- HashMap over TreeMap when order des not matter.

- Avoid creating mutable maps when not necessary.
- Moderize iteration for readability.
- Unify on Set.of instead of Collections.emptySet.

6 files changed, 57 insertions, 84 deletions

diff --git a/container-search/src/main/java/com/yahoo/prelude/IndexFacts.java b/container-search/src/main/java/com/yahoo/prelude/IndexFacts.java
index 92ce6abb319..88a37ea5a02 100644
--- a/container-search/src/main/java/com/yahoo/prelude/IndexFacts.java
+++ b/container-search/src/main/java/com/yahoo/prelude/IndexFacts.java
@@ -6,11 +6,11 @@ import com.yahoo.search.Query;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.TreeSet;
 
 import static com.yahoo.text.Lowercase.toLowerCase;
 
@@ -32,16 +32,6 @@ public class IndexFacts {
 
     private Map<String, List<String>> clusterByDocument;
 
-    private static class DocumentTypeListOffset {
-        public final int offset;
-        public final SearchDefinition searchDefinition;
-
-        public DocumentTypeListOffset(int offset, SearchDefinition searchDefinition) {
-            this.offset = offset;
-            this.searchDefinition = searchDefinition;
-        }
-    }
-
     /** A Map of all known search definitions indexed by name */
     private Map<String, SearchDefinition> searchDefinitions = new LinkedHashMap<>();
 
@@ -110,34 +100,32 @@ public class IndexFacts {
     private boolean isIndexFromDocumentTypes(String indexName, List<String> documentTypes) {
         if ( ! isInitialized()) return true;
 
-        if (documentTypes.isEmpty()) {
-            return unionSearchDefinition.getIndex(indexName) != null;
-        }
+        if (documentTypes.isEmpty()) return unionSearchDefinition.getIndex(indexName) != null;
 
-        DocumentTypeListOffset sd = chooseSearchDefinition(documentTypes, 0);
-        while (sd != null) {
-            Index index = sd.searchDefinition.getIndex(indexName);
-            if (index != null) {
-                return true;
+        for (String docName : documentTypes) {
+            SearchDefinition sd = searchDefinitions.get(docName);
+            if (sd != null) {
+                Index index = sd.getIndex(indexName);
+                if (index != null) return true;
             }
-            sd = chooseSearchDefinition(documentTypes, sd.offset);
         }
-
         return false;
     }
 
     private String getCanonicNameFromDocumentTypes(String indexName, List<String> documentTypes) {
         if (!isInitialized()) return indexName;
+        String lowerCased = toLowerCase(indexName);
 
         if (documentTypes.isEmpty()) {
-            Index index = unionSearchDefinition.getIndexByLowerCase(toLowerCase(indexName));
+            Index index = unionSearchDefinition.getIndexByLowerCase(lowerCased);
             return index == null ? indexName : index.getName();
         }
-        DocumentTypeListOffset sd = chooseSearchDefinition(documentTypes, 0);
-        while (sd != null) {
-            Index index = sd.searchDefinition.getIndexByLowerCase(toLowerCase(indexName));
-            if (index != null) return index.getName();
-            sd = chooseSearchDefinition(documentTypes, sd.offset);
+        for (String docName : documentTypes) {
+            SearchDefinition sd = searchDefinitions.get(docName);
+            if (sd != null) {
+                Index index = sd.getIndexByLowerCase(lowerCased);
+                if (index != null) return index.getName();
+            }
         }
         return indexName;
     }
@@ -158,13 +146,12 @@ public class IndexFacts {
             return index;
         }
 
-        DocumentTypeListOffset sd = chooseSearchDefinition(documentTypes, 0);
-
-        while (sd != null) {
-            Index index = sd.searchDefinition.getIndex(canonicName);
-
-            if (index != null) return index;
-            sd = chooseSearchDefinition(documentTypes, sd.offset);
+        for (String docName : documentTypes) {
+            SearchDefinition sd = searchDefinitions.get(docName);
+            if (sd != null) {
+                Index index = sd.getIndex(canonicName);
+                if (index != null) return index;
+            }
         }
         return Index.nullIndex;
     }
@@ -187,7 +174,7 @@ public class IndexFacts {
      * Given a search list which is a mixture of document types and cluster
      * names, and a restrict list which is a list of document types, return a
      * set of all valid document types for this combination. Most use-cases for
-     * fetching index settings will involve calling this method with the the
+     * fetching index settings will involve calling this method with the
      * incoming query's {@link com.yahoo.search.query.Model#getSources()} and
      * {@link com.yahoo.search.query.Model#getRestrict()} as input parameters
      * before calling any other method of this class.
@@ -196,20 +183,20 @@ public class IndexFacts {
      * @param restrict the restrict list for a query
      * @return a (possibly empty) set of valid document types
      */
-    private Set<String> resolveDocumentTypes(Collection<String> sources, Collection<String> restrict,
+    private Set<String> resolveDocumentTypes(Collection<String> sources, Set<String> restrict,
                                              Set<String> candidateDocumentTypes) {
         sources = emptyCollectionIfNull(sources);
-        restrict = emptyCollectionIfNull(restrict);
+        restrict = emptySetIfNull(restrict);
 
