/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.config;
import com.hazelcast.internal.eviction.EvictionConfiguration;
import com.hazelcast.internal.eviction.EvictionPolicyComparator;
import com.hazelcast.internal.eviction.EvictionPolicyType;
import com.hazelcast.internal.eviction.EvictionStrategyType;
import com.hazelcast.nio.ObjectDataInput;
import com.hazelcast.nio.ObjectDataOutput;
import com.hazelcast.nio.serialization.DataSerializable;
import com.hazelcast.nio.serialization.BinaryInterface;
import java.io.IOException;
import java.io.Serializable;
import static com.hazelcast.util.Preconditions.checkNotNull;
import static com.hazelcast.util.Preconditions.checkPositive;
/**
* Configuration for eviction.
* You can set a limit for number of entries or total memory cost of entries.
* <p/>
* The default values of the eviction configuration are
* <ul>
* <li>{@link EvictionPolicy#LRU} as eviction policy</li>
* <li>{@link EvictionConfig.MaxSizePolicy#ENTRY_COUNT} as max size policy</li>
* <li>{@value DEFAULT_MAX_ENTRY_COUNT_FOR_ON_HEAP_MAP} as maximum size for on-heap {@link com.hazelcast.core.IMap}</li>
* <li>{@value DEFAULT_MAX_ENTRY_COUNT} as maximum size for all other data structures and configurations</li>
* </ul>
*/
@BinaryInterface
public class EvictionConfig implements EvictionConfiguration, DataSerializable, Serializable {
/**
* Default maximum entry count.
*/
public static final int DEFAULT_MAX_ENTRY_COUNT = 10000;
/**
* Default maximum entry count for Map on-heap Near Caches.
*/
public static final int DEFAULT_MAX_ENTRY_COUNT_FOR_ON_HEAP_MAP = Integer.MAX_VALUE;
/**
* Default Max-Size Policy.
*/
public static final MaxSizePolicy DEFAULT_MAX_SIZE_POLICY = MaxSizePolicy.ENTRY_COUNT;
/**
* Default Eviction Policy.
*/
public static final EvictionPolicy DEFAULT_EVICTION_POLICY = EvictionPolicy.LRU;
/**
* Maximum Size Policy
*/
public enum MaxSizePolicy {
/**
* Policy based on maximum number of entries stored per data structure (map, cache etc)
*/
ENTRY_COUNT,
/**
* Policy based on maximum used native memory in megabytes per data structure (map, cache etc)
* on each Hazelcast instance
*/
USED_NATIVE_MEMORY_SIZE,
/**
* Policy based on maximum used native memory percentage per data structure (map, cache etc)
* on each Hazelcast instance
*/
USED_NATIVE_MEMORY_PERCENTAGE,
/**
* Policy based on minimum free native memory in megabytes per Hazelcast instance
*/
FREE_NATIVE_MEMORY_SIZE,
/**
* Policy based on minimum free native memory percentage per Hazelcast instance
*/
FREE_NATIVE_MEMORY_PERCENTAGE
}
protected int size = DEFAULT_MAX_ENTRY_COUNT;
protected MaxSizePolicy maxSizePolicy = DEFAULT_MAX_SIZE_POLICY;
protected EvictionPolicy evictionPolicy = DEFAULT_EVICTION_POLICY;
protected String comparatorClassName;
protected EvictionPolicyComparator comparator;
protected EvictionConfig readOnly;
/**
* Used by the {@link NearCacheConfigAccessor} to initialize the proper default value for on-heap maps.
*/
boolean sizeConfigured;
public EvictionConfig() {
}
public EvictionConfig(int size, MaxSizePolicy maxSizePolicy, EvictionPolicy evictionPolicy) {
this.sizeConfigured = true;
this.size = checkPositive(size, "Size must be positive number!");
this.maxSizePolicy = checkNotNull(maxSizePolicy, "Max-Size policy cannot be null!");
this.evictionPolicy = checkNotNull(evictionPolicy, "Eviction policy cannot be null!");
}
public EvictionConfig(int size, MaxSizePolicy maxSizePolicy, String comparatorClassName) {
this.sizeConfigured = true;
this.size = checkPositive(size, "Size must be positive number!");
this.maxSizePolicy = checkNotNull(maxSizePolicy, "Max-Size policy cannot be null!");
this.comparatorClassName = checkNotNull(comparatorClassName, "Comparator classname cannot be null!");
}
public EvictionConfig(int size, MaxSizePolicy maxSizePolicy, EvictionPolicyComparator comparator) {
this.sizeConfigured = true;
this.size = checkPositive(size, "Size must be positive number!");
this.maxSizePolicy = checkNotNull(maxSizePolicy, "Max-Size policy cannot be null!");
this.comparator = checkNotNull(comparator, "Comparator cannot be null!");
}
public EvictionConfig(EvictionConfig config) {
this.sizeConfigured = true;
this.size = checkPositive(config.size, "Size must be positive number!");
this.maxSizePolicy = checkNotNull(config.maxSizePolicy, "Max-Size policy cannot be null!");
if (config.evictionPolicy != null) {
this.evictionPolicy = config.evictionPolicy;
}
// Eviction policy comparator class name is not allowed to be null
if (config.comparatorClassName != null) {
this.comparatorClassName = config.comparatorClassName;
}
// Eviction policy comparator is not allowed to be null
if (config.comparator != null) {
this.comparator = config.comparator;
}
}
/**
* Gets immutable version of this configuration.
*
* @return Immutable version of this configuration.
* @deprecated this method will be removed in 4.0; it is meant for internal usage only.
