com.google.dart.tools.debug.core.util.DebuggerUtils.java Source code

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Here is the source code for com.google.dart.tools.debug.core.util.DebuggerUtils.java

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/*
 * Copyright 2012 Dart project authors.
 * 
 * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html
 * 
 * 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.dart.tools.debug.core.util;

import com.google.common.io.CharStreams;
import com.google.common.io.Closeables;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.model.IStackFrame;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.Arrays;
import java.util.List;

/**
 * This class contains static utility methods for use by the debugger.
 */
public class DebuggerUtils {

    /**
     * Returns whether the given frame needs some additional disambiguating information from its two
     * surrounding frames.
     * 
     * @param frame
     * @return
     * @throws DebugException
     */
    public static boolean areSiblingNamesUnique(IExceptionStackFrame frame) throws DebugException {
        List<IStackFrame> frames = Arrays.asList(frame.getThread().getStackFrames());

        int index = frames.indexOf(frame);

        if (index == -1) {
            return true;
        }

        if (index > 0) {
            IExceptionStackFrame other = (IExceptionStackFrame) frames.get(index - 1);

            if (needsDisambiguating(other, frame)) {
                return false;
            }
        }

        if ((index + 1) < frames.size()) {
            IExceptionStackFrame other = (IExceptionStackFrame) frames.get(index + 1);

            if (needsDisambiguating(frame, other)) {
                return false;
            }
        }

        return true;
    }

    /**
     * The names of private fields are mangled by the VM.
     * <p>
     * _foo@652376 ==> _foo
     * <p>
     * Also, remove "set:" and "get:", as these are artifacts of the VM implementation.
     * <p>
     * e.x., Cat.get:color() ==> Cat.color()
     * 
     * @param name
     * @return
     */
    public static String demangleVmName(String name) {
        if (name == null) {
            return null;
        }

        int atIndex = name.indexOf('@');

        while (atIndex != -1) {
            // check for _foo@76876.bar (or _Process@14117cc4._reportError@14117cc4)
            int endIndex = name.indexOf('.', atIndex);

            if (endIndex == -1) {
                name = name.substring(0, atIndex);
            } else {
                name = name.substring(0, atIndex) + name.substring(endIndex);
            }

            atIndex = name.indexOf('@');
        }

        // Also remove the trailing '.' for default constructors.
        if (name.endsWith(".")) {
            name = name.substring(0, name.length() - 1);
        }

        // remove "set:" and "get:"
        // Cat.get:color() ==> Cat.color()
        if (name.indexOf(".set:") != -1) {
            int index = name.indexOf(".set:");
            name = name.substring(0, index + 1) + name.substring(index + 5);
        }

        if (name.indexOf(".get:") != -1) {
            int index = name.indexOf(".get:");
            name = name.substring(0, index + 1) + name.substring(index + 5);
        }

        return name;
    }

    public static String extractFileLine(IFile file, int lineNumber) {
        if (file == null) {
            return null;
        }

        try {
            return extractFileLine(file.getContents(), file.getCharset(), lineNumber);
        } catch (CoreException ce) {

        }

        return null;
    }

    public static String extractFileLine(InputStream contents, String charset, int lineNumber) {
        if (contents == null) {
            return null;
        }

        try {
            Reader r = charset != null ? new InputStreamReader(contents, charset) : new InputStreamReader(contents);

            List<String> lines = CharStreams.readLines(r);
            Closeables.close(r, true);

            if (lineNumber >= 0 && lineNumber < lines.size()) {
                String lineStr = lines.get(lineNumber).trim();

                return lineStr.length() == 0 ? null : lineStr;
            }
        } catch (IOException ioe) {

        }

        return null;
    }

    public static boolean isInternalMethodName(String methodName) {
        return methodName.startsWith("Object._noSuchMethod@");
    }

    /**
     * @return whether the given debugger symbol name represents a private symbol
     */
    public static boolean isPrivateName(String name) {
        // These are special names generated by dart2js.
        if (name.startsWith("$.") || name.startsWith("$$.")) {
            return false;
        }

        // A private top-level method (_foo()).
        if (name.startsWith("_")) {
            return true;
        }

        // A private static or instance method (i.e Foo._bar()).
        return name.indexOf("._") != -1;
    }

    public static String printString(String str) {
        if (str == null) {
            return null;
        }

        if (str.indexOf('\n') != -1) {
            str = str.replace("\n", "\\n");
        }

        if (str.indexOf('\r') != -1) {
            str = str.replace("\r", "\\r");
        }

        if (str.indexOf('\t') != -1) {
            str = str.replace("\t", "\\t");
        }

        // Don't re-quote already quoted strings.
        if (str.length() > 1 && str.startsWith("\"") && str.endsWith("\"")) {
            return str;
        } else {
            return "\"" + str + "\"";
        }
    }

    private static boolean needsDisambiguating(IExceptionStackFrame frame1, IExceptionStackFrame frame2) {
        if (frame1.getShortName().equals(frame2.getShortName())) {
            // These will need disambiguating if the long names are different.

            return !frame1.getLongName().equals(frame2.getLongName());
        }

        return false;
    }

    private DebuggerUtils() {

    }

}