yacy_search_server/source/de/anomic/kelondro/kelondroTree.java

1458 lines
59 KiB
Java

// kelondroTree.java
// -----------------------
// part of The Kelondro Database
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 07.02.2005
//
// 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
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
/*
This class extends the kelondroRecords and adds a tree 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.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.Vector;
public class kelondroTree extends kelondroRecords implements Comparator {
// define the Over-Head-Array
private static short thisOHBytes = 2; // our record definition of two bytes
private static short thisOHHandles = 3; // and three handles overhead
private static short thisFHandles = 1; // file handles: one for a root pointer
// define pointers for OH array access
private static int magic = 0; // pointer for OHByte-array: marker for Node purpose; defaults to 1
private static int balance = 1; // pointer for OHByte-array: balance value of tree node; balanced = 0
private static int parent = 0; // pointer for OHHandle-array: handle()-Value of parent Node
private static int leftchild = 1; // pointer for OHHandle-array: handle()-Value of left child Node
private static int rightchild = 2; // pointer for OHHandle-array: handle()-Value of right child Node
private static int root = 0; // pointer for FHandles-array: pointer to root node
public kelondroTree(File file, long buffersize, int key, int value) throws IOException {
this(file, buffersize, new int[] {key, value}, 1, 8);
}
public kelondroTree(kelondroRA ra, long buffersize, int key, int value) throws IOException {
this(ra, buffersize, new int[] {key, value}, 1, 8);
}
public kelondroTree(File file, long buffersize, int[] columns) throws IOException {
// this creates a new tree file
this(file, buffersize, columns, columns.length /*txtProps*/, 80 /*txtPropWidth*/);
}
public kelondroTree(File file, long buffersize,
int[] columns, int txtProps, int txtPropsWidth) throws IOException {
// this creates a new tree file
super(file, buffersize,
thisOHBytes, thisOHHandles,
columns, thisFHandles, columns.length /*txtProps*/, 80 /*txtPropWidth*/);
setHandle(root, null); // define the root value
}
public kelondroTree(kelondroRA ra, long buffersize, int[] columns) throws IOException {
// this creates a new tree within a kelondroRA
this(ra, buffersize, columns, columns.length /*txtProps*/, 80 /*txtPropWidth*/);
}
public kelondroTree(kelondroRA ra, long buffersize, int[] columns, int txtProps, int txtPropsWidth) throws IOException {
// this creates a new tree within a kelondroRA
super(ra, buffersize, thisOHBytes, thisOHHandles, columns, thisFHandles, txtProps, txtPropsWidth);
setHandle(root, null); // define the root value
}
public kelondroTree(File file, long buffersize) throws IOException{
// this opens a file with an existing tree file
super(file, buffersize);
}
public kelondroTree(kelondroRA ra, long buffersize) throws IOException{
// this opens a file with an existing tree in a kelondroRA
super(ra, buffersize);
}
public void clear() throws IOException {
super.clear();
setHandle(root, null); // reset the root value
}
// Returns the value to which this map maps the specified key.
public synchronized byte[][] get(byte[] key) throws IOException {
//System.out.println("kelondroTree.get " + new String(key) + " in " + filename);
Search search = new Search(key);
if (search.found()) {
byte[][] result = search.getMatcher().getValues();
search = null;
return result;
} else {
search = null;
return null;
}
}
public long[] getLong(byte[] key) throws IOException {
byte[][] row = get(key);
long[] longs = new long[columns() - 1];
if (row == null) {
for (int i = 0; i < columns() - 1; i++) {
longs[i] = 0;
}
} else {
for (int i = 0; i < columns() - 1; i++) {
longs[i] = bytes2long(row[i + 1]);
}
}
return longs;
}
public class Search {
// a search object combines the results of a search in the tree, which are
// - the searched object is found, an index pointing to the node can be returned
// - the object was not found, an index pointing to an appropriate possible parent node can
// be returned, together with the information wether the new key shall be left or right child.
//
private byte[] key;
private Node thenode, parentnode;
private boolean found; // property if node was found
private byte child; // -1: left child; 0: root node; 1: right child
protected Search(byte[] key) throws IOException {
this.key = key;
searchproc();
}
protected Search(Node node) throws IOException {
this.key = node.getKey();
searchproc();
}
private void searchproc() throws IOException {
// searchs the database for the key and stores the result in the thisHandle
// if the key was found, then found=true, thisHandle and leftchild is set;
// else found=false and thisHandle and leftchild is undefined
Handle thisHandle = getHandle(root);
parentnode = null;
if (key == null) {
child = 0;
if (thisHandle == null) {
thenode = null;
found = false;
} else {
thenode = getNode(thisHandle, null, 0);
found = true;
}
} else {
thenode = null;
child = 0;
found = false;
int c;
Handle[] handles;
HashMap visitedNodeKeys = new HashMap(); // to detect loops
String otherkey;
//System.out.println("Starting Compare Loop in Database " + filename); // debug
while (thisHandle != null) {
try {
parentnode = thenode;
thenode = getNode(thisHandle, thenode, (child == -1) ? leftchild : rightchild);
} catch (IllegalArgumentException e) {
System.out.println("WARNING: kelondroTree.Search.searchproc: fixed a broken handle");
found = false;
return;
}
otherkey = new String(thenode.getKey());
if (visitedNodeKeys.containsKey(otherkey)) {
// we have loops in the database.
// to fix this, all affected nodes must be patched
thenode.setOHByte(new byte[] {1, 0});
thenode.setOHHandle(new Handle[] {null, null, null});
Iterator fix = visitedNodeKeys.entrySet().iterator();
Map.Entry entry;
while (fix.hasNext()) {
entry = (Map.Entry) fix.next();
thenode = (Node) entry.getValue();
thenode.setOHByte(new byte[] {1, 0});
thenode.setOHHandle(new Handle[] {null, null, null});
}
throw new kelondroException(filename, "database contains loops; the loop-nodes have been auto-fixed");
}
//System.out.print("Comparing key = '" + new String(key) + "' with '" + otherkey + "':"); // debug
c = compare(key, thenode.getKey());
//System.out.println(c); // debug
if (c == 0) {
found = true;
return;
} else if (c < 0) {
child = -1;
thisHandle = thenode.getOHHandle()[leftchild];
} else {
child = 1;
thisHandle = thenode.getOHHandle()[rightchild];
}
visitedNodeKeys.put(otherkey, thenode);
}
}
// we reached a node where we must insert the new value
// all values are set, just return
}
public boolean found() {
return found;
}
public Node getMatcher() throws IOException {
if (found) return thenode;
else throw new IllegalArgumentException("wrong access of matcher");
}
public Node getParent() throws IOException {
if (found) return parentnode; else return thenode;
}
public boolean isRoot() throws IOException {
if (found) throw new IllegalArgumentException("wrong access of isRoot");
else return (child == 0);
}
public boolean isLeft() throws IOException {
if (found) throw new IllegalArgumentException("wrong access of leftchild");
else return (child == -1);
}
public boolean isRight() throws IOException {
if (found) throw new IllegalArgumentException("wrong access of leftchild");
else return (child == 1);
}
}
public boolean isChild(Node childn, Node parentn, int child) throws IOException {
if (childn == null) throw new IllegalArgumentException("isLeftChild: Node parameter is NULL");
Handle lc = parentn.getOHHandle()[child];
if (lc == null) return false;
return (lc.equals(childn.handle()));
}
public long[] putLong(byte[] key, long[] newlongs) throws IOException {
byte[][] newrow = new byte[newlongs.length + 1][];
newrow[0] = key;
for (int i = 0; i < newlongs.length; i++) {
newrow[i + 1] = long2bytes(newlongs[i], columnSize(i + 1));
}
byte[][] oldrow = put(newrow);
long[] oldlongs = new long[columns() - 1];
if (oldrow == null) {
for (int i = 0; i < columns() - 1; i++) {
oldlongs[i] = 0;
}
} else {
for (int i = 0; i < columns() - 1; i++) {
oldlongs[i] = bytes2long(oldrow[i + 1]);
}
}
return oldlongs;
}
// Associates the specified value with the specified key in this map
public synchronized byte[][] put(byte[][] newrow) throws IOException {
if (newrow.length != columns()) throw new IllegalArgumentException("put: wrong row length " + newrow.length + "; must be " + columns());
// first try to find the key element in the database
Search searchResult = new Search(newrow[0]);
if (searchResult.found()) {
// a node with this key exist. simply overwrite the content and return old content
Node e = searchResult.getMatcher();
byte[][] result = e.setValues(newrow);
searchResult = null;
return result;
} else if (searchResult.isRoot()) {
// a node with this key does not exist and there is no node at all
// this therefore creates the root node if an only if there was no root Node yet
if (getHandle(root) != null)
throw new kelondroException(filename, "tried to create root node twice");
// we dont have any Nodes in the file, so start here to create one
Node e = newNode(newrow);
e.save();
// write the propetries
e.setOHByte(new byte[] {1, 0}); // {magic, balance}
e.setOHHandle(new Handle[] {null, null, null}); // {parent, leftchild, rightchild}
// do updates
setHandle(root, e.handle());
searchResult = null;
return null;
} else {
// a node with this key does not exist
// this creates a new node if there is already at least a root node
// to create the new node, it is necessary to assign it to a parent
// it must also be defined weather this new node is a left child of the
// parent or not. It is checked if the parent node already has a child on
// that side, but not if the assigned position is appropriate.
// create new node and assign values
Node theNode = newNode(newrow); theNode.save();
Node parentNode = searchResult.getParent();
Handle[] parentOHHandle;
byte[] parentOHByte;
theNode.setOHByte(new byte[] {1, 0}); // fresh {magic, balance}
theNode.setOHHandle(new Handle[] {parentNode.handle(), null, null}); // {parent, leftchild, rightchild}
// check consistency and link new node to parent node
parentOHHandle = parentNode.getOHHandle(); // {parent, leftchild, rightchild}
if (searchResult.isLeft()) {
if (parentOHHandle[leftchild] != null) throw new kelondroException(filename, "tried to create leftchild node twice");
parentOHHandle[leftchild] = theNode.handle();
} else if (searchResult.isRight()) {
if (parentOHHandle[rightchild] != null) throw new kelondroException(filename, "tried to create rightchild node twice");
parentOHHandle[rightchild] = theNode.handle();
} else {
throw new kelondroException(filename, "neither left nor right child");
}
parentNode.setOHHandle(parentOHHandle);
// now update recursively the node balance of the parentNode
// what do we have:
// - new Node, called 'theNode'
// - parent Node
// set balance factor in parent node(s)
boolean increasedHight = true;
byte prevHight;
String path = "";
while (increasedHight) {
// update balance
parentOHByte = parentNode.getOHByte(); // {magic, balance}
parentOHHandle = parentNode.getOHHandle(); // {parent, leftchild, rightchild}
prevHight = parentOHByte[balance];
if ((parentOHHandle[leftchild] != null) && (parentOHHandle[leftchild].equals(theNode.handle()))) {
//isLeftchild
parentOHByte[balance]++;
path = "L" + path;
}
if ((parentOHHandle[rightchild] != null) && (parentOHHandle[rightchild].equals(theNode.handle()))) {
parentOHByte[balance]--;
path = "R" + path;
}
increasedHight = ((java.lang.Math.abs((int) parentOHByte[balance]) - java.lang.Math.abs((int) prevHight)) > 0);
parentNode.setOHByte(parentOHByte);
// here we either stop because we had no increased hight,
// or we have a balance greater then 1 or less than -1 and we do rotation
// or we crawl up the tree and change the next balance
if (!(increasedHight)) break; // finished
// check rotation need
if (java.lang.Math.abs((int) parentOHByte[balance]) > 1) {
// rotate and stop then
