Use set for renamed files in history

fixes #3529

Author: ahornace

opengrok-indexer/src/main/java/org/opengrok/indexer/history/History.java

@@ -24,7 +24,11 @@
 package org.opengrok.indexer.history;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Objects;
+import java.util.Set;
 
 /**
  * Class representing the history of a file.
@@ -37,19 +41,19 @@ public class History {
      * SCMs) during cache creation.
      * These are relative to repository root.
      */
-    private List<String> renamedFiles = new ArrayList<>();
+    private final Set<String> renamedFiles;
 
     public History() {
         this(new ArrayList<>());
     }
 
     History(List<HistoryEntry> entries) {
-        this.entries = entries;
+        this(entries, Collections.emptyList());
     }
 
     History(List<HistoryEntry> entries, List<String> renamed) {
         this.entries = entries;
-        this.renamedFiles = renamed;
+        this.renamedFiles = new HashSet<>(renamed);
     }
 
     /**
@@ -83,21 +87,18 @@ public List<HistoryEntry> getHistoryEntries(int limit, int offset) {
         offset = Math.max(offset, 0);
         limit = offset + limit > entries.size() ? entries.size() - offset : limit;
         return entries.subList(offset, offset + limit);
-    }    
-    
+    }
+
     /**
      * Check if at least one history entry has a file list.
      *
      * @return {@code true} if at least one of the entries has a non-empty
      * file list, {@code false} otherwise
      */
     public boolean hasFileList() {
-        for (HistoryEntry entry : entries) {
-            if (!entry.getFiles().isEmpty()) {
-                return true;
-            }
-        }
-        return false;
+        return entries.stream()
+                .map(HistoryEntry::getFiles)
+                .anyMatch(files -> !files.isEmpty());
     }
 
     /**
@@ -107,24 +108,19 @@ public boolean hasFileList() {
      * tag list, {@code false} otherwise
      */
     public boolean hasTags() {
-        // TODO Use a private variable instead of for loop?
-        for (HistoryEntry entry : entries) {
-            if (entry.getTags() != null) {
-                return true;
-            }
-        }
-        return false;
+        return entries.stream()
+                .map(HistoryEntry::getTags)
+                .anyMatch(Objects::nonNull);
     }
 
     /**
      * Gets a value indicating if {@code file} is in the list of renamed files.
-     * TODO: Warning -- this does a slow {@link List} search.
      */
     public boolean isRenamed(String file) {
         return renamedFiles.contains(file);
     }
 
-    public List<String> getRenamedFiles() {
+    public Set<String> getRenamedFiles() {
         return renamedFiles;
     }
 }

opengrok-indexer/src/test/java/org/opengrok/indexer/history/BitKeeperRepositoryTest.java

@@ -38,6 +38,7 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Scanner;
+import java.util.Set;
 import java.util.TreeSet;
 
 import org.junit.jupiter.api.AfterEach;
@@ -91,7 +92,7 @@ public void tearDown() {
 
     private static void validateHistory(History history) {
         final List<HistoryEntry> entries = history.getHistoryEntries();
-        final List<String> renames = history.getRenamedFiles();
+        final Set<String> renames = history.getRenamedFiles();
 
         assertTrue(entries.size() > 0, "File history has no entries.");