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/*
* 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.spark.serializer
import java.util.concurrent.ConcurrentHashMap
import org.apache.spark.SparkConf
/**
* A service that returns a serializer object given the serializer's class name. If a previous
* instance of the serializer object has been created, the get method returns that instead of
* creating a new one.
*/
private[spark] class SerializerManager {
private val serializers = new ConcurrentHashMap[String, Serializer]
private var _default: Serializer = _
def default = _default
def setDefault(clsName: String, conf: SparkConf): Serializer = {
_default = get(clsName, conf)
_default
}
def get(clsName: String, conf: SparkConf): Serializer = {
if (clsName == null) {
default
} else {
var serializer = serializers.get(clsName)
if (serializer != null) {
// If the serializer has been created previously, reuse that.
serializer
} else this.synchronized {
// Otherwise, create a new one. But make sure no other thread has attempted
// to create another new one at the same time.
serializer = serializers.get(clsName)
if (serializer == null) {
val clsLoader = Thread.currentThread.getContextClassLoader
val cls = Class.forName(clsName, true, clsLoader)
val constructor = cls.getConstructor(classOf[SparkConf])
serializer = constructor.newInstance(conf).asInstanceOf[Serializer]
serializers.put(clsName, serializer)
}
serializer
}
}
}
}
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