// enumerateFiles.java
// -------------------------------------
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
//
// $LastChangedDate: 2011-03-08 02:51:51 +0100 (Di, 08. Mär 2011) $
// $LastChangedRevision: 7567 $
// $LastChangedBy: low012 $
//
// 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.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// 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 de.anomic.tools;
import java.io.File;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.TreeSet;
import net.yacy.kelondro.util.FileUtils;
public class enumerateFiles implements Enumeration<File> {
// implements iterative search through recursively defined subdirectories
// and return all paths to the files
private final List<TreeSet<File>> hierarchy; // contains TreeSet elements, each TreeSet contains File Entries
private final boolean incOrder; // if true, the smallest value is returned first
private File buffer; // the prefetch-buffer
private final boolean return_files;
private final boolean return_folders;
private final boolean delete_emptyFolders;
public enumerateFiles(final File root, final boolean files, final boolean folders, final boolean increasing, final boolean deleteEmptyFolders) {
// we define our data structures first
this.return_files = files;
this.return_folders = folders;
this.delete_emptyFolders = deleteEmptyFolders;
this.hierarchy = new ArrayList<TreeSet<File>>();
this.incOrder = increasing;
// the we initially fill the hierarchy with the content of the root folder
final TreeSet<File> t = new TreeSet<File>();
final String[] l = root.list();
// System.out.println("D " + l.toString());
if (l != null) for (int i = 0; i < l.length; i++) t.add(new File(root, l[i]));
this.hierarchy.add(t);
// start with search by filling the buffer
this.buffer = nextElement0();
}
private File nextElement0() {
// the object is a File pointing to the corresponding file
File f;
TreeSet<File> t;
do {
// System.out.println("D " + hierarchy.toString());
t = null;
while ((t == null) && (!hierarchy.isEmpty())) {
t = hierarchy.get(hierarchy.size() - 1);
if (t.isEmpty()) {
hierarchy.remove(hierarchy.size() - 1); // we step up one hierarchy
t = null;
}
}
if (hierarchy.isEmpty() || (t == null || t.isEmpty())) return null; // this is the end
// fetch value
if (incOrder) f = t.first(); else f = t.last();
t.remove(f);
// if the value represents another folder, we step into the next hierarchy
if (f.isDirectory()) {
t = new TreeSet<File>();
final String[] l = f.list();
if (l == null) {
// f has disappeared
f = null;
} else {
if (l.length == 0) {
if (delete_emptyFolders) {
FileUtils.deletedelete(f);
f = null;
} else {
if (!(return_folders)) f = null;
}
} else {
for (int i = 0; i < l.length; i++) t.add(new File(f, l[i]));
hierarchy.add(t);
if (!(return_folders)) f = null;
}
}
} else {
if (!(return_files)) f = null;
}
} while (f == null);
// thats it
return f;
}
public boolean hasMoreElements() {
return buffer != null;
}
public File nextElement() {
final File r = buffer;
buffer = nextElement0();
return r;
}
}