--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common/src/main/java/digilib/io/DocuDirCache.java	Tue Apr 26 20:24:31 2011 +0200
@@ -0,0 +1,362 @@
+/*
+ * DocuDirCache.java
+ * 
+ * Digital Image Library servlet components
+ * 
+ * Copyright (C) 2003 Robert Casties (robcast@mail.berlios.de)
+ * 
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ * 
+ * Please read license.txt for the full details. A copy of the GPL may be found
+ * at http://www.gnu.org/copyleft/lgpl.html
+ * 
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place, Suite 330, Boston, MA 02111-1307 USA
+ * 
+ * Created on 03.03.2003
+ */
+
+package digilib.io;
+
+import java.io.File;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.apache.log4j.Logger;
+
+import digilib.io.FileOps.FileClass;
+import digilib.servlet.DigilibConfiguration;
+
+/**
+ * @author casties
+ */
+public class DocuDirCache {
+
+	/** general logger for this class */
+	Logger logger = Logger.getLogger(this.getClass());
+
+	/** HashMap of directories */
+	ConcurrentMap<String, DocuDirectory> map = new ConcurrentHashMap<String, DocuDirectory>();
+
+	/** names of base directories */
+	String[] baseDirNames = null;
+
+	/** array of allowed file classes (image/text) */
+	private FileClass[] fileClasses = null;
+
+	/** number of files in the whole cache (approximate) */
+	long numFiles = 0;
+
+	/** number of cache hits */
+	long hits = 0;
+
+	/** number of cache misses */
+	long misses = 0;
+
+	/** the root directory element */
+	public static Directory ROOT = null;
+
+	/**
+	 * Constructor with array of base directory names and file classes.
+	 * 
+	 * @param bd
+	 *            base directory names
+	 */
+	public DocuDirCache(String[] bd, FileClass[] fcs,
+			DigilibConfiguration dlConfig) {
+		baseDirNames = bd;
+		this.fileClasses = fcs;
+	}
+
+	/**
+	 * Constructor with array of base directory names.
+	 * 
+	 * @param bd
+	 *            base directory names
+	 */
+	public DocuDirCache(String[] bd) {
+		baseDirNames = bd;
+		// default file class is CLASS_IMAGE
+		fileClasses = new FileClass[] { FileClass.IMAGE };
+	}
+
+	/**
+	 * The number of directories in the cache.
+	 * 
+	 * @return
+	 */
+	public int size() {
+		return (map != null) ? map.size() : 0;
+	}
+
+	/**
+	 * Add a DocuDirectory to the cache.
+	 * Always returns the correct Object from the cache, 
+	 * either newdir one or another one.
+	 * 
+	 * @param newdir
+	 * @return dir
+	 */
+	public DocuDirectory put(DocuDirectory newdir) {
+		String s = newdir.getDirName();
+		logger.debug("DocuDirCache.put for "+s+" in "+this);
+		DocuDirectory olddir = map.putIfAbsent(s, newdir);
+		if (olddir != null) {
+			logger.warn("Duplicate key in DocuDirCache.put -- ignoring!");
+			return olddir;
+		}
+		numFiles += newdir.size();
+		return newdir;
+	}
+
+	/**
+	 * Add a directory to the cache and check its parents.
+	 * Always returns the correct Object from the cache, 
+	 * either newDir one or another one.
+	 *
+	 * @param newDir
+	 * @return dir
+	 */
+	public DocuDirectory putDir(DocuDirectory newDir) {
+		DocuDirectory dd = put(newDir);
+		if (dd.getParent() == null) {
+			// no parent link yet
+			String parent = FileOps.parent(newDir.getDirName());
+			if (parent != "") {
+				// check the parent in the cache
+				DocuDirectory pd = map.get(parent);
+				if (pd == null) {
+					// the parent is unknown
+					pd = new DocuDirectory(parent, this);
+					pd = putDir(pd);
+				}
+				newDir.setParent(pd);
+			}
+		}
+		return dd;
+	}
+
+	/**
+	 * Get a list with all children of a directory.
+	 * 
+	 * Returns a List of DocuDirectory's. Returns an empty List if the directory
+	 * has no children. If recurse is false then only direct children are
+	 * returned.
+	 * 
+	 * @param dirname
+	 * @param recurse
+	 *            find all children and their children.
+	 * @return
+	 */
+	public List<DocuDirectory> getChildren(String dirname, boolean recurse) {
+		List<DocuDirectory> l = new LinkedList<DocuDirectory>();
+		for (DocuDirectory dd: map.values()) {
+			if (recurse) {
+				if (dd.getDirName().startsWith(dirname)) {
+					l.add(dd);
+				}
+			} else {
+				if (FileOps.parent(dd.getDirName()).equals(dirname)) {
+					l.add(dd);
+				}
+			}
+		}
+		return l;
+	}
+
+	/**
+	 * Returns the DocuDirent with the pathname <code>fn</code> and the index
+	 * <code>in</code> and the class <code>fc</code>.
