1 files changed, 141 insertions, 0 deletions
diff --git a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/ServiceOperations.java b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/ServiceOperations.java
new file mode 100644
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--- /dev/null
+++ b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/ServiceOperations.java
@@ -0,0 +1,141 @@
+/**
+ * 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.hive.service;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hive.conf.HiveConf;
+
+/**
+ * ServiceOperations.
+ *
+ */
+public final class ServiceOperations {
+  private static final Log LOG = LogFactory.getLog(AbstractService.class);
+
+  private ServiceOperations() {
+  }
+
+  /**
+   * Verify that that a service is in a given state.
+   * @param state the actual state a service is in
+   * @param expectedState the desired state
+   * @throws IllegalStateException if the service state is different from
+   * the desired state
+   */
+  public static void ensureCurrentState(Service.STATE state,
+                                        Service.STATE expectedState) {
+    if (state != expectedState) {
+      throw new IllegalStateException("For this operation, the " +
+                                          "current service state must be "
+                                          + expectedState
+                                          + " instead of " + state);
+    }
+  }
+
+  /**
+   * Initialize a service.
+   * <p/>
+   * The service state is checked <i>before</i> the operation begins.
+   * This process is <i>not</i> thread safe.
+   * @param service a service that must be in the state
+   *   {@link Service.STATE#NOTINITED}
+   * @param configuration the configuration to initialize the service with
+   * @throws RuntimeException on a state change failure
+   * @throws IllegalStateException if the service is in the wrong state
+   */
+
+  public static void init(Service service, HiveConf configuration) {
+    Service.STATE state = service.getServiceState();
+    ensureCurrentState(state, Service.STATE.NOTINITED);
+    service.init(configuration);
+  }
+
+  /**
+   * Start a service.
+   * <p/>
+   * The service state is checked <i>before</i> the operation begins.
+   * This process is <i>not</i> thread safe.
+   * @param service a service that must be in the state
+   *   {@link Service.STATE#INITED}
+   * @throws RuntimeException on a state change failure
+   * @throws IllegalStateException if the service is in the wrong state
+   */
+
+  public static void start(Service service) {
+    Service.STATE state = service.getServiceState();
+    ensureCurrentState(state, Service.STATE.INITED);
+    service.start();
+  }
+
+  /**
+   * Initialize then start a service.
+   * <p/>
+   * The service state is checked <i>before</i> the operation begins.
+   * This process is <i>not</i> thread safe.
+   * @param service a service that must be in the state
+   *   {@link Service.STATE#NOTINITED}
+   * @param configuration the configuration to initialize the service with
+   * @throws RuntimeException on a state change failure
+   * @throws IllegalStateException if the service is in the wrong state
+   */
+  public static void deploy(Service service, HiveConf configuration) {
+    init(service, configuration);
+    start(service);
+  }
+
+  /**
+   * Stop a service.
+   * <p/>Do nothing if the service is null or not
+   * in a state in which it can be/needs to be stopped.
+   * <p/>
+   * The service state is checked <i>before</i> the operation begins.
+   * This process is <i>not</i> thread safe.
+   * @param service a service or null
+   */
+  public static void stop(Service service) {
+    if (service != null) {
+      Service.STATE state = service.getServiceState();
+      if (state == Service.STATE.STARTED) {
+        service.stop();
+      }
+    }
+  }
+
+  /**
+   * Stop a service; if it is null do nothing. Exceptions are caught and
+   * logged at warn level. (but not Throwables). This operation is intended to
+   * be used in cleanup operations
+   *
+   * @param service a service; may be null
+   * @return any exception that was caught; null if none was.
+   */
+  public static Exception stopQuietly(Service service) {
+    try {
+      stop(service);
+    } catch (Exception e) {
+      LOG.warn("When stopping the service " + service.getName()
+                   + " : " + e,
+               e);
+      return e;
+    }
+    return null;
+  }
+
+}