Xowd_regy_mgr_.java

/*
XOWA: the XOWA Offline Wiki Application
Copyright (C) 2012-2017 gnosygnu@gmail.com

XOWA is licensed under the terms of the General Public License (GPL) Version 3,
or alternatively under the terms of the Apache License Version 2.0.

You may use XOWA according to either of these licenses as is most appropriate
for your project on a case-by-case basis.

The terms of each license can be found in the source code repository:

GPLv3 License: https://github.com/gnosygnu/xowa/blob/master/LICENSE-GPLv3.txt
Apache License: https://github.com/gnosygnu/xowa/blob/master/LICENSE-APACHE2.txt
*/
package gplx.xowa.wikis.tdbs.hives; import gplx.*; import gplx.xowa.*; import gplx.xowa.wikis.*; import gplx.xowa.wikis.tdbs.*;
import gplx.core.lists.*;
public class Xowd_regy_mgr_ {
	public static int FindSlot(ComparerAble comparer, Object[] ary, Object itm) {if (itm == null) throw Err_.new_null();
		int aryLen = ary.length;
		switch (aryLen) {
			case 0: throw Err_.new_wo_type("ary cannot have 0 itms");
			case 1: return 0;
		}
		int lo = -1, hi = aryLen - 1; // NOTE: -1 is necessary; see test
		int curPos = (hi - lo) / 2;
		int delta = 1;
		while (true) {
			Object curSeg = ary[curPos];
			int comp = curSeg == null ? CompareAble_.More : comparer.compare(itm, curSeg);	// nulls should only happen for lastAry 
//				if (dbg) {
//					Tfds.Write(curPos, itm.toString(), comp, comp.toString(), curSeg.toString());
//				}
			if		(comp == CompareAble_.Same) return curPos;
			else if	(comp >  CompareAble_.Same) {lo = curPos; delta = 1;}
			else if	(comp <  CompareAble_.Same) {hi = curPos; delta = -1;}
			int dif = hi - lo;
			if (dif == 1 || dif == 0)	return hi;	// NOTE: can be 0 when ary.length == 1 || 2; also, sometimes 0 in some situations
			else						curPos += (dif / 2) * delta;
		}
	}
}