// kelondroStack.java
// -----------------------
// part of The Kelondro Database
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last change: 11.01.2004
//
// 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
/*
This class extends the kelondroRecords and adds a stack structure
*/
package de.anomic.kelondro;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Iterator;
import java.util.StringTokenizer;
public final class kelondroStack extends kelondroFullRecords {
// define the Over-Head-Array
private static short thisOHBytes = 0; // our record definition does not need extra bytes
private static short thisOHHandles = 2; // and two handles overhead for a double-chained list
private static short thisFHandles = 2; // two file handles for root handle and handle to last element
// define pointers for OH array access
protected static final int left = 0; // pointer for OHHandle-array: handle()-Value of left child Node
protected static final int right = 1; // pointer for OHHandle-array: handle()-Value of right child Node
protected static final int root = 0; // pointer for FHandles-array: pointer to root node
protected static final int toor = 1; // pointer for FHandles-array: pointer to root node
public kelondroStack(final File file, final kelondroRow rowdef) throws IOException {
// this creates a new stack
super(file, thisOHBytes, thisOHHandles, rowdef, thisFHandles, rowdef.columns() /* txtProps */, 80 /* txtPropWidth */);
if (super.fileExisted) {
//if ((getHandle(root) == null) && (getHandle(toor) == null)) clear();
} else {
setHandle(root, null); // define the root value
setHandle(toor, null); // define the toor value
}
}
public static final kelondroStack open(final File file, final kelondroRow rowdef) {
try {
return new kelondroStack(file, rowdef);
} catch (final IOException e) {
file.delete();
try {
return new kelondroStack(file, rowdef);
} catch (final IOException ee) {
System.out.println("kelondroStack: cannot open or create file " + file.toString());
e.printStackTrace();
ee.printStackTrace();
return null;
}
}
}
public static kelondroStack reset(final kelondroStack stack) {
// memorize settings to this file
final File f = new File(stack.filename);
final kelondroRow row = stack.row();
// close and delete the file
try {stack.close();} catch (final Exception e) {}
if (f.exists()) f.delete();
// re-open a database with same settings as before
return open(f, row);
}
public Iterator<kelondroRow.Entry> stackIterator(final boolean up) {
// iterates the elements in an ordered way.
// returns kelondroRow.Entry - type Objects
return new stackIterator(up);
}
public class stackIterator implements Iterator<kelondroRow.Entry> {
kelondroHandle nextHandle = null;
kelondroHandle lastHandle = null;
boolean up;
public stackIterator(final boolean up) {
this.up = up;
nextHandle = getHandle((up) ? root : toor);
}
public boolean hasNext() {
return (nextHandle != null);
}
public kelondroRow.Entry next() {
lastHandle = nextHandle;
try {
nextHandle = new EcoNode(nextHandle).getOHHandle((up) ? right : left);
return row().newEntry(new EcoNode(lastHandle).getValueRow());
} catch (final IOException e) {
throw new kelondroException(filename, "IO error at Counter:next()");
}
}
public void remove() {
try {
unlinkNode(new EcoNode(lastHandle));
} catch (final IOException e) {
e.printStackTrace();
}
}
}
public synchronized int size() {
return super.size();
}
public synchronized void push(final kelondroRow.Entry row) throws IOException {
// check if there is already a stack
if (getHandle(toor) == null) {
if (getHandle(root) != null) throw new RuntimeException("push: internal organisation of root and toor");
// create node
final kelondroNode n = new EcoNode(row.bytes());
n.setOHHandle(left, null);
n.setOHHandle(right, null);
n.commit();
// assign handles
setHandle(root, n.handle());
setHandle(toor, n.handle());
// thats it
} else {
// expand the list at the end
final kelondroNode n = new EcoNode(row.bytes());
n.setOHHandle(left, getHandle(toor));
n.setOHHandle(right, null);
final kelondroNode n1 = new EcoNode(getHandle(toor));
n1.setOHHandle(right, n.handle());
n.commit();
n1.commit();
// assign handles
setHandle(toor, n.handle());
// thats it
}
}
public synchronized kelondroRow.Entry pop() throws IOException {
// return row ontop of the stack and shrink stack by one
final kelondroNode n = topNode();
if (n == null) return null;
final kelondroRow.Entry ret = row().newEntry(n.getValueRow());
// remove node
unlinkNode(n);
deleteNode(n.handle());
return ret;
}
public synchronized kelondroRow.Entry top() throws IOException {
// return row ontop of the stack
final kelondroNode n = topNode();
if (n == null) return null;
return row().newEntry(n.getValueRow());
}
public synchronized kelondroRow.Entry pot() throws IOException {
// return row on the bottom of the stack and remove record
final kelondroNode n = botNode();
if (n == null) return null;
final kelondroRow.Entry ret = row().newEntry(n.getValueRow());
// remove node
unlinkNode(n);
deleteNode(n.handle());
return ret;
}
public synchronized kelondroRow.Entry bot() throws IOException {
// return row on the bottom of the stack
final kelondroNode n = botNode();
if (n == null) return null;
return row().newEntry(n.getValueRow());
}
