1 files changed, 44 insertions, 10 deletions

diff --git a/core/src/main/java/org/elasticsearch/common/geo/GeoHashUtils.java b/core/src/main/java/org/elasticsearch/common/geo/GeoHashUtils.java
index 0f1ddcd376..cb31940a49 100644
--- a/core/src/main/java/org/elasticsearch/common/geo/GeoHashUtils.java
+++ b/core/src/main/java/org/elasticsearch/common/geo/GeoHashUtils.java
@@ -18,13 +18,13 @@
  */
 package org.elasticsearch.common.geo;
 
-import java.util.ArrayList;
-import java.util.Collection;
-
-import org.apache.lucene.spatial.geopoint.document.GeoPointField;
 import org.apache.lucene.geo.Rectangle;
+import org.apache.lucene.spatial.util.MortonEncoder;
 import org.apache.lucene.util.BitUtil;
 
+import java.util.ArrayList;
+import java.util.Collection;
+
 /**
  * Utilities for converting to/from the GeoHash standard
  *
@@ -42,19 +42,35 @@ public class GeoHashUtils {
 
     /** maximum precision for geohash strings */
     public static final int PRECISION = 12;
-    private static final short MORTON_OFFSET = (GeoPointField.BITS<<1) - (PRECISION*5);
+    /** number of bits used for quantizing latitude and longitude values */
+    public static final short BITS = 31;
+    /** scaling factors to convert lat/lon into unsigned space */
+    private static final double LAT_SCALE = (0x1L<<BITS)/180.0D;
+    private static final double LON_SCALE = (0x1L<<BITS)/360.0D;
+    private static final short MORTON_OFFSET = (BITS<<1) - (PRECISION*5);
 
     // No instance:
     private GeoHashUtils() {
     }
 
+    /*************************
+     * 31 bit encoding utils *
+     *************************/
+    public static long encodeLatLon(final double lat, final double lon) {
+      long result = MortonEncoder.encode(lat, lon);
+      if (result == 0xFFFFFFFFFFFFFFFFL) {
+        return result & 0xC000000000000000L;
+      }
+      return result >>> 2;
+    }
+
     /**
      * Encode lon/lat to the geohash based long format (lon/lat interleaved, 4 least significant bits = level)
      */
     public static final long longEncode(final double lon, final double lat, final int level) {
         // shift to appropriate level
         final short msf = (short)(((12 - level) * 5) + MORTON_OFFSET);
-        return ((BitUtil.flipFlop(GeoPointField.encodeLatLon(lat, lon)) >>> msf) << 4) | level;
+        return ((BitUtil.flipFlop(encodeLatLon(lat, lon)) >>> msf) << 4) | level;
     }
 
     /**
@@ -120,7 +136,7 @@ public class GeoHashUtils {
      */
     public static final String stringEncode(final double lon, final double lat, final int level) {
         // convert to geohashlong
-        final long ghLong = fromMorton(GeoPointField.encodeLatLon(lat, lon), level);
+        final long ghLong = fromMorton(encodeLatLon(lat, lon), level);
         return stringEncode(ghLong);
 
     }
@@ -141,7 +157,7 @@ public class GeoHashUtils {
 
         StringBuilder geoHash = new StringBuilder();
         short precision = 0;
-        final short msf = (GeoPointField.BITS<<1)-5;
+        final short msf = (BITS<<1)-5;
         long mask = 31L<<msf;
         do {
             geoHash.append(BASE_32[(int)((mask & hashedVal)>>>(msf-(precision*5)))]);
@@ -303,13 +319,31 @@ public class GeoHashUtils {
         return neighbors;
     }
 
+    /** decode longitude value from morton encoded geo point */
+    public static final double decodeLongitude(final long hash) {
+      return unscaleLon(BitUtil.deinterleave(hash));
+    }
+
+    /** decode latitude value from morton encoded geo point */
+    public static final double decodeLatitude(final long hash) {
+      return unscaleLat(BitUtil.deinterleave(hash >>> 1));
+    }
+
+    private static double unscaleLon(final long val) {
+      return (val / LON_SCALE) - 180;
+    }
+
+    private static double unscaleLat(final long val) {
+      return (val / LAT_SCALE) - 90;
+    }
+
     /** returns the latitude value from the string based geohash */
     public static final double decodeLatitude(final String geohash) {
-        return GeoPointField.decodeLatitude(mortonEncode(geohash));
+        return decodeLatitude(mortonEncode(geohash));
     }
 
     /** returns the latitude value from the string based geohash */
     public static final double decodeLongitude(final String geohash) {
-        return GeoPointField.decodeLongitude(mortonEncode(geohash));
+        return decodeLongitude(mortonEncode(geohash));
     }
 }