io.druid.query.expression.ExprUtils.java Source code

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Here is the source code for io.druid.query.expression.ExprUtils.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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.
 */

package io.druid.query.expression;

import io.druid.java.util.common.IAE;
import io.druid.java.util.common.granularity.PeriodGranularity;
import io.druid.math.expr.Expr;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import org.joda.time.Period;

public class ExprUtils {
    private static final Expr.ObjectBinding NIL_BINDINGS = name -> null;

    public static Expr.ObjectBinding nilBindings() {
        return NIL_BINDINGS;
    }

    public static DateTimeZone toTimeZone(final Expr timeZoneArg) {
        if (!timeZoneArg.isLiteral()) {
            throw new IAE("Time zone must be a literal");
        }

        final Object literalValue = timeZoneArg.getLiteralValue();
        return literalValue == null ? DateTimeZone.UTC : DateTimeZone.forID((String) literalValue);
    }

    public static PeriodGranularity toPeriodGranularity(final Expr periodArg, final Expr originArg,
            final Expr timeZoneArg, final Expr.ObjectBinding bindings) {
        final Period period = new Period(periodArg.eval(bindings).asString());
        final DateTime origin;
        final DateTimeZone timeZone;

        if (originArg == null) {
            origin = null;
        } else {
            final Object value = originArg.eval(bindings).value();
            origin = value != null ? new DateTime(value) : null;
        }

        if (timeZoneArg == null) {
            timeZone = null;
        } else {
            final String value = timeZoneArg.eval(bindings).asString();
            timeZone = value != null ? DateTimeZone.forID(value) : null;
        }

        return new PeriodGranularity(period, origin, timeZone);
    }
}