org.ehcache.config.builders.ExpiryPolicyBuilder Maven / Gradle / Ivy
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/*
* Copyright Terracotta, Inc.
*
* 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 org.ehcache.config.builders;
import org.ehcache.config.Builder;
import org.ehcache.expiry.ExpiryPolicy;
import java.time.Duration;
import java.util.Objects;
import java.util.function.BiFunction;
import java.util.function.Supplier;
/**
* Builder and utilities for getting predefined {@link ExpiryPolicy} instances.
*/
public final class ExpiryPolicyBuilder implements Builder>{
/**
* Get an {@link ExpiryPolicy} instance for a non expiring (ie. "eternal") cache.
*
* @return the no expiry instance
*/
public static ExpiryPolicy noExpiration() {
return ExpiryPolicy.NO_EXPIRY;
}
/**
* Get a time-to-live (TTL) {@link ExpiryPolicy} instance for the given {@link Duration}.
*
* @param timeToLive the TTL duration
* @return a TTL expiry
*/
public static ExpiryPolicy timeToLiveExpiration(Duration timeToLive) {
Objects.requireNonNull(timeToLive, "TTL duration cannot be null");
if (timeToLive.isNegative()) {
throw new IllegalArgumentException("TTL duration cannot be negative");
}
return new TimeToLiveExpiryPolicy(timeToLive);
}
/**
* Get a time-to-idle (TTI) {@link ExpiryPolicy} instance for the given {@link Duration}.
*
* @param timeToIdle the TTI duration
* @return a TTI expiry
*/
public static ExpiryPolicy timeToIdleExpiration(Duration timeToIdle) {
Objects.requireNonNull(timeToIdle, "TTI duration cannot be null");
if (timeToIdle.isNegative()) {
throw new IllegalArgumentException("TTI duration cannot be negative");
}
return new TimeToIdleExpiryPolicy(timeToIdle);
}
@FunctionalInterface
public interface TriFunction {
/**
* Applies this function to the given arguments.
*
* @param t the first function argument
* @param u the second function argument
* @param v the third function argument
* @return the function result
*/
R apply(T t, U u, V v);
}
/**
* Fluent API for creating an {@link ExpiryPolicy} instance where you can specify constant values for creation, access and update time.
* Unspecified values will be set to {@link ExpiryPolicy#INFINITE INFINITE} for create and {@code null} for access and update, matching
* the {@link #noExpiration()} no expiration} expiry.
*
* @return an {@link ExpiryPolicy} builder
*/
public static ExpiryPolicyBuilder expiry() {
return new ExpiryPolicyBuilder<>();
}
private final BiFunction create;
private final BiFunction, Duration> access;
private final TriFunction, ? super V, Duration> update;
private ExpiryPolicyBuilder() {
this((k, v) -> ExpiryPolicy.INFINITE, (k, v) -> null, (k, oldV, newV) -> null);
}
private ExpiryPolicyBuilder(BiFunction create,
BiFunction, Duration> access,
TriFunction, ? super V, Duration> update) {
this.create = create;
this.access = access;
this.update = update;
}
/**
* Set TTL since creation.
*
* Note: Calling this method on a builder with an existing TTL since creation will override the previous value or function.
*
* @param create TTL since creation
* @return a new builder with the TTL since creation
*/
public ExpiryPolicyBuilder create(Duration create) {
Objects.requireNonNull(create, "Create duration cannot be null");
if (create.isNegative()) {
throw new IllegalArgumentException("Create duration must be positive");
}
return create((a, b) -> create);
}
/**
* Set a function giving the TTL since creation.
*
* Note: Calling this method on a builder with an existing TTL since creation will override the previous value or function.
*
* @param create Function giving the TTL since creation
* @return a new builder with the TTL creation calculation function
*/
public ExpiryPolicyBuilder create(BiFunction create) {
return new ExpiryPolicyBuilder<>(Objects.requireNonNull(create), access, update);
}
/**
* Set TTI since last access.