         if (sources.isEmpty()) {
             if ( ! restrict.isEmpty()) {
-                return new TreeSet<>(restrict);
+                return Set.copyOf(restrict);
             } else {
                 return candidateDocumentTypes;
             }
         }
 
-        Set<String> toSearch = new TreeSet<>();
+        Set<String> toSearch = new HashSet<>();
         for (String source : sources) { // source: a document type or a cluster containing them
             List<String> clusterDocTypes = clusters.get(source);
             if (clusterDocTypes == null) { // source was a document type
@@ -235,21 +222,8 @@ public class IndexFacts {
     private Collection<String> emptyCollectionIfNull(Collection<String> collection) {
         return collection == null ? List.of() : collection;
     }
-
-    /**
-     * Chooses the correct search definition, default if in doubt.
-     *
-     * @return the search definition to use
-     */
-    private DocumentTypeListOffset chooseSearchDefinition(List<String> documentTypes, int index) {
-        while (index < documentTypes.size()) {
-            String docName = documentTypes.get(index++);
-            SearchDefinition sd = searchDefinitions.get(docName);
-            if (sd != null) {
-                return new DocumentTypeListOffset(index, sd);
-            }
-        }
-        return null;
+    private Set<String> emptySetIfNull(Set<String> collection) {
+        return collection == null ? Set.of() : collection;
     }
 
     /**
@@ -279,10 +253,6 @@ public class IndexFacts {
         return frozen;
     }
 
-    private void ensureNotFrozen() {
-        if (frozen) throw new IllegalStateException("Tried to modify frozen IndexFacts instance.");
-    }
-
     public String getDefaultPosition(String sdName) {
         SearchDefinition sd;
         if (sdName == null) {
@@ -300,12 +270,16 @@ public class IndexFacts {
         return new Session(query);
     }
 
-    public Session newSession(Collection<String> sources, Collection<String> restrict) {
+    public Session newSession() {
+        return new Session(Set.of(), Set.of());
+    }
+
+    public Session newSession(Collection<String> sources, Set<String> restrict) {
         return new Session(sources, restrict);
     }
 
     public Session newSession(Collection<String> sources,
-                              Collection<String> restrict,
+                              Set<String> restrict,
                               Set<String> candidateDocumentTypes) {
         return new Session(sources, restrict, candidateDocumentTypes);
     }
@@ -323,12 +297,12 @@ public class IndexFacts {
             documentTypes = List.copyOf(resolveDocumentTypes(query));
         }
 
-        private Session(Collection<String> sources, Collection<String> restrict) {
+        private Session(Collection<String> sources, Set<String> restrict) {
             // Assumption: Search definition name equals document name.
             documentTypes = List.copyOf(resolveDocumentTypes(sources, restrict, searchDefinitions.keySet()));
         }
 
-        private Session(Collection<String> sources, Collection<String> restrict, Set<String> candidateDocumentTypes) {
+        private Session(Collection<String> sources, Set<String> restrict, Set<String> candidateDocumentTypes) {
             documentTypes = List.copyOf(resolveDocumentTypes(sources, restrict, candidateDocumentTypes));
         }
 
