/*
 * Copyright 2021 webtau maintainers
 *
 * 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.testingisdocumenting.webtau.db;

public class LabeledDataSourceCachedProvider implements LabeledDataSourceProvider {
    private final LabeledDataSourceProvider provider;

    private volatile boolean initialized;
    private LabeledDataSource labeledDataSource;

    public LabeledDataSourceCachedProvider(LabeledDataSourceProvider provider) {
        this.provider = provider;
    }

    public void reset() {
        initialized = false;
    }

    @Override
    public LabeledDataSource provide() {
        if (!initialized) {
            synchronized (this) {
                if (!initialized) {
                    labeledDataSource = provider.provide();
                    initialized = true;
                    return labeledDataSource;
                }
            }
        }

        return labeledDataSource;
    }
}
