| /* |
| * ==================================================================== |
| * 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. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| package org.apache.hc.client5.http.impl.cache; |
| |
| import java.io.Closeable; |
| import java.lang.ref.ReferenceQueue; |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| |
| import org.apache.hc.client5.http.cache.HttpCacheCASOperation; |
| import org.apache.hc.client5.http.cache.HttpCacheEntry; |
| import org.apache.hc.client5.http.cache.HttpCacheStorage; |
| import org.apache.hc.client5.http.cache.Resource; |
| import org.apache.hc.client5.http.cache.ResourceIOException; |
| import org.apache.hc.core5.annotation.Contract; |
| import org.apache.hc.core5.annotation.ThreadingBehavior; |
| import org.apache.hc.core5.util.Args; |
| |
| /** |
| * <p> |
| * {@link HttpCacheStorage} implementation capable of deallocating resources associated with |
| * the cache entries. |
| * <p> |
| * This cache keeps track of cache entries using |
| * {@link java.lang.ref.PhantomReference} and maintains a collection of all resources that |
| * are no longer in use. The cache, however, does not automatically deallocates associated |
| * resources by invoking {@link Resource#dispose()} method. The consumer MUST periodically |
| * call {@link #cleanResources()} method to trigger resource deallocation. The cache can be |
| * permanently shut down using {@link #shutdown()} method. All resources associated with |
| * the entries used by the cache will be deallocated. |
| * </p> |
| * <p> |
| * This {@link HttpCacheStorage} implementation is intended for use with {@link FileResource} |
| * and similar. |
| * </p> |
| * <p> |
| * Compatibility note. Prior to version 4.4 this storage implementation used to dispose of |
| * all resource entries upon {@link #close()}. As of version 4.4 the {@link #close()} method |
| * disposes only of those resources that have been explicitly removed from the cache with |
| * {@link #removeEntry(String)} method. |
| * </p> |
| * <p> |
| * The {@link #shutdown()} ()} method can still be used to shut down the storage and dispose of |
| * all resources currently managed by it. |
| * </p> |
| * |
| * @since 4.1 |
| */ |
| @Contract(threading = ThreadingBehavior.SAFE) |
| public class ManagedHttpCacheStorage implements HttpCacheStorage, Closeable { |
| |
| private final CacheMap entries; |
| private final ReferenceQueue<HttpCacheEntry> morque; |
| private final Set<ResourceReference> resources; |
| private final AtomicBoolean active; |
| |
| public ManagedHttpCacheStorage(final CacheConfig config) { |
| super(); |
| this.entries = new CacheMap(config.getMaxCacheEntries()); |
| this.morque = new ReferenceQueue<>(); |
| this.resources = new HashSet<>(); |
| this.active = new AtomicBoolean(true); |
| } |
| |
| private void ensureValidState() { |
| if (!this.active.get()) { |
| throw new IllegalStateException("Cache has been shut down"); |
| } |
| } |
| |
| private void keepResourceReference(final HttpCacheEntry entry) { |
| final Resource resource = entry.getResource(); |
| if (resource != null) { |
| // Must deallocate the resource when the entry is no longer in used |
| final ResourceReference ref = new ResourceReference(entry, this.morque); |
| this.resources.add(ref); |
| } |
| } |
| |
| @Override |
| public void putEntry(final String url, final HttpCacheEntry entry) throws ResourceIOException { |
| Args.notNull(url, "URL"); |
| Args.notNull(entry, "Cache entry"); |
| ensureValidState(); |
| synchronized (this) { |
| this.entries.put(url, entry); |
| keepResourceReference(entry); |
| } |
| } |
| |
| @Override |
| public HttpCacheEntry getEntry(final String url) throws ResourceIOException { |
| Args.notNull(url, "URL"); |
| ensureValidState(); |
| synchronized (this) { |
| return this.entries.get(url); |
| } |
| } |
| |
| @Override |
| public void removeEntry(final String url) throws ResourceIOException { |
| Args.notNull(url, "URL"); |
| ensureValidState(); |
| synchronized (this) { |
| // Cannot deallocate the associated resources immediately as the |
| // cache entry may still be in use |
| this.entries.remove(url); |
| } |
| } |
| |
| @Override |
| public void updateEntry( |
| final String url, |
| final HttpCacheCASOperation casOperation) throws ResourceIOException { |
| Args.notNull(url, "URL"); |
| Args.notNull(casOperation, "CAS operation"); |
| ensureValidState(); |
| synchronized (this) { |
| final HttpCacheEntry existing = this.entries.get(url); |
| final HttpCacheEntry updated = casOperation.execute(existing); |
| this.entries.put(url, updated); |
| if (existing != updated) { |
| keepResourceReference(updated); |
| } |
| } |
| } |
| |
| @Override |
| public Map<String, HttpCacheEntry> getEntries(final Collection<String> keys) throws ResourceIOException { |
| Args.notNull(keys, "Key"); |
| final Map<String, HttpCacheEntry> resultMap = new HashMap<>(keys.size()); |
| for (final String key: keys) { |
| final HttpCacheEntry entry = getEntry(key); |
| if (entry != null) { |
| resultMap.put(key, entry); |
| } |
| } |
| return resultMap; |
| } |
| |
| public void cleanResources() { |
| if (this.active.get()) { |
| ResourceReference ref; |
| while ((ref = (ResourceReference) this.morque.poll()) != null) { |
| synchronized (this) { |
| this.resources.remove(ref); |
| } |
| ref.getResource().dispose(); |
| } |
| } |
| } |
| |
| public void shutdown() { |
| if (this.active.compareAndSet(true, false)) { |
| synchronized (this) { |
| this.entries.clear(); |
| for (final ResourceReference ref: this.resources) { |
| ref.getResource().dispose(); |
| } |
| this.resources.clear(); |
| while (this.morque.poll() != null) { |
| } |
| } |
| } |
| } |
| |
| @Override |
| public void close() { |
| if (this.active.compareAndSet(true, false)) { |
| synchronized (this) { |
| ResourceReference ref; |
| while ((ref = (ResourceReference) this.morque.poll()) != null) { |
| this.resources.remove(ref); |
| ref.getResource().dispose(); |
| } |
| } |
| } |
| } |
| |
| } |