com.google.javascript.jscomp.fuzzing.Dispatcher.java Source code

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Here is the source code for com.google.javascript.jscomp.fuzzing.Dispatcher.java

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/*
 * Copyright 2013 The Closure Compiler Authors.
 *
 * 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.google.javascript.jscomp.fuzzing;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.javascript.rhino.Node;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.EnumSet;
import java.util.Set;

/**
 * UNDER DEVELOPMENT. DO NOT USE!
 */
abstract class Dispatcher extends AbstractFuzzer {
    private Set<Type> supportedTypes;

    Dispatcher(FuzzingContext context) {
        super(context);
    }

    protected AbstractFuzzer[] candidates;

    @Override
    protected boolean isEnough(int budget) {
        if (budget < 1) {
            return false;
        }
        Preconditions.checkNotNull(getCandidates(), "Candidate fuzzers need to be initialized before being used.");

        for (AbstractFuzzer fuzzer : getCandidates()) {
            if (fuzzer.isEnough(budget)) {
                return true;
            }
        }
        return false;
    }

    /* (non-Javadoc)
     * @see com.google.javascript.jscomp.fuzzing.AbstractFuzzer#generate(int, Set<Type>)
     */
    @Override
    protected Node generate(int budget, Set<Type> types) {
        AbstractFuzzer fuzzer = selectFuzzer(budget, types);
        return fuzzer.generate(budget, types);
    }

    @Override
    protected Set<Type> supportedTypes() {
        if (supportedTypes == null) {
            supportedTypes = EnumSet.noneOf(Type.class);
            for (AbstractFuzzer fuzzer : getCandidates()) {
                supportedTypes.addAll(fuzzer.supportedTypes());
            }
        }
        return Sets.immutableEnumSet(supportedTypes);
    }

    protected AbstractFuzzer selectFuzzer(int budget, Set<Type> types) {
        Preconditions.checkNotNull(getCandidates(), "Candidate fuzzers need to be initialized before being used.");
        ArrayList<AbstractFuzzer> typeCorrectCandidates;
        typeCorrectCandidates = Lists.newArrayList();
        for (AbstractFuzzer fuzzer : getCandidates()) {
            if (!Sets.intersection(fuzzer.supportedTypes(), types).isEmpty()) {
                typeCorrectCandidates.add(fuzzer);
            }
        }
        JSONObject weightConfig = getOwnConfig().optJSONObject("weights");
        ArrayList<AbstractFuzzer> validFuzzers = Lists.newArrayList();
        ArrayList<Double> weights = Lists.newArrayList();
        int stepSize = 2;
        budget -= stepSize;
        do {
            // increase the budget until it is enough for some fuzzers
            budget += stepSize;
            for (AbstractFuzzer fuzzer : typeCorrectCandidates) {
                if (fuzzer.isEnough(budget)) {
                    validFuzzers.add(fuzzer);
                    try {
                        weights.add(weightConfig.getDouble(fuzzer.getConfigName()));
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            }
        } while (validFuzzers.isEmpty());
        DiscreteDistribution<AbstractFuzzer> dd = new DiscreteDistribution<>(context.random, validFuzzers, weights);
        return dd.nextItem();
    }

    protected abstract void initCandidates();

    private AbstractFuzzer[] getCandidates() {
        if (candidates == null) {
            initCandidates();
        }
        return candidates;
    }
}