From dd7782bac0afad92eba5690a37e670cdb000a0b3 Mon Sep 17 00:00:00 2001
From: reger <reger18@arcor.de>
Date: Tue, 26 May 2015 04:26:26 +0200
Subject: [PATCH] revert deletion of BinSearch (accident)

---
 source/net/yacy/kelondro/index/BinSearch.java | 117 ++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 source/net/yacy/kelondro/index/BinSearch.java

diff --git a/source/net/yacy/kelondro/index/BinSearch.java b/source/net/yacy/kelondro/index/BinSearch.java
new file mode 100644
index 000000000..61426c4de
--- /dev/null
+++ b/source/net/yacy/kelondro/index/BinSearch.java
@@ -0,0 +1,117 @@
+// BinSearch.java
+// -----------------------
+// part of The Kelondro Database
+// (C) by Michael Peter Christen; mc@yacy.net
+// first published on http://www.anomic.de
+// Frankfurt, Germany, 2005
+// created 22.11.2005
+//
+// $LastChangedDate$
+// $LastChangedRevision$
+// $LastChangedBy$
+//
+// 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 net.yacy.kelondro.index;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+import net.yacy.cora.order.ByteOrder;
+import net.yacy.cora.order.NaturalOrder;
+
+
+public final class BinSearch {
+    
+    private final byte[] chunks;
+    private final int    chunksize;
+    private final int    count;
+    private static final ByteOrder objectOrder = new NaturalOrder(true); // the natural order is much faster than the b64Order
+    
+    public BinSearch(final byte[] chunks, final int chunksize) {
+        this.chunks = chunks;
+        this.chunksize = chunksize;
+        this.count = chunks.length / chunksize;
+    }
+    
+    public BinSearch(final List<byte[]> chunkList, final int chunksize) {
+        byte[][] chunksa = new byte[chunkList.size()][];
+        chunksa = chunkList.toArray(chunksa);
+        Arrays.sort(chunksa, objectOrder);
+        this.chunks = new byte[chunkList.size() * chunksize];
+        for (int i = 0; i < chunksa.length; i++) System.arraycopy(chunksa[i], 0, this.chunks, i * chunksize, chunksize);
+        this.chunksize = chunksize;
+        this.count = chunks.length / chunksize;
+        assert this.count == chunkList.size();
+    }
+    
+    public final boolean contains(final byte[] t) {
+        return contains(t, 0, this.count);
+    }
+
+    private final boolean contains(final byte[] t, int beginPos, int endPos) {
+        // the endPos is exclusive, beginPos is inclusive
+        // this method is synchronized to make the use of the buffer possible
+        assert t.length == this.chunksize;
+        while (true) {
+            if (beginPos >= endPos) return false;
+            final int pivot = (beginPos + endPos) / 2;
+            if ((pivot < 0) || (pivot >= this.count)) return false;
+            assert this.chunksize == t.length;
+            final int c = objectOrder.compare(this.chunks, pivot * this.chunksize, t, 0, this.chunksize);
+            if (c == 0) return true;
+            if (c < 0) /* buffer < t */ {beginPos = pivot + 1; continue;}
+            if (c > 0) /* buffer > t */ {endPos = pivot; continue;}
+            return false;
+        }
+    }
+    
+    public final int size() {
+        return count;
+    }
+    
+    public final byte[] get(final int element) {
+        final byte[] a = new byte[chunksize];
+        System.arraycopy(this.chunks, element * this.chunksize, a, 0, chunksize);
+        return a;
+    }
+    
+    public final byte[] get(final int element, byte[] a) {
+        assert a.length == chunksize;
+        System.arraycopy(this.chunks, element * this.chunksize, a, 0, chunksize);
+        return a;
+    }
+    
+    public final void write(File f) throws IOException {
+        FileOutputStream os = new FileOutputStream(f);
+        os.write(this.chunks);
+        os.flush();
+        os.close();
+    }
+    
+    public static void main(final String[] args) {
+        final String s = "4CEvsI8FRczRBo_ApRCkwfEbFLn1pIFXg39QGMgj5RHM6HpIMJq67QX3M5iQYr_LyI_5aGDaa_bYbRgJ9XnQjpmq6QkOoGWAoEaihRqhV3kItLFHjRtqauUR";
+        final BinSearch bs = new BinSearch(s.getBytes(), 6);
+        for (int i = 0; i + 6 <= s.length(); i = i + 6) {
+            System.out.println(s.substring(i, i + 6) + ":" + ((bs.contains(s.substring(i, i + 6).getBytes())) ? "drin" : "draussen"));
+        }
+        for (int i = 0; i + 7 <= s.length(); i = i + 6) {
+            System.out.println(s.substring(i + 1, i + 7) + ":" + ((bs.contains(s.substring(i + 1, i + 7).getBytes())) ? "drin" : "draussen"));
+        }
+    }
+}