smaputil.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.jasper.compiler;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;

/**
 * Contains static utilities for generating SMAP data based on the
 * current version of Jasper.
 * 
 * @author Jayson Falkner
 * @author Shawn Bayern
 * @author Robert Field (inner SDEInstaller class)
 * @author Mark Roth
 * @author Kin-man Chung
 */
public class SmapUtil {

    private org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog( SmapUtil.class );

    //*********************************************************************
    // Constants

    public static final String SMAP_ENCODING = "UTF-8";

    //*********************************************************************
    // Public entry points

    /**
     * Generates an appropriate SMAP representing the current compilation
     * context.  (JSR-045.)
     *
     * @param ctxt Current compilation context
     * @param pageNodes The current JSP page
     * @return a SMAP for the page
     */
    public static String[] generateSmap(
        JspCompilationContext ctxt,
        Node.Nodes pageNodes)
        throws IOException {

        // Scan the nodes for presence of Jasper generated inner classes
        PreScanVisitor psVisitor = new PreScanVisitor();
        try {
            pageNodes.visit(psVisitor);
        } catch (JasperException ex) {
        }
        HashMap map = psVisitor.getMap();

        // set up our SMAP generator
        SmapGenerator g = new SmapGenerator();
        
        /** Disable reading of input SMAP because:
            1. There is a bug here: getRealPath() is null if .jsp is in a jar
        	Bugzilla 14660.
            2. Mappings from other sources into .jsp files are not supported.
            TODO: fix 1. if 2. is not true.
        // determine if we have an input SMAP
        String smapPath = inputSmapPath(ctxt.getRealPath(ctxt.getJspFile()));
            File inputSmap = new File(smapPath);
            if (inputSmap.exists()) {
                byte[] embeddedSmap = null;
            byte[] subSmap = SDEInstaller.readWhole(inputSmap);
            String subSmapString = new String(subSmap, SMAP_ENCODING);
            g.addSmap(subSmapString, "JSP");
        }
        **/

        // now, assemble info about our own stratum (JSP) using JspLineMap
        SmapStratum s = new SmapStratum("JSP");

        g.setOutputFileName(unqualify(ctxt.getServletJavaFileName()));

        // Map out Node.Nodes
        evaluateNodes(pageNodes, s, map, ctxt.getOptions().getMappedFile());
        s.optimizeLineSection();
        g.addStratum(s, true);

        if (ctxt.getOptions().isSmapDumped()) {
            File outSmap = new File(ctxt.getClassFileName() + ".smap");
            PrintWriter so =
                new PrintWriter(
                    new OutputStreamWriter(
                        new FileOutputStream(outSmap),
                        SMAP_ENCODING));
            so.print(g.getString());
            so.close();
        }

        String classFileName = ctxt.getClassFileName();
        int innerClassCount = map.size();
        String [] smapInfo = new String[2 + innerClassCount*2];
        smapInfo[0] = classFileName;
        smapInfo[1] = g.getString();

        int count = 2;
        Iterator iter = map.entrySet().iterator();
        while (iter.hasNext()) {
            Map.Entry entry = (Map.Entry) iter.next();
            String innerClass = (String) entry.getKey();
            s = (SmapStratum) entry.getValue();
            s.optimizeLineSection();
            g = new SmapGenerator();
            g.setOutputFileName(unqualify(ctxt.getServletJavaFileName()));
            g.addStratum(s, true);

            String innerClassFileName =
                classFileName.substring(0, classFileName.indexOf(".class")) +
                '$' + innerClass + ".class";
            if (ctxt.getOptions().isSmapDumped()) {
                File outSmap = new File(innerClassFileName + ".smap");
                PrintWriter so =
                    new PrintWriter(
                        new OutputStreamWriter(
                            new FileOutputStream(outSmap),
                            SMAP_ENCODING));
                so.print(g.getString());
                so.close();
            }
            smapInfo[count] = innerClassFileName;
            smapInfo[count+1] = g.getString();
            count += 2;
        }

        return smapInfo;
    }

    public static void installSmap(String[] smap)
        throws IOException {
        if (smap == null) {
            return;
        }

        for (int i = 0; i < smap.length; i += 2) {
            File outServlet = new File(smap[i]);
            SDEInstaller.install(outServlet, smap[i+1].getBytes());
        }
    }

    //*********************************************************************
    // Private utilities

    /**
     * Returns an unqualified version of the given file path.
     */
    private static String unqualify(String path) {
        path = path.replace('\\', '/');
        return path.substring(path.lastIndexOf('/') + 1);
    }

    /**
     * Returns a file path corresponding to a potential SMAP input
     * for the given compilation input (JSP file).
     */
    private static String inputSmapPath(String path) {
        return path.substring(0, path.lastIndexOf('.') + 1) + "smap";
    }