*/
public EvictionConfig getAsReadOnly() {
if (readOnly == null) {
readOnly = new EvictionConfigReadOnly(this);
}
return readOnly;
}
/**
* Returns the size which is used by the {@link MaxSizePolicy}.
* <p/>
* The interpretation of the value depends on the configured {@link MaxSizePolicy}.
*
* @return the size which is used by the {@link MaxSizePolicy}
*/
public int getSize() {
return size;
}
/**
* Sets the size which is used by the {@link MaxSizePolicy}.
* <p/>
* The interpretation of the value depends on the configured {@link MaxSizePolicy}.
* <p/>
* Accepts any positive number. The default value is {@value #DEFAULT_MAX_ENTRY_COUNT}.
*
* @param size the size which is used by the {@link MaxSizePolicy}
* @return this EvictionConfig instance
*/
public EvictionConfig setSize(int size) {
this.sizeConfigured = true;
this.size = checkPositive(size, "size must be positive number!");
return this;
}
/**
* Returns the {@link MaxSizePolicy} of this eviction configuration.
*
* @return the {@link MaxSizePolicy} of this eviction configuration
*/
public MaxSizePolicy getMaximumSizePolicy() {
return maxSizePolicy;
}
/**
* Sets the {@link MaxSizePolicy} of this eviction configuration.
*
* @param maxSizePolicy the {@link MaxSizePolicy} of this eviction configuration
* @return this EvictionConfig instance
*/
public EvictionConfig setMaximumSizePolicy(MaxSizePolicy maxSizePolicy) {
this.maxSizePolicy = checkNotNull(maxSizePolicy, "maxSizePolicy cannot be null!");
return this;
}
/**
* Returns the {@link EvictionPolicy} of this eviction configuration.
*
* @return the {@link EvictionPolicy} of this eviction configuration
*/
@Override
public EvictionPolicy getEvictionPolicy() {
return evictionPolicy;
}
/**
* Sets the {@link EvictionPolicy} of this eviction configuration.
*
* @param evictionPolicy the {@link EvictionPolicy} of this eviction configuration
* @return this EvictionConfig instance
*/
public EvictionConfig setEvictionPolicy(EvictionPolicy evictionPolicy) {
this.evictionPolicy = checkNotNull(evictionPolicy, "Eviction policy cannot be null!");
return this;
}
/**
* Returns the {@link EvictionStrategyType} of this eviction configuration.
*
* @return the {@link EvictionStrategyType} of this eviction configuration
*/
@Override
public EvictionStrategyType getEvictionStrategyType() {
return EvictionStrategyType.DEFAULT_EVICTION_STRATEGY;
}
/**
* Returns the {@link EvictionPolicyType} of this eviction configuration.
*
* @return the {@link EvictionPolicyType} of this eviction configuration
* @deprecated since 3.9, please use {@link #getEvictionPolicy()}
*/
@Deprecated
public EvictionPolicyType getEvictionPolicyType() {
switch (evictionPolicy) {
case LFU:
return EvictionPolicyType.LFU;
case LRU:
return EvictionPolicyType.LRU;
case RANDOM:
return EvictionPolicyType.RANDOM;
case NONE:
return EvictionPolicyType.NONE;
default:
return null;
}
}
/**
* Returns the class name of the configured {@link EvictionPolicyComparator} implementation.
*
* @return the class name of the configured {@link EvictionPolicyComparator} implementation
*/
@Override
public String getComparatorClassName() {
return comparatorClassName;
}
/**
* Sets the class name of the configured {@link EvictionPolicyComparator} implementation.
* <p/>
* Only one of the {@code comparator class name} and {@code comparator} can be configured in the eviction configuration.
*
* @param comparatorClassName the class name of the configured {@link EvictionPolicyComparator} implementation
* @return this EvictionConfig instance
*/
public EvictionConfig setComparatorClassName(String comparatorClassName) {
this.comparatorClassName = checkNotNull(comparatorClassName, "Eviction policy comparator class name cannot be null!");
return this;
}
/**
* Returns the instance of the configured {@link EvictionPolicyComparator} implementation.
*
* @return the instance of the configured {@link EvictionPolicyComparator} implementation
*/
@Override
public EvictionPolicyComparator getComparator() {
return comparator;
}
/**
* Sets the instance of the configured {@link EvictionPolicyComparator} implementation.
* <p/>
* Only one of the {@code comparator class name} and {@code comparator} can be configured in the eviction configuration.
*
* @param comparator the instance of the configured {@link EvictionPolicyComparator} implementation
* @return this EvictionConfig instance
*/
public EvictionConfig setComparator(EvictionPolicyComparator comparator) {
this.comparator = checkNotNull(comparator, "Eviction policy comparator cannot be null!");
return this;
}
@Override
public void writeData(ObjectDataOutput out) throws IOException {
out.writeInt(size);
out.writeUTF(maxSizePolicy.toString());
out.writeUTF(evictionPolicy.toString());
out.writeUTF(comparatorClassName);
out.writeObject(comparator);
}
@Override
public void readData(ObjectDataInput in) throws IOException {
size = in.readInt();
maxSizePolicy = MaxSizePolicy.valueOf(in.readUTF());
evictionPolicy = EvictionPolicy.valueOf(in.readUTF());
comparatorClassName = in.readUTF();
comparator = in.readObject();
}
@Override
public String toString() {
return "EvictionConfig{"
+ "size=" + size
+ ", maxSizePolicy=" + maxSizePolicy
+ ", evictionPolicy=" + evictionPolicy
+ ", comparatorClassName=" + comparatorClassName
+ ", comparator=" + comparator
+ '}';
}
}