org.apache.samza.table.caching.descriptors.CachingTableProvider.java Source code

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Here is the source code for org.apache.samza.table.caching.descriptors.CachingTableProvider.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.samza.table.caching.descriptors;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

import org.apache.samza.table.ReadWriteTable;
import org.apache.samza.table.ReadableTable;
import org.apache.samza.table.Table;
import org.apache.samza.table.TableSpec;
import org.apache.samza.table.caching.CachingTable;
import org.apache.samza.table.caching.guava.GuavaCacheTable;
import org.apache.samza.table.utils.descriptors.BaseTableProvider;

import com.google.common.cache.CacheBuilder;

/**
 * Table provider for {@link CachingTable}.
 */
public class CachingTableProvider extends BaseTableProvider {

    public static final String REAL_TABLE_ID = "realTableId";
    public static final String CACHE_TABLE_ID = "cacheTableId";
    public static final String READ_TTL_MS = "readTtl";
    public static final String WRITE_TTL_MS = "writeTtl";
    public static final String CACHE_SIZE = "cacheSize";
    public static final String WRITE_AROUND = "writeAround";

    // Store the cache instances created by default
    private final List<ReadWriteTable> defaultCaches = new ArrayList<>();

    public CachingTableProvider(TableSpec tableSpec) {
        super(tableSpec);
    }

    @Override
    public Table getTable() {
        String realTableId = tableSpec.getConfig().get(REAL_TABLE_ID);
        ReadableTable table = (ReadableTable) this.context.getTaskContext().getTable(realTableId);

        String cacheTableId = tableSpec.getConfig().get(CACHE_TABLE_ID);
        ReadWriteTable cache;

        if (cacheTableId != null) {
            cache = (ReadWriteTable) this.context.getTaskContext().getTable(cacheTableId);
        } else {
            cache = createDefaultCacheTable(realTableId);
            defaultCaches.add(cache);
        }

        boolean isWriteAround = Boolean.parseBoolean(tableSpec.getConfig().get(WRITE_AROUND));
        CachingTable cachingTable = new CachingTable(tableSpec.getId(), table, cache, isWriteAround);
        cachingTable.init(this.context);
        return cachingTable;
    }

    @Override
    public void close() {
        defaultCaches.forEach(c -> c.close());
    }

    private ReadWriteTable createDefaultCacheTable(String tableId) {
        long readTtlMs = Long.parseLong(tableSpec.getConfig().getOrDefault(READ_TTL_MS, "-1"));
        long writeTtlMs = Long.parseLong(tableSpec.getConfig().getOrDefault(WRITE_TTL_MS, "-1"));
        long cacheSize = Long.parseLong(tableSpec.getConfig().getOrDefault(CACHE_SIZE, "-1"));

        CacheBuilder cacheBuilder = CacheBuilder.newBuilder();
        if (readTtlMs != -1) {
            cacheBuilder.expireAfterAccess(readTtlMs, TimeUnit.MILLISECONDS);
        }
        if (writeTtlMs != -1) {
            cacheBuilder.expireAfterWrite(writeTtlMs, TimeUnit.MILLISECONDS);
        }
        if (cacheSize != -1) {
            cacheBuilder.maximumSize(cacheSize);
        }

        logger.info(String.format("Creating default cache with: readTtl=%d, writeTtl=%d, maxSize=%d", readTtlMs,
                writeTtlMs, cacheSize));

        GuavaCacheTable cacheTable = new GuavaCacheTable(tableId + "-def-cache", cacheBuilder.build());
        cacheTable.init(this.context);

        return cacheTable;
    }
}