| /* |
| * 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.drill.exec.server; |
| /* |
| State manager to manage the state of drillbit. |
| */ |
| public class DrillbitStateManager { |
| |
| public enum DrillbitState { |
| STARTUP, ONLINE, GRACE, DRAINING, OFFLINE, SHUTDOWN |
| } |
| |
| private DrillbitState currentState; |
| |
| public DrillbitStateManager(DrillbitState currentState) { |
| this.currentState = currentState; |
| } |
| |
| public DrillbitState getState() { |
| return currentState; |
| } |
| |
| public void setState(DrillbitState newState) { |
| switch (newState) { |
| case ONLINE: |
| if (currentState == DrillbitState.STARTUP) { |
| currentState = newState; |
| } else { |
| throw new IllegalStateException("Cannot set drillbit to" + newState + "from" + currentState); |
| } |
| break; |
| case GRACE: |
| if (currentState == DrillbitState.ONLINE) { |
| currentState = newState; |
| } else { |
| throw new IllegalStateException("Cannot set drillbit to" + newState + "from" + currentState); |
| } |
| break; |
| case DRAINING: |
| if (currentState == DrillbitState.GRACE) { |
| currentState = newState; |
| } else { |
| throw new IllegalStateException("Cannot set drillbit to" + newState + "from" + currentState); |
| } |
| break; |
| case OFFLINE: |
| if (currentState == DrillbitState.DRAINING) { |
| currentState = newState; |
| } else { |
| throw new IllegalStateException("Cannot set drillbit to" + newState + "from" + currentState); |
| } |
| break; |
| case SHUTDOWN: |
| if (currentState == DrillbitState.OFFLINE) { |
| currentState = newState; |
| } else { |
| throw new IllegalStateException("Cannot set drillbit to" + newState + "from" + currentState); |
| } |
| break; |
| } |
| } |
| |
| } |
| |