基于Redis的shiro集中式缓存解决方案实现

/** * Copyright (c) 2016-2021, Bosco.Liao (bosco_liao@126.com). * * 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.iherus.shiro.util.concurrent; import org.iherus.shiro.util.Utils; import java.lang.ref.ReferenceQueue; import java.lang.ref.SoftReference; import java.lang.ref.WeakReference; import java.lang.reflect.Array; import java.util.AbstractMap; import java.util.AbstractSet; import java.util.Collections; import java.util.EnumSet; import java.util.HashSet; import java.util.Iterator; import java.util.Map; import java.util.NoSuchElementException; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import java.util.concurrent.locks.ReentrantLock; /** * Copy from {@link org.springframework.util.ConcurrentReferenceHashMap}. * <p> * A {@link ConcurrentHashMap} that uses {@link ReferenceType#SOFT soft} or * {@linkplain ReferenceType#WEAK weak} references for both {@code keys} and {@code values}. * * <p>This class can be used as an alternative to * {@code Collections.synchronizedMap(new WeakHashMap<K, Reference<V>>())} in order to * support better performance when accessed concurrently. This implementation follows the * same design constraints as {@link ConcurrentHashMap} with the exception that * {@code null} values and {@code null} keys are supported. * * <p><b>NOTE:</b> The use of references means that there is no guarantee that items * placed into the map will be subsequently available. The garbage collector may discard * references at any time, so it may appear that an unknown thread is silently removing * entries. * * <p>If not explicitly specified, this implementation will use * {@linkplain SoftReference soft entry references}. * * @param <K> the key type * @param <V> the value type * * @author Phillip Webb * @author Juergen Hoeller * @modifier Bosco.Liao */ public class ConcurrentReferenceHashMap<K, V> extends AbstractMap<K, V> implements ConcurrentMap<K, V> { private static final int DEFAULT_INITIAL_CAPACITY = 16; private static final float DEFAULT_LOAD_FACTOR = 0.75f; private static final int DEFAULT_CONCURRENCY_LEVEL = 16; private static final ReferenceType DEFAULT_REFERENCE_TYPE = ReferenceType.WEAK; private static final int MAXIMUM_CONCURRENCY_LEVEL = 1 << 16; private static final int MAXIMUM_SEGMENT_SIZE = 1 << 30; /** * Array of segments indexed using the high order bits from the hash. */ private final Segment[] segments; /** * When the average number of references per table exceeds this value resize will be attempted. */ private final float loadFactor; /** * The reference type: SOFT or WEAK. */ private final ReferenceType referenceType; /** * The shift value used to calculate the size of the segments array and an index from the hash. */ private final int shift; /** * Late binding entry set. */ private volatile Set<Map.Entry<K, V>> entrySet; /** * Create a new {@code ConcurrentReferenceHashMap} instance. */ public ConcurrentReferenceHashMap() { this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL, DEFAULT_REFERENCE_TYPE); } /** * Create a new {@code ConcurrentReferenceHashMap} instance. * * @param initialCapacity the initial capacity of the map */ public ConcurrentReferenceHashMap(int initialCapacity) { this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL, DEFAULT_REFERENCE_TYPE); } /** * Create a new {@code ConcurrentReferenceHashMap} instance. * * @param initialCapacity the initial capacity of the map * @param loadFactor the load factor. When the average number of references per table * exceeds this value resize will be attempted */ public ConcurrentReferenceHashMap(int initialCapacity, float loadFactor) { this(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL, DEFAULT_REFERENCE_TYPE); } /** * Create a new {@code ConcurrentReferenceHashMap} instance. * * @param initialCapacity the initial capacity of the map * @param concurrencyLevel the expected number of threads that will concurrently * write to the map */ public ConcurrentReferenceHashMap(int initialCapacity, int concurrencyLevel) { this(initialCapacity, DEFAULT_LOAD_FACTOR, concurrencyLevel, DEFAULT_REFERENCE_TYPE); } /** * Create a new {@code ConcurrentReferenceHashMap} instance. * * @param initialCapacity the initial capacity of the map * @param referenceType the reference type used for entries (soft or weak) */ public ConcurrentReferenceHashMap(int initialCapacity, ReferenceType referenceType) { this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_CONCURRENCY_LEVEL, referenceType); } /** * Create a new {@code ConcurrentReferenceHashMap} instance. * * @param initialCapacity the initial capacity of the map * @param loadFactor the load factor. When the average number of references per * table exceeds this value, resize will be attempted. * @param concurrencyLevel the expected number of threads that will concurrently * write to the map */ public ConcurrentReferenceHashMap(int initialCapacity, float loadFactor, int concurrencyLevel) { this(initialCapacity, loadFactor, concurrencyLevel, DEFAULT_REFERENCE_TYPE); } /** * Create a new {@code ConcurrentReferenceHashMap} instance. * * @param initialCapacity the initial capacity of the map * @param loadFactor the load factor. When the average number of references per * table exceeds this value, resize will be attempted. * @param concurrencyLevel the expected number of threads that will concurrently * write to the map * @param referenceType the reference type used for entries (soft or weak) */ @SuppressWarnings("unchecked") public ConcurrentReferenceHashMap( int initialCapacity, float loadFactor, int concurrencyLevel, ReferenceType referenceType) { isTrue(initialCapacity >= 0, "Initial capacity must not be negative"); isTrue(loadFactor > 0f, "Load factor must be positive"); isTrue(concurrencyLevel > 0, "Concurrency level must be positive"); notNull(referenceType, "Reference type must not be null"); this.loadFactor = loadFactor; this.shift = calculateShift(concurrencyLevel, MAXIMUM_CONCURRENCY_LEVEL); int size = 1 << this.shift; this.referenceType = referenceType; int roundedUpSegmentCapacity = (int) ((initialCapacity + size - 1L) / size); this.segments = (Segment[]) Array.newInstance(Segment.class, size); for (int i = 0; i < this.segments.length; i++) { this.segments[i] = new Segment(roundedUpSegmentCapacity); } } protected final float getLoadFactor() { return this.loadFactor; } protected final int getSegmentsSize() { return this.segments.length; } protected final Segment getSegment(int index) { return this.segments[index]; } /** * Factory method that returns the {@link ReferenceManager}. * Thi