Fix compile test and add java doc

Signed-off-by: Louis Chu <[email protected]>

plugins/examples/script-expert-scoring/src/main/java/org/opensearch/example/expertscript/ExpertScriptPlugin.java

@@ -35,6 +35,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.PostingsEnum;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.search.IndexSearcher;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.plugins.ScriptPlugin;
@@ -120,20 +121,23 @@ public boolean isResultDeterministic() {
             @Override
             public LeafFactory newFactory(
                 Map<String, Object> params,
-                SearchLookup lookup
+                SearchLookup lookup,
+                IndexSearcher indexSearcher
             ) {
-                return new PureDfLeafFactory(params, lookup);
+                return new PureDfLeafFactory(params, lookup, indexSearcher);
             }
         }
 
         private static class PureDfLeafFactory implements LeafFactory {
             private final Map<String, Object> params;
             private final SearchLookup lookup;
+
+            private final IndexSearcher indexSearcher;
             private final String field;
             private final String term;
 
             private PureDfLeafFactory(
-                        Map<String, Object> params, SearchLookup lookup) {
+                        Map<String, Object> params, SearchLookup lookup, IndexSearcher indexSearcher) {
                 if (params.containsKey("field") == false) {
                     throw new IllegalArgumentException(
                             "Missing parameter [field]");
@@ -144,6 +148,7 @@ private PureDfLeafFactory(
                 }
                 this.params = params;
                 this.lookup = lookup;
+                this.indexSearcher = indexSearcher;
                 field = params.get("field").toString();
                 term = params.get("term").toString();
             }
@@ -163,7 +168,7 @@ public ScoreScript newInstance(LeafReaderContext context)
                      * the field and/or term don't exist in this segment,
                      * so always return 0
                      */
-                    return new ScoreScript(params, lookup, context) {
+                    return new ScoreScript(params, lookup, indexSearcher, context) {
                         @Override
                         public double execute(
                             ExplanationHolder explanation
@@ -172,7 +177,7 @@ public double execute(
                         }
                     };
                 }
-                return new ScoreScript(params, lookup, context) {
+                return new ScoreScript(params, lookup, indexSearcher, context) {
                     int currentDocid = -1;
                     @Override
                     public void setDocument(int docid) {

server/src/main/java/org/opensearch/index/query/functionscore/TermFrequencyFunction.java

@@ -19,6 +19,9 @@
 import java.io.IOException;
 import java.util.Map;
 
+/**
+ * Abstract class representing a term frequency function.
+ */
 public abstract class TermFrequencyFunction {
 
     protected final String field;
@@ -35,6 +38,9 @@ public TermFrequencyFunction(String field, String term, int docId, Map<Object, O
 
     public abstract Object execute(LeafReaderContext readerContext) throws IOException;
 
+    /**
+     * Factory class to create term frequency functions.
+     */
     public static class TermFrequencyFunctionFactory {
         public static TermFrequencyFunction createFunction(
             TermFrequencyFunctionNamesEnum functionName,
@@ -58,6 +64,9 @@ public static TermFrequencyFunction createFunction(
         }
     }
 
+    /**
+     * TermFreqFunction computes the term frequency in a field.
+     */
     public static class TermFreqFunction extends TermFrequencyFunction {
 
         public TermFreqFunction(String field, String term, int docId, Map<Object, Object> context) {
@@ -71,6 +80,9 @@ public Integer execute(LeafReaderContext readerContext) throws IOException {
         }
     }
 
+    /**
+     * TFFunction computes the term frequency-inverse document frequency (tf-idf) in a field.
+     */
     public static class TFFunction extends TermFrequencyFunction {
 
         public TFFunction(String field, String term, int docId, Map<Object, Object> context) {
@@ -84,6 +96,9 @@ public Float execute(LeafReaderContext readerContext) throws IOException {
         }
     }
 
+    /**
+     * TotalTermFreq computes the total term frequency in a field.
+     */
     public static class TotalTermFreq extends TermFrequencyFunction {
 
         public TotalTermFreq(String field, String term, int docId, Map<Object, Object> context) {
@@ -98,6 +113,9 @@ public Long execute(LeafReaderContext readerContext) throws IOException {
         }
     }
 
+    /**
+     * SumTotalTermFreq computes the sum of total term frequencies within a field.
+     */
     public static class SumTotalTermFreq extends TermFrequencyFunction {
 
         public SumTotalTermFreq(String field, String term, int docId, Map<Object, Object> context) {
@@ -112,6 +130,9 @@ public Long execute(LeafReaderContext readerContext) throws IOException {
         }
     }
 