//System.out.println("* DB DEBUG: " + path.substring(0,2) + " ROTATION AT NODE " + parentNode.handle().toString() + ": BALANCE=" + parentOHByte[balance]);
if (path.startsWith("LL")) {
LL_RightRotation(parentNode, theNode);
break;
}
if (path.startsWith("RR")) {
RR_LeftRotation(parentNode, theNode);
break;
}
if (path.startsWith("RL")) {
Handle parentHandle = parentNode.handle();
LL_RightRotation(theNode, getNode(theNode.getOHHandle()[leftchild], theNode, leftchild));
parentNode = getNode(parentHandle, null, 0); // reload the parent node
RR_LeftRotation(parentNode, getNode(parentNode.getOHHandle()[rightchild], parentNode, rightchild));
break;
}
if (path.startsWith("LR")) {
Handle parentHandle = parentNode.handle();
RR_LeftRotation(theNode, getNode(theNode.getOHHandle()[rightchild], theNode, rightchild));
parentNode = getNode(parentHandle, null, 0); // reload the parent node
LL_RightRotation(parentNode, getNode(parentNode.getOHHandle()[leftchild], parentNode, leftchild));
break;
}
break;
} else {
// crawl up the tree
if (parentOHHandle[parent] == null) {
// root reached: stop
break;
} else {
theNode = parentNode;
parentNode = getNode(parentOHHandle[parent] /*previous handles*/, null, 0);
}
}
}
return null; // that means: no previous stored value present
}
}
private void assignChild(Node parentNode, Node childNode, int childType) throws IOException {
Handle[] parentHandle = parentNode.getOHHandle();
Handle[] childHandle = childNode.getOHHandle();
parentHandle[childType] = childNode.handle();
childHandle[parent] = parentNode.handle();
parentNode.setOHHandle(parentHandle);
childNode.setOHHandle(childHandle);
}
private void replace(Node oldNode, Node oldNodeParent, Node newNode) throws IOException {
// this routine looks where the oldNode is connected to, and replaces
// the anchor's link to the oldNode by the newNode-link
// the new link gets the anchor as parent link assigned
// the oldNode will not be updated, so this must be done outside this routine
Handle[] oldHandle = oldNode.getOHHandle(); // {parent, leftchild, rightchild}
// distinguish case where the oldNode is the root node
if (oldNodeParent == null) {
// this is the root, update root
setHandle(root, newNode.handle());
// update new Node
Handle[] newHandle = newNode.getOHHandle();
newHandle[parent] = null;
newNode.setOHHandle(newHandle);
} else {
// not the root, find parent
Handle[] parentHandle = oldNodeParent.getOHHandle();
// ok, we have the parent, but for updating the child link we must know
// if the oldNode was left or right child
if ((parentHandle[leftchild] != null) && (parentHandle[leftchild].equals(oldNode.handle()))) {
// update left node from parent
parentHandle[leftchild] = newNode.handle();
}
if ((parentHandle[rightchild] != null) && (parentHandle[rightchild].equals(oldNode.handle()))) {
// update right node from parent
parentHandle[rightchild] = newNode.handle();
}
oldNodeParent.setOHHandle(parentHandle);
// update new Node
Handle[] newHandle = newNode.getOHHandle();
newHandle[parent] = oldNodeParent.handle();
newNode.setOHHandle(newHandle);
}
// finished. remember that we did not set the links to the oldNode
// we have also not set the children of the newNode.
// this must be done somewhere outside this function.
// if the oldNode is not needed any more, it can be disposed (check childs first).
}
private static byte max0(byte b) {
if (b > 0) return b; else return 0;
}
private static byte min0(byte b) {
if (b < 0) return b; else return 0;
}
private void LL_RightRotation(Node parentNode, Node childNode) throws IOException {
// replace the parent node; the parent is afterwards unlinked
Handle p2Handle = parentNode.getOHHandle()[parent];
Node p2Node = (p2Handle == null) ? null : getNode(p2Handle, null, 0);
replace(parentNode, p2Node, childNode);
// set the left son of the parent to the right son of the childNode
Handle childOfChild = childNode.getOHHandle()[rightchild];
if (childOfChild == null) {
Handle[] parentHandle = parentNode.getOHHandle();
parentHandle[leftchild] = null;
parentNode.setOHHandle(parentHandle);
} else {
assignChild(parentNode, getNode(childOfChild, childNode, rightchild), leftchild);
}
// link the old parent node as the right child of childNode
assignChild(childNode, parentNode, rightchild);
// - newBal(parent) = oldBal(parent) - 1 - max(oldBal(leftChild), 0)
// - newBal(leftChild) = oldBal(leftChild) - 1 + min(newBal(parent), 0)
byte[] parentBytes = parentNode.getOHByte();
byte[] childBytes = childNode.getOHByte();
byte oldBalParent = parentBytes[balance];
byte oldBalChild = childBytes[balance];
parentBytes[balance] = (byte) (oldBalParent - 1 - max0(oldBalChild));
childBytes[balance] = (byte) (oldBalChild - 1 + min0(parentBytes[balance]));
parentNode.setOHByte(parentBytes);
childNode.setOHByte(childBytes);
}
private void RR_LeftRotation(Node parentNode, Node childNode) throws IOException {
// replace the parent node; the parent is afterwards unlinked
Handle p2Handle = parentNode.getOHHandle()[parent];
Node p2Node = (p2Handle == null) ? null : getNode(p2Handle, null, 0);
replace(parentNode, p2Node, childNode);
// set the left son of the parent to the right son of the childNode
Handle childOfChild = childNode.getOHHandle()[leftchild];
if (childOfChild == null) {
Handle[] parentHandle = parentNode.getOHHandle();
parentHandle[rightchild] = null;
parentNode.setOHHandle(parentHandle);
} else {
assignChild(parentNode, getNode(childOfChild, childNode, leftchild), rightchild);
}
// link the old parent node as the left child of childNode
assignChild(childNode, parentNode, leftchild);
// - newBal(parent) = oldBal(parent) + 1 - min(oldBal(rightChild), 0)
// - newBal(rightChild) = oldBal(rightChild) + 1 + max(newBal(parent), 0)
byte[] parentBytes = parentNode.getOHByte();
byte[] childBytes = childNode.getOHByte();
byte oldBalParent = parentBytes[balance];
byte oldBalChild = childBytes[balance];
parentBytes[balance] = (byte) (oldBalParent + 1 - min0(oldBalChild));
childBytes[balance] = (byte) (oldBalChild + 1 + max0(parentBytes[balance]));
parentNode.setOHByte(parentBytes);
childNode.setOHByte(childBytes);
}
// Associates the specified value with the specified key in this map
public byte[] put(byte[] key, byte[] value) throws IOException {
byte[][] row = new byte[2][];
row[0] = key;
row[1] = value;
byte[][] ret = put(row);
if (ret == null) return null; else return ret[1];
}
// Removes the mapping for this key from this map if present (optional operation).
