branch-2.0.4-alpha/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/BufferSizeParam.java

/**
 * 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.hdfs.web.resources;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeysPublic;

/** Buffer size parameter. */
public class BufferSizeParam extends IntegerParam {
  /** Parameter name. */
  public static final String NAME = "buffersize";
  /** Default parameter value. */
  public static final String DEFAULT = NULL;

  private static final Domain DOMAIN = new Domain(NAME);

  /**
   * Constructor.
   * @param value the parameter value.
   */
  public BufferSizeParam(final Integer value) {
    super(DOMAIN, value, 1, null);
  }

  /**
   * Constructor.
   * @param str a string representation of the parameter value.
   */
  public BufferSizeParam(final String str) {
    this(DOMAIN.parse(str));
  }

  @Override
  public String getName() {
    return NAME;
  }

  /** @return the value or, if it is null, return the default from conf. */
  public int getValue(final Configuration conf) {
    return getValue() != null? getValue()
        : conf.getInt(
            CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_KEY,
            CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT);
  }
}