com.stratio.decision.functions.SaveToCassandraActionExecutionFunction.java Source code

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Here is the source code for com.stratio.decision.functions.SaveToCassandraActionExecutionFunction.java

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/**
 * Copyright (C) 2014 Stratio (http://stratio.com)
 *
 * 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.stratio.decision.functions;

import com.datastax.driver.core.*;
import com.google.common.collect.Iterables;
import com.stratio.decision.commons.constants.STREAMING;
import com.stratio.decision.commons.messages.ColumnNameTypeValue;
import com.stratio.decision.commons.messages.StratioStreamingMessage;
import com.stratio.decision.service.SaveToCassandraOperationsService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.*;

public class SaveToCassandraActionExecutionFunction extends BaseActionExecutionFunction {

    private static final long serialVersionUID = -3116164624590830333L;

    private static final Logger log = LoggerFactory.getLogger(SaveToCassandraActionExecutionFunction.class);

    private Session cassandraSession;

    private final String cassandraQuorum;
    private final int cassandraPort;
    private final int maxBatchSize;
    private final BatchStatement.Type batchType;

    private HashMap<String, Integer> tablenames = new HashMap<>();

    private SaveToCassandraOperationsService cassandraTableOperationsService;

    public SaveToCassandraActionExecutionFunction(String cassandraQuorum, int cassandraPort, int maxBatchSize,
            BatchStatement.Type batchType) {
        this.cassandraQuorum = cassandraQuorum;
        this.cassandraPort = cassandraPort;
        this.maxBatchSize = maxBatchSize;
        this.batchType = batchType;
    }

    @Override
    public Boolean check() throws Exception {
        try {
            return getSession().getState().getConnectedHosts().size() > 0;
        } catch (Exception e) {
            return false;
        }
    }

    @Override
    public void process(Iterable<StratioStreamingMessage> messages) throws Exception {

        Integer partitionSize = maxBatchSize;

        if (partitionSize <= 0) {
            partitionSize = Iterables.size(messages);
        }

        Iterable<List<StratioStreamingMessage>> partitionIterables = Iterables.partition(messages, partitionSize);

        try {

            for (List<StratioStreamingMessage> messageList : partitionIterables) {

                BatchStatement batch = new BatchStatement(batchType);

                for (StratioStreamingMessage stratioStreamingMessage : messageList) {
                    Set<String> columns = getColumnSet(stratioStreamingMessage.getColumns());
                    if (tablenames.get(stratioStreamingMessage.getStreamName()) == null) {
                        getCassandraTableOperationsService().createTable(stratioStreamingMessage.getStreamName(),
                                stratioStreamingMessage.getColumns(), TIMESTAMP_FIELD);
                        refreshTablenames();
                    }
                    if (tablenames.get(stratioStreamingMessage.getStreamName()) != columns.hashCode()) {
                        getCassandraTableOperationsService().alterTable(stratioStreamingMessage.getStreamName(),
                                columns, stratioStreamingMessage.getColumns());
                        refreshTablenames();
                    }

                    batch.add(getCassandraTableOperationsService().createInsertStatement(
                            stratioStreamingMessage.getStreamName(), stratioStreamingMessage.getColumns(),
                            TIMESTAMP_FIELD));
                }

                getSession().execute(batch);
            }

        } catch (Exception e) {
            log.error("Error in Cassandra for batch size {}: {}", Iterables.size(partitionIterables),
                    e.getMessage());
        }

    }

    private SaveToCassandraOperationsService getCassandraTableOperationsService() {
        if (cassandraTableOperationsService == null) {
            cassandraTableOperationsService = new SaveToCassandraOperationsService(getSession());
        }

        return cassandraTableOperationsService;
    }

    private Session getSession() {
        if (cassandraSession == null) {
            cassandraSession = Cluster.builder().addContactPoints(cassandraQuorum.split(","))
                    .withPort(cassandraPort).build().connect();
            if (cassandraSession.getCluster().getMetadata()
                    .getKeyspace(STREAMING.STREAMING_KEYSPACE_NAME) == null) {
                getCassandraTableOperationsService().createKeyspace(STREAMING.STREAMING_KEYSPACE_NAME);
            }
            refreshTablenames();
        }
        return cassandraSession;
    }

    private void refreshTablenames() {
        Collection<TableMetadata> tableMetadatas = getSession().getCluster().getMetadata()
                .getKeyspace(STREAMING.STREAMING_KEYSPACE_NAME).getTables();
        tablenames = new HashMap<>();
        for (TableMetadata tableMetadata : tableMetadatas) {
            Set<String> columns = new HashSet<>();
            for (ColumnMetadata columnMetadata : tableMetadata.getColumns()) {
                columns.add(columnMetadata.getName());
            }
            tablenames.put(tableMetadata.getName(), columns.hashCode());
        }
    }

    private Set<String> getColumnSet(List<ColumnNameTypeValue> columns) {
        Set<String> columnsSet = new HashSet<>();
        for (ColumnNameTypeValue column : columns) {
            columnsSet.add(column.getColumn());
        }
        columnsSet.add(TIMESTAMP_FIELD);

        return columnsSet;
    }
}