OAK-11413 : extracted out Deque methods from CollectionUtils (#2007)

* OAK-11413 : extracted out Deque methods from CollectionUtils

* OAK-11413 : added missing license header

---------

Co-authored-by: Rishabh Kumar <[email protected]>

oak-commons/src/main/java/org/apache/jackrabbit/oak/commons/collections/CollectionUtils.java

@@ -18,11 +18,6 @@
  */
 package org.apache.jackrabbit.oak.commons.collections;
 
-import java.util.ArrayDeque;
-import java.util.Objects;
-
-import org.jetbrains.annotations.NotNull;
-
 /**
  * Utility methods for collections conversions.
  */
@@ -36,21 +31,6 @@ private CollectionUtils() {
         // no instances for you
     }
 
-    /**
-     * Convert an iterable to a {@link java.util.ArrayDeque}.
-     * The returning array deque is mutable and supports all optional operations.
-     *
-     * @param iterable the iterable to convert
-     * @param <T>      the type of the elements
-     * @return the arrayDeque
-     */
-    public static <T> ArrayDeque<T> toArrayDeque(@NotNull Iterable<? extends T> iterable) {
-        Objects.requireNonNull(iterable);
-        ArrayDeque<T> arrayDeque = new ArrayDeque<>();
-        iterable.forEach(arrayDeque::add);
-        return arrayDeque;
-    }
-
     /**
      * Ensure the capacity of a map or set given the expected number of elements.
      *

oak-commons/src/main/java/org/apache/jackrabbit/oak/commons/collections/DequeUtils.java

@@ -0,0 +1,49 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.jackrabbit.oak.commons.collections;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayDeque;
+import java.util.Objects;
+
+/**
+ * Utility methods for {@link java.util.Deque} conversions.
+ */
+public class DequeUtils {
+
+    private DequeUtils() {
+        // no instances for you
+    }
+
+    /**
+     * Convert an iterable to a {@link java.util.ArrayDeque}.
+     * The returning array deque is mutable and supports all optional operations.
+     *
+     * @param iterable the iterable to convert
+     * @param <T>      the type of the elements
+     * @return the arrayDeque
+     */
+    public static <T> ArrayDeque<T> toArrayDeque(@NotNull Iterable<? extends T> iterable) {
+        Objects.requireNonNull(iterable);
+        ArrayDeque<T> arrayDeque = new ArrayDeque<>();
+        iterable.forEach(arrayDeque::add);
+        return arrayDeque;
+    }
+}

oak-commons/src/test/java/org/apache/jackrabbit/oak/commons/collections/CollectionUtilsTest.java

@@ -21,34 +21,10 @@
 import org.junit.Assert;
 import org.junit.Test;
 
-import java.util.ArrayDeque;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-
 import static org.junit.Assert.fail;
 
 public class CollectionUtilsTest {
 
-    @Test
-    public void toArrayDequeWithNonEmptyIterable() {
-        List<String> list = Arrays.asList("one", "two", "three");
-        ArrayDeque<String> result = CollectionUtils.toArrayDeque(list);
-
-        Assert.assertNotNull(result);
-        Assert.assertEquals(3, result.size());
-        Assert.assertEquals("one", result.peekFirst());
-        Assert.assertEquals("three", result.peekLast());
-    }
-
-    @Test
-    public void toArrayDequeWithEmptyIterable() {
-        List<String> emptyList = Collections.emptyList();
-        ArrayDeque<String> result = CollectionUtils.toArrayDeque(emptyList);
-
-        Assert.assertNotNull(result);
-        Assert.assertTrue(result.isEmpty());
-    }
     @Test
     public void ensureCapacity() {
         int capacity = CollectionUtils.ensureCapacity(8);

oak-commons/src/test/java/org/apache/jackrabbit/oak/commons/collections/DequeUtilsTest.java

@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.jackrabbit.oak.commons.collections;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Unit tests for the {@link DequeUtils} class.
+ * <p>
+ * This class contains test cases to verify the functionality of the methods
+ * in the {@link DequeUtils} class.
+ */
+public class DequeUtilsTest {
+
+    @Test
+    public void toArrayDequeWithNonEmptyIterable() {
+        List<String> list = Arrays.asList("one", "two", "three");
+        ArrayDeque<String> result = DequeUtils.toArrayDeque(list);
+
+        Assert.assertNotNull(result);
+        Assert.assertEquals(3, result.size());
+        Assert.assertEquals("one", result.peekFirst());
+        Assert.assertEquals("three", result.peekLast());
+    }
+
+    @Test
+    public void toArrayDequeWithEmptyIterable() {
+        List<String> emptyList = Collections.emptyList();
+        ArrayDeque<String> result = DequeUtils.toArrayDeque(emptyList);
+
+        Assert.assertNotNull(result);
+        Assert.assertTrue(result.isEmpty());
+    }
+
+    @Test
+    public void testToArrayDequeWithNullIterable() {
+        Assert.assertThrows(NullPointerException.class, () -> DequeUtils.toArrayