Refactor GeoHashUtils

libs/geo/src/main/java/org/elasticsearch/geo/geometry/Rectangle.java

@@ -163,6 +163,14 @@ public boolean crossesDateline() {
         return maxLon < minLon;
     }
 
+    /** returns true if rectangle (defined by minLat, maxLat, minLon, maxLon) contains the lat lon point */
+    public boolean containsPoint(final double lat, final double lon) {
+        if (lat >= minLat && lat <= maxLat) {
+            return crossesDateline() ? lon >= minLon || lon <= maxLon : lon >= minLon && lon <= maxLon;
+        }
+        return false;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

libs/geo/src/main/java/org/elasticsearch/geo/utils/BitUtil.java

@@ -0,0 +1,75 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.elasticsearch.geo.utils;
+
+/**
+ * Utilities for common Bit twiddling methods. Borrowed heavily from Lucene (org.apache.lucene.util.BitUtil).
+ */
+public class BitUtil {  // magic numbers for bit interleaving
+    private static final long MAGIC[] = {
+        0x5555555555555555L, 0x3333333333333333L,
+        0x0F0F0F0F0F0F0F0FL, 0x00FF00FF00FF00FFL,
+        0x0000FFFF0000FFFFL, 0x00000000FFFFFFFFL,
+        0xAAAAAAAAAAAAAAAAL
+    };
+    // shift values for bit interleaving
+    private static final short SHIFT[] = {1, 2, 4, 8, 16};
+
+    /**
+     * Interleaves the first 32 bits of each long value
+     *
+     * Adapted from: http://graphics.stanford.edu/~seander/bithacks.html#InterleaveBMN
+     */
+    public static long interleave(int even, int odd) {
+        long v1 = 0x00000000FFFFFFFFL & even;
+        long v2 = 0x00000000FFFFFFFFL & odd;
+        v1 = (v1 | (v1 << SHIFT[4])) & MAGIC[4];
+        v1 = (v1 | (v1 << SHIFT[3])) & MAGIC[3];
+        v1 = (v1 | (v1 << SHIFT[2])) & MAGIC[2];
+        v1 = (v1 | (v1 << SHIFT[1])) & MAGIC[1];
+        v1 = (v1 | (v1 << SHIFT[0])) & MAGIC[0];
+        v2 = (v2 | (v2 << SHIFT[4])) & MAGIC[4];
+        v2 = (v2 | (v2 << SHIFT[3])) & MAGIC[3];
+        v2 = (v2 | (v2 << SHIFT[2])) & MAGIC[2];
+        v2 = (v2 | (v2 << SHIFT[1])) & MAGIC[1];
+        v2 = (v2 | (v2 << SHIFT[0])) & MAGIC[0];
+
+        return (v2<<1) | v1;
+    }
+
+    /**
+     * Extract just the even-bits value as a long from the bit-interleaved value
+     */
+    public static long deinterleave(long b) {
+        b &= MAGIC[0];
+        b = (b ^ (b >>> SHIFT[0])) & MAGIC[1];
+        b = (b ^ (b >>> SHIFT[1])) & MAGIC[2];
+        b = (b ^ (b >>> SHIFT[2])) & MAGIC[3];
+        b = (b ^ (b >>> SHIFT[3])) & MAGIC[4];
+        b = (b ^ (b >>> SHIFT[4])) & MAGIC[5];
+        return b;
+    }
+
+    /**
+     * flip flops odd with even bits
+     */
+    public static final long flipFlop(final long b) {
+        return ((b & MAGIC[6]) >>> 1) | ((b & MAGIC[0]) << 1 );
+    }
+}