/*
 *  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.owasp.dependencycheck.org.apache.tools.ant;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
import org.owasp.dependencycheck.org.apache.tools.ant.taskdefs.condition.Os;
import org.owasp.dependencycheck.org.apache.tools.ant.types.Resource;
import org.owasp.dependencycheck.org.apache.tools.ant.types.ResourceFactory;
import org.owasp.dependencycheck.org.apache.tools.ant.types.resources.FileResource;
import org.owasp.dependencycheck.org.apache.tools.ant.types.selectors.FileSelector;
import org.owasp.dependencycheck.org.apache.tools.ant.types.selectors.SelectorScanner;
import org.owasp.dependencycheck.org.apache.tools.ant.types.selectors.SelectorUtils;
import org.owasp.dependencycheck.org.apache.tools.ant.types.selectors.TokenizedPath;
import org.owasp.dependencycheck.org.apache.tools.ant.types.selectors.TokenizedPattern;
import org.owasp.dependencycheck.org.apache.tools.ant.util.CollectionUtils;
import org.owasp.dependencycheck.org.apache.tools.ant.util.FileUtils;
import org.owasp.dependencycheck.org.apache.tools.ant.util.SymbolicLinkUtils;
import org.owasp.dependencycheck.org.apache.tools.ant.util.VectorSet;

/**
 * Class for scanning a directory for files/directories which match certain criteria.
 * <p>
 * These criteria consist of selectors and patterns which have been specified. With the selectors you can select which
 * files you want to have included. Files which are not selected are excluded. With patterns you can include or exclude
 * files based on their filename.
 * <p>
 * The idea is simple. A given directory is recursively scanned for all files and directories. Each file/directory is
 * matched against a set of selectors, including special support for matching against filenames with include and and
 * exclude patterns. Only files/directories which match at least one pattern of the include pattern list or other file
 * selector, and don't match any pattern of the exclude pattern list or fail to match against a required selector will
 * be placed in the list of files/directories found.
 * <p>
 * When no list of include patterns is supplied, "**" will be used, which means that everything will be matched. When no
 * list of exclude patterns is supplied, an empty list is used, such that nothing will be excluded. When no selectors
 * are supplied, none are applied.
 * <p>
 * The filename pattern matching is done as follows: The name to be matched is split up in path segments. A path segment
 * is the name of a directory or file, which is bounded by <code>File.separator</code> ('/' under UNIX, '\' under
 * Windows). For example, "abc/def/ghi/xyz.java" is split up in the segments "abc", "def","ghi" and "xyz.java". The same
 * is done for the pattern against which should be matched.
 * <p>
 * The segments of the name and the pattern are then matched against each other. When '**' is used for a path segment in
 * the pattern, it matches zero or more path segments of the name.
 * <p>
 * There is a special case regarding the use of <code>File.separator</code>s at the beginning of the pattern and the
 * string to match:<br>
 * When a pattern starts with a <code>File.separator</code>, the string to match must also start with a
 * <code>File.separator</code>. When a pattern does not start with a <code>File.separator</code>, the string to match
 * may not start with a <code>File.separator</code>. When one of these rules is not obeyed, the string will not match.
 * <p>
 * When a name path segment is matched against a pattern path segment, the following special characters can be used:<br>
 * '*' matches zero or more characters<br>
 * '?' matches one character.
 * <p>
 * Examples:
 * <p>
 * "**\*.class" matches all .class files/dirs in a directory tree.
 * <p>
 * "test\a??.java" matches all files/dirs which start with an 'a', then two more characters and then ".java", in a
 * directory called test.
 * <p>
 * "**" matches everything in a directory tree.
 * <p>
 * "**\test\**\XYZ*" matches all files/dirs which start with "XYZ" and where there is a parent directory called test
 * (e.g. "abc\test\def\ghi\XYZ123").
 * <p>
 * Case sensitivity may be turned off if necessary. By default, it is turned on.
 * <p>
 * Example of usage:
 * <pre>
 *   String[] includes = {"**\\*.class"};
 *   String[] excludes = {"modules\\*\\**"};
 *   ds.setIncludes(includes);
 *   ds.setExcludes(excludes);
 *   ds.setBasedir(new File("test"));
 *   ds.setCaseSensitive(true);
 *   ds.scan();
 *
 *   System.out.println("FILES:");
 *   String[] files = ds.getIncludedFiles();
 *   for (int i = 0; i &lt; files.length; i++) {
 *     System.out.println(files[i]);
 *   }
 * </pre> This will scan a directory called test for .class files, but excludes all files in all proper subdirectories
 * of a directory called "modules".
 *
 */
public class DirectoryScanner
        implements FileScanner, SelectorScanner, ResourceFactory {

    /**
     * Is OpenVMS the operating system we're running on?
     */
    private static final boolean ON_VMS = Os.isFamily("openvms");

    /**
     * Patterns which should be excluded by default.
     *
     * <p>
     * Note that you can now add patterns to the list of default excludes. Added patterns will not become part of this
     * array that has only been kept around for backwards compatibility reasons.</p>
     *
     * @deprecated since 1.6.x. Use the {@link #getDefaultExcludes getDefaultExcludes} method instead.
     */
    protected static final String[] DEFAULTEXCLUDES = {
        // Miscellaneous typical temporary files
        SelectorUtils.DEEP_TREE_MATCH + "/*~",
        SelectorUtils.DEEP_TREE_MATCH + "/#*#",
        SelectorUtils.DEEP_TREE_MATCH + "/.#*",
        SelectorUtils.DEEP_TREE_MATCH + "/%*%",
        SelectorUtils.DEEP_TREE_MATCH + "/._*",
        // CVS
        SelectorUtils.DEEP_TREE_MATCH + "/CVS",
        SelectorUtils.DEEP_TREE_MATCH + "/CVS/" + SelectorUtils.DEEP_TREE_MATCH,
        SelectorUtils.DEEP_TREE_MATCH + "/.cvsignore",
        // SCCS
        SelectorUtils.DEEP_TREE_MATCH + "/SCCS",
        SelectorUtils.DEEP_TREE_MATCH + "/SCCS/" + SelectorUtils.DEEP_TREE_MATCH,
        // Visual SourceSafe
        SelectorUtils.DEEP_TREE_MATCH + "/vssver.scc",
        // Subversion
        SelectorUtils.DEEP_TREE_MATCH + "/.svn",
        SelectorUtils.DEEP_TREE_MATCH + "/.svn/" + SelectorUtils.DEEP_TREE_MATCH,
        // Git
        SelectorUtils.DEEP_TREE_MATCH + "/.git",
        SelectorUtils.DEEP_TREE_MATCH + "/.git/" + SelectorUtils.DEEP_TREE_MATCH,
        SelectorUtils.DEEP_TREE_MATCH + "/.gitattributes",
        SelectorUtils.DEEP_TREE_MATCH + "/.gitignore",
        SelectorUtils.DEEP_TREE_MATCH + "/.gitmodules",
        // Mercurial
        SelectorUtils.DEEP_TREE_MATCH + "/.hg",
        SelectorUtils.DEEP_TREE_MATCH + "/.hg/" + SelectorUtils.DEEP_TREE_MATCH,
        SelectorUtils.DEEP_TREE_MATCH + "/.hgignore",
        SelectorUtils.DEEP_TREE_MATCH + "/.hgsub",
        SelectorUtils.DEEP_TREE_MATCH + "/.hgsubstate",
        SelectorUtils.DEEP_TREE_MATCH + "/.hgtags",
        // Bazaar
        SelectorUtils.DEEP_TREE_MATCH + "/.bzr",
        SelectorUtils.DEEP_TREE_MATCH + "/.bzr/" + SelectorUtils.DEEP_TREE_MATCH,
        SelectorUtils.DEEP_TREE_MATCH + "/.bzrignore",
        // Mac
        SelectorUtils.DEEP_TREE_MATCH + "/.DS_Store"
    };

