| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.cassandra.service; |
| |
| import java.net.InetAddress; |
| import java.util.UUID; |
| import java.util.concurrent.ThreadLocalRandom; |
| |
| import org.apache.cassandra.tracing.Tracing; |
| |
| /** |
| * Represents the state related to a given query. |
| */ |
| public class QueryState |
| { |
| private final ClientState clientState; |
| private volatile UUID preparedTracingSession; |
| |
| public QueryState(ClientState clientState) |
| { |
| this.clientState = clientState; |
| } |
| |
| /** |
| * @return a QueryState object for internal C* calls (not limited by any kind of auth). |
| */ |
| public static QueryState forInternalCalls() |
| { |
| return new QueryState(ClientState.forInternalCalls()); |
| } |
| |
| public ClientState getClientState() |
| { |
| return clientState; |
| } |
| |
| /** |
| * This clock guarantees that updates for the same QueryState will be ordered |
| * in the sequence seen, even if multiple updates happen in the same millisecond. |
| */ |
| public long getTimestamp() |
| { |
| return clientState.getTimestamp(); |
| } |
| |
| public boolean traceNextQuery() |
| { |
| if (preparedTracingSession != null) |
| { |
| return true; |
| } |
| |
| double traceProbability = StorageService.instance.getTraceProbability(); |
| return traceProbability != 0 && ThreadLocalRandom.current().nextDouble() < traceProbability; |
| } |
| |
| public void prepareTracingSession(UUID sessionId) |
| { |
| this.preparedTracingSession = sessionId; |
| } |
| |
| public void createTracingSession() |
| { |
| UUID session = this.preparedTracingSession; |
| if (session == null) |
| { |
| Tracing.instance.newSession(); |
| } |
| else |
| { |
| Tracing.instance.newSession(session); |
| this.preparedTracingSession = null; |
| } |
| } |
| |
| public InetAddress getClientAddress() |
| { |
| return clientState.isInternal |
| ? null |
| : clientState.getRemoteAddress().getAddress(); |
| } |
| } |