pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / contrib / facet / src / java / org / apache / lucene / facet / search / AdaptiveFacetsAccumulator.java

diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/search/AdaptiveFacetsAccumulator.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/search/AdaptiveFacetsAccumulator.java
new file mode 100644 (file)
index 0000000..3c41787
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/facet/search/AdaptiveFacetsAccumulator.java
@@ -0,0 +1,119 @@
+package org.apache.lucene.facet.search;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Random;
+
+import org.apache.lucene.index.IndexReader;
+
+import org.apache.lucene.facet.search.params.FacetSearchParams;
+import org.apache.lucene.facet.search.results.FacetResult;
+import org.apache.lucene.facet.search.results.FacetResultNode;
+import org.apache.lucene.facet.search.sampling.RandomSampler;
+import org.apache.lucene.facet.search.sampling.RepeatableSampler;
+import org.apache.lucene.facet.search.sampling.Sampler;
+import org.apache.lucene.facet.search.sampling.SamplingAccumulator;
+import org.apache.lucene.facet.taxonomy.TaxonomyReader;
+
+/**
+ * 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.
+ */
+
+/**
+ * {@link FacetsAccumulator} whose behavior regarding complements, sampling,
+ * etc. is not set up front but rather is determined at accumulation time
+ * according to the statistics of the accumulated set of documents and the
+ * index.
+ * <p>
+ * Note: Sampling accumulation (Accumulation over a sampled-set of the results),
+ * does not guarantee accurate values for
+ * {@link FacetResult#getNumValidDescendants()} &
+ * {@link FacetResultNode#getResidue()}.
+ * 
+ * @lucene.experimental
+ */
+public final class AdaptiveFacetsAccumulator extends StandardFacetsAccumulator {
+  
+  private Sampler sampler = new RandomSampler();
+
+  /**
+   * Create an {@link AdaptiveFacetsAccumulator} 
+   * @see StandardFacetsAccumulator#StandardFacetsAccumulator(FacetSearchParams, IndexReader, TaxonomyReader)
+   */
+  public AdaptiveFacetsAccumulator(FacetSearchParams searchParams, IndexReader indexReader,
+      TaxonomyReader taxonomyReader) {
+    super(searchParams, indexReader, taxonomyReader);
+  }
+
+  /**
+   * Create an {@link AdaptiveFacetsAccumulator} 
+   * @see StandardFacetsAccumulator#StandardFacetsAccumulator(FacetSearchParams, IndexReader, TaxonomyReader, 
+   *                               IntArrayAllocator, FloatArrayAllocator)
+   */
+  public AdaptiveFacetsAccumulator(FacetSearchParams searchParams, IndexReader indexReader,
+      TaxonomyReader taxonomyReader, IntArrayAllocator intArrayAllocator,
+      FloatArrayAllocator floatArrayAllocator) {
+    super(searchParams, indexReader, taxonomyReader, intArrayAllocator, floatArrayAllocator);
+  }
+
+  /**
+   * Set the sampler.
+   * @param sampler sampler to set
+   */
+  public void setSampler(Sampler sampler) {
+    this.sampler = sampler;
+  }
+  
+  @Override
+  public List<FacetResult> accumulate(ScoredDocIDs docids) throws IOException {
+    FacetsAccumulator delegee = appropriateFacetCountingAccumulator(docids);
+
+    if (delegee == this) {
+      return super.accumulate(docids);
+    }
+
+    return delegee.accumulate(docids);
+  }
+
+  /**
+   * Compute the appropriate facet accumulator to use.
+   * If no special/clever adaptation is possible/needed return this (self).
+   */
+  private FacetsAccumulator appropriateFacetCountingAccumulator(ScoredDocIDs docids) {
+    // Verify that searchPareams permit sampling/complement/etc... otherwise do default
+    if (!mayComplement()) {
+      return this;
+    }
+    
+    // Now we're sure we can use the sampling methods as we're in a counting only mode
+    
+    // Verify that sampling is enabled and required ... otherwise do default
+    if (sampler == null || !sampler.shouldSample(docids)) {
+      return this;
+    }
+    
+    SamplingAccumulator samplingAccumulator = new SamplingAccumulator(sampler, searchParams, indexReader, taxonomyReader);
+    samplingAccumulator.setComplementThreshold(getComplementThreshold());
+    return samplingAccumulator;
+  }
+
+  /**
+   * @return the sampler in effect
+   */
+  public final Sampler getSampler() {
+    return sampler;
+  }
+}
\ No newline at end of file