diff --git a/container-search/src/main/java/com/yahoo/prelude/cluster/ClusterSearcher.java b/container-search/src/main/java/com/yahoo/prelude/cluster/ClusterSearcher.java
index 08d8d54bc53..709d5d5cda8 100644
--- a/container-search/src/main/java/com/yahoo/prelude/cluster/ClusterSearcher.java
+++ b/container-search/src/main/java/com/yahoo/prelude/cluster/ClusterSearcher.java
@@ -29,7 +29,6 @@ import com.yahoo.yolean.Exceptions;
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -306,7 +305,7 @@ public class ClusterSearcher extends Searcher {
             Set<String> sources = query.getModel().getSources();
             return (sources == null || sources.isEmpty())
                     ? schemas
-                    : new HashSet<>(indexFacts.newSession(sources, Collections.emptyList(), schemas).documentTypes());
+                    : new HashSet<>(indexFacts.newSession(sources, Set.of(), schemas).documentTypes());
         } else {
             return filterValidDocumentTypes(restrict);
         }
diff --git a/container-search/src/main/java/com/yahoo/prelude/query/parser/CustomParser.java b/container-search/src/main/java/com/yahoo/prelude/query/parser/CustomParser.java
index e3b2278475b..2bd408220cd 100644
--- a/container-search/src/main/java/com/yahoo/prelude/query/parser/CustomParser.java
+++ b/container-search/src/main/java/com/yahoo/prelude/query/parser/CustomParser.java
@@ -6,7 +6,6 @@ import com.yahoo.prelude.IndexFacts;
 import com.yahoo.prelude.query.Item;
 import com.yahoo.search.query.parser.Parser;
 
-import java.util.Collections;
 import java.util.Set;
 
 /**
@@ -23,7 +22,7 @@ public interface CustomParser extends Parser {
                        Set<String> toSearch, IndexFacts indexFacts, String defaultIndexName) {
         if (indexFacts == null)
             indexFacts = new IndexFacts();
-        return parse(queryToParse, filterToParse, parsingLanguage, indexFacts.newSession(toSearch, Collections.emptySet()), defaultIndexName);
+        return parse(queryToParse, filterToParse, parsingLanguage, indexFacts.newSession(toSearch, Set.of()), defaultIndexName);
     }
 
     Item parse(String queryToParse, String filterToParse, Language parsingLanguage,
diff --git a/container-search/src/main/java/com/yahoo/prelude/query/parser/Tokenizer.java b/container-search/src/main/java/com/yahoo/prelude/query/parser/Tokenizer.java
index c1d415b8e27..9952ec64d13 100644
--- a/container-search/src/main/java/com/yahoo/prelude/query/parser/Tokenizer.java
+++ b/container-search/src/main/java/com/yahoo/prelude/query/parser/Tokenizer.java
@@ -8,7 +8,6 @@ import com.yahoo.prelude.Index;
 import com.yahoo.prelude.IndexFacts;
 import com.yahoo.prelude.query.Substring;
 
-import java.util.Collections;
 import java.util.List;
 
 import static com.yahoo.prelude.query.parser.Token.Kind.*;
@@ -63,7 +62,7 @@ public final class Tokenizer {
      * @return a read-only list of tokens. This list can only be used by this thread
      */
     public List<Token> tokenize(String string) {
-        return tokenize(string, new IndexFacts().newSession(Collections.emptySet(), Collections.emptySet()));
+        return tokenize(string, new IndexFacts().newSession());
     }
 
     /**
@@ -171,13 +170,10 @@ public final class Tokenizer {
         // this is a heuristic to check whether we probably have reached the end of an URL element
         for (int i = tokens.size() - 1; i >= 0; --i) {
             switch (tokens.get(i).kind) {
-                case COLON:
-                    if (i == indexLastExplicitlyChangedAt) return false;
-                    break;
-                case SPACE:
-                    return true;
-                default:
-                    // do nothing
+                case COLON -> { if (i == indexLastExplicitlyChangedAt) return false; }
+                case SPACE -> { return true; }
+                default -> { }
+                // do nothing
             }
         }
         // really not sure whether we should choose false instead, on cause of the guard at
diff --git a/container-search/src/test/java/com/yahoo/prelude/query/parser/test/TokenizerTestCase.java b/container-search/src/test/java/com/yahoo/prelude/query/parser/test/TokenizerTestCase.java
index 1ff5574ec03..3a6be1521e2 100644
--- a/container-search/src/test/java/com/yahoo/prelude/query/parser/test/TokenizerTestCase.java
+++ b/container-search/src/test/java/com/yahoo/prelude/query/parser/test/TokenizerTestCase.java
@@ -13,7 +13,6 @@ import com.yahoo.prelude.query.parser.Tokenizer;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import static com.yahoo.prelude.query.parser.Token.Kind.COLON;
@@ -29,7 +28,9 @@ import static com.yahoo.prelude.query.parser.Token.Kind.SPACE;
 import static com.yahoo.prelude.query.parser.Token.Kind.STAR;
 import static com.yahoo.prelude.query.parser.Token.Kind.UNDERSCORE;
 import static com.yahoo.prelude.query.parser.Token.Kind.WORD;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * Tests the tokenizer
@@ -283,7 +284,7 @@ public class TokenizerTestCase {
         sd.addIndex(index2);
 
