DefaultRequestCache.java
/*
* 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
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*/
package org.apache.maven.impl.cache;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.function.Function;
import org.apache.maven.api.Session;
import org.apache.maven.api.SessionData;
import org.apache.maven.api.cache.CacheMetadata;
import org.apache.maven.api.cache.CacheRetention;
import org.apache.maven.api.services.Request;
import org.apache.maven.api.services.RequestTrace;
import org.apache.maven.api.services.Result;
public class DefaultRequestCache extends AbstractRequestCache {
protected static final SessionData.Key<ConcurrentMap> KEY =
SessionData.key(ConcurrentMap.class, CacheMetadata.class);
protected static final Object ROOT = new Object();
protected final Map<Object, CachingSupplier<?, ?>> forever = new ConcurrentHashMap<>();
@Override
@SuppressWarnings("unchecked")
protected <REQ extends Request<?>, REP extends Result<REQ>> CachingSupplier<REQ, REP> doCache(
REQ req, Function<REQ, REP> supplier) {
CacheRetention retention = Objects.requireNonNullElse(
req instanceof CacheMetadata metadata ? metadata.getCacheRetention() : null,
CacheRetention.SESSION_SCOPED);
Map<Object, CachingSupplier<?, ?>> cache = null;
if ((retention == CacheRetention.REQUEST_SCOPED || retention == CacheRetention.SESSION_SCOPED)
&& req.getSession() instanceof Session session) {
Object key = retention == CacheRetention.REQUEST_SCOPED ? doGetOuterRequest(req) : ROOT;
Map<Object, Map<Object, CachingSupplier<?, ?>>> caches =
session.getData().computeIfAbsent(KEY, ConcurrentHashMap::new);
cache = caches.computeIfAbsent(key, k -> new SoftIdentityMap<>());
} else if (retention == CacheRetention.PERSISTENT) {
cache = forever;
}
if (cache != null) {
return (CachingSupplier<REQ, REP>) cache.computeIfAbsent(req, r -> new CachingSupplier<>(supplier));
} else {
return new CachingSupplier<>(supplier);
}
}
private <REQ extends Request<?>> Object doGetOuterRequest(REQ req) {
RequestTrace trace = req.getTrace();
while (trace != null && trace.parent() != null) {
trace = trace.parent();
}
return trace != null && trace.data() != null ? trace.data() : req;
}
}