+    /**
+     * Enum representing the names of term frequency functions.
+     */
     public enum TermFrequencyFunctionNamesEnum {
         TERM_FREQ("termFreq"),
         TF("tf"),

server/src/main/java/org/opensearch/script/ScoreScript.java

@@ -153,6 +153,7 @@ public Map<String, ScriptDocValues<?>> getDoc() {
     }
 
     public Object getTermFrequency(TermFrequencyFunctionNamesEnum functionName, String field, String val) throws IOException {
+        // Fetch data from local cache
         Map<Object, Object> context = new HashMap<>() {
             {
                 put("searcher", indexSearcher);

server/src/main/java/org/opensearch/script/ScoreScriptUtils.java

@@ -73,6 +73,11 @@ public static double sigmoid(double value, double k, double a) {
         return Math.pow(value, a) / (Math.pow(k, a) + Math.pow(value, a));
     }
 
+    /**
+     * Retrieves the term frequency within a field for a specific term.
+     *
+     * @opensearch.internal
+     */
     public static final class TermFreq {
         private final ScoreScript scoreScript;
 
@@ -89,6 +94,11 @@ public int termFreq(String field, String term) {
         }
     }
 
+    /**
+     * Calculates the term frequency-inverse document frequency (tf-idf) for a specific term within a field.
+     *
+     * @opensearch.internal
+     */
     public static final class TF {
         private final ScoreScript scoreScript;
 
@@ -105,6 +115,11 @@ public float tf(String field, String term) {
         }
     }
 
+    /**
+     * Retrieves the total term frequency within a field for a specific term.
+     *
+     * @opensearch.internal
+     */
     public static final class TotalTermFreq {
         private final ScoreScript scoreScript;
 
@@ -121,6 +136,11 @@ public long totalTermFreq(String field, String term) {
         }
     }
 
+    /**
+     * Retrieves the sum of total term frequencies within a field.
+     *
+     * @opensearch.internal
+     */
     public static final class SumTotalTermFreq {
         private final ScoreScript scoreScript;
 

server/src/test/java/org/opensearch/search/query/ScriptScoreQueryTests.java

@@ -184,6 +184,7 @@ private ScoreScript.LeafFactory newFactory(
     ) {
         SearchLookup lookup = mock(SearchLookup.class);
         LeafSearchLookup leafLookup = mock(LeafSearchLookup.class);
+        IndexSearcher indexSearcher = mock(IndexSearcher.class);
         when(lookup.getLeafSearchLookup(any())).thenReturn(leafLookup);
         return new ScoreScript.LeafFactory() {
             @Override
@@ -193,7 +194,7 @@ public boolean needs_score() {
 
             @Override
             public ScoreScript newInstance(LeafReaderContext ctx) throws IOException {
-                return new ScoreScript(script.getParams(), lookup, leafReaderContext) {
+                return new ScoreScript(script.getParams(), lookup, indexSearcher, leafReaderContext) {
                     @Override
                     public double execute(ExplanationHolder explanation) {
                         return function.apply(explanation);

test/framework/src/main/java/org/opensearch/script/MockScriptEngine.java

@@ -33,6 +33,7 @@
 package org.opensearch.script;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Scorable;
 import org.opensearch.index.query.IntervalFilterScript;
 import org.opensearch.index.similarity.ScriptedSimilarity.Doc;
@@ -624,7 +625,7 @@ public MockScoreScript(MockDeterministicScript script) {
         }
 
         @Override
-        public ScoreScript.LeafFactory newFactory(Map<String, Object> params, SearchLookup lookup) {
+        public ScoreScript.LeafFactory newFactory(Map<String, Object> params, SearchLookup lookup, IndexSearcher indexSearcher) {
             return new ScoreScript.LeafFactory() {
                 @Override
                 public boolean needs_score() {
@@ -634,7 +635,7 @@ public boolean needs_score() {
                 @Override
                 public ScoreScript newInstance(LeafReaderContext ctx) throws IOException {
                     Scorable[] scorerHolder = new Scorable[1];
-                    return new ScoreScript(params, lookup, ctx) {
+                    return new ScoreScript(params, lookup, indexSearcher, ctx) {
                         @Override
                         public double execute(ExplanationHolder explanation) {
                             Map<String, Object> vars = new HashMap<>(getParams());