com.ibm.wala.cast.js.nodejs.NodejsRequiredSourceModule.java Source code

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Here is the source code for com.ibm.wala.cast.js.nodejs.NodejsRequiredSourceModule.java

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/******************************************************************************
 * Copyright (c) 2002 - 2016 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Brian Pfretzschner - initial implementation
 *****************************************************************************/
package com.ibm.wala.cast.js.nodejs;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;

import com.ibm.wala.cast.ipa.callgraph.CAstCallGraphUtil;
import com.ibm.wala.classLoader.SourceFileModule;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.io.Streams;

/**
 * This class is intended to be used whenever a JavaScript module is dynamically
 * required by JavaScript (CommonJS). The required file will be loaded and
 * wrapped in a function call to simulate the real behavior of a CommonJS
 * environment. The resulting function will be named GLOBAL_PREFIX + relative
 * file-name. To retrieve the final function name, use getFunctioName().
 * 
 * @author Brian Pfretzschner <brian.pfretzschner@gmail.com>
 */
public class NodejsRequiredSourceModule extends SourceFileModule {

    private final static String MODULE_WRAPPER_FILENAME = "module-wrapper.js";
    private final static String JSON_WRAPPER_FILENAME = "json-wrapper.js";

    private final static String FILENAME_PLACEHOLDER = "/*/ WALA-INSERT-FILENAME-HERE /*/";
    private final static String DIRNAME_PLACEHOLDER = "/*/ WALA-INSERT-DIRNAME-HERE /*/";
    private final static String CODE_PLACEHOLDER = "/*/ WALA-INSERT-CODE-HERE /*/";

    private static String MODULE_WRAPPER_SOURCE = null;
    private static String JSON_WRAPPER_SOURCE = null;

    private final String className;

    /**
     * @param f
     *            Must be a file located below folder workingDir.
     * @param clonedFrom
     * @throws IOException
     */
    protected NodejsRequiredSourceModule(String className, File f, SourceFileModule clonedFrom) throws IOException {
        super(f, clonedFrom);

        // Generate className based on the given file name
        this.className = className;
        assert className.matches("[a-zA-Z_$][0-9a-zA-Z_$]*") : "Invalid className: " + className;

        if (MODULE_WRAPPER_SOURCE == null || JSON_WRAPPER_SOURCE == null) {
            // Populate the cache that hold the module wrapper source code
            loadWrapperSources();
        }
    }

    @Override
    public InputStream getInputStream() {
        String moduleSource = null;
        try (final InputStream inputStream = super.getInputStream()) {
            moduleSource = IOUtils.toString(inputStream);
        } catch (IOException e) {
            Assertions.UNREACHABLE(e.getMessage());
        }

        String wrapperSource = null;
        String ext = FilenameUtils.getExtension(getFile().toString()).toLowerCase();
        if (ext.equals("js")) {
            // JS file -> use module wrapper
            wrapperSource = MODULE_WRAPPER_SOURCE;
        } else if (ext.equals("json")) {
            // JSON file -> use JSON wrapper
            wrapperSource = JSON_WRAPPER_SOURCE;
        } else {
            // No clue -> try module wrapper
            System.err.println("NodejsRequiredSourceModule: Unsupported file type (" + ext + "), continue anyway.");
            wrapperSource = MODULE_WRAPPER_SOURCE;
        }

        String wrappedModuleSource = wrapperSource.replace(FILENAME_PLACEHOLDER, getFile().getName())
                .replace(DIRNAME_PLACEHOLDER, getFile().getParent().toString())
                .replace(CODE_PLACEHOLDER, moduleSource);

        return IOUtils.toInputStream(wrappedModuleSource);
    }

    @Override
    public String getClassName() {
        return className;
    }

    @Override
    public String getName() {
        return className;
    }

    private static void loadWrapperSources() throws IOException {
        MODULE_WRAPPER_SOURCE = loadWrapperSource(MODULE_WRAPPER_FILENAME);
        JSON_WRAPPER_SOURCE = loadWrapperSource(JSON_WRAPPER_FILENAME);
    }

    private static String loadWrapperSource(String filename) throws IOException {
        try (final InputStream url = NodejsRequiredSourceModule.class.getClassLoader()
                .getResourceAsStream(filename)) {
            return new String(Streams.inputStream2ByteArray(url));
        }
    }

    /**
     * Generate a className based on the file name and path of the module file.
     * The path should be encoded in the className since the file name is not unique.
     * 
     * @param rootDir
     * @param file
     */
    public static String convertFileToClassName(File rootDir, File file) {
        URI normalizedWorkingDirURI = rootDir.getAbsoluteFile().toURI().normalize();
        URI normalizedFileURI = file.getAbsoluteFile().toURI().normalize();
        String relativePath = normalizedWorkingDirURI.relativize(normalizedFileURI).getPath();

        return FilenameUtils.removeExtension(relativePath).replace("/", "_").replace("-", "__").replace(".", "__");
    }

    public static NodejsRequiredSourceModule make(File rootDir, File file) throws IOException {
        String className = convertFileToClassName(rootDir, file);
        SourceFileModule sourceFileModule = CAstCallGraphUtil.makeSourceModule(file.toURI().toURL(),
                file.getName());
        return new NodejsRequiredSourceModule(className, file, sourceFileModule);
    }
}