org.apache.drill.exec.store.sys.local.LocalPStoreProvider.java Source code

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Here is the source code for org.apache.drill.exec.store.sys.local.LocalPStoreProvider.java

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/**
 * 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.
 */
package org.apache.drill.exec.store.sys.local;

import java.io.File;
import java.io.IOException;
import java.util.concurrent.ConcurrentMap;

import org.apache.drill.common.config.DrillConfig;
import org.apache.drill.exec.ExecConstants;
import org.apache.drill.exec.store.sys.PStore;
import org.apache.drill.exec.store.sys.PStoreConfig;
import org.apache.drill.exec.store.sys.PStoreProvider;
import org.apache.drill.exec.store.sys.PStoreRegistry;

import com.google.common.collect.Maps;

/**
 * A really simple provider that stores data in the local file system, one value per file.
 */
public class LocalPStoreProvider implements PStoreProvider {
    static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(LocalPStoreProvider.class);

    private File path;
    private final boolean enableWrite;
    private ConcurrentMap<PStoreConfig<?>, PStore<?>> pstores;

    public LocalPStoreProvider(DrillConfig config) {
        path = new File(config.getString(ExecConstants.SYS_STORE_PROVIDER_LOCAL_PATH));
        enableWrite = config.getBoolean(ExecConstants.SYS_STORE_PROVIDER_LOCAL_ENABLE_WRITE);
        if (!enableWrite) {
            pstores = Maps.newConcurrentMap();
        }
    }

    public LocalPStoreProvider(PStoreRegistry registry) {
        this(registry.getConfig());
    }

    @Override
    public void close() {
    }

    @Override
    public <V> PStore<V> getPStore(PStoreConfig<V> storeConfig) throws IOException {
        if (enableWrite) {
            return new LocalPStore<V>(path, storeConfig);
        } else {
            PStore<V> p = new NoWriteLocalPStore<V>();
            PStore<?> p2 = pstores.putIfAbsent(storeConfig, p);
            if (p2 != null)
                return (PStore<V>) p2;
            return p;
        }
    }

    @Override
    public void start() {
    }

}