io.warp10.script.functions.DURATION.java Source code

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Here is the source code for io.warp10.script.functions.DURATION.java

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//
//   Copyright 2016  Cityzen Data
//
//   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 io.warp10.script.functions;

import io.warp10.continuum.store.Constants;
import io.warp10.script.NamedWarpScriptFunction;
import io.warp10.script.WarpScriptStackFunction;
import io.warp10.script.WarpScriptException;
import io.warp10.script.WarpScriptStack;

import java.util.Locale;

import org.joda.time.Duration;
import org.joda.time.Instant;
import org.joda.time.MutablePeriod;
import org.joda.time.Period;
import org.joda.time.ReadWritablePeriod;
import org.joda.time.format.ISOPeriodFormat;

/**
 * Pushes onto the stack the number of time units described by the ISO8601 duration
 * on top of the stack (String).
 *
 * @see http://en.wikipedia.org/wiki/ISO_8601#Durations
 */
public class DURATION extends NamedWarpScriptFunction implements WarpScriptStackFunction {

    public DURATION(String name) {
        super(name);
    }

    @Override
    public Object apply(WarpScriptStack stack) throws WarpScriptException {

        Object o = stack.pop();

        if (!(o instanceof String)) {
            throw new WarpScriptException(getName()
                    + " expects an ISO8601 duration (a string) on top of the stack. See http://en.wikipedia.org/wiki/ISO_8601#Durations");
        }

        ReadWritablePeriod period = new MutablePeriod();

        ISOPeriodFormat.standard().getParser().parseInto(period, o.toString(), 0, Locale.US);

        Period p = period.toPeriod();

        if (p.getMonths() != 0 || p.getYears() != 0) {
            throw new WarpScriptException(getName()
                    + " doesn't support ambiguous durations containing years or months, please convert those to days.");
        }

        Duration duration = p.toDurationFrom(new Instant());

        stack.push(duration.getMillis() * Constants.TIME_UNITS_PER_MS);

        return stack;
    }
}