    /**
     * default value for {@link #maxLevelsOfSymlinks maxLevelsOfSymlinks}
     *
     * @since Ant 1.8.0
     */
    public static final int MAX_LEVELS_OF_SYMLINKS = 5;
    /**
     * The end of the exception message if something that should be there doesn't exist.
     */
    public static final String DOES_NOT_EXIST_POSTFIX = " does not exist.";

    /**
     * Helper.
     */
    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();

    /**
     * Helper.
     */
    private static final SymbolicLinkUtils SYMLINK_UTILS
            = SymbolicLinkUtils.getSymbolicLinkUtils();

    /**
     * Patterns which should be excluded by default.
     *
     * @see #addDefaultExcludes()
     */
    private static final Set<String> defaultExcludes = new HashSet<String>();

    static {
        resetDefaultExcludes();
    }

    // CheckStyle:VisibilityModifier OFF - bc
    /**
     * The base directory to be scanned.
     */
    protected File basedir;

    /**
     * The patterns for the files to be included.
     */
    protected String[] includes;

    /**
     * The patterns for the files to be excluded.
     */
    protected String[] excludes;

    /**
     * Selectors that will filter which files are in our candidate list.
     */
    protected FileSelector[] selectors = null;

    /**
     * The files which matched at least one include and no excludes and were selected.
     */
    protected Vector<String> filesIncluded;

    /**
     * The files which did not match any includes or selectors.
     */
    protected Vector<String> filesNotIncluded;

    /**
     * The files which matched at least one include and at least one exclude.
     */
    protected Vector<String> filesExcluded;

    /**
     * The directories which matched at least one include and no excludes and were selected.
     */
    protected Vector<String> dirsIncluded;

    /**
     * The directories which were found and did not match any includes.
     */
    protected Vector<String> dirsNotIncluded;

    /**
     * The directories which matched at least one include and at least one exclude.
     */
    protected Vector<String> dirsExcluded;

    /**
     * The files which matched at least one include and no excludes and which a selector discarded.
     */
    protected Vector<String> filesDeselected;

    /**
     * The directories which matched at least one include and no excludes but which a selector discarded.
     */
    protected Vector<String> dirsDeselected;

    /**
     * Whether or not our results were built by a slow scan.
     */
    protected boolean haveSlowResults = false;

    /**
     * Whether or not the file system should be treated as a case sensitive one.
     */
    protected boolean isCaseSensitive = true;

    /**
     * Whether a missing base directory is an error.
     *
     * @since Ant 1.7.1
     */
    protected boolean errorOnMissingDir = true;

    /**
     * Whether or not symbolic links should be followed.
     *
     * @since Ant 1.5
     */
    private boolean followSymlinks = true;

    /**
     * Whether or not everything tested so far has been included.
     */
    protected boolean everythingIncluded = true;

    // CheckStyle:VisibilityModifier ON
    /**
     * List of all scanned directories.
     *
     * @since Ant 1.6
     */
    private Set<String> scannedDirs = new HashSet<String>();

    /**
     * Map of all include patterns that are full file names and don't contain any wildcards.
     *
     * <p>
     * Maps pattern string to TokenizedPath.</p>
     *
     * <p>
     * If this instance is not case sensitive, the file names get turned to upper case.</p>
     *
     * <p>
     * Gets lazily initialized on the first invocation of isIncluded or isExcluded and cleared at the end of the scan
     * method (cleared in clearCaches, actually).</p>
     *
     * @since Ant 1.8.0
     */
    private Map<String, TokenizedPath> includeNonPatterns = new HashMap<String, TokenizedPath>();

    /**
     * Map of all exclude patterns that are full file names and don't contain any wildcards.
     *
     * <p>
     * Maps pattern string to TokenizedPath.</p>
     *
     * <p>
     * If this instance is not case sensitive, the file names get turned to upper case.</p>
     *
     * <p>
     * Gets lazily initialized on the first invocation of isIncluded or isExcluded and cleared at the end of the scan
     * method (cleared in clearCaches, actually).</p>
     *
     * @since Ant 1.8.0
     */
    private Map<String, TokenizedPath> excludeNonPatterns = new HashMap<String, TokenizedPath>();

    /**
     * Array of all include patterns that contain wildcards.
     *
     * <p>
     * Gets lazily initialized on the first invocation of isIncluded or isExcluded and cleared at the end of the scan
     * method (cleared in clearCaches, actually).</p>
     */
    private TokenizedPattern[] includePatterns;

    /**
     * Array of all exclude patterns that contain wildcards.
     *
     * <p>
     * Gets lazily initialized on the first invocation of isIncluded or isExcluded and cleared at the end of the scan
     * method (cleared in clearCaches, actually).</p>
     */
    private TokenizedPattern[] excludePatterns;

    /**
     * Have the non-pattern sets and pattern arrays for in- and excludes been initialized?
     *
     * @since Ant 1.6.3
     */
    private boolean areNonPatternSetsReady = false;

    /**
     * Scanning flag.
     *
     * @since Ant 1.6.3
     */
    private boolean scanning = false;

    /**
     * Scanning lock.
     *
     * @since Ant 1.6.3
     */
    private Object scanLock = new Object();

    /**
     * Slow scanning flag.
     *
     * @since Ant 1.6.3
     */
    private boolean slowScanning = false;

    /**
     * Slow scanning lock.
     *
     * @since Ant 1.6.3
     */
    private Object slowScanLock = new Object();

    /**
     * Exception thrown during scan.
     *
     * @since Ant 1.6.3
     */
    private IllegalStateException illegal = null;

    /**
     * The maximum number of times a symbolic link may be followed during a scan.
     *
     * @since Ant 1.8.0
     */
    private int maxLevelsOfSymlinks = MAX_LEVELS_OF_SYMLINKS;

    /**
     * Absolute paths of all symlinks that haven't been followed but would have been if followsymlinks had been true or
     * maxLevelsOfSymlinks had been higher.
     *
     * @since Ant 1.8.0
     */
    private Set<String> notFollowedSymlinks = new HashSet<String>();

    /**
     * Sole constructor.
     */
    public DirectoryScanner() {
    }

    /**
     * Test whether or not a given path matches the start of a given pattern up to the first "**".
     * <p>
     * This is not a general purpose test and should only be used if you can live with false positives. For example,
     * <code>pattern=**\a</code> and <code>str=b</code> will yield <code>true</code>.
     *
     * @param pattern The pattern to match against. Must not be <code>null</code>.
     * @param str The path to match, as a String. Must not be <code>null</code>.
     *
     * @return whether or not a given path matches the start of a given pattern up to the first "**".
     */
    protected static boolean matchPatternStart(String pattern, String str) {
        return SelectorUtils.matchPatternStart(pattern, str);
    }