    //*********************************************************************
    // Installation logic (from Robert Field, JSR-045 spec lead)
    private static class SDEInstaller {

        private org.apache.juli.logging.Log log=
            org.apache.juli.logging.LogFactory.getLog( SDEInstaller.class );

        static final String nameSDE = "SourceDebugExtension";

        byte[] orig;
        byte[] sdeAttr;
        byte[] gen;

        int origPos = 0;
        int genPos = 0;

        int sdeIndex;

        public static void main(String[] args) throws IOException {
            if (args.length == 2) {
                install(new File(args[0]), new File(args[1]));
            } else if (args.length == 3) {
                install(
                    new File(args[0]),
                    new File(args[1]),
                    new File(args[2]));
            } else {
                System.err.println(
                    "Usage: <command> <input class file> "
                        + "<attribute file> <output class file name>\n"
                        + "<command> <input/output class file> <attribute file>");
            }
        }

        static void install(File inClassFile, File attrFile, File outClassFile)
            throws IOException {
            new SDEInstaller(inClassFile, attrFile, outClassFile);
        }

        static void install(File inOutClassFile, File attrFile)
            throws IOException {
            File tmpFile = new File(inOutClassFile.getPath() + "tmp");
            new SDEInstaller(inOutClassFile, attrFile, tmpFile);
            if (!inOutClassFile.delete()) {
                throw new IOException("inOutClassFile.delete() failed");
            }
            if (!tmpFile.renameTo(inOutClassFile)) {
                throw new IOException("tmpFile.renameTo(inOutClassFile) failed");
            }
        }

        static void install(File classFile, byte[] smap) throws IOException {
            File tmpFile = new File(classFile.getPath() + "tmp");
            new SDEInstaller(classFile, smap, tmpFile);
            if (!classFile.delete()) {
                throw new IOException("classFile.delete() failed");
            }
            if (!tmpFile.renameTo(classFile)) {
                throw new IOException("tmpFile.renameTo(classFile) failed");
            }
        }

        SDEInstaller(File inClassFile, byte[] sdeAttr, File outClassFile)
            throws IOException {
            if (!inClassFile.exists()) {
                throw new FileNotFoundException("no such file: " + inClassFile);
            }

            this.sdeAttr = sdeAttr;
            // get the bytes
            orig = readWhole(inClassFile);
            gen = new byte[orig.length + sdeAttr.length + 100];

            // do it
            addSDE();

            // write result
            FileOutputStream outStream = new FileOutputStream(outClassFile);
            outStream.write(gen, 0, genPos);
            outStream.close();
        }

        SDEInstaller(File inClassFile, File attrFile, File outClassFile)
            throws IOException {
            this(inClassFile, readWhole(attrFile), outClassFile);
        }

        static byte[] readWhole(File input) throws IOException {
            FileInputStream inStream = new FileInputStream(input);
            int len = (int)input.length();
            byte[] bytes = new byte[len];
            if (inStream.read(bytes, 0, len) != len) {
                throw new IOException("expected size: " + len);
            }
            inStream.close();
            return bytes;
        }

        void addSDE() throws UnsupportedEncodingException, IOException {
            int i;
            copy(4 + 2 + 2); // magic min/maj version
            int constantPoolCountPos = genPos;
            int constantPoolCount = readU2();
            if (log.isDebugEnabled())
                log.debug("constant pool count: " + constantPoolCount);
            writeU2(constantPoolCount);

            // copy old constant pool return index of SDE symbol, if found
            sdeIndex = copyConstantPool(constantPoolCount);
            if (sdeIndex < 0) {
                // if "SourceDebugExtension" symbol not there add it
                writeUtf8ForSDE();

                // increment the countantPoolCount
                sdeIndex = constantPoolCount;
                ++constantPoolCount;
                randomAccessWriteU2(constantPoolCountPos, constantPoolCount);

                if (log.isDebugEnabled())
                    log.debug("SourceDebugExtension not found, installed at: " + sdeIndex);
            } else {
                if (log.isDebugEnabled())
                    log.debug("SourceDebugExtension found at: " + sdeIndex);
            }
            copy(2 + 2 + 2); // access, this, super
            int interfaceCount = readU2();
            writeU2(interfaceCount);
            if (log.isDebugEnabled())
                log.debug("interfaceCount: " + interfaceCount);
            copy(interfaceCount * 2);
            copyMembers(); // fields
            copyMembers(); // methods
            int attrCountPos = genPos;
            int attrCount = readU2();
            writeU2(attrCount);
            if (log.isDebugEnabled())
                log.debug("class attrCount: " + attrCount);
            // copy the class attributes, return true if SDE attr found (not copied)
            if (!copyAttrs(attrCount)) {
                // we will be adding SDE and it isn't already counted
                ++attrCount;
                randomAccessWriteU2(attrCountPos, attrCount);
                if (log.isDebugEnabled())
                    log.debug("class attrCount incremented");
            }
            writeAttrForSDE(sdeIndex);
        }

        void copyMembers() {
            int count = readU2();
            writeU2(count);
            if (log.isDebugEnabled())
                log.debug("members count: " + count);
            for (int i = 0; i < count; ++i) {
                copy(6); // access, name, descriptor
                int attrCount = readU2();
                writeU2(attrCount);
                if (log.isDebugEnabled())
                    log.debug("member attr count: " + attrCount);
                copyAttrs(attrCount);
            }
        }

        boolean copyAttrs(int attrCount) {
            boolean sdeFound = false;
            for (int i = 0; i < attrCount; ++i) {
                int nameIndex = readU2();
                // don't write old SDE
                if (nameIndex == sdeIndex) {
                    sdeFound = true;
                    if (log.isDebugEnabled())
                        log.debug("SDE attr found");
                } else {
                    writeU2(nameIndex); // name
                    int len = readU4();
                    writeU4(len);
                    copy(len);
                    if (log.isDebugEnabled())