public synchronized byte[][] remove(byte[] key) throws IOException {
Search search = new Search(key);
if (search.found()) {
Node result = search.getMatcher();
byte[][] values = result.getValues();
remove(result, search.getParent());
search = null;
return values;
} else {
return null;
}
}
public void removeAll() throws IOException {
while (size() > 0) remove(lastNode(), null);
}
private void remove(Node node, Node parentOfNode) throws IOException {
// there are three cases when removing a node
// - the node is a leaf - it can be removed easily
// - the node has one child - the child replaces the node
// - the node has two childs - it can be replaced either
// by the greatest node of the left child or the smallest
// node of the right child
Handle[] handles = node.getOHHandle();
Node childnode;
if ((handles[leftchild] == null) && (handles[rightchild] == null)) {
// easy case: the node is a leaf
if (parentOfNode == null) {
// this is the root!
setHandle(root, null);
} else {
Handle[] h = parentOfNode.getOHHandle();
if ((h[leftchild] != null) && (h[leftchild].equals(node.handle()))) h[leftchild] = null;
if ((h[rightchild] != null) && (h[rightchild].equals(node.handle()))) h[rightchild] = null;
parentOfNode.setOHHandle(h);
}
} else if ((handles[leftchild] != null) && (handles[rightchild] == null)) {
replace(node, parentOfNode, getNode(handles[leftchild], node, leftchild));
} else if ((handles[leftchild] == null) && (handles[rightchild] != null)) {
replace(node, parentOfNode, getNode(handles[rightchild], node, rightchild));
} else {
// difficult case: node has two children
Node repl = lastNode(getNode(handles[leftchild], node, leftchild));
//System.out.println("last node is " + repl.toString());
// we remove that replacement node and put it where the node was
// this seems to be recursive, but is not since the replacement
// node cannot have two children (it would not have been the smallest or greatest)
Handle[] replha = repl.getOHHandle();
Node n;
Handle[] h;
// remove leaf
if ((replha[leftchild] == null) && (replha[rightchild] == null)) {
// the replacement cannot be the root, so simply remove from parent node
n = getNode(replha[parent], null, 0); // parent node of replacement node
h = n.getOHHandle();
if ((h[leftchild] != null) && (h[leftchild].equals(repl.handle()))) h[leftchild] = null;
if ((h[rightchild] != null) && (h[rightchild].equals(repl.handle()))) h[rightchild] = null;
n.setOHHandle(h);
} else if ((replha[leftchild] != null) && (replha[rightchild] == null)) {
try {
childnode = getNode(replha[leftchild], repl, leftchild);
replace(repl, getNode(replha[parent], null, 0), childnode);
} catch (IllegalArgumentException e) {
// now treat the situation as if that link had been null before
n = getNode(replha[parent], null, 0); // parent node of replacement node
h = n.getOHHandle();
if ((h[leftchild] != null) && (h[leftchild].equals(repl.handle()))) h[leftchild] = null;
if ((h[rightchild] != null) && (h[rightchild].equals(repl.handle()))) h[rightchild] = null;
n.setOHHandle(h);
}
} else if ((replha[leftchild] == null) && (replha[rightchild] != null)) {
try {
childnode = getNode(replha[rightchild], repl, rightchild);
replace(repl, getNode(replha[parent], null, 0), childnode);
} catch (IllegalArgumentException e) {
// now treat the situation as if that link had been null before
n = getNode(replha[parent], null, 0); // parent node of replacement node
h = n.getOHHandle();
if ((h[leftchild] != null) && (h[leftchild].equals(repl.handle()))) h[leftchild] = null;
if ((h[rightchild] != null) && (h[rightchild].equals(repl.handle()))) h[rightchild] = null;
n.setOHHandle(h);
}
}
//System.out.println("node before reload is " + node.toString());
node = getNode(node.handle(), null, 0); // reload the node, it is possible that it has been changed
//System.out.println("node after reload is " + node.toString());
// now plant in the replha node
byte[] b = node.getOHByte(); // save bytes of disappearing node
handles = node.getOHHandle(); // save handles of disappearing node
replace(node, parentOfNode, repl);
repl.setOHByte(b); // restore bytes
repl.setOHHandle(handles); // restore handles
// last thing to do: change uplinks of children to this new node
if (handles[leftchild] != null) {
n = getNode(handles[leftchild], node, leftchild);
h = n.getOHHandle();
h[parent] = repl.handle();
n.setOHHandle(h);
}
if (handles[rightchild] != null) {
n = getNode(handles[rightchild], node, rightchild);
h = n.getOHHandle();
h[parent] = repl.handle();
n.setOHHandle(h);
}
}
deleteNode(node.handle());
}
private Node firstNode() throws IOException {
Handle h = getHandle(root);
if (h == null) return null;
return firstNode(getNode(h, null, 0));
}
private Node firstNode(Node node) throws IOException {
if (node == null) throw new IllegalArgumentException("firstNode: node=null");
Handle h = node.getOHHandle()[leftchild];
while (h != null) {
try {
node = getNode(h, node, leftchild);
} catch (IllegalArgumentException e) {
// return what we have
return node;
}
h = node.getOHHandle()[leftchild];
}
return node;
}
private Node lastNode() throws IOException {