    /**
     * Test whether or not a given path matches the start of a given pattern up to the first "**".
     * <p>
     * This is not a general purpose test and should only be used if you can live with false positives. For example,
     * <code>pattern=**\a</code> and <code>str=b</code> will yield <code>true</code>.
     *
     * @param pattern The pattern to match against. Must not be <code>null</code>.
     * @param str The path to match, as a String. Must not be <code>null</code>.
     * @param isCaseSensitive Whether or not matching should be performed case sensitively.
     *
     * @return whether or not a given path matches the start of a given pattern up to the first "**".
     */
    protected static boolean matchPatternStart(String pattern, String str,
            boolean isCaseSensitive) {
        return SelectorUtils.matchPatternStart(pattern, str, isCaseSensitive);
    }

    /**
     * Test whether or not a given path matches a given pattern.
     *
     * @param pattern The pattern to match against. Must not be <code>null</code>.
     * @param str The path to match, as a String. Must not be <code>null</code>.
     *
     * @return <code>true</code> if the pattern matches against the string, or <code>false</code> otherwise.
     */
    protected static boolean matchPath(String pattern, String str) {
        return SelectorUtils.matchPath(pattern, str);
    }

    /**
     * Test whether or not a given path matches a given pattern.
     *
     * @param pattern The pattern to match against. Must not be <code>null</code>.
     * @param str The path to match, as a String. Must not be <code>null</code>.
     * @param isCaseSensitive Whether or not matching should be performed case sensitively.
     *
     * @return <code>true</code> if the pattern matches against the string, or <code>false</code> otherwise.
     */
    protected static boolean matchPath(String pattern, String str,
            boolean isCaseSensitive) {
        return SelectorUtils.matchPath(pattern, str, isCaseSensitive);
    }

    /**
     * Test whether or not a string matches against a pattern. The pattern may contain two special characters:<br>
     * '*' means zero or more characters<br>
     * '?' means one and only one character
     *
     * @param pattern The pattern to match against. Must not be <code>null</code>.
     * @param str The string which must be matched against the pattern. Must not be <code>null</code>.
     *
     * @return <code>true</code> if the string matches against the pattern, or <code>false</code> otherwise.
     */
    public static boolean match(String pattern, String str) {
        return SelectorUtils.match(pattern, str);
    }

    /**
     * Test whether or not a string matches against a pattern. The pattern may contain two special characters:<br>
     * '*' means zero or more characters<br>
     * '?' means one and only one character
     *
     * @param pattern The pattern to match against. Must not be <code>null</code>.
     * @param str The string which must be matched against the pattern. Must not be <code>null</code>.
     * @param isCaseSensitive Whether or not matching should be performed case sensitively.
     *
     *
     * @return <code>true</code> if the string matches against the pattern, or <code>false</code> otherwise.
     */
    protected static boolean match(String pattern, String str,
            boolean isCaseSensitive) {
        return SelectorUtils.match(pattern, str, isCaseSensitive);
    }

    /**
     * Get the list of patterns that should be excluded by default.
     *
     * @return An array of <code>String</code> based on the current contents of the <code>defaultExcludes</code>
     * <code>Set</code>.
     *
     * @since Ant 1.6
     */
    public static String[] getDefaultExcludes() {
        synchronized (defaultExcludes) {
            return (String[]) defaultExcludes.toArray(new String[defaultExcludes
                    .size()]);
        }
    }

    /**
     * Add a pattern to the default excludes unless it is already a default exclude.
     *
     * @param s A string to add as an exclude pattern.
     * @return    <code>true</code> if the string was added; <code>false</code> if it already existed.
     *
     * @since Ant 1.6
     */
    public static boolean addDefaultExclude(String s) {
        synchronized (defaultExcludes) {
            return defaultExcludes.add(s);
        }
    }

    /**
     * Remove a string if it is a default exclude.
     *
     * @param s The string to attempt to remove.
     * @return    <code>true</code> if <code>s</code> was a default exclude (and thus was removed); <code>false</code> if
     * <code>s</code> was not in the default excludes list to begin with.
     *
     * @since Ant 1.6
     */
    public static boolean removeDefaultExclude(String s) {
        synchronized (defaultExcludes) {
            return defaultExcludes.remove(s);
        }
    }

    /**
     * Go back to the hardwired default exclude patterns.
     *
     * @since Ant 1.6
     */
    public static void resetDefaultExcludes() {
        synchronized (defaultExcludes) {
            defaultExcludes.clear();
            for (int i = 0; i < DEFAULTEXCLUDES.length; i++) {
                defaultExcludes.add(DEFAULTEXCLUDES[i]);
            }
        }
    }

    /**
     * Set the base directory to be scanned. This is the directory which is scanned recursively. All '/' and '\'
     * characters are replaced by <code>File.separatorChar</code>, so the separator used need not match
     * <code>File.separatorChar</code>.
     *
     * @param basedir The base directory to scan.
     */
    public void setBasedir(String basedir) {
        setBasedir(basedir == null ? (File) null
                : new File(basedir.replace('/', File.separatorChar).replace(
                                '\\', File.separatorChar)));
    }

    /**
     * Set the base directory to be scanned. This is the directory which is scanned recursively.
     *
     * @param basedir The base directory for scanning.
     */
    public synchronized void setBasedir(File basedir) {
        this.basedir = basedir;
    }

    /**
     * Return the base directory to be scanned. This is the directory which is scanned recursively.
     *
     * @return the base directory to be scanned.
     */
    public synchronized File getBasedir() {
        return basedir;
    }

    /**
     * Find out whether include exclude patterns are matched in a case sensitive way.
     *
     * @return whether or not the scanning is case sensitive.
     * @since Ant 1.6
     */
    public synchronized boolean isCaseSensitive() {
        return isCaseSensitive;
    }

    /**
     * Set whether or not include and exclude patterns are matched in a case sensitive way.
     *
     * @param isCaseSensitive whether or not the file system should be regarded as a case sensitive one.
     */
    public synchronized void setCaseSensitive(boolean isCaseSensitive) {
        this.isCaseSensitive = isCaseSensitive;
    }

    /**
     * Sets whether or not a missing base directory is an error
     *
     * @param errorOnMissingDir whether or not a missing base directory is an error
     * @since Ant 1.7.1
     */
    public void setErrorOnMissingDir(boolean errorOnMissingDir) {
        this.errorOnMissingDir = errorOnMissingDir;
    }

    /**
     * Get whether or not a DirectoryScanner follows symbolic links.
     *
     * @return flag indicating whether symbolic links should be followed.
     *
     * @since Ant 1.6
     */
    public synchronized boolean isFollowSymlinks() {
        return followSymlinks;
    }

    /**
     * Set whether or not symbolic links should be followed.
     *
     * @param followSymlinks whether or not symbolic links should be followed.
     */
    public synchronized void setFollowSymlinks(boolean followSymlinks) {
        this.followSymlinks = followSymlinks;
    }

    /**
     * The maximum number of times a symbolic link may be followed during a scan.
     *
     * @since Ant 1.8.0
     */
    public void setMaxLevelsOfSymlinks(int max) {
        maxLevelsOfSymlinks = max;
    }

