| /* |
| * 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.pig.data; |
| |
| import org.apache.pig.PigConfiguration; |
| import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce; |
| import org.apache.pig.classification.InterfaceAudience; |
| import org.apache.pig.classification.InterfaceStability; |
| |
| import java.io.Serializable; |
| |
| /** |
| * Class to hold code common to self spilling bags such as InternalCachedBag |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public abstract class SelfSpillBag extends DefaultAbstractBag { |
| private static final long serialVersionUID = 1L; |
| // SelfSpillBag$MemoryLimits is not serializable |
| protected MemoryLimits memLimit; |
| |
| public SelfSpillBag(int bagCount) { |
| memLimit = new MemoryLimits(bagCount, -1); |
| } |
| |
| public SelfSpillBag(int bagCount, float percent) { |
| memLimit = new MemoryLimits(bagCount, percent); |
| } |
| |
| /** |
| * This class helps to compute the number of entries that should be held in |
| * memory so that memory consumption is limited. The memory limit is |
| * computed using the percentage of max memory that the user of this class |
| * is allowed to use, and number of similar objects that share this limit. |
| * The number of objects that will fit into this memory limit is computed |
| * using the average memory size of the objects whose size is given to this |
| * class. |
| * In spark mode, MemoryLimits needs implement Serializable interface otherwise NotSerializableExecption will be thrown (See PIG-4611) |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public static class MemoryLimits implements Serializable { |
| |
| private long maxMemUsage; |
| private long cacheLimit = Integer.MAX_VALUE; |
| private long memUsage = 0; |
| private long numObjsSizeChecked = 0; |
| |
| private static float cachedMemUsage = 0.2F; |
| private static long maxMem = 0; |
| static { |
| maxMem = Runtime.getRuntime().maxMemory(); |
| if (PigMapReduce.sJobConfInternal.get() != null) { |
| String usage = PigMapReduce.sJobConfInternal.get().get( |
| PigConfiguration.PIG_CACHEDBAG_MEMUSAGE); |
| if (usage != null) { |
| cachedMemUsage = Float.parseFloat(usage); |
| } |
| } |
| } |
| |
| /** |
| * @param bagCount |
| * @param percent |
| */ |
| public MemoryLimits(int bagCount, float percent) { |
| init(bagCount, percent); |
| } |
| |
| private void init(int bagCount, float percent) { |
| |
| if (percent < 0) { |
| percent = cachedMemUsage; |
| } |
| |
| maxMemUsage = (long) ((maxMem * percent) / bagCount); |
| |
| // set limit to 0, if memusage is 0 or really really small. |
| // then all tuples are put into disk |
| if (maxMemUsage < 1) { |
| cacheLimit = 0; |
| } |
| } |
| |
| /** |
| * Computes the number of objects that would fit into memory based on |
| * the memory limit and average size of each object. |
| * |
| * @return number of objects limit |
| */ |
| public long getCacheLimit() { |
| if (numObjsSizeChecked > 0) { |
| long avgUsage = memUsage / numObjsSizeChecked; |
| if (avgUsage > 0) { |
| cacheLimit = maxMemUsage / avgUsage; |
| } |
| } |
| return cacheLimit; |
| } |
| |
| /** |
| * Submit information about size of another object |
| * |
| * @param memorySize |
| */ |
| public void addNewObjSize(long memorySize) { |
| memUsage += memorySize; |
| ++numObjsSizeChecked; |
| } |
| |
| /** |
| * @return the size of |
| */ |
| public long getNumObjectsSizeAdded() { |
| return numObjsSizeChecked; |
| } |
| } |
| |
| } |