MedSplunkColumnSet.java

/*******************************************************************************
   Copyright [2011] Splunk 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.splunk.udx;

import java.math.*;
import java.net.URLEncoder;

import java.sql.*;

import java.util.*;

import net.sf.farrago.catalog.FarragoCatalogUtil;
import net.sf.farrago.namespace.FarragoMedColumnSet;
import net.sf.farrago.namespace.impl.MedAbstractColumnSet;
import net.sf.farrago.plugin.FarragoAbstractPluginBase;
import net.sf.farrago.query.FarragoUserDefinedRoutine;
import net.sf.farrago.resource.FarragoResource;

import org.eigenbase.rel.*;
import org.eigenbase.rel.convert.*;
import org.eigenbase.rel.jdbc.*;
import org.eigenbase.relopt.*;
import org.eigenbase.reltype.*;
import org.eigenbase.rex.*;
import org.eigenbase.sql.*;
import org.eigenbase.sql.parser.SqlParser;
import org.eigenbase.util.*;

import com.splunk.util.HTTPUtils;
import com.splunk.util.StringUtils;


/**
 * MedSplunkColumnSet provides an implementation of the {@link
 * FarragoMedColumnSet} interface for MQL.
 *
 * @author Ledion Bitincka
 */
class MedSplunkColumnSet
    extends MedAbstractColumnSet
{

    public static final String PROP_SEARCH      = "BASE_SEARCH";
    public static final String DEFAULT_SEARCH   = "search *";

    public static final String PROP_LATEST      = "LATEST";
    public static final String DEFAULT_LATEST   = "now";

    public static final String PROP_EARLIEST    = "EARLIEST";

    final MedSplunkDataServer server;
    final String udxSpecificName;

    final String search, earliest, latest, fields;
    List<String> fieldList;
    
    MedSplunkColumnSet(
        MedSplunkDataServer server,
        Properties tableProps,
        String [] localName,
        RelDataType rowType,
        String udxSpecificName)
    {
        super(localName, null, rowType, null, null);
        this.server = server;
        this.udxSpecificName = udxSpecificName;
        
        FarragoAbstractPluginBase.
        requireProperty(tableProps, PROP_EARLIEST);
        
        search   = tableProps.getProperty(PROP_SEARCH, DEFAULT_SEARCH);
        latest   = tableProps.getProperty(PROP_LATEST, DEFAULT_LATEST);
        earliest = tableProps.getProperty(PROP_EARLIEST);

        this.fieldList = new LinkedList<String>();
        for (RelDataTypeField field : rowType.getFieldList()) {
            this.fieldList.add(field.getName());
        }
        fields = StringUtils.encodeList(fieldList, '|').toString();

    }

    // implement RelOptTable
    public RelNode toRel(
        RelOptCluster cluster,
        RelOptConnection connection)
    {
        RexBuilder rexBuilder = cluster.getRexBuilder();
        RexNode rnSearch   = rexBuilder.makeLiteral(this.search);
        RexNode rnEarliest = rexBuilder.makeLiteral(this.earliest);
        RexNode rnLatest   = rexBuilder.makeLiteral(this.latest);

        RexNode rnUrl       = rexBuilder.makeLiteral(server.getUrl());
        RexNode rnUsername  = rexBuilder.makeLiteral(server.getUsername());
        RexNode rnPassword  = rexBuilder.makeLiteral(server.getPassword());

       
        RexNode rnFields   = rexBuilder.makeLiteral(this.fields);

        // Call to super handles the rest.
        return toUdxRel(
            cluster,
            connection,
            udxSpecificName,
            server.getServerMofId(),
            new RexNode[] { rnSearch, rnEarliest, rnLatest, rnUrl, rnUsername, rnPassword, rnFields });
        
    }

    // override FarragoMedColumnSet
    // return a SplunkUdxRel instead of a FarragoJavaUdxRel
    protected RelNode toUdxRel(
        RelOptCluster cluster,
        RelOptConnection connection,
        String udxSpecificName,
        String serverMofId,
        RexNode [] args)
    {
        // Parse the specific name of the UDX.
        SqlIdentifier udxId;
        try {
            SqlParser parser = new SqlParser(udxSpecificName);
            SqlNode parsedId = parser.parseExpression();
            udxId = (SqlIdentifier) parsedId;
        } catch (Exception ex) {
            // FIXME schoi 16-Sep-2010: generate resources
            // throw FarragoResource.instance().MedInvalidUdxId.ex(
            // udxSpecificName,
            // ex);
            return null;
        }

        // Look up the UDX in the catalog.
        List list =
            getPreparingStmt().getSqlOperatorTable().lookupOperatorOverloads(
                udxId,
                SqlFunctionCategory.UserDefinedSpecificFunction,
                SqlSyntax.Function);
        FarragoUserDefinedRoutine udx = null;
        if (list.size() == 1) {
            Object obj = list.iterator().next();
            if (obj instanceof FarragoUserDefinedRoutine) {
                udx = (FarragoUserDefinedRoutine) obj;
                if (!FarragoCatalogUtil.isTableFunction(udx.getFemRoutine())) {
                    // Not a UDX.
                    udx = null;
                }
            }
        }
        if (udx == null) {
            // FIXME schoi 16-Sep-2010: generate resources
            // throw FarragoResource.instance().MedUnknownUdx.ex(udxId.toString());
            return null;
        }

        // UDX wants all types nullable, so construct a corresponding
        // type descriptor for the result of the call.
        RexBuilder rexBuilder = cluster.getRexBuilder();
        RelDataTypeFactory typeFactory = rexBuilder.getTypeFactory();
        RelDataType resultType =
            typeFactory.createTypeWithNullability(
                this.rowType,
                true);

        // Create a relational algebra expression for invoking the UDX.
        RexNode rexCall = rexBuilder.makeCall(udx, args);

        RelNode udxRel =
            new SplunkUdxRel(
                cluster,
                rexCall,
                resultType,
                this,
                udx);

        // Optimizer wants us to preserve original types,
        // so cast back for the final result.
        return RelOptUtil.createCastRel(udxRel, this.rowType, true);
    }

    public List<String> getFieldList(){
        return this.fieldList;
    }
    
    public String getServerMofId(){
        return this.server.getServerMofId();
    }
    
}