    /**
     * Set the list of include patterns to use. All '/' and '\' characters are replaced by
     * <code>File.separatorChar</code>, so the separator used need not match <code>File.separatorChar</code>.
     * <p>
     * When a pattern ends with a '/' or '\', "**" is appended.
     *
     * @param includes A list of include patterns. May be <code>null</code>, indicating that all files should be
     * included. If a non-<code>null</code> list is given, all elements must be non-<code>null</code>.
     */
    public synchronized void setIncludes(String[] includes) {
        if (includes == null) {
            this.includes = null;
        } else {
            this.includes = new String[includes.length];
            for (int i = 0; i < includes.length; i++) {
                this.includes[i] = normalizePattern(includes[i]);
            }
        }
    }

    public synchronized void setIncludes(String include) {
        if (include == null) {
            this.includes = null;
        } else {
            this.includes = new String[1];
            this.includes[0] = normalizePattern(include);
        }
    }

    /**
     * Set the list of exclude patterns to use. All '/' and '\' characters are replaced by
     * <code>File.separatorChar</code>, so the separator used need not match <code>File.separatorChar</code>.
     * <p>
     * When a pattern ends with a '/' or '\', "**" is appended.
     *
     * @param excludes A list of exclude patterns. May be <code>null</code>, indicating that no files should be
     * excluded. If a non-<code>null</code> list is given, all elements must be non-<code>null</code>.
     */
    public synchronized void setExcludes(String[] excludes) {
        if (excludes == null) {
            this.excludes = null;
        } else {
            this.excludes = new String[excludes.length];
            for (int i = 0; i < excludes.length; i++) {
                this.excludes[i] = normalizePattern(excludes[i]);
            }
        }
    }

    /**
     * Add to the list of exclude patterns to use. All '/' and '\' characters are replaced by
     * <code>File.separatorChar</code>, so the separator used need not match <code>File.separatorChar</code>.
     * <p>
     * When a pattern ends with a '/' or '\', "**" is appended.
     *
     * @param excludes A list of exclude patterns. May be <code>null</code>, in which case the exclude patterns don't
     * get changed at all.
     *
     * @since Ant 1.6.3
     */
    public synchronized void addExcludes(String[] excludes) {
        if (excludes != null && excludes.length > 0) {
            if (this.excludes != null && this.excludes.length > 0) {
                String[] tmp = new String[excludes.length
                        + this.excludes.length];
                System.arraycopy(this.excludes, 0, tmp, 0,
                        this.excludes.length);
                for (int i = 0; i < excludes.length; i++) {
                    tmp[this.excludes.length + i]
                            = normalizePattern(excludes[i]);
                }
                this.excludes = tmp;
            } else {
                setExcludes(excludes);
            }
        }
    }

    /**
     * All '/' and '\' characters are replaced by <code>File.separatorChar</code>, so the separator used need not match
     * <code>File.separatorChar</code>.
     *
     * <p>
     * When a pattern ends with a '/' or '\', "**" is appended.
     *
     * @since Ant 1.6.3
     */
    private static String normalizePattern(String p) {
        String pattern = p.replace('/', File.separatorChar)
                .replace('\\', File.separatorChar);
        if (pattern.endsWith(File.separator)) {
            pattern += SelectorUtils.DEEP_TREE_MATCH;
        }
        return pattern;
    }

    /**
     * Set the selectors that will select the filelist.
     *
     * @param selectors specifies the selectors to be invoked on a scan.
     */
    public synchronized void setSelectors(FileSelector[] selectors) {
        this.selectors = selectors;
    }

    /**
     * Return whether or not the scanner has included all the files or directories it has come across so far.
     *
     * @return <code>true</code> if all files and directories which have been found so far have been included.
     */
    public synchronized boolean isEverythingIncluded() {
        return everythingIncluded;
    }

    /**
     * Scan for files which match at least one include pattern and don't match any exclude patterns. If there are
     * selectors then the files must pass muster there, as well. Scans under basedir, if set; otherwise the include
     * patterns without leading wildcards specify the absolute paths of the files that may be included.
     *
     * @exception IllegalStateException if the base directory was set incorrectly (i.e. if it doesn't exist or isn't a
     * directory).
     */
    public void scan() throws IllegalStateException {
        synchronized (scanLock) {
            if (scanning) {
                while (scanning) {
                    try {
                        scanLock.wait();
                    } catch (InterruptedException e) {
                        continue;
                    }
                }
                if (illegal != null) {
                    throw illegal;
                }
                return;
            }
            scanning = true;
        }
        File savedBase = basedir;
        try {
            synchronized (this) {
                illegal = null;
                clearResults();

                // set in/excludes to reasonable defaults if needed:
                boolean nullIncludes = (includes == null);
                includes = nullIncludes
                        ? new String[]{SelectorUtils.DEEP_TREE_MATCH} : includes;
                boolean nullExcludes = (excludes == null);
                excludes = nullExcludes ? new String[0] : excludes;

                if (basedir != null && !followSymlinks
                        && SYMLINK_UTILS.isSymbolicLink(basedir)) {
                    notFollowedSymlinks.add(basedir.getAbsolutePath());
                    basedir = null;
                }

                if (basedir == null) {
                    // if no basedir and no includes, nothing to do:
                    if (nullIncludes) {
                        return;
                    }
                } else {
                    if (!basedir.exists()) {
                        if (errorOnMissingDir) {
                            illegal = new IllegalStateException("basedir "
                                    + basedir
                                    + DOES_NOT_EXIST_POSTFIX);
                        } else {
                            // Nothing to do - basedir does not exist
                            return;
                        }
                    } else if (!basedir.isDirectory()) {
                        illegal = new IllegalStateException("basedir "
                                + basedir
                                + " is not a"
                                + " directory.");
                    }
                    if (illegal != null) {
                        throw illegal;
                    }
                }
                if (isIncluded(TokenizedPath.EMPTY_PATH)) {
                    if (!isExcluded(TokenizedPath.EMPTY_PATH)) {
                        if (isSelected("", basedir)) {
                            dirsIncluded.addElement("");
                        } else {
                            dirsDeselected.addElement("");
                        }
                    } else {
                        dirsExcluded.addElement("");
                    }
                } else {
                    dirsNotIncluded.addElement("");
                }
                checkIncludePatterns();
                clearCaches();
                includes = nullIncludes ? null : includes;
                excludes = nullExcludes ? null : excludes;
            }
        } catch (IOException ex) {
            throw new BuildException(ex);
        } finally {
            basedir = savedBase;
            synchronized (scanLock) {
                scanning = false;
                scanLock.notifyAll();
            }
        }
    }

    /**
     * This routine is actually checking all the include patterns in order to avoid scanning everything under base dir.
     *
     * @since Ant 1.6
     */
    private void checkIncludePatterns() {
        ensureNonPatternSetsReady();
        Map<TokenizedPath, String> newroots = new HashMap<TokenizedPath, String>();

