org.teiid.translator.solr.SolrQueryExecution.java Source code

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Here is the source code for org.teiid.translator.solr.SolrQueryExecution.java

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/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */
package org.teiid.translator.solr;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.solr.client.solrj.SolrQuery;
import org.apache.solr.client.solrj.response.QueryResponse;
import org.apache.solr.common.SolrDocument;
import org.apache.solr.common.SolrDocumentList;
import org.teiid.language.Command;
import org.teiid.language.QueryExpression;
import org.teiid.logging.LogManager;
import org.teiid.metadata.RuntimeMetadata;
import org.teiid.translator.DataNotAvailableException;
import org.teiid.translator.ExecutionContext;
import org.teiid.translator.ResultSetExecution;
import org.teiid.translator.TranslatorException;

public class SolrQueryExecution implements ResultSetExecution {
    private ExecutionContext executionContext;
    private SolrConnection connection;
    private SolrSQLHierarchyVistor visitor;
    private Iterator<SolrDocument> resultsItr;
    private Class<?>[] expectedTypes;
    private SolrExecutionFactory executionFactory;
    private int offset = 0;
    private Long resultSize;

    public SolrQueryExecution(SolrExecutionFactory ef, Command command, ExecutionContext executionContext,
            RuntimeMetadata metadata, SolrConnection connection) {
        this.executionFactory = ef;
        this.executionContext = executionContext;
        this.connection = connection;
        if (command instanceof QueryExpression) {
            this.expectedTypes = ((QueryExpression) command).getColumnTypes();
        }

        this.visitor = new SolrSQLHierarchyVistor(metadata, this.executionFactory);
        this.visitor.visitNode(command);
    }

    @Override
    public void execute() throws TranslatorException {
        LogManager.logDetail("Solr Source Query:", this.visitor.getSolrQuery()); //$NON-NLS-1$
        nextBatch();
    }

    public void nextBatch() throws TranslatorException {
        SolrQuery query = this.visitor.getSolrQuery();
        if (!this.visitor.isLimitInUse()) {
            query.setStart(this.offset);
            query.setRows(this.executionContext.getBatchSize());
        }

        QueryResponse queryResponse = connection.query(this.visitor.getSolrQuery());
        SolrDocumentList docList = queryResponse.getResults();
        this.resultSize = docList.getNumFound();
        this.resultsItr = docList.iterator();
    }

    /*
     * This iterates through the documents from Solr and maps their fields to
     * rows in the Teiid table
     * 
     * @see org.teiid.translator.ResultSetExecution#next()
     */
    @Override
    public List<?> next() throws TranslatorException, DataNotAvailableException {

        final List<Object> row = new ArrayList<Object>();

        if (this.visitor.isCountStarInUse() && this.resultsItr != null) {
            row.add(this.resultSize);
            this.resultsItr = null;
            return row;
        }

        // is there any solr docs
        if (this.resultsItr != null && this.resultsItr.hasNext()) {
            SolrDocument doc = this.resultsItr.next();
            for (int i = 0; i < this.visitor.getFieldNameList().size(); i++) {
                String columnName = this.visitor.getFieldNameList().get(i);
                Object obj = doc.getFieldValue(columnName);
                row.add(this.executionFactory.convertFromSolrType(obj, this.expectedTypes[i]));
            }
            this.offset++;

            // if we are at the end of the current cursor set, then get next ones.
            if (!this.resultsItr.hasNext() && !this.visitor.isLimitInUse()) {
                nextBatch();
            }
            return row;
        }
        return null;
    }

    interface SolrDocumentCallback {
        void walk(SolrDocument doc);
    }

    public void walkDocuments(SolrDocumentCallback callback) throws TranslatorException {
        while (this.resultsItr != null && this.resultsItr.hasNext()) {
            SolrDocument doc = this.resultsItr.next();
            callback.walk(doc);
            this.offset++;

            // if we are at the end of the current cursor set, then get next ones.
            if (!this.resultsItr.hasNext()) {
                nextBatch();
            }
        }
    }

    @Override
    public void close() {
    }

    @Override
    public void cancel() throws TranslatorException {
    }
}