Merge pull request #16130 from cbuescher/refactor-smoothingModel

Enable Writeable serialization and parsing from xContent for SmoothingModels

Author: cbuescher

core/src/main/java/org/elasticsearch/search/suggest/phrase/LaplaceScorer.java

@@ -27,22 +27,26 @@
 import java.io.IOException;
 //TODO public for tests
 public final class LaplaceScorer extends WordScorer {
-    
+
     public static final WordScorerFactory FACTORY = new WordScorer.WordScorerFactory() {
         @Override
         public WordScorer newScorer(IndexReader reader, Terms terms, String field, double realWordLikelyhood, BytesRef separator) throws IOException {
             return new LaplaceScorer(reader, terms, field, realWordLikelyhood, separator, 0.5);
         }
     };
-    
+
     private double alpha;
 
     public LaplaceScorer(IndexReader reader, Terms terms, String field,
             double realWordLikelyhood, BytesRef separator, double alpha) throws IOException {
         super(reader, terms, field, realWordLikelyhood, separator);
         this.alpha = alpha;
     }
-    
+
+    double alpha() {
+        return this.alpha;
+    }
+
     @Override
     protected double scoreBigram(Candidate word, Candidate w_1) throws IOException {
         SuggestUtils.join(separator, spare, w_1.term, word.term);

core/src/main/java/org/elasticsearch/search/suggest/phrase/LinearInterpoatingScorer.java

@@ -41,7 +41,19 @@ public LinearInterpoatingScorer(IndexReader reader, Terms terms, String field,
         this.bigramLambda = bigramLambda / sum;
         this.trigramLambda = trigramLambda / sum;
     }
-    
+
+    double trigramLambda() {
+        return this.trigramLambda;
+    }
+
+    double bigramLambda() {
+        return this.bigramLambda;
+    }
+
+    double unigramLambda() {
+        return this.unigramLambda;
+    }
+
     @Override
     protected double scoreBigram(Candidate word, Candidate w_1) throws IOException {
         SuggestUtils.join(separator, spare, w_1.term, word.term);

core/src/main/java/org/elasticsearch/search/suggest/phrase/PhraseSuggestParser.java

@@ -35,6 +35,8 @@
 import org.elasticsearch.search.suggest.SuggestContextParser;
 import org.elasticsearch.search.suggest.SuggestUtils;
 import org.elasticsearch.search.suggest.SuggestionSearchContext;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder.Laplace;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder.StupidBackoff;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestionContext.DirectCandidateGenerator;
 
 import java.io.IOException;
@@ -262,7 +264,7 @@ public WordScorer newScorer(IndexReader reader, Terms terms, String field, doubl
                     });
                 } else if ("laplace".equals(fieldName)) {
                     ensureNoSmoothing(suggestion);
-                    double theAlpha = 0.5;
+                    double theAlpha = Laplace.DEFAULT_LAPLACE_ALPHA;
 
                     while ((token = parser.nextToken()) != Token.END_OBJECT) {
                         if (token == XContentParser.Token.FIELD_NAME) {
@@ -283,7 +285,7 @@ public WordScorer newScorer(IndexReader reader, Terms terms, String field, doubl
 
                 } else if ("stupid_backoff".equals(fieldName) || "stupidBackoff".equals(fieldName)) {
                     ensureNoSmoothing(suggestion);
-                    double theDiscount = 0.4;
+                    double theDiscount = StupidBackoff.DEFAULT_BACKOFF_DISCOUNT;
                     while ((token = parser.nextToken()) != Token.END_OBJECT) {
                         if (token == XContentParser.Token.FIELD_NAME) {
                             fieldName = parser.currentName();