        // put in the newroots map the include patterns without
        // wildcard tokens
        for (int i = 0; i < includePatterns.length; i++) {
            String pattern = includePatterns[i].toString();
            if (!shouldSkipPattern(pattern)) {
                newroots.put(includePatterns[i].rtrimWildcardTokens(),
                        pattern);
            }
        }
        for (Map.Entry<String, TokenizedPath> entry : includeNonPatterns.entrySet()) {
            String pattern = entry.getKey();
            if (!shouldSkipPattern(pattern)) {
                newroots.put(entry.getValue(), pattern);
            }
        }

        if (newroots.containsKey(TokenizedPath.EMPTY_PATH)
                && basedir != null) {
            // we are going to scan everything anyway
            scandir(basedir, "", true);
        } else {
            File canonBase = null;
            if (basedir != null) {
                try {
                    canonBase = basedir.getCanonicalFile();
                } catch (IOException ex) {
                    throw new BuildException(ex);
                }
            }
            // only scan directories that can include matched files or
            // directories
            for (Map.Entry<TokenizedPath, String> entry : newroots.entrySet()) {
                TokenizedPath currentPath = entry.getKey();
                String currentelement = currentPath.toString();
                if (basedir == null
                        && !FileUtils.isAbsolutePath(currentelement)) {
                    continue;
                }
                File myfile = new File(basedir, currentelement);

                if (myfile.exists()) {
                    // may be on a case insensitive file system.  We want
                    // the results to show what's really on the disk, so
                    // we need to double check.
                    try {
                        String path = (basedir == null)
                                ? myfile.getCanonicalPath()
                                : FILE_UTILS.removeLeadingPath(canonBase,
                                        myfile.getCanonicalFile());
                        if (!path.equals(currentelement) || ON_VMS) {
                            myfile = currentPath.findFile(basedir, true);
                            if (myfile != null && basedir != null) {
                                currentelement = FILE_UTILS.removeLeadingPath(
                                        basedir, myfile);
                                if (!currentPath.toString()
                                        .equals(currentelement)) {
                                    currentPath
                                            = new TokenizedPath(currentelement);
                                }
                            }
                        }
                    } catch (IOException ex) {
                        throw new BuildException(ex);
                    }
                }

                if ((myfile == null || !myfile.exists()) && !isCaseSensitive()) {
                    File f = currentPath.findFile(basedir, false);
                    if (f != null && f.exists()) {
                        // adapt currentelement to the case we've
                        // actually found
                        currentelement = (basedir == null)
                                ? f.getAbsolutePath()
                                : FILE_UTILS.removeLeadingPath(basedir, f);
                        myfile = f;
                        currentPath = new TokenizedPath(currentelement);
                    }
                }

                if (myfile != null && myfile.exists()) {
                    if (!followSymlinks && currentPath.isSymlink(basedir)) {
                        accountForNotFollowedSymlink(currentPath, myfile);
                        continue;
                    }
                    if (myfile.isDirectory()) {
                        if (isIncluded(currentPath)
                                && currentelement.length() > 0) {
                            accountForIncludedDir(currentPath, myfile, true);
                        } else {
                            scandir(myfile, currentPath, true);
                        }
                    } else if (myfile.isFile()) {
                        String originalpattern = (String) entry.getValue();
                        boolean included = isCaseSensitive()
                                ? originalpattern.equals(currentelement)
                                : originalpattern.equalsIgnoreCase(currentelement);
                        if (included) {
                            accountForIncludedFile(currentPath, myfile);
                        }
                    }
                }
            }
        }
    }

    /**
     * true if the pattern specifies a relative path without basedir or an absolute path not inside basedir.
     *
     * @since Ant 1.8.0
     */
    private boolean shouldSkipPattern(String pattern) {
        if (FileUtils.isAbsolutePath(pattern)) {
            //skip abs. paths not under basedir, if set:
            if (basedir != null
                    && !SelectorUtils.matchPatternStart(pattern,
                            basedir.getAbsolutePath(),
                            isCaseSensitive())) {
                return true;
            }
        } else if (basedir == null) {
            //skip non-abs. paths if basedir == null:
            return true;
        }
        return false;
    }

    /**
     * Clear the result caches for a scan.
     */
    protected synchronized void clearResults() {
        filesIncluded = new VectorSet<String>();
        filesNotIncluded = new VectorSet<String>();
        filesExcluded = new VectorSet<String>();
        filesDeselected = new VectorSet<String>();
        dirsIncluded = new VectorSet<String>();
        dirsNotIncluded = new VectorSet<String>();
        dirsExcluded = new VectorSet<String>();
        dirsDeselected = new VectorSet<String>();
        everythingIncluded = (basedir != null);
        scannedDirs.clear();
        notFollowedSymlinks.clear();
    }

    /**
     * Top level invocation for a slow scan. A slow scan builds up a full list of excluded/included files/directories,
     * whereas a fast scan will only have full results for included files, as it ignores directories which can't
     * possibly hold any included files/directories.
     * <p>
     * Returns immediately if a slow scan has already been completed.
     */
    protected void slowScan() {
        synchronized (slowScanLock) {
            if (haveSlowResults) {
                return;
            }
            if (slowScanning) {
                while (slowScanning) {
                    try {
                        slowScanLock.wait();
                    } catch (InterruptedException e) {
                        // Empty
                    }
                }
                return;
            }
            slowScanning = true;
        }
        try {
            synchronized (this) {

                // set in/excludes to reasonable defaults if needed:
                boolean nullIncludes = (includes == null);
                includes = nullIncludes
                        ? new String[]{SelectorUtils.DEEP_TREE_MATCH} : includes;
                boolean nullExcludes = (excludes == null);
                excludes = nullExcludes ? new String[0] : excludes;

                String[] excl = new String[dirsExcluded.size()];
                dirsExcluded.copyInto(excl);

                String[] notIncl = new String[dirsNotIncluded.size()];
                dirsNotIncluded.copyInto(notIncl);

                ensureNonPatternSetsReady();

                processSlowScan(excl);
                processSlowScan(notIncl);
                clearCaches();
                includes = nullIncludes ? null : includes;
                excludes = nullExcludes ? null : excludes;
            }
        } finally {
            synchronized (slowScanLock) {
                haveSlowResults = true;
                slowScanning = false;
                slowScanLock.notifyAll();
            }
        }
    }

    private void processSlowScan(String[] arr) {
        for (int i = 0; i < arr.length; i++) {
            TokenizedPath path = new TokenizedPath(arr[i]);
            if (!couldHoldIncluded(path) || contentsExcluded(path)) {
                scandir(new File(basedir, arr[i]), path, false);
            }
        }
    }

    /**
     * Scan the given directory for files and directories. Found files and directories are placed in their respective
     * collections, based on the matching of includes, excludes, and the selectors. When a directory is found, it is
     * scanned recursively.
     *
     * @param dir The directory to scan. Must not be <code>null</code>.
     * @param vpath The path relative to the base directory (needed to prevent problems with an absolute path when using
     * dir). Must not be <code>null</code>.
     * @param fast Whether or not this call is part of a fast scan.
     *
     * @see #filesIncluded
     * @see #filesNotIncluded
     * @see #filesExcluded
     * @see #dirsIncluded
     * @see #dirsNotIncluded
     * @see #dirsExcluded
     * @see #slowScan
     */
    protected void scandir(File dir, String vpath, boolean fast) {
        scandir(dir, new TokenizedPath(vpath), fast);
    }