Handle h = getHandle(root);
if (h == null) return null;
return lastNode(getNode(h, null, 0));
}
private Node lastNode(Node node) throws IOException {
if (node == null) throw new IllegalArgumentException("lastNode: node=null");
Handle h = node.getOHHandle()[rightchild];
while (h != null) {
try {
node = getNode(h, node, rightchild);
} catch (IllegalArgumentException e) {
// return what we have
return node;
}
h = node.getOHHandle()[rightchild];
}
return node;
}
public synchronized Iterator nodeIterator(boolean up, boolean rotating) {
// iterates the elements in a sorted way. returns Node - type Objects
try {
return new nodeIterator(up, rotating);
} catch (IOException e) {
throw new RuntimeException("error creating an iteration: " + e.getMessage());
}
}
public synchronized Iterator nodeIterator(boolean up, boolean rotating, byte[] firstKey) {
// iterates the elements in a sorted way. returns Node - type Objects
try {
Search s = new Search(firstKey);
if (s.found()) {
Node matcher = s.getMatcher();
s = null;
return new nodeIterator(up, rotating, matcher);
} else {
Node nn = s.getParent();
s = null;
if (nn == null) {
return (new HashSet()).iterator(); // an empty iterator
} else {
return new nodeIterator(up, rotating, nn);
}
}
} catch (IOException e) {
throw new RuntimeException("error creating an iteration: " + e.getMessage());
}
}
private class nodeIterator implements Iterator {
// we implement an iteration! (not a recursive function as the structure would suggest...)
// the iterator iterates Node objects
Node nextNode = null;
boolean up, rot;
LinkedList nodeStack;
int count;
public nodeIterator(boolean up, boolean rotating) throws IOException {
this(up, rotating, (up) ? firstNode() : lastNode());
}
public nodeIterator(boolean up, boolean rotating, Node start) throws IOException {
this.count = 0;
this.up = up;
this.rot = rotating;
this.nextNode = start;
// fill node stack for start node
nodeStack = new LinkedList();
Handle searchHandle = getHandle(root);
if (searchHandle == null) {nextNode = null; return;}
Node searchNode = getNode(searchHandle, null, 0);
byte[] startKey = start.getKey();
int c, ct;
while ((c = compare(startKey, searchNode.getKey())) != 0) {
// the current 'thisNode' is not the start node, put it on the stack
ct = (c < 0) ? leftchild : rightchild;
nodeStack.addLast(new Object[]{searchNode, new Integer(ct)});
// go to next node
searchHandle = searchNode.getOHHandle()[ct];
if (searchHandle == null) throw new kelondroException(filename, "start node does not exist (handle null)");
searchNode = getNode(searchHandle, searchNode, ct);
if (searchNode == null) throw new kelondroException(filename, "start node does not exist (node null)");
}
// now every parent node to the start node is on the stack
}
public void finalize() {
nextNode = null;
nodeStack = null;
}
public boolean hasNext() {
return nextNode != null;
}
public Object next() {
count++;
if (nextNode == null) throw new kelondroException(filename, "no more entries available");
if ((count > size()) && (!(rot))) throw new kelondroException(filename, "internal loopback; database corrupted");
Object ret = nextNode;
// middle-case
try {
int childtype = (up) ? rightchild : leftchild;
Handle childHandle = nextNode.getOHHandle()[childtype];
if (childHandle != null) {
//System.out.println("go to other leg, stack size=" + nodeStack.size());
// we have walked one leg of the tree; now go to the other one: step down to next child
nodeStack.addLast(new Object[]{nextNode, new Integer(childtype)});
nextNode = getNode(childHandle, nextNode, childtype);
childtype = (up) ? leftchild : rightchild;
while ((childHandle = nextNode.getOHHandle()[childtype]) != null) {
try {
nodeStack.addLast(new Object[]{nextNode, new Integer(childtype)});
nextNode = getNode(childHandle, nextNode, childtype);
} catch (IllegalArgumentException e) {
// return what we have
nodeStack.removeLast();
return ret;
}
}
// thats it: we are at a place where we can't go further
// nextNode is correct
} else {
//System.out.println("go up");
// we have walked along both legs of the child-trees.
// Now step up.
if (nodeStack.size() == 0) {
nextNode = null;
} else {
Object[] stacktop;
Node parent = null;
int parentpointer = (up) ? rightchild : leftchild;
while ((nodeStack.size() != 0) && (parentpointer == ((up) ? rightchild : leftchild))) {
//System.out.println("step up");
// go on, walk up further
stacktop = (Object[]) nodeStack.removeLast(); // top of stack: Node/parentpointer pair
parent = (Node) stacktop[0];
parentpointer = ((Integer) stacktop[1]).intValue();
}
if ((nodeStack.size() == 0) && (parentpointer == ((up) ? rightchild : leftchild))) {
nextNode = null;
} else {
nextNode = parent;
}
}
}
} catch (IOException e) {
nextNode = null;
}
return ret;
}
public void remove() {
throw new java.lang.UnsupportedOperationException("kelondroTree: remove in kelondro Tables not yet supported");
}
}
public synchronized rowIterator rows(boolean up, boolean rotating) throws IOException {
// iterates the rows of the Nodes
// enumerated objects are of type byte[][]
// iterates the elements in a sorted way.
