| /** |
| * 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.hadoop.fs; |
| |
| import java.io.InputStream; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Static methods to implement policies for {@link StreamCapabilities}. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class StreamCapabilitiesPolicy { |
| public static final String CAN_UNBUFFER_NOT_IMPLEMENTED_MESSAGE = |
| "claims unbuffer capabilty but does not implement CanUnbuffer"; |
| static final Logger LOG = LoggerFactory.getLogger( |
| StreamCapabilitiesPolicy.class); |
| /** |
| * Implement the policy for {@link CanUnbuffer#unbuffer()}. |
| * |
| * @param in the input stream |
| */ |
| public static void unbuffer(InputStream in) { |
| try { |
| if (in instanceof StreamCapabilities |
| && ((StreamCapabilities) in).hasCapability( |
| StreamCapabilities.UNBUFFER)) { |
| ((CanUnbuffer) in).unbuffer(); |
| } else { |
| LOG.debug(in.getClass().getName() + ":" |
| + " does not implement StreamCapabilities" |
| + " and the unbuffer capability"); |
| } |
| } catch (ClassCastException e) { |
| throw new UnsupportedOperationException(in.getClass().getName() + ": " |
| + CAN_UNBUFFER_NOT_IMPLEMENTED_MESSAGE); |
| } |
| } |
| } |
| |