org.xBaseJ.indexes.Index Maven / Gradle / Ivy
/**
* eobjects.org MetaModel
* Copyright (C) 2010 eobjects.org
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.xBaseJ.indexes;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.Vector;
import org.xBaseJ.DBF;
import org.xBaseJ.DbaseUtils;
import org.xBaseJ.xBaseJException;
import org.xBaseJ.fields.Field;
/**
* This class is courtesy of the xBaseJ project: http://xbasej.sourceforge.net/
*
* Copyright 1997-2007 - American Coders, LTD - Raleigh NC USA
*
*
* American Coders, Ltd
* P. O. Box 97462
* Raleigh, NC 27615 USA
* 1-919-846-2014
* http://www.americancoders.com
*
*
* @author Joe McVerry, American Coders Ltd.
*/
public abstract class Index {
public int top_Node;
public int next_available;
public int reserved_02;
public short key_length;
public short key_per_Node;
public char keyType;
public short key_entry_size;
public byte reserved_01;
public byte reserved_03;
public byte reserved_04;
public byte unique_key;
public byte key_definition[];
public Vector keyControl;
public NodeKey activeKey;
public int record; // the current key's record
public Node topNode = null;
public Node workNode;
public File file;
public RandomAccessFile nfile;
public FileChannel channel;
public ByteBuffer bytebuffer;
public String dosname;
public DBF database;
public String stringKey;
public final static int findFirstMatchingKey = -1;
public final static int findAnyKey = -2;
public final static int keyNotFound = -3;
public final static int foundMatchingKeyButNotRecord = -4;
public boolean foundExact = false;
public Index() {
key_definition = new byte[488];
keyControl = new Vector();
dosname = new String("");
activeKey = null;
}
public boolean compareKey(String keyToCompare) throws xBaseJException,
IOException {
NodeKey tempKey;
if (keyType == 'F')
tempKey = new NodeKey(new NodeFloat(Double.valueOf(keyToCompare)
.doubleValue()));
else if (keyType == 'N') {
Double d = new Double(keyToCompare);
tempKey = new NodeKey(d);
} else
tempKey = new NodeKey(keyToCompare);
return (activeKey.compareKey(tempKey) == 0);
}
public abstract int add_entry(NodeKey key, int recno)
throws xBaseJException, IOException;
public int add_entry(int recno) throws xBaseJException, IOException {
NodeKey newkey = build_key();
return add_entry(newkey, recno);
}
public abstract int find_entry(NodeKey key) throws xBaseJException,
IOException;
public abstract int find_entry(NodeKey key, int recno)
throws xBaseJException, IOException;
public int find_entry(String key) throws xBaseJException, IOException {
if (keyType == 'F')
return find_entry(new NodeKey(new NodeFloat(Double.valueOf(key)
.doubleValue())));
if (keyType == 'N') { // 20091009_rth - begin
double d = 0.0;
Field f;
f = (Field) keyControl.elementAt(0);
if (f.get() == null)
;
else if (f.get().length() == 0)
;
else if (f.getType() == 'D')
d = DbaseUtils.doubleDate(key);
else
d = Double.valueOf(key).doubleValue();
// 20091009_rth - end
return find_entry(new NodeKey(new Double(d)));
}
return find_entry(new NodeKey(key));
}
public int find_entry(String key, int recno) throws xBaseJException,
IOException {
if (keyType == 'F')
record = find_entry(new NodeKey(new NodeFloat(Double.valueOf(key)
.doubleValue())), recno);
else if (keyType == 'N')
record = find_entry(new NodeKey(new Double(key)), recno);
else
record = find_entry(new NodeKey(key), recno);
return record;
}
public abstract int get_next_key() throws xBaseJException, IOException;
public abstract int get_prev_key() throws xBaseJException, IOException;
public abstract void del_entry(Node inNode) throws IOException,
xBaseJException;
public abstract void reIndex() throws xBaseJException, IOException;
public void check_for_duplicates(int count) throws xBaseJException,
IOException {
if (topNode == null) // no index records yet
return;
int ret = find_entry(build_key(), findFirstMatchingKey);
if (unique_key == 0)
return;
if (ret == keyNotFound)
return;
if (count == findFirstMatchingKey) // write request.
if (ret == count)
return;
if (count > 0) { // update request sends a specific record number if it
// matches it's okay.
if (ret == count) {
return;
}
}
if (ret > 0)
throw new xBaseJException("Duplicate key error");
}
public String getName() {
return dosname.trim();
}
public String getKeyFields() {
return stringKey;
}
public String buildKey() throws xBaseJException {
return build_key().toString();
}
public NodeKey build_key() throws xBaseJException {
NodeKey dataptr;
int i;
Field f;
double doubleer = 0.0;
switch (keyType) {
case 'F':
for (i = 0; i < keyControl.size(); i++) {
f = (Field) keyControl.elementAt(i);
if (f.get() == null)
;
else if (f.get().length() == 0)
;
else if (f.getType() == 'D')
doubleer += DbaseUtils.doubleDate(f.get());
else
doubleer += Double.valueOf(f.get()).doubleValue();
} /* endfor */
dataptr = new NodeKey(new NodeFloat(doubleer));
break;
case 'N':
for (i = 0; i < keyControl.size(); i++) {
f = (Field) keyControl.elementAt(i);
if (f.get() == null)
;
else if (f.get().length() == 0)
;
else if (f.getType() == 'D')
doubleer += DbaseUtils.doubleDate(f.get());
else
doubleer += Double.valueOf(f.get()).doubleValue();
} /* endfor */
dataptr = new NodeKey(new Double(doubleer));
break;
default:
StringBuffer sb = new StringBuffer();
for (i = 0; i < keyControl.size(); i++) {
f = (Field) keyControl.elementAt(i);
sb.append(f.get());
} /* endfor */
dataptr = new NodeKey(new String(sb));
break;
}
return dataptr;
}
public boolean is_unique_key() {
return (unique_key != 0);
}
public void set_active_key(NodeKey key) {
activeKey = key;
}
public NodeKey get_active_key() {
return activeKey;
}
public void set_key_definition(String definition) {
byte kd[];
try {
kd = definition.getBytes(DBF.encodedType);
} catch (UnsupportedEncodingException UEE) {
kd = definition.getBytes();
}
for (int x = 0; x < kd.length; x++)
key_definition[x] = kd[x];
}
public void update(int recno) throws xBaseJException, IOException {
NodeKey bkey = build_key();
record = find_entry(activeKey, recno);
if (record == recno) {
if (bkey.compareKey(activeKey) != 0) {
del_entry(workNode);
add_entry(recno);
}
} else
add_entry(recno);
}
public void position_at_first() throws xBaseJException, IOException {
String startKey;
if (keyType == 'N')
startKey = new NodeKey(new Double(-1.78e308)).toString();
else if (keyType == 'F')
startKey = new NodeKey(new NodeFloat(-1.78e308)).toString();
else
startKey = new NodeKey(new String("\u0000")).toString();
find_entry(startKey, -1);
workNode.set_pos(-1);
}
public void position_at_last() throws xBaseJException, IOException {
String startKey;
if (keyType == 'N')
startKey = new NodeKey(new Double(1.78e308)).toString();
else if (keyType == 'F')
startKey = new NodeKey(new NodeFloat(1.78e308)).toString();
else
startKey = new NodeKey(new String("\uFFFF")).toString();
find_entry(startKey, -1);
}
/**
* return to return if the find_entry function found the exact key requested
*
* @return boolean
*/
public boolean didFindFindExact() {
return foundExact;
}
}
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