return new rowIterator(new nodeIterator(up, rotating));
}
public synchronized Iterator rows(boolean up, boolean rotating, byte[] firstKey) throws IOException {
Search s = new Search(firstKey);
if (s.found()) {
Node matcher = s.getMatcher();
s = null;
return new rowIterator(new nodeIterator(up, rotating, matcher));
} else {
Node nn = s.getParent();
s = null;
if (nn == null) {
return (Iterator) (new HashSet()).iterator();
} else {
return new rowIterator(new nodeIterator(up, rotating, nn));
}
}
}
public class rowIterator implements Iterator {
Iterator nodeIterator;
public rowIterator(Iterator nodeIterator) {
this.nodeIterator = nodeIterator;
}
public boolean hasNext() {
return (nodeIterator.hasNext());
}
public Object next() {
try {
Node nextNode = (Node) nodeIterator.next();
if (nextNode == null) throw new kelondroException(filename, "no more elements available");
return nextNode.getValues();
} catch (IOException e) {
throw new kelondroException(filename, "io-error: " + e.getMessage());
}
}
public void remove() {
}
}
public synchronized keyIterator keys(boolean up, boolean rotating) throws IOException {
// iterates only the keys of the Nodes
// enumerated objects are of type String
// iterates the elements in a sorted way.
return new keyIterator(new nodeIterator(up, rotating));
}
public synchronized Iterator keys(boolean up, boolean rotating, byte[] firstKey) throws IOException {
Search s = new Search(firstKey);
if (s.found()) {
Node matcher = s.getMatcher();
s = null;
return new keyIterator(new nodeIterator(up, rotating, matcher));
} else {
Node nn = s.getParent();
s = null;
if (nn == null) {
return (Iterator) (new HashSet()).iterator();
} else {
return new keyIterator(new nodeIterator(up, rotating, nn));
}
}
}
public class keyIterator implements Iterator {
Iterator nodeIterator;
public keyIterator(Iterator nodeIterator) {
this.nodeIterator = nodeIterator;
}
public void finalize() {
nodeIterator = null;
}
public boolean hasNext() {
return (nodeIterator.hasNext());
}
public Object next() {
try {
Node nextNode = (Node) nodeIterator.next();
if (nextNode == null) throw new kelondroException(filename, "no more elements available");
return new String(nextNode.getKey());
} catch (IOException e) {
throw new kelondroException(filename, "io-error: " + e.getMessage());
}
}
public void remove() {
}
}
public int imp(File file, String separator) throws IOException {
// imports a value-separated file, returns number of records that have been read
RandomAccessFile f = new RandomAccessFile(file,"r");
String s;
StringTokenizer st;
int recs = 0;
byte[][] buffer = new byte[columns()][];
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 < columns()) && (st.hasMoreTokens())) {
buffer[c++] = st.nextToken().trim().getBytes();
}
if ((st.hasMoreTokens()) || (c != columns())) {
System.err.println("inapropriate number of entries in line " + line);
} else {
put(buffer);
recs++;
}
}
}
return recs;
}
public synchronized int height() {
try {
Handle h = getHandle(root);
if (h == null) return 0;
return height(getNode(h, null, 0));
} catch (IOException e) {
return 0;
}
}
private int height(Node node) throws IOException {
if (node == null) return 0;
Handle[] childs = node.getOHHandle();
int hl = (childs[leftchild] == null) ? 0 : height(getNode(childs[leftchild], node, leftchild));
int hr = (childs[rightchild] == null) ? 0 : height(getNode(childs[rightchild], node, rightchild));
if (hl > hr) return hl + 1; else return hr + 1;
}
public String np(Object n) {
if (n == null) return "NULL"; else return n.toString();
}
public void print() throws IOException {
super.print(false);
int height = height();
System.out.println("HEIGHT = " + height);
Vector thisline = new Vector();
thisline.add(getHandle(root));
Vector nextline;
Handle handle;
Node node;
int linelength, width = (1 << (height - 1)) * (columnSize(0) + 1);
Handle[] childs;
String key;
for (int h = 1; h < height; h++) {
linelength = width / (thisline.size() * 2);
nextline = new Vector();
for (int i = 0; i < thisline.size(); i++) {
handle = (Handle) thisline.elementAt(i);
if (handle == null) {
node = null;
key = "[..]";
} else {
node = getNode(handle, null, 0);
if (node == null) key = "NULL"; else key = new String(node.getKey());
}
System.out.print(key);
for (int j = 0; j < (linelength - key.length()); j++) System.out.print("-");
System.out.print("+");
for (int j = 0; j < (linelength - 1); j++) System.out.print(" ");
if (node == null) {
nextline.add(null);
nextline.add(null);
} else {
childs = node.getOHHandle();
nextline.add(childs[leftchild]);
nextline.add(childs[rightchild]);
}
}
System.out.println();
for (int i = 0; i < thisline.size(); i++) {
System.out.print("|");
for (int j = 0; j < (linelength - 1); j++) System.out.print(" ");
System.out.print("|");
for (int j = 0; j < (linelength - 1); j++) System.out.print(" ");
}
System.out.println();
thisline = nextline;
nextline = null;
}
// now print last line
if ((thisline != null) && (width >= 0)) {
linelength = width / thisline.size();
for (int i = 0; i < thisline.size(); i++) {
handle = (Handle) thisline.elementAt(i);
