--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/servlet/src/digilib/auth/HashTree.java	Thu Jan 17 15:25:46 2002 +0100
@@ -0,0 +1,80 @@
+/*  HashTree -- Tree in a Hashtable
+
+  Digital Image Library servlet components
+
+  Copyright (C) 2001, 2002 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
+
+*/
+
+package digilib.auth;
+
+import java.util.*;
+
+public class HashTree {
+
+  private Hashtable table;
+  private String twigSep = "/";
+  private String leafSep = ",";
+
+  public HashTree() {
+    table = new Hashtable();
+  }
+
+  public HashTree(Hashtable t, String twig_separator, String leaf_separator) {
+    table = t;
+    twigSep = twig_separator;
+    leafSep = leaf_separator;
+    optimizeTable();
+  }
+
+  void optimizeTable() {
+  }
+
+  List match(String branch) {
+    String b = "";
+    String m;
+    LinkedList matches = new LinkedList();
+
+    // split branch
+    StringTokenizer twig = new StringTokenizer(branch, twigSep);
+    // walk branch and check with tree
+    while (twig.hasMoreTokens()) {
+      if (b.length() == 0) {
+        b = twig.nextToken();
+      } else {
+        b += twigSep + twig.nextToken();
+      }
+      m = (String)table.get(b);
+      //System.out.println("CHECK: "+b+" = "+m);
+      if (m != null) {
+        if (m.indexOf(leafSep) < 0) {
+          // single leaf
+          matches.add(m);
+        } else {
+          // split leaves
+          StringTokenizer leaf = new StringTokenizer(m, leafSep);
+          while (leaf.hasMoreTokens()) {
+            matches.add(leaf.nextToken());
+          }
+        }
+      }
+    }
+    if (matches.size() > 0) {
+      return matches;
+    } else {
+      return null;
+    }
+  }
+}