pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / spatial / src / java / org / apache / lucene / spatial / tier / LatLongDistanceFilter.java

diff --git a/lucene-java-3.5.0/lucene/contrib/spatial/src/java/org/apache/lucene/spatial/tier/LatLongDistanceFilter.java b/lucene-java-3.5.0/lucene/contrib/spatial/src/java/org/apache/lucene/spatial/tier/LatLongDistanceFilter.java
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+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF 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.apache.lucene.spatial.tier;
+
+import java.io.IOException;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.FilteredDocIdSet;
+import org.apache.lucene.search.FieldCache;
+import org.apache.lucene.search.Filter;
+import org.apache.lucene.search.DocIdSet;
+import org.apache.lucene.spatial.DistanceUtils;
+
+
+/**
+ * <p><font color="red"><b>NOTE:</b> This API is still in
+ * flux and might change in incompatible ways in the next
+ * release.</font>
+ */
+public class LatLongDistanceFilter extends DistanceFilter {
+
+  /**
+   * 
+   */
+  private static final long serialVersionUID = 1L;
+  
+  double lat;
+  double lng;
+  String latField;
+  String lngField;
+
+  int nextOffset = 0;
+  
+  /**
+   * Provide a distance filter based from a center point with a radius
+   * in miles.
+   * @param startingFilter Filter to start from
+   * @param lat
+   * @param lng
+   * @param miles
+   * @param latField
+   * @param lngField
+   */
+  public LatLongDistanceFilter(Filter startingFilter, double lat, double lng, double miles, String latField, String lngField) {
+    super(startingFilter, miles);
+    this.lat = lat;
+    this.lng = lng;
+    this.latField = latField;
+    this.lngField = lngField;
+  }
+  
+  @Override
+  public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
+
+    final double[] latIndex = FieldCache.DEFAULT.getDoubles(reader, latField);
+    final double[] lngIndex = FieldCache.DEFAULT.getDoubles(reader, lngField);
+
+    final int docBase = nextDocBase;
+    nextDocBase += reader.maxDoc();
+
+    return new FilteredDocIdSet(startingFilter.getDocIdSet(reader)) {
+      @Override
+      protected boolean match(int doc) {
+        double x = latIndex[doc];
+        double y = lngIndex[doc];
+      
+        // round off lat / longs if necessary
+        //      x = DistanceHandler.getPrecision(x, precise);
+        //      y = DistanceHandler.getPrecision(y, precise);
+      
+        String ck = Double.toString(x)+","+Double.toString(y);
+        Double cachedDistance = distanceLookupCache.get(ck);
+
+        double d;
+        if (cachedDistance != null){
+          d = cachedDistance.doubleValue();
+        } else {
+          d = DistanceUtils.getDistanceMi(lat, lng, x, y);
+          distanceLookupCache.put(ck, d);
+        }
+
+        if (d < distance) {
+          // Save distances, so they can be pulled for
+          // sorting after filtering is done:
+          distances.put(doc+docBase, d);
+          return true;
+        } else {
+          return false;
+        }
+      }
+    };
+  }
+
+  /** Returns true if <code>o</code> is equal to this. */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) return true;
+    if (!(o instanceof LatLongDistanceFilter)) return false;
+    LatLongDistanceFilter other = (LatLongDistanceFilter) o;
+
+    if (!this.startingFilter.equals(other.startingFilter) ||
+        this.distance != other.distance ||
+        this.lat != other.lat ||
+        this.lng != other.lng ||
+        !this.latField.equals(other.latField) ||
+        !this.lngField.equals(other.lngField)) {
+      return false;
+    }
+    return true;
+  }
+
+  /** Returns a hash code value for this object.*/
+  @Override
+  public int hashCode() {
+    int h = Double.valueOf(distance).hashCode();
+    h ^= startingFilter.hashCode();
+    h ^= Double.valueOf(lat).hashCode();
+    h ^= Double.valueOf(lng).hashCode();
+    h ^= latField.hashCode();
+    h ^= lngField.hashCode();
+    return h;
+  }
+}