if (handle == null) {
node = null;
key = "NULL";
} else {
node = getNode(handle, null, 0);
if (node == null) key = "NULL"; else key = new String(node.getKey());
}
System.out.print(key);
for (int j = 0; j < (linelength - key.length()); j++) System.out.print(" ");
}
}
System.out.println();
}
/*
public void print() {
super.print(false);
Handle h;
Node n;
Iterator it = iterator(true);
while (it.hasNext()) {
n = (Node) it.next();
System.out.println("> NODE " + np(n));
try {
System.out.println(" magic " + n.getOHByte()[magic] +
", balance " + n.getOHByte()[balance] +
", parent " + np(n.getOHHandle()[parent]) +
", left " + np(n.getOHHandle()[leftchild]) +
", right " + np(n.getOHHandle()[rightchild]));
} catch (IOException e) {
System.out.println("File error: " + e.getMessage());
}
System.out.print(" KEY:'" + (new String(n.getValue(0))).trim() + "'");
for (int j = 1; j < columns(); j++)
System.out.print(", V[" + j + "]:'" + (new String(n.getValue(j))).trim() + "'");
//System.out.println();
}
System.out.println();
}
*/
private static void cmd(String[] args) {
System.out.print("kelondroTree ");
for (int i = 0; i < args.length; i++) System.out.print(args[i] + " ");
System.out.println("");
byte[] ret = null;
try {
if ((args.length > 4) || (args.length < 1)) {
System.err.println("usage: kelondroTree -c|-u|-v|-g|-d|-i|-s [file]|[key [value]] <db-file>");
System.err.println("( create, update, view, get, delete, imp, shell)");
System.exit(0);
} else if (args.length == 1) {
if (args[0].equals("-t")) {
// test script
File testFile = new File("test.db");
while (testFile.exists()) testFile.delete();
kelondroTree fm = new kelondroTree(testFile, 0x100000, 4, 4);
byte[] dummy = "".getBytes();
fm.put("abc0".getBytes(), dummy); fm.put("bcd0".getBytes(), dummy);
fm.put("def0".getBytes(), dummy); fm.put("bab0".getBytes(), dummy);
fm.put("abc1".getBytes(), dummy); fm.put("bcd1".getBytes(), dummy);
fm.put("def1".getBytes(), dummy); fm.put("bab1".getBytes(), dummy);
fm.put("abc2".getBytes(), dummy); fm.put("bcd2".getBytes(), dummy);
fm.put("def2".getBytes(), dummy); fm.put("bab2".getBytes(), dummy);
fm.put("abc3".getBytes(), dummy); fm.put("bcd3".getBytes(), dummy);
fm.put("def3".getBytes(), dummy); fm.put("bab3".getBytes(), dummy);
fm.print();
fm.remove("def1".getBytes()); fm.remove("bab1".getBytes());
fm.remove("abc2".getBytes()); fm.remove("bcd2".getBytes());
fm.remove("def2".getBytes()); fm.remove("bab2".getBytes());
fm.put("def1".getBytes(), dummy); fm.put("bab1".getBytes(), dummy);
fm.put("abc2".getBytes(), dummy); fm.put("bcd2".getBytes(), dummy);
fm.put("def2".getBytes(), dummy); fm.put("bab2".getBytes(), dummy);
fm.print();
fm.close();
ret = null;
}
} else if (args.length == 2) {
kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000);
if (args[0].equals("-v")) {
fm.print();
ret = null;
}
fm.close();
} else if (args.length == 3) {
if (args[0].equals("-d")) {
kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000);
fm.remove(args[2].getBytes());
fm.close();
} else if (args[0].equals("-i")) {
kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000);
int i = fm.imp(new File(args[1]),";");
fm.close();
ret = (i + " records imported").getBytes();
} else if (args[0].equals("-s")) {
String db = args[2];
BufferedReader 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;
} else if (args[0].equals("-g")) {
kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000);
byte[][] ret2 = fm.get(args[2].getBytes());
ret = ((ret2 == null) ? null : ret2[1]);
fm.close();
} else if (args[0].equals("-n")) {
kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000);
//byte[][] keys = fm.getSequentialKeys(args[2].getBytes(), 500, true);
Iterator rowIt = fm.rows(true, false, args[2].getBytes());
Vector v = new Vector();
while (rowIt.hasNext()) v.add(new String(((byte[][]) rowIt.next())[0]));
ret = v.toString().getBytes();
fm.close();
}
} else if (args.length == 4) {
if (args[0].equals("-c")) {
// create <keylen> <valuelen> <filename>
File f = new File(args[3]);
if (f.exists()) f.delete();
int[] lens = new int[2];
lens[0] = Integer.parseInt(args[1]);
lens[1] = Integer.parseInt(args[2]);
kelondroTree fm = new kelondroTree(f, 0x100000, lens);
fm.close();
} else if (args[0].equals("-u")) {
kelondroTree fm = new kelondroTree(new File(args[3]), 0x100000);
ret = fm.put(args[1].getBytes(), args[2].getBytes());
fm.close();
}
}
if (ret == null)
System.out.println("NULL");
else
System.out.println(new String(ret));
} catch (Exception e) {
e.printStackTrace();
}
}
public int compare(Object a, Object b) {
try {
if ((a instanceof byte[]) && (b instanceof byte[])) {
return compare((byte[]) a, (byte[]) b);
} else if ((a instanceof Node) && (b instanceof Node)) {
return compare(((Node) a).getKey(), ((Node) b).getKey());
} else throw new IllegalArgumentException("Object type or Object type combination not supported");
} catch (IOException e) {
throw new kelondroException(filename, "IOException: " + e.getMessage());
}
}
// Compares its two arguments for order.
// Returns -1, 0, or 1 as the first argument
// is less than, equal to, or greater than the second.