    /**
     * Scan the given directory for files and directories. Found files and directories are placed in their respective
     * collections, based on the matching of includes, excludes, and the selectors. When a directory is found, it is
     * scanned recursively.
     *
     * @param dir The directory to scan. Must not be <code>null</code>.
     * @param path The path relative to the base directory (needed to prevent problems with an absolute path when using
     * dir). Must not be <code>null</code>.
     * @param fast Whether or not this call is part of a fast scan.
     *
     * @see #filesIncluded
     * @see #filesNotIncluded
     * @see #filesExcluded
     * @see #dirsIncluded
     * @see #dirsNotIncluded
     * @see #dirsExcluded
     * @see #slowScan
     */
    private void scandir(File dir, TokenizedPath path, boolean fast) {
        if (dir == null) {
            throw new BuildException("dir must not be null.");
        }
        String[] newfiles = dir.list();
        if (newfiles == null) {
            if (!dir.exists()) {
                throw new BuildException(dir + DOES_NOT_EXIST_POSTFIX);
            } else if (!dir.isDirectory()) {
                throw new BuildException(dir + " is not a directory.");
            } else {
                throw new BuildException("IO error scanning directory '"
                        + dir.getAbsolutePath() + "'");
            }
        }
        scandir(dir, path, fast, newfiles, new LinkedList<String>());
    }

    private void scandir(File dir, TokenizedPath path, boolean fast,
            String[] newfiles, LinkedList<String> directoryNamesFollowed) {
        String vpath = path.toString();
        if (vpath.length() > 0 && !vpath.endsWith(File.separator)) {
            vpath += File.separator;
        }

        // avoid double scanning of directories, can only happen in fast mode
        if (fast && hasBeenScanned(vpath)) {
            return;
        }
        if (!followSymlinks) {
            ArrayList<String> noLinks = new ArrayList<String>();
            for (int i = 0; i < newfiles.length; i++) {
                try {
                    if (SYMLINK_UTILS.isSymbolicLink(dir, newfiles[i])) {
                        String name = vpath + newfiles[i];
                        File file = new File(dir, newfiles[i]);
                        if (file.isDirectory()) {
                            dirsExcluded.addElement(name);
                        } else if (file.isFile()) {
                            filesExcluded.addElement(name);
                        }
                        accountForNotFollowedSymlink(name, file);
                    } else {
                        noLinks.add(newfiles[i]);
                    }
                } catch (IOException ioe) {
                    String msg = "IOException caught while checking "
                            + "for links, couldn't get canonical path!";
                    // will be caught and redirected to Ant's logging system
                    System.err.println(msg);
                    noLinks.add(newfiles[i]);
                }
            }
            newfiles = (String[]) (noLinks.toArray(new String[noLinks.size()]));
        } else {
            directoryNamesFollowed.addFirst(dir.getName());
        }

        for (int i = 0; i < newfiles.length; i++) {
            String name = vpath + newfiles[i];
            TokenizedPath newPath = new TokenizedPath(path, newfiles[i]);
            File file = new File(dir, newfiles[i]);
            String[] children = file.list();
            if (children == null || (children.length == 0 && file.isFile())) {
                if (isIncluded(newPath)) {
                    accountForIncludedFile(newPath, file);
                } else {
                    everythingIncluded = false;
                    filesNotIncluded.addElement(name);
                }
            } else if (file.isDirectory()) { // dir

                if (followSymlinks
                        && causesIllegalSymlinkLoop(newfiles[i], dir,
                                directoryNamesFollowed)) {
                    // will be caught and redirected to Ant's logging system
                    System.err.println("skipping symbolic link "
                            + file.getAbsolutePath()
                            + " -- too many levels of symbolic"
                            + " links.");
                    notFollowedSymlinks.add(file.getAbsolutePath());
                    continue;
                }

                if (isIncluded(newPath)) {
                    accountForIncludedDir(newPath, file, fast, children,
                            directoryNamesFollowed);
                } else {
                    everythingIncluded = false;
                    dirsNotIncluded.addElement(name);
                    if (fast && couldHoldIncluded(newPath)
                            && !contentsExcluded(newPath)) {
                        scandir(file, newPath, fast, children,
                                directoryNamesFollowed);
                    }
                }
                if (!fast) {
                    scandir(file, newPath, fast, children, directoryNamesFollowed);
                }
            }
        }

        if (followSymlinks) {
            directoryNamesFollowed.removeFirst();
        }
    }

    /**
     * Process included file.
     *
     * @param name path of the file relative to the directory of the FileSet.
     * @param file included File.
     */
    private void accountForIncludedFile(TokenizedPath name, File file) {
        processIncluded(name, file, filesIncluded, filesExcluded,
                filesDeselected);
    }

    /**
     * Process included directory.
     *
     * @param name path of the directory relative to the directory of the FileSet.
     * @param file directory as File.
     * @param fast whether to perform fast scans.
     */
    private void accountForIncludedDir(TokenizedPath name, File file,
            boolean fast) {
        processIncluded(name, file, dirsIncluded, dirsExcluded, dirsDeselected);
        if (fast && couldHoldIncluded(name) && !contentsExcluded(name)) {
            scandir(file, name, fast);
        }
    }

    private void accountForIncludedDir(TokenizedPath name,
            File file, boolean fast,
            String[] children,
            LinkedList<String> directoryNamesFollowed) {
        processIncluded(name, file, dirsIncluded, dirsExcluded, dirsDeselected);
        if (fast && couldHoldIncluded(name) && !contentsExcluded(name)) {
            scandir(file, name, fast, children, directoryNamesFollowed);
        }
    }

    private void accountForNotFollowedSymlink(String name, File file) {
        accountForNotFollowedSymlink(new TokenizedPath(name), file);
    }

    private void accountForNotFollowedSymlink(TokenizedPath name, File file) {
        if (!isExcluded(name)
                && (isIncluded(name)
                || (file.isDirectory() && couldHoldIncluded(name)
                && !contentsExcluded(name)))) {
            notFollowedSymlinks.add(file.getAbsolutePath());
        }
    }

    private void processIncluded(TokenizedPath path,
            File file, Vector<String> inc, Vector<String> exc,
            Vector<String> des) {
        String name = path.toString();
        if (inc.contains(name) || exc.contains(name) || des.contains(name)) {
            return;
        }

        boolean included = false;
        if (isExcluded(path)) {
            exc.add(name);
        } else if (isSelected(name, file)) {
            included = true;
            inc.add(name);
        } else {
            des.add(name);
        }
        everythingIncluded &= included;
    }

    /**
     * Test whether or not a name matches against at least one include pattern.
     *
     * @param name The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against at least one include pattern, or <code>false</code>
     * otherwise.
     */
    protected boolean isIncluded(String name) {
        return isIncluded(new TokenizedPath(name));
    }

    /**
     * Test whether or not a name matches against at least one include pattern.
     *
     * @param name The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against at least one include pattern, or <code>false</code>
     * otherwise.
     */
    private boolean isIncluded(TokenizedPath path) {
        ensureNonPatternSetsReady();

        if (isCaseSensitive()
                ? includeNonPatterns.containsKey(path.toString())
                : includeNonPatterns.containsKey(path.toString().toUpperCase())) {
            return true;
        }
        for (int i = 0; i < includePatterns.length; i++) {
            if (includePatterns[i].matchPath(path, isCaseSensitive())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Test whether or not a name matches the start of at least one include pattern.
     *
     * @param name The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against the start of at least one include pattern, or
     * <code>false</code> otherwise.
     */
    protected boolean couldHoldIncluded(String name) {
        return couldHoldIncluded(new TokenizedPath(name));
    }

