Better cache of weights by scorer

Author: glorieux-f

common/src/java/com/github/oeuvres/alix/lucene/terms/FieldStats.java

@@ -162,7 +162,8 @@ public final class FieldStats implements ReferenceStats
      * Written once and then read-only; declared volatile for safe publication.
      */
     private volatile double[] termWeights;
-
+    /** The scorer used to calculate termeights */
+    private volatile TermScorer termWeightsScorer;
     /** Number of distinct terms in the field. */
     private final int vocabSize;
 
@@ -266,7 +267,9 @@ public void buildWeights(final IndexReader reader, final TermScorer scorer) thro
             throw new IllegalStateException(
                 "Field '" + field + "' was not indexed with term frequencies");
         }
- 
+        // weights already calculated with same scorer
+        if (scorer.equals(termWeightsScorer)) return;
+        
         scorer.corpus(fieldTokens, fieldDocs);
 
         final double[] weights = new double[vocabSize];

common/src/java/com/github/oeuvres/alix/lucene/terms/TermScorer.java

@@ -149,6 +149,17 @@ public String toString()
     {
         return this.getClass().getSimpleName();
     }
+    
+    @Override
+    public boolean equals(final Object o) {
+        return o != null && o.getClass() == this.getClass();
+    }
+
+    @Override
+    public int hashCode() {
+        return getClass().hashCode();
+    }
+    
     /**
      * Signed G-test contribution against the corpus expectation.
      *
@@ -270,5 +281,17 @@ public String toString()
         {
             return "BM25 " + idfExp;
         }
+        
+        @Override
+        public boolean equals(final Object o) {
+            if (this == o) return true;
+            if (!(o instanceof BM25 other)) return false;
+            return Double.compare(this.idfExp, other.idfExp) == 0;
+        }
+
+        @Override
+        public int hashCode() {
+            return Double.hashCode(idfExp);
+        }
     }
 }

web/src/main/java/com/github/oeuvres/alix/web/Op.java

@@ -73,7 +73,7 @@ else switch (format) {
     protected void page(LuceneIndex index,
         HttpServletRequest req, HttpServletResponse resp) throws IOException
     {
-        AlixServlet.sendError(resp, 406, name() + ": page not implemented");
+        AlixServlet.sendError(resp, 406, name() + ": default html not implemented");
     }
 
     /** Structured JSON. */
@@ -87,7 +87,7 @@ protected void json(LuceneIndex index,
     protected void html(LuceneIndex index,
         HttpServletRequest req, HttpServletResponse resp) throws IOException
     {
-        AlixServlet.sendError(resp, 406, name() + ": html not implemented");
+        AlixServlet.sendError(resp, 406, name() + ": html fragment not implemented");
     }
 
     /** JSON Lines — one object per line. */

web/src/main/java/com/github/oeuvres/alix/web/OpTerms.java

@@ -56,6 +56,7 @@ public final class OpTerms extends Op
 
     /** Default BM25 IDF exponent. */
     private static final double DEFAULT_IDF_EXP = 1d;
+    
 
     @Override
     public String name() { return "terms"; }
@@ -73,8 +74,8 @@ protected void json(
         TopTerms topTerms;
         final int topK = pars.getInt("top", TOP_RANGE, DEFAULT_TOP);
         final String q = pars.getString("q", null);
+        final double idfExp = pars.getDouble("idfexp", DEFAULT_IDF_EXP);
 
-        final double idfExp;
         final long t0 = System.nanoTime();
 
         if (q != null) {
@@ -91,7 +92,6 @@ protected void json(
                     "terms: field '" + field + "' not found or not a text field");
                 return;
             }
-            idfExp = pars.getDouble("idfExp", DEFAULT_IDF_EXP);
             final TermScorer scorer = new TermScorer.BM25(idfExp);
             FieldStats fieldStats = fluc.fieldStats();
             fieldStats.buildWeights(lucene.reader(), scorer);
@@ -108,15 +108,15 @@ protected void json(
             jw.name("meta");
             jw.beginObject();
             jw.name("time").value(qTime);
-            jw.name("params");
+            jw.name("params"); // start params
             jw.beginObject();
             jw.name("field").value(field);
             jw.name("top").value(topK);
+            jw.name("idfexp").value(idfExp);
             if (q != null) {
                 jw.name("q").value(q);
             }
             else {
-                jw.name("idfExp").value(idfExp);
             }
             jw.endObject(); // params
             jw.endObject(); // meta