cosmos.sql.DataTable.java Source code

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Here is the source code for cosmos.sql.DataTable.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.
 *
 *  Copyright 2013 
 *
 */
package cosmos.sql;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Queue;

import net.hydromatic.linq4j.AbstractQueryable;
import net.hydromatic.linq4j.Enumerable;
import net.hydromatic.linq4j.Enumerator;
import net.hydromatic.linq4j.Linq4j;
import net.hydromatic.linq4j.QueryProvider;
import net.hydromatic.linq4j.expressions.Expression;
import net.hydromatic.linq4j.expressions.Expressions;
import net.hydromatic.optiq.DataContext;
import net.hydromatic.optiq.Statistic;
import net.hydromatic.optiq.Statistics;
import net.hydromatic.optiq.TranslatableTable;
import net.hydromatic.optiq.impl.java.JavaTypeFactory;

import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.RelOptTable;
import org.eigenbase.relopt.RelOptTable.ToRelContext;
import org.eigenbase.reltype.RelDataType;

import com.google.common.base.Preconditions;
import com.google.common.collect.Queues;

import cosmos.records.impl.MultimapRecord;
import cosmos.sql.CosmosRelNode.Plan;

/**
 * Accumulo table representation. Is a queryable mechanism
 * 
 * @param <T>
 */
public class DataTable<T> extends AbstractQueryable<T> implements TranslatableTable<T> {

    protected JavaTypeFactory javaFactory;

    protected RelDataType rowType;

    private SchemaDefiner<?> metadata;

    protected String table;

    protected TableSchema<? extends SchemaDefiner<?>> schema;

    protected String tableName;

    protected BaseIterable<T> resultSet;

    /**
     * plans that perform aggreation
     */
    protected Queue<Plan> aggregationPlans;

    /**
     * Queue of plans to execute
     */
    protected Queue<Plan> plans;

    public DataTable(final TableSchema<? extends SchemaDefiner<?>> schema, final String tableName,
            JavaTypeFactory typeFactory) {
        this.schema = schema;
        this.tableName = tableName;
        plans = Queues.newPriorityQueue();
        aggregationPlans = Queues.newPriorityQueue();
        resultSet = new BaseIterable<T>();
        javaFactory = typeFactory;
        this.metadata = schema.metaData;

    }

    @Override
    public Expression getExpression() {
        return Expressions.convert_(Expressions.call(schema.getExpression(), "getTable",
                Expressions.constant(tableName), Expressions.constant(getElementType())), DataTable.class);

    }

    @Override
    public QueryProvider getProvider() {
        return schema.getQueryProvider();
    }

    @Override
    public Iterator<T> iterator() {
        return Linq4j.enumeratorIterator(enumerator());
    }

    @Override
    public DataContext getDataContext() {
        return schema;
    }

    @Override
    public Statistic getStatistic() {
        return Statistics.UNKNOWN;
    }

    public boolean groupBy(Plan plan) {
        return aggregationPlans.add(plan);
    }

    public boolean enqueue(Plan plan) {
        return plans.add(plan);
    }

    @Override
    public Enumerator<T> enumerator() {

        return Linq4j.enumerator(new ArrayList<T>());
    }

    public void execute(Plan relationalExpression) {

    }

    @Override
    public RelDataType getRowType() {

        return rowType;
    }

    @Override
    public RelNode toRel(ToRelContext context, RelOptTable relOptTable) {

        return new TableScanner(context.getCluster(), context.getCluster().traitSetOf(CosmosRelNode.CONVENTION),
                relOptTable, this, relOptTable.getRowType().getFieldNames());
    }

    @SuppressWarnings("unchecked")
    public Enumerable<T> accumulate(List<String> fieldNames) {
        Plan query = plans.poll();

        Plan aggregatePlan = aggregationPlans.poll();

        Preconditions.checkNotNull(query);

        resultSet = (BaseIterable<T>) metadata.iterator(fieldNames, query, aggregatePlan);

        return Linq4j.asEnumerable(resultSet);
    }

    @Override
    public Type getElementType() {
        return MultimapRecord.class;
    }

    public String getTable() {
        return table;
    }

}