azkaban.trigger.Condition.java Source code

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Here is the source code for azkaban.trigger.Condition.java

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/*
 * Copyright 2012 LinkedIn Corp.
 *
 * 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 azkaban.trigger;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.jexl2.Expression;
import org.apache.commons.jexl2.JexlEngine;
import org.apache.commons.jexl2.MapContext;
import org.apache.log4j.Logger;
import org.joda.time.DateTime;

public class Condition {

    private static Logger logger = Logger.getLogger(Condition.class);

    private static JexlEngine jexl = new JexlEngine();
    private static CheckerTypeLoader checkerLoader = null;
    private Expression expression;
    private Map<String, ConditionChecker> checkers = new HashMap<String, ConditionChecker>();
    private MapContext context = new MapContext();
    private Long nextCheckTime = -1L;

    public Condition(Map<String, ConditionChecker> checkers, String expr) {
        setCheckers(checkers);
        this.expression = jexl.createExpression(expr);
        updateNextCheckTime();
    }

    public Condition(Map<String, ConditionChecker> checkers, String expr, long nextCheckTime) {
        this.nextCheckTime = nextCheckTime;
        setCheckers(checkers);
        this.expression = jexl.createExpression(expr);
    }

    public synchronized static void setJexlEngine(JexlEngine jexl) {
        Condition.jexl = jexl;
    }

    public synchronized static void setCheckerLoader(CheckerTypeLoader loader) {
        Condition.checkerLoader = loader;
    }

    protected static CheckerTypeLoader getCheckerLoader() {
        return checkerLoader;
    }

    protected void registerChecker(ConditionChecker checker) {
        checkers.put(checker.getId(), checker);
        context.set(checker.getId(), checker);
        updateNextCheckTime();
    }

    public long getNextCheckTime() {
        return nextCheckTime;
    }

    public Map<String, ConditionChecker> getCheckers() {
        return this.checkers;
    }

    public void setCheckers(Map<String, ConditionChecker> checkers) {
        this.checkers = checkers;
        for (ConditionChecker checker : checkers.values()) {
            this.context.set(checker.getId(), checker);
        }
        updateNextCheckTime();
    }

    public void updateCheckTime(Long ct) {
        if (nextCheckTime < ct) {
            nextCheckTime = ct;
        }
    }

    private void updateNextCheckTime() {
        long time = Long.MAX_VALUE;
        for (ConditionChecker checker : checkers.values()) {
            time = Math.min(time, checker.getNextCheckTime());
        }
        this.nextCheckTime = time;
    }

    public void resetCheckers() {
        for (ConditionChecker checker : checkers.values()) {
            checker.reset();
        }
        updateNextCheckTime();
        logger.info("Done resetting checkers. The next check time will be " + new DateTime(nextCheckTime));
    }

    public String getExpression() {
        return this.expression.getExpression();
    }

    public void setExpression(String expr) {
        this.expression = jexl.createExpression(expr);
    }

    public boolean isMet() {
        if (logger.isDebugEnabled()) {
            logger.debug("Testing condition " + expression);
        }
        return expression.evaluate(context).equals(Boolean.TRUE);
    }

    public Object toJson() {
        Map<String, Object> jsonObj = new HashMap<String, Object>();
        jsonObj.put("expression", expression.getExpression());

        List<Object> checkersJson = new ArrayList<Object>();
        for (ConditionChecker checker : checkers.values()) {
            Map<String, Object> oneChecker = new HashMap<String, Object>();
            oneChecker.put("type", checker.getType());
            oneChecker.put("checkerJson", checker.toJson());
            checkersJson.add(oneChecker);
        }
        jsonObj.put("checkers", checkersJson);
        jsonObj.put("nextCheckTime", String.valueOf(nextCheckTime));

        return jsonObj;
    }

    @SuppressWarnings("unchecked")
    public static Condition fromJson(Object obj) throws Exception {
        if (checkerLoader == null) {
            throw new Exception("Condition Checker loader not initialized!");
        }

        Map<String, Object> jsonObj = (HashMap<String, Object>) obj;
        Condition cond = null;

        try {
            Map<String, ConditionChecker> checkers = new HashMap<String, ConditionChecker>();
            List<Object> checkersJson = (List<Object>) jsonObj.get("checkers");
            for (Object oneCheckerJson : checkersJson) {
                Map<String, Object> oneChecker = (HashMap<String, Object>) oneCheckerJson;
                String type = (String) oneChecker.get("type");
                ConditionChecker ck = checkerLoader.createCheckerFromJson(type, oneChecker.get("checkerJson"));
                checkers.put(ck.getId(), ck);
            }
            String expr = (String) jsonObj.get("expression");
            Long nextCheckTime = Long.valueOf((String) jsonObj.get("nextCheckTime"));

            cond = new Condition(checkers, expr, nextCheckTime);

        } catch (Exception e) {
            e.printStackTrace();
            logger.error("Failed to recreate condition from json.", e);
            throw new Exception("Failed to recreate condition from json.", e);
        }

        return cond;
    }

}