*
* Note: Calling this method on a builder with an existing TTI since last access will override the previous value or function.
*
* @param access TTI since last access
* @return a new builder with the TTI since last access
*/
public ExpiryPolicyBuilder access(Duration access) {
if (access != null && access.isNegative()) {
throw new IllegalArgumentException("Access duration must be positive");
}
return access((a, b) -> access);
}
/**
* Set a function giving the TTI since last access.
*
* Note: Calling this method on a builder with an existing TTI since last access will override the previous value or function.
*
* @param access Function giving the TTI since last access
* @return a new builder with the TTI since last access calculation function
*/
public ExpiryPolicyBuilder access(BiFunction, Duration> access) {
return new ExpiryPolicyBuilder<>(create, Objects.requireNonNull(access), update);
}
/**
* Set TTL since last update.
*
* Note: Calling this method on a builder with an existing TTL since last access will override the previous value or function.
*
* @param update TTL since last update
* @return a new builder with the TTL since last update
*/
public ExpiryPolicyBuilder update(Duration update) {
if (update != null && update.isNegative()) {
throw new IllegalArgumentException("Update duration must be positive");
}
return update((a, b, c) -> update);
}
/**
* Set a function giving the TTL since last update.
*
* Note: Calling this method on a builder with an existing TTL since last update will override the previous value or function.
*
* @param update Function giving the TTL since last update
* @return a new builder with the TTL since last update calculation function
*/
public ExpiryPolicyBuilder update(TriFunction, V2, Duration> update) {
return new ExpiryPolicyBuilder<>(create, access, Objects.requireNonNull(update));
}
/**
* Builds an expiry policy instance.
*
* @return an {@link ExpiryPolicy}
*/
public ExpiryPolicy build() {
return new BaseExpiryPolicy<>(create, access, update);
}
/**
* Simple implementation of the {@link ExpiryPolicy} interface allowing to set constants to each expiry types.
*/
private static class BaseExpiryPolicy implements ExpiryPolicy {
private final BiFunction create;
private final BiFunction, Duration> access;
private final TriFunction, ? super V, Duration> update;
BaseExpiryPolicy(BiFunction create,
BiFunction, Duration> access,
TriFunction, ? super V, Duration> update) {
this.create = create;
this.access = access;
this.update = update;
}
@Override
public Duration getExpiryForCreation(K key, V value) {
return create.apply(key, value);
}
@Override
public Duration getExpiryForAccess(K key, Supplier value) {
return access.apply(key, value);
}
@Override
public Duration getExpiryForUpdate(K key, Supplier oldValue, V newValue) {
return update.apply(key, oldValue, newValue);
}
}
private static final class TimeToLiveExpiryPolicy extends BaseExpiryPolicy {
private final Duration ttl;
TimeToLiveExpiryPolicy(Duration ttl) {
super(
(a, b) -> ttl,
(a, b) -> null,
(a, b, c) -> ttl);
this.ttl = ttl;
}
@Override
public int hashCode() {
return ttl.hashCode();
}
@Override
public boolean equals(Object obj) {
return obj instanceof TimeToLiveExpiryPolicy && ttl.equals(((TimeToLiveExpiryPolicy) obj).ttl);
}
@Override
public String toString() {
return "TTL of " + ttl;
}
}
private static final class TimeToIdleExpiryPolicy extends BaseExpiryPolicy {
private final Duration tti;
TimeToIdleExpiryPolicy(Duration tti) {
super(
(a, b) -> tti,
(a, b) -> tti,
(a, b, c) -> tti);
this.tti = tti;
}
@Override
public int hashCode() {
return tti.hashCode();
}
@Override
public boolean equals(Object obj) {
return obj instanceof TimeToIdleExpiryPolicy && tti.equals(((TimeToIdleExpiryPolicy) obj).tti);
}
@Override
public String toString() {
return "TTI of " + tti;
}
}
}