         IndexFacts facts = new IndexFacts(new IndexModel(sd));
-        IndexFacts.Session session = facts.newSession(Collections.emptySet(), Collections.emptySet());
+        IndexFacts.Session session = facts.newSession();
         Tokenizer tokenizer = new Tokenizer(new SimpleLinguistics());
         List<?> tokens = tokenizer.tokenize("normal a:b (normal testexact1:/,%#%&+-+ ) testexact2:ho_/&%&/()/aa*::*& b:c", "default", session);
         // tokenizer.print();
@@ -328,7 +329,7 @@ public class TokenizerTestCase {
 
         IndexFacts facts = new IndexFacts(new IndexModel(sd));
         Tokenizer tokenizer = new Tokenizer(new SimpleLinguistics());
-        IndexFacts.Session session = facts.newSession(Collections.emptySet(), Collections.emptySet());
+        IndexFacts.Session session = facts.newSession();
         List<?> tokens = tokenizer.tokenize("normal a:b (normal testexact1:/,%#%&+-+ ) testexact2:ho_/&%&/()/aa*::*&", session);
         assertEquals(new Token(WORD, "normal"), tokens.get(0));
         assertEquals(new Token(SPACE, " "), tokens.get(1));
@@ -365,7 +366,7 @@ public class TokenizerTestCase {
 
         IndexFacts facts = new IndexFacts(new IndexModel(sd));
         Tokenizer tokenizer = new Tokenizer(new SimpleLinguistics());
-        IndexFacts.Session session = facts.newSession(Collections.emptySet(), Collections.emptySet());
+        IndexFacts.Session session = facts.newSession();
         List<?> tokens = tokenizer.tokenize("normal a:b (normal testexact1:/,%#%&+-+ ) testexact2:ho_/&%&/()/aa*::*", session);
         assertEquals(new Token(WORD, "normal"), tokens.get(0));
         assertEquals(new Token(SPACE, " "), tokens.get(1));
@@ -402,7 +403,7 @@ public class TokenizerTestCase {
 
         IndexFacts facts = new IndexFacts(new IndexModel(sd));
         Tokenizer tokenizer = new Tokenizer(new SimpleLinguistics());
-        IndexFacts.Session session = facts.newSession(Collections.emptySet(), Collections.emptySet());
+        IndexFacts.Session session = facts.newSession();
         List<?> tokens = tokenizer.tokenize("normal a:b (normal testexact1:!/%#%&+-+ ) testexact2:ho_/&%&/()/aa*::*&b:", session);
         assertEquals(new Token(WORD, "normal"), tokens.get(0));
         assertEquals(new Token(SPACE, " "), tokens.get(1));
@@ -439,7 +440,7 @@ public class TokenizerTestCase {
         sd.addIndex(index2);
 
         IndexFacts indexFacts = new IndexFacts(new IndexModel(sd));
-        IndexFacts.Session facts = indexFacts.newSession(Collections.emptySet(), Collections.emptySet());
+        IndexFacts.Session facts = indexFacts.newSession();
 
         Tokenizer tokenizer = new Tokenizer(new SimpleLinguistics());
         List<?> tokens = tokenizer.tokenize("normal a:b (normal testexact1:foo) testexact2:bar", facts);
diff --git a/container-search/src/test/java/com/yahoo/prelude/test/IndexFactsTestCase.java b/container-search/src/test/java/com/yahoo/prelude/test/IndexFactsTestCase.java
index e6c5a18c9da..dbcb393c922 100644
--- a/container-search/src/test/java/com/yahoo/prelude/test/IndexFactsTestCase.java
+++ b/container-search/src/test/java/com/yahoo/prelude/test/IndexFactsTestCase.java
@@ -15,8 +15,12 @@ import org.junit.jupiter.api.Test;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * Tests using synthetic index names for IndexFacts class.
@@ -180,7 +184,7 @@ public class IndexFactsTestCase {
         query.getModel().getSources().add("one");
         query.getModel().getRestrict().add("two");
 
-        IndexFacts.Session indexFacts = createIndexFacts().newSession(List.of("clusterOne"), List.of());
+        IndexFacts.Session indexFacts = createIndexFacts().newSession(List.of("clusterOne"), Set.of());
         assertTrue(indexFacts.isIndex("a"));
         assertFalse(indexFacts.isIndex("b"));
         assertTrue(indexFacts.isIndex("d"));