io.devbench.uibuilder.spring.page.BeanStore Maven / Gradle / Ivy

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/*
 *
 * Copyright © 2018 Webvalto Ltd.
 *
 * 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 io.devbench.uibuilder.spring.page;

import com.vaadin.flow.server.VaadinSession;
import org.springframework.beans.factory.ObjectFactory;

import java.io.Serializable;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.stream.Collectors;

class BeanStore implements Serializable {

    private final VaadinSession vaadinSession;
    private final Map> destructionCallbacks;
    private final Map beans;

    BeanStore(VaadinSession vaadinSession) {
        this.vaadinSession = vaadinSession;
        this.beans = new ConcurrentHashMap<>();
        this.destructionCallbacks = new HashMap<>();
    }

    public Object get(BEAN_ID beanId, ObjectFactory objectFactory) {
        return inLock(() -> {
            beans.computeIfAbsent(beanId, id -> objectFactory.getObject());
            return beans.get(beanId);
        });
    }

    private  T inLock(Supplier supplier) {
        if (vaadinSession.hasLock()) {
            return supplier.get();
        } else {
            try {
                vaadinSession.lock();
                return supplier.get();
            } finally {
                vaadinSession.unlock();
            }
        }
    }

    public void destroyBeans(Predicate predicate) {
        inLock(() -> {
            List toRemoveKeys = beans.keySet().stream().filter(predicate).collect(Collectors.toList());
            toRemoveKeys.forEach(beanId -> {
                destructionCallbacks.getOrDefault(beanId, Collections.emptyList()).forEach(Runnable::run);
                destructionCallbacks.remove(beanId);
            });
            toRemoveKeys.forEach(beans::remove);
            return null;
        });
    }

    public void registerDestructionCallback(BEAN_ID beanIdForBean, Runnable callback) {
        inLock(() -> {
            destructionCallbacks.computeIfAbsent(beanIdForBean, id -> new ArrayList<>());
            destructionCallbacks.get(beanIdForBean).add(callback);
            return null;
        });
    }
}