void unlinkNode(final kelondroNode n) throws IOException {
// join chaines over node
final kelondroHandle l = n.getOHHandle(left);
final kelondroHandle r = n.getOHHandle(right);
// look left
if (l == null) {
// reached the root on left side
setHandle(root, r);
} else {
// un-link the previous record
final kelondroNode k = new EcoNode(l);
k.setOHHandle(left, k.getOHHandle(left));
k.setOHHandle(right, r);
k.commit();
}
// look right
if (r == null) {
// reached the root on right side
setHandle(toor, l);
} else {
// un-link the following record
final kelondroNode k = new EcoNode(r);
k.setOHHandle(left, l);
k.setOHHandle(right, k.getOHHandle(right));
k.commit();
}
}
private kelondroNode topNode() throws IOException {
// return node ontop of the stack
if (size() == 0) return null;
final kelondroHandle h = getHandle(toor);
if (h == null) return null;
return new EcoNode(h);
}
private kelondroNode botNode() throws IOException {
// return node on bottom of the stack
if (size() == 0) return null;
final kelondroHandle h = getHandle(root);
if (h == null) return null;
return new EcoNode(h);
}
public int imp(final File file, final String separator) throws IOException {
// imports a value-separated file, returns number of records that have been read
RandomAccessFile f = null;
try {
f = new RandomAccessFile(file,"r");
String s;
StringTokenizer st;
int recs = 0;
final kelondroRow.Entry buffer = row().newEntry();
int c;
int line = 0;
while ((s = f.readLine()) != null) {
s = s.trim();
line++;
if ((s.length() > 0) && (!(s.startsWith("#")))) {
st = new StringTokenizer(s, separator);
// buffer the entry
c = 0;
while ((c < row().columns()) && (st.hasMoreTokens())) {
buffer.setCol(c++, st.nextToken().trim().getBytes());
}
if ((st.hasMoreTokens()) || (c != row().columns())) {
System.err.println("inapropriate number of entries in line " + line);
} else {
push(buffer);
recs++;
}
}
}
return recs;
} finally {
if (f!=null) try{f.close();}catch(final Exception e){}
}
}
public String hp(final kelondroHandle h) {
if (h == null)
return "NULL";
return h.toString();
}
public void print() throws IOException {
super.print();
final Iterator<kelondroRow.Entry> it = stackIterator(true);
kelondroRow.Entry r;
while (it.hasNext()) {
r = it.next();
System.out.print(" KEY:'" + r.getColString(0, null) + "'");
for (int j = 1; j < row().columns(); j++)
System.out.print(", V[" + j + "]:'" + r.getColString(j, null) + "'");
System.out.println();
}
System.out.println();
}
private static void cmd(final String[] args) {
System.out.print("kelondroStack ");
for (int i = 0; i < args.length; i++) System.out.print(args[i] + " ");
System.out.println("");
byte[] ret = null;
final kelondroRow lens = new kelondroRow("byte[] key-" + Integer.parseInt(args[1]) + ", byte[] value-" + Integer.parseInt(args[2]), kelondroNaturalOrder.naturalOrder, 0);
try {
if ((args.length > 4) || (args.length < 2)) {
System.err.println("usage: kelondroStack -c|-p|-v|-g|-i|-s [file]|[key [value]] <db-file>");
System.err.println("( create, push, view, (g)pop, imp, shell)");
System.exit(0);
} else if (args.length == 2) {
kelondroStack fm = new kelondroStack(new File(args[1]), lens);
if (args[0].equals("-v")) {
fm.print();
ret = null;
} else if (args[0].equals("-g")) {
fm = new kelondroStack(new File(args[1]), lens);
final kelondroRow.Entry ret2 = fm.pop();
ret = ((ret2 == null) ? null : ret2.getColBytes(1));
fm.close();
}
fm.close();
} else if (args.length == 3) {
if (args[0].equals("-i")) {
final kelondroStack fm = new kelondroStack(new File(args[2]), lens);
final int i = fm.imp(new File(args[1]),";");
fm.close();
ret = (i + " records imported").getBytes();
} else if (args[0].equals("-s")) {
final String db = args[2];
BufferedReader f = null;
try {
f = new BufferedReader(new FileReader(args[1]));
String m;
while (true) {
m = f.readLine();
if (m == null) break;
if ((m.length() > 1) && (!m.startsWith("#"))) {
m = m + " " + db;
cmd(line2args(m));
}
}
ret = null;
} finally {
if (f != null) try {f.close();}catch(final Exception e) {}
}
} else if (args[0].equals("-g")) {
final kelondroStack fm = new kelondroStack(new File(args[2]), lens);
final kelondroRow.Entry ret2 = fm.pop();
ret = ((ret2 == null) ? null : ret2.getColBytes(1));
fm.close();
}
} else if (args.length == 4) {
if (args[0].equals("-c")) {
// create <keylen> <valuelen> <filename>
final File f = new File(args[3]);
if (f.exists()) f.delete();
final kelondroStack fm = new kelondroStack(f, lens);
fm.close();
} else if (args[0].equals("-p")) {
final kelondroStack fm = new kelondroStack(new File(args[3]), lens);
fm.push(fm.row().newEntry(new byte[][] {args[1].getBytes(), args[2].getBytes()}));
fm.close();
}
}
if (ret == null)
System.out.println("NULL");
else
System.out.println(new String(ret));
} catch (final Exception e) {
e.printStackTrace();
}
}
public static void main(final String[] args) {
// -c 10 20 test.stack
// -p a a1 test.stack
// -p b b1 test.stack
// -p c c1 test.stack
// -v test.stack
// -g test.stack
// -v test.stack
// -g 1 test.stack
cmd(args);
/*
kelondroStack s = new kelondroStack(new File("/Users/admin/dev/yacy/trunk/test.stack"), 1024, new int[]{10,10}, false);
try {
s.push(s.row().newEntry(new byte[][]{"test123".getBytes(), "abcdefg".getBytes()}));
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
*/
}
}