HTTP2PriorityQueue::Handle
HTTP2PriorityQueue::addTransaction(HTTPCodec::StreamID id,
http2::PriorityUpdate pri,
HTTPTransaction *txn,
bool permanent,
uint64_t* depth) {
CHECK_NE(id, 0);
CHECK_NE(id, pri.streamDependency) << "Tried to create a loop in the tree";
CHECK(!txn || !permanent);
Node *existingNode = find(id);
if (existingNode) {
CHECK(txn);
CHECK(!permanent);
existingNode->convertVirtualNode(txn);
updatePriority(existingNode, pri);
return existingNode;
}
if (!txn) {
if (numVirtualNodes_ >= maxVirtualNodes_) {
return nullptr;
}
numVirtualNodes_++;
}
Node* parent = &root_;
if (depth) {
*depth = 0;
}
if (pri.streamDependency != 0) {
Node* dep = find(pri.streamDependency, depth);
if (dep == nullptr) {
// specified a missing parent (timed out an idle node)?
VLOG(4) << "assigning default priority to txn=" << id;
} else {
parent = dep;
}
}
VLOG(4) << "Adding id=" << id << " with parent=" << parent->getID() <<
" and weight=" << ((uint16_t)pri.weight + 1);
auto node = folly::make_unique<Node>(*this, parent, id, pri.weight, txn);
if (permanent) {
node->setPermanent();
} else if (!txn) {
scheduleNodeExpiration(node.get());
}
auto result = parent->emplaceNode(std::move(node), pri.exclusive);
pendingWeightChange_ = true;
return result;
}
void
HTTP2PriorityQueue::removeTransaction(HTTP2PriorityQueue::Handle handle) {
Node* node = handle;
pendingWeightChange_ = true;
// TODO: or require the node to do it?
if (node->isEnqueued()) {
clearPendingEgress(handle);
}
if (allowDanglingNodes() && numVirtualNodes_ < maxVirtualNodes_) {
node->clearTransaction();
numVirtualNodes_++;
scheduleNodeExpiration(node);
} else {
VLOG(5) << "Deleting dangling node over max id=" << handle->getID();
node->removeFromTree();
}
}