pylucene 3.5.0-3

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

diff --git a/lucene-java-3.5.0/lucene/contrib/spatial/src/java/org/apache/lucene/spatial/tier/DistanceFilter.java b/lucene-java-3.5.0/lucene/contrib/spatial/src/java/org/apache/lucene/spatial/tier/DistanceFilter.java
new file mode 100644 (file)
index 0000000..497c45e
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/spatial/src/java/org/apache/lucene/spatial/tier/DistanceFilter.java
@@ -0,0 +1,111 @@
+/** 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.util.Map;
+import java.util.WeakHashMap;
+import java.util.HashMap;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+
+import org.apache.lucene.search.Filter;
+import org.apache.lucene.spatial.tier.DistanceHandler.Precision;
+
+/**
+ * <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 abstract class DistanceFilter extends Filter {
+
+  final protected Filter startingFilter;
+  protected Precision precise;
+  protected Map<Integer,Double> distances;
+  protected double distance;
+
+  protected int nextDocBase; 
+  protected transient WeakHashMap<String,Double> distanceLookupCache;
+
+  /** Filters the startingFilter by precise distance
+   *  checking filter */
+  public DistanceFilter(Filter startingFilter, double distance) {
+    if (startingFilter == null) {
+      throw new IllegalArgumentException("please provide a non-null startingFilter; you can use QueryWrapperFilter(MatchAllDocsQuery) as a no-op filter");
+    }
+    this.startingFilter = startingFilter;
+    this.distance = distance;
+
+    // NOTE: neither of the distance filters use precision
+    // now - if we turn that on, we'll need to pass top
+    // reader into here
+    // setPrecision(reader.maxDoc());
+
+    /* store calculated distances for reuse by other components */
+    distances = new HashMap<Integer,Double>();
+
+    // create an intermediate cache to avoid recomputing
+    //   distances for the same point 
+    //   TODO: Why is this a WeakHashMap? 
+    distanceLookupCache = new WeakHashMap<String,Double>();
+  }
+
+  /** needed for deserialization, because the cache is transient */
+  private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
+    stream.defaultReadObject();
+    distanceLookupCache = new WeakHashMap<String,Double>();
+  }
+
+  public Map<Integer,Double> getDistances(){
+    return distances;
+  }
+  
+  public Double getDistance(int docid){
+    return distances.get(docid);
+  }
+  
+  public void setDistances(Map<Integer, Double> distances) {
+    this.distances = distances;
+  }
+
+  /** You must call this before re-using this DistanceFilter
+   *  across searches */
+  public void reset() {
+    nextDocBase = 0;
+  }
+
+  /** Returns true if <code>o</code> is equal to this. */
+  @Override
+  public abstract boolean equals(Object o);
+
+  /** Returns a hash code value for this object.*/
+  @Override
+  public abstract int hashCode();
+
+  /*
+  private void setPrecision(int maxDocs) {
+    precise = Precision.EXACT;
+    
+    if (maxDocs > 1000 && distance > 10) {
+      precise = Precision.TWENTYFEET;
+    }
+    
+    if (maxDocs > 10000 && distance > 10){
+      precise = Precision.TWOHUNDREDFEET;
+    }
+  }
+  */
+}