org.apache.drill.exec.compile.DrillJavaFileObject.java Source code

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Here is the source code for org.apache.drill.exec.compile.DrillJavaFileObject.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.drill.exec.compile;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Reader;
import java.io.StringReader;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Map;

import javax.tools.SimpleJavaFileObject;

import com.google.common.collect.Maps;

/* package */
final class DrillJavaFileObject extends SimpleJavaFileObject {
    private final String sourceCode;

    private final ByteArrayOutputStream outputStream;

    private Map<String, DrillJavaFileObject> outputFiles;

    public DrillJavaFileObject(final String className, final String sourceCode) {
        super(makeURI(className), Kind.SOURCE);
        this.sourceCode = sourceCode;
        this.outputStream = null;
    }

    private DrillJavaFileObject(final String name, final Kind kind) {
        super(makeURI(name), kind);
        this.outputStream = new ByteArrayOutputStream();
        this.sourceCode = null;
    }

    public boolean isCompiled() {
        return (outputFiles != null);
    }

    public byte[][] getByteCode() {
        if (!isCompiled()) {
            return null;
        } else {
            int index = 0;
            byte[][] byteCode = new byte[outputFiles.size()][];
            for (DrillJavaFileObject outputFile : outputFiles.values()) {
                byteCode[index++] = outputFile.outputStream.toByteArray();
            }
            return byteCode;
        }
    }

    public DrillJavaFileObject addOutputJavaFile(String className) {
        if (outputFiles == null) {
            outputFiles = Maps.newLinkedHashMap();
        }
        DrillJavaFileObject outputFile = new DrillJavaFileObject(className, Kind.CLASS);
        outputFiles.put(className, outputFile);
        return outputFile;
    }

    @Override
    public Reader openReader(final boolean ignoreEncodingErrors) throws IOException {
        return new StringReader(sourceCode);
    }

    @Override
    public CharSequence getCharContent(final boolean ignoreEncodingErrors) throws IOException {
        if (sourceCode == null) {
            throw new UnsupportedOperationException("This instance of DrillJavaFileObject is not an input object.");
        }
        return sourceCode;
    }

    @Override
    public OutputStream openOutputStream() {
        if (outputStream == null) {
            throw new UnsupportedOperationException(
                    "This instance of DrillJavaFileObject is not an output object.");
        }
        return outputStream;
    }

    private static URI makeURI(final String canonicalClassName) {
        final int dotPos = canonicalClassName.lastIndexOf('.');
        final String simpleClassName = dotPos == -1 ? canonicalClassName : canonicalClassName.substring(dotPos + 1);
        try {
            return new URI(simpleClassName + Kind.SOURCE.extension);
        } catch (URISyntaxException e) {
            throw new RuntimeException(e);
        }
    }

}