+	 * 
+	 * If <code>fn</code> is a file then the corresponding DocuDirent is
+	 * returned and the index is ignored.
+	 * 
+	 * @param fn
+	 *            digilib pathname
+	 * @param in
+	 *            file index
+	 * @param fc
+	 *            file class
+	 * @return
+	 */
+	public DocuDirent getFile(String fn, int in, FileClass fc) {
+		DocuDirectory dd;
+		// file number is 1-based, vector index is 0-based
+		int n = in - 1;
+		// first, assume fn is a directory and look in the cache
+		dd = map.get(fn);
+		if (dd == null) {
+			// cache miss
+			misses++;
+			/*
+			 * see if fn is a directory
+			 */
+			File f = new File(baseDirNames[0], fn);
+			if (f.isDirectory()) {
+                // logger.debug(fn + " is a dir");
+				dd = new DocuDirectory(fn, this);
+				if (dd.isValid()) {
+					// add to the cache
+					dd = putDir(dd);
+				}
+			} else {
+				/*
+				 * maybe it's a file
+				 */
+				// get the parent directory string (like we store it in the
+				// cache)
+				String d = FileOps.parent(fn);
+				// try it in the cache
+                // logger.debug(fn + " is a file in dir " + d);
+				dd = map.get(d);
+				if (dd == null) {
+					// try to read from disk
+					dd = new DocuDirectory(d, this);
+					if (dd.isValid()) {
+						// add to the cache
+                        // logger.debug(dd + " is valid");
+						dd = putDir(dd);
+					} else {
+						// invalid path
+						return null;
+					}
+				} else {
+					// it was not a real cache miss
+					misses--;
+				}
+				// get the file's index
+				n = dd.indexOf(f.getName(), fc);
+			}
+		} else {
+			// cache hit
+			hits++;
+		}
+		dd.refresh();
+		if (dd.isValid()) {
+			try {
+				return dd.get(n, fc);
+			} catch (IndexOutOfBoundsException e) {
+                // logger.debug(fn + " not found in directory");
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * Returns the DocuDirectory indicated by the pathname <code>fn</code>.
+	 * 
+	 * If <code>fn</code> is a file then its parent directory is returned.
+	 * 
+	 * @param fn
+	 *            digilib pathname
+	 * @return
+	 */
+	public DocuDirectory getDirectory(String fn) {
+		DocuDirectory dd;
+		// first, assume fn is a directory and look in the cache
+		dd = map.get(fn);
+		if (dd == null) {
+			// cache miss
+			misses++;
+			// see if it's a directory
+			File f = new File(baseDirNames[0], fn);
+			if (f.isDirectory()) {
+				dd = new DocuDirectory(fn, this);
+				if (dd.isValid()) {
+					// add to the cache
+					dd = putDir(dd);
+				}
+			} else {
+				// maybe it's a file
+				if (f.canRead()) {
+					// try the parent directory in the cache
+					dd = map.get(f.getParent());
+					if (dd == null) {
+						// try to read from disk
+						dd = new DocuDirectory(f.getParent(), this);
+						if (dd.isValid()) {
+							// add to the cache
+							dd = putDir(dd);
+						} else {
+							// invalid path
+							return null;
+						}
+					} else {
+						// not a real cache miss then
+						misses--;
+					}
+				} else {
+					// it's not even a file :-(
+					return null;
+				}
+			}
+		} else {
+			// cache hit
+			hits++;
+		}
+		dd.refresh();
+		if (dd.isValid()) {
+			return dd;
+		}
+		return null;
+	}
+
+	/**
+	 * @return String[]
+	 */
+	public String[] getBaseDirNames() {
+		return baseDirNames;
+	}
+
+	/**
+	 * @return long
+	 */
+	public long getNumFiles() {
+		return numFiles;
+	}
+
+	/**
+	 * Sets the baseDirNames.
+	 * 
+	 * @param baseDirNames
+	 *            The baseDirNames to set
+	 */
+	public void setBaseDirNames(String[] baseDirNames) {
+		this.baseDirNames = baseDirNames;
+	}
+
+	/**
+	 * @return long
+	 */
+	public long getHits() {
+		return hits;
+	}
+
+	/**
+	 * @return long
+	 */
+	public long getMisses() {
+		return misses;
+	}
+
+	/**
+	 * @return
+	 */
+	public FileClass[] getFileClasses() {
+		return fileClasses;
+	}
+
+	/**
+	 * @param fileClasses
+	 */
+	public void setFileClasses(FileClass[] fileClasses) {
+		this.fileClasses = fileClasses;
+	}
+
+}