com.streamsets.pipeline.lib.jdbc.multithread.cache.SQLServerCTContextLoader.java Source code

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Here is the source code for com.streamsets.pipeline.lib.jdbc.multithread.cache.SQLServerCTContextLoader.java

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/*
 * Copyright 2017 StreamSets Inc.
 *
 * 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 com.streamsets.pipeline.lib.jdbc.multithread.cache;

import com.google.common.cache.CacheLoader;
import com.streamsets.pipeline.lib.jdbc.multithread.ConnectionManager;
import com.streamsets.pipeline.lib.jdbc.multithread.TableContext;
import com.streamsets.pipeline.lib.jdbc.multithread.TableReadContext;
import com.streamsets.pipeline.lib.jdbc.multithread.TableRuntimeContext;
import com.streamsets.pipeline.lib.jdbc.multithread.util.OffsetQueryUtil;
import com.streamsets.pipeline.lib.jdbc.multithread.util.MSQueryUtil;
import org.apache.commons.lang3.tuple.Pair;

import java.sql.Connection;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class SQLServerCTContextLoader extends CacheLoader<TableRuntimeContext, TableReadContext> {
    private final ConnectionManager connectionManager;
    private final Map<String, String> offsets;
    private final int fetchSize;
    private final boolean includeJoin;

    public SQLServerCTContextLoader(ConnectionManager connectionManager, Map<String, String> offsets, int fetchSize,
            boolean includeJoin) {
        this.connectionManager = connectionManager;
        this.offsets = offsets;
        this.fetchSize = fetchSize;
        this.includeJoin = includeJoin;
    }

    @Override
    public TableReadContext load(TableRuntimeContext tableRuntimeContext) throws Exception {
        TableContext tableContext = tableRuntimeContext.getSourceTableContext();

        final Map<String, String> offset = OffsetQueryUtil
                .getColumnsToOffsetMapFromOffsetFormat(offsets.get(tableRuntimeContext.getOffsetKey()));

        String query = MSQueryUtil.buildQuery(offset, fetchSize, tableContext.getQualifiedName(),
                tableContext.getOffsetColumns(), tableContext.getOffsetColumnToStartOffset(), includeJoin,
                tableContext.getOffset());

        Pair<String, List<Pair<Integer, String>>> queryAndParamValToSet = Pair.of(query, new ArrayList<>());

        Connection connection = connectionManager.getConnection();

        TableReadContext tableReadContext = new TableReadContext(connection, queryAndParamValToSet.getLeft(),
                queryAndParamValToSet.getRight(), fetchSize);

        return tableReadContext;
    }
}