id == child_id) {
|
| - return false;
|
| - }
|
| - child_id = GetChild(child_id);
|
| - ++count;
|
| - }
|
| - }
|
| - return true;
|
| -}
|
| -
|
| -} // namespace net
|
| -
|
| -#endif // NET_SPDY_SPDY_PRIORITY_FOREST_H_
|
|
|