// two arrays are also equal if one array is a subset of the other's array with filled-up char(0)-values
public int compare(byte[] a, byte[] b) {
int i = 0;
int al = a.length;
int bl = b.length;
int len = (al > bl) ? bl : al;
while (i < len) {
if (a[i] > b[i]) return 1;
if (a[i] < b[i]) return -1;
// else the bytes are equal and it may go on yet undecided
i++;
}
// check if we have a zero-terminated equality
if ((i == al) && (i < bl) && (b[i] == 0)) return 0;
if ((i == bl) && (i < al) && (a[i] == 0)) return 0;
// no, decide by length
if (al > bl) return 1;
if (al < bl) return -1;
// no, they are equal
return 0;
}
// Returns the comparator used to order this map,
// or null if this map uses its keys' natural order.
public synchronized Comparator comparator() {
return this;
}
public static void main(String[] args) {
//cmd(args);
//bigtest(Integer.parseInt(args[0]));
randomtest(Integer.parseInt(args[0]));
//smalltest();
}
public static String[] permutations(int letters) {
String p = "";
for (int i = 0; i < letters; i++) p = p + ((char) (((int)'A') + i));
return permutations(p);
}
public static String[] permutations(String source) {
if (source.length() == 0) return new String[0];
if (source.length() == 1) return new String[]{source};
char c = source.charAt(0);
String[] recres = permutations(source.substring(1));
String[] result = new String[source.length() * recres.length];
for (int perm = 0; perm < recres.length; perm++) {
result[perm * source.length()] = c + recres[perm];
for (int pos = 1; pos < source.length() - 1; pos++) {
result[perm * source.length() + pos] = recres[perm].substring(0, pos) + c + recres[perm].substring(pos);
}
result[perm * source.length() + source.length() - 1] = recres[perm] + c;
}
return result;
}
public static byte[] testWord(char c) {
return new byte[]{(byte) c, 32, 32, 32};
}
public static kelondroTree testTree(File f, String testentities) throws IOException {
if (f.exists()) f.delete();
kelondroTree tt = new kelondroTree(f, 0, 4, 4);
byte[] b;
for (int i = 0; i < testentities.length(); i++) {
b = testWord(testentities.charAt(i));
tt.put(b, b);
}
return tt;
}
public static void randomtest(int elements) {
System.out.println("random " + elements + ":");
String s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".substring(0, elements);
String t, d;
char c;
kelondroTree tt = null;
File testFile = new File("test.db");
byte[] b;
try {
int steps = 0;
while (true) {
if (testFile.exists()) testFile.delete();
tt = new kelondroTree(testFile, 20000, 4 ,4);
steps = 10 + ((int) System.currentTimeMillis() % 7) * (((int) System.currentTimeMillis() + 17) % 11);
t = s;
d = "";
System.out.println("NEW SESSION");
for (int i = 0; i < steps; i++) {
if ((d.length() < 3) || ((t.length() > 0) && (((int) System.currentTimeMillis() % 7) < 2))) {
// add one
c = t.charAt((int) (System.currentTimeMillis() % (long) t.length()));
b = testWord(c);
tt.put(b, b);
d = d + c;
t = t.substring(0, t.indexOf(c)) + t.substring(t.indexOf(c) + 1);
System.out.println("added " + new String(b));
} else {
// delete one
c = d.charAt((int) (System.currentTimeMillis() % (long) d.length()));
b = testWord(c);
tt.remove(b);
d = d.substring(0, d.indexOf(c)) + d.substring(d.indexOf(c) + 1);
t = t + c;
System.out.println("removed " + new String(b));
}
//tt.print();
if (countElements(tt) != tt.size()) {
System.out.println("wrong size for ");
tt.print();
}
// check all words within
for (int j = 0; j < d.length(); j++) {
if (tt.get(testWord(d.charAt(j))) == null) {
System.out.println("missing entry " + d.charAt(j));
tt.print();
}
}
// check all words outside
for (int j = 0; j < t.length(); j++) {
if (tt.get(testWord(t.charAt(j))) != null) {
System.out.println("superfluous entry " + t.charAt(j));
tt.print();
}
}
if (tt.get(testWord('z')) != null) {
System.out.println("superfluous entry z");
tt.print();
}
}
tt.print();
tt.close();
}
} catch (Exception e) {
e.printStackTrace();
try {tt.print();} catch (IOException ee) {}
System.out.println("TERMINATED");
}
}
public static void smalltest() {
File f = new File("test.db");
if (f.exists()) f.delete();
try {
kelondroTree tt = new kelondroTree(f, 1000, 4, 4);
byte[] b;
b = testWord('b'); tt.put(b, b);
b = testWord('c'); tt.put(b, b);
b = testWord('a'); tt.put(b, b);
System.out.println("elements: " + countElements(tt));
tt.print();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void bigtest(int elements) {
System.out.println("perm " + elements + ":");
String[] s = permutations(elements);
kelondroTree tt;
File testFile = new File("test.db");
byte[] b;
try {
for (int i = 0; i < s.length; i++) {
System.out.println("probing tree " + i + " for permutation " + s[i]);
// generate tree and delete elements
tt = testTree(testFile, s[i]);
//tt.print();
if (countElements(tt) != tt.size()) {
System.out.println("wrong size for " + s[i]);
tt.print();
}
tt.close();
for (int j = 0; j < s.length; j++) {
tt = testTree(testFile, s[i]);
//tt.print();
// delete by permutation j
for (int elt = 0; elt < s[j].length(); elt++) {
tt.remove(testWord(s[j].charAt(elt)));
//tt.print();
if (countElements(tt) != tt.size()) {
System.out.println("ERROR! wrong size for probe tree " + s[i] + "; probe delete " + s[j] + "; position " + elt);
tt.print();
}
}
// add another one
//tt.print();
/*
b = testWord('0'); tt.put(b, b);
b = testWord('z'); tt.put(b, b);
b = testWord('G'); tt.put(b, b);
b = testWord('t'); tt.put(b, b);
if (countElements(tt) != tt.size()) {
System.out.println("ERROR! wrong size for probe tree " + s[i] + "; probe delete " + s[j] + "; final add");
tt.print();
}
tt.print();
*/
// close this
tt.close();
}
}
System.out.println("FINISHED");
} catch (Exception e) {
e.printStackTrace();
System.out.println("TERMINATED");
}
}
public static int countElements(kelondroTree t) {
int count = 0;
Iterator iter = t.nodeIterator(true, false);
while (iter.hasNext()) {count++; if (iter.next() == null) System.out.println("ERROR! null element found");}
return count;
}
}