guru.nidi.graphviz.engine.GraphvizV8Engine Maven / Gradle / Ivy

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/*
 * Copyright (C) 2015 Stefan Niederhauser ([email protected])
 *
 * 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 guru.nidi.graphviz.engine;

import com.eclipsesource.v8.V8;
import com.eclipsesource.v8.V8Array;
import com.eclipsesource.v8.V8RuntimeException;
import com.eclipsesource.v8.utils.V8ObjectUtils;

import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class GraphvizV8Engine extends AbstractGraphvizEngine {
    private final static Pattern ABORT = Pattern.compile("^undefined:\\d+: abort");
    private V8 v8;
    private V8Array messages;

    public GraphvizV8Engine() {
        this(null);
    }

    public GraphvizV8Engine(EngineInitListener engineInitListener) {
        super(true, engineInitListener);
    }

    @Override
    public void release() {
        messages.release();
        v8.release(true);
    }

    @Override
    protected void doInit() throws Exception {
        v8 = V8.createV8Runtime();
        v8.executeVoidScript("var $$prints=[]; print=function(s){$$prints.push(s);};");
        messages = v8.getArray("$$prints");
        v8.executeVoidScript(vizCode());
    }

    @Override
    protected String doExecute(String dot) {
        try {
            return v8.executeStringScript("$$prints.splice(0,100); Viz('" + jsEscape(dot) + "');");
        } catch (V8RuntimeException e) {
            if (ABORT.matcher(e.getMessage()).find()) {
                throw new GraphvizException(IntStream.range(0, messages.length())
                        .mapToObj(i -> V8ObjectUtils.getValue(messages, i).toString())
                        .collect(Collectors.joining("\n")));
            }
            throw new GraphvizException("Problem executing graphviz", e);
        }
    }
}