    /**
     * Test whether or not a name matches the start of at least one include pattern.
     *
     * @param tokenizedName The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against the start of at least one include pattern, or
     * <code>false</code> otherwise.
     */
    private boolean couldHoldIncluded(TokenizedPath tokenizedName) {
        for (int i = 0; i < includePatterns.length; i++) {
            if (couldHoldIncluded(tokenizedName, includePatterns[i])) {
                return true;
            }
        }
        for (Iterator<TokenizedPath> iter = includeNonPatterns.values().iterator();
                iter.hasNext();) {
            if (couldHoldIncluded(tokenizedName,
                    iter.next().toPattern())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Test whether or not a name matches the start of the given include pattern.
     *
     * @param tokenizedName The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against the start of the include pattern, or <code>false</code>
     * otherwise.
     */
    private boolean couldHoldIncluded(TokenizedPath tokenizedName,
            TokenizedPattern tokenizedInclude) {
        return tokenizedInclude.matchStartOf(tokenizedName, isCaseSensitive())
                && isMorePowerfulThanExcludes(tokenizedName.toString())
                && isDeeper(tokenizedInclude, tokenizedName);
    }

    /**
     * Verify that a pattern specifies files deeper than the level of the specified file.
     *
     * @param pattern the pattern to check.
     * @param name the name to check.
     * @return whether the pattern is deeper than the name.
     * @since Ant 1.6.3
     */
    private boolean isDeeper(TokenizedPattern pattern, TokenizedPath name) {
        return pattern.containsPattern(SelectorUtils.DEEP_TREE_MATCH)
                || pattern.depth() > name.depth();
    }

    /**
     * Find out whether one particular include pattern is more powerful than all the excludes. Note: the power
     * comparison is based on the length of the include pattern and of the exclude patterns without the wildcards.
     * Ideally the comparison should be done based on the depth of the match; that is to say how many file separators
     * have been matched before the first ** or the end of the pattern.
     *
     * IMPORTANT : this function should return false "with care".
     *
     * @param name the relative path to test.
     * @return true if there is no exclude pattern more powerful than this include pattern.
     * @since Ant 1.6
     */
    private boolean isMorePowerfulThanExcludes(String name) {
        final String soughtexclude
                = name + File.separatorChar + SelectorUtils.DEEP_TREE_MATCH;
        for (int counter = 0; counter < excludePatterns.length; counter++) {
            if (excludePatterns[counter].toString().equals(soughtexclude)) {
                return false;
            }
        }
        return true;
    }

    /**
     * Test whether all contents of the specified directory must be excluded.
     *
     * @param path the path to check.
     * @return whether all the specified directory's contents are excluded.
     */
    /* package */ boolean contentsExcluded(TokenizedPath path) {
        for (int i = 0; i < excludePatterns.length; i++) {
            if (excludePatterns[i].endsWith(SelectorUtils.DEEP_TREE_MATCH)
                    && excludePatterns[i].withoutLastToken()
                    .matchPath(path, isCaseSensitive())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Test whether or not a name matches against at least one exclude pattern.
     *
     * @param name The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against at least one exclude pattern, or <code>false</code>
     * otherwise.
     */
    protected boolean isExcluded(String name) {
        return isExcluded(new TokenizedPath(name));
    }

    /**
     * Test whether or not a name matches against at least one exclude pattern.
     *
     * @param name The name to match. Must not be <code>null</code>.
     * @return <code>true</code> when the name matches against at least one exclude pattern, or <code>false</code>
     * otherwise.
     */
    private boolean isExcluded(TokenizedPath name) {
        ensureNonPatternSetsReady();

        if (isCaseSensitive()
                ? excludeNonPatterns.containsKey(name.toString())
                : excludeNonPatterns.containsKey(name.toString().toUpperCase())) {
            return true;
        }
        for (int i = 0; i < excludePatterns.length; i++) {
            if (excludePatterns[i].matchPath(name, isCaseSensitive())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Test whether a file should be selected.
     *
     * @param name the filename to check for selecting.
     * @param file the java.io.File object for this filename.
     * @return <code>false</code> when the selectors says that the file should not be selected, <code>true</code>
     * otherwise.
     */
    protected boolean isSelected(String name, File file) {
        if (selectors != null) {
            for (int i = 0; i < selectors.length; i++) {
                if (!selectors[i].isSelected(basedir, name, file)) {
                    return false;
                }
            }
        }
        return true;
    }

    /**
     * Return the names of the files which matched at least one of the include patterns and none of the exclude
     * patterns. The names are relative to the base directory.
     *
     * @return the names of the files which matched at least one of the include patterns and none of the exclude
     * patterns.
     */
    public String[] getIncludedFiles() {
        String[] files;
        synchronized (this) {
            if (filesIncluded == null) {
                throw new IllegalStateException("Must call scan() first");
            }
            files = new String[filesIncluded.size()];
            filesIncluded.copyInto(files);
        }
        Arrays.sort(files);
        return files;
    }

    /**
     * Return the count of included files.
     *
     * @return <code>int</code>.
     * @since Ant 1.6.3
     */
    public synchronized int getIncludedFilesCount() {
        if (filesIncluded == null) {
            throw new IllegalStateException("Must call scan() first");
        }
        return filesIncluded.size();
    }

    /**
     * Return the names of the files which matched none of the include patterns. The names are relative to the base
     * directory. This involves performing a slow scan if one has not already been completed.
     *
     * @return the names of the files which matched none of the include patterns.
     *
     * @see #slowScan
     */
    public synchronized String[] getNotIncludedFiles() {
        slowScan();
        String[] files = new String[filesNotIncluded.size()];
        filesNotIncluded.copyInto(files);
        return files;
    }

    /**
     * Return the names of the files which matched at least one of the include patterns and at least one of the exclude
     * patterns. The names are relative to the base directory. This involves performing a slow scan if one has not
     * already been completed.
     *
     * @return the names of the files which matched at least one of the include patterns and at least one of the exclude
     * patterns.
     *
     * @see #slowScan
     */
    public synchronized String[] getExcludedFiles() {
        slowScan();
        String[] files = new String[filesExcluded.size()];
        filesExcluded.copyInto(files);
        return files;
    }

    /**
     * <p>
     * Return the names of the files which were selected out and therefore not ultimately included.</p>
     *
     * <p>
     * The names are relative to the base directory. This involves performing a slow scan if one has not already been
     * completed.</p>
     *
     * @return the names of the files which were deselected.
     *
     * @see #slowScan
     */
    public synchronized String[] getDeselectedFiles() {
        slowScan();
        String[] files = new String[filesDeselected.size()];
        filesDeselected.copyInto(files);
        return files;
    }

    /**
     * Return the names of the directories which matched at least one of the include patterns and none of the exclude
     * patterns. The names are relative to the base directory.
     *
     * @return the names of the directories which matched at least one of the include patterns and none of the exclude
     * patterns.
     */
    public String[] getIncludedDirectories() {
        String[] directories;
        synchronized (this) {
            if (dirsIncluded == null) {
                throw new IllegalStateException("Must call scan() first");
            }
            directories = new String[dirsIncluded.size()];
            dirsIncluded.copyInto(directories);
        }
        Arrays.sort(directories);
        return directories;
    }

    /**
     * Return the count of included directories.
     *
     * @return <code>int</code>.
     * @since Ant 1.6.3
     */
    public synchronized int getIncludedDirsCount() {
        if (dirsIncluded == null) {
            throw new IllegalStateException("Must call scan() first");
        }
        return dirsIncluded.size();
    }

    /**
     * Return the names of the directories which matched none of the include patterns. The names are relative to the
     * base directory. This involves performing a slow scan if one has not already been completed.
     *
     * @return the names of the directories which matched none of the include patterns.
     *
     * @see #slowScan
     */
    public synchronized String[] getNotIncludedDirectories() {
        slowScan();
        String[] directories = new String[dirsNotIncluded.size()];
        dirsNotIncluded.copyInto(directories);
        return directories;
    }

    /**
     * Return the names of the directories which matched at least one of the include patterns and at least one of the
     * exclude patterns. The names are relative to the base directory. This involves performing a slow scan if one has
     * not already been completed.
     *
     * @return the names of the directories which matched at least one of the include patterns and at least one of the
     * exclude patterns.
     *
     * @see #slowScan
     */
    public synchronized String[] getExcludedDirectories() {
        slowScan();
        String[] directories = new String[dirsExcluded.size()];
        dirsExcluded.copyInto(directories);
        return directories;
    }

    /**
     * <p>
     * Return the names of the directories which were selected out and therefore not ultimately included.</p>
     *
     * <p>
     * The names are relative to the base directory. This involves performing a slow scan if one has not already been
     * completed.</p>
     *
     * @return the names of the directories which were deselected.
     *
     * @see #slowScan
     */
    public synchronized String[] getDeselectedDirectories() {
        slowScan();
        String[] directories = new String[dirsDeselected.size()];
        dirsDeselected.copyInto(directories);
        return directories;
    }

    /**
     * Absolute paths of all symbolic links that haven't been followed but would have been followed had followsymlinks
     * been true or maxLevelsOfSymlinks been bigger.
     *
     * @return sorted array of not followed symlinks
     * @since Ant 1.8.0
     * @see #notFollowedSymlinks
     */
    public synchronized String[] getNotFollowedSymlinks() {
        String[] links;
        synchronized (this) {
            links = (String[]) notFollowedSymlinks
                    .toArray(new String[notFollowedSymlinks.size()]);
        }
        Arrays.sort(links);
        return links;
    }

    /**
     * Add default exclusions to the current exclusions set.
     */
    public synchronized void addDefaultExcludes() {
        int excludesLength = excludes == null ? 0 : excludes.length;
        String[] newExcludes;
        String[] defaultExcludesTemp = getDefaultExcludes();
        newExcludes = new String[excludesLength + defaultExcludesTemp.length];
        if (excludesLength > 0) {
            System.arraycopy(excludes, 0, newExcludes, 0, excludesLength);
        }
        for (int i = 0; i < defaultExcludesTemp.length; i++) {
            newExcludes[i + excludesLength]
                    = defaultExcludesTemp[i].replace('/', File.separatorChar)
                    .replace('\\', File.separatorChar);
        }
        excludes = newExcludes;
    }

    /**
     * Get the named resource.
     *
     * @param name path name of the file relative to the dir attribute.
     *
     * @return the resource with the given name.
     * @since Ant 1.5.2
     */
    public synchronized Resource getResource(String name) {
        return new FileResource(basedir, name);
    }

    /**
     * Has the directory with the given path relative to the base directory already been scanned?
     *
     * <p>
     * Registers the given directory as scanned as a side effect.</p>
     *
     * @since Ant 1.6
     */
    private boolean hasBeenScanned(String vpath) {
        return !scannedDirs.add(vpath);
    }

    /**
     * This method is of interest for testing purposes. The returned Set is live and should not be modified.
     *
     * @return the Set of relative directory names that have been scanned.
     */
    /* package-private */ Set<String> getScannedDirs() {
        return scannedDirs;
    }

    /**
     * Clear internal caches.
     *
     * @since Ant 1.6
     */
    private synchronized void clearCaches() {
        includeNonPatterns.clear();
        excludeNonPatterns.clear();
        includePatterns = null;
        excludePatterns = null;
        areNonPatternSetsReady = false;
    }

    /**
     * Ensure that the in|exclude &quot;patterns&quot; have been properly divided up.
     *
     * @since Ant 1.6.3
     */
    /* package */ synchronized void ensureNonPatternSetsReady() {
        if (!areNonPatternSetsReady) {
            includePatterns = fillNonPatternSet(includeNonPatterns, includes);
            excludePatterns = fillNonPatternSet(excludeNonPatterns, excludes);
            areNonPatternSetsReady = true;
        }
    }

    /**
     * Add all patterns that are not real patterns (do not contain wildcards) to the set and returns the real patterns.
     *
     * @param map Map to populate.
     * @param patterns String[] of patterns.
     * @since Ant 1.8.0
     */
    private TokenizedPattern[] fillNonPatternSet(Map<String, TokenizedPath> map, String[] patterns) {
        ArrayList<TokenizedPattern> al = new ArrayList<TokenizedPattern>(patterns.length);
        for (int i = 0; i < patterns.length; i++) {
            if (!SelectorUtils.hasWildcards(patterns[i])) {
                String s = isCaseSensitive()
                        ? patterns[i] : patterns[i].toUpperCase();
                map.put(s, new TokenizedPath(s));
            } else {
                al.add(new TokenizedPattern(patterns[i]));
            }
        }
        return (TokenizedPattern[]) al.toArray(new TokenizedPattern[al.size()]);
    }

    /**
     * Would following the given directory cause a loop of symbolic links deeper than allowed?
     *
     * <p>
     * Can only happen if the given directory has been seen at least more often than allowed during the current scan and
     * it is a symbolic link and enough other occurrences of the same name higher up are symbolic links that point to
     * the same place.</p>
     *
     * @since Ant 1.8.0
     */
    private boolean causesIllegalSymlinkLoop(String dirName, File parent,
            LinkedList<String> directoryNamesFollowed) {
        try {
            if (directoryNamesFollowed.size() >= maxLevelsOfSymlinks
                    && CollectionUtils.frequency(directoryNamesFollowed, dirName)
                    >= maxLevelsOfSymlinks
                    && SYMLINK_UTILS.isSymbolicLink(parent, dirName)) {

                ArrayList<String> files = new ArrayList<String>();
                File f = FILE_UTILS.resolveFile(parent, dirName);
                String target = f.getCanonicalPath();
                files.add(target);

                String relPath = "";
                for (String dir : directoryNamesFollowed) {
                    relPath += "../";
                    if (dirName.equals(dir)) {
                        f = FILE_UTILS.resolveFile(parent, relPath + dir);
                        files.add(f.getCanonicalPath());
                        if (files.size() > maxLevelsOfSymlinks
                                && CollectionUtils.frequency(files, target)
                                > maxLevelsOfSymlinks) {
                            return true;
                        }
                    }
                }

            }
            return false;
        } catch (IOException ex) {
            throw new BuildException("Caught error while checking for"
                    + " symbolic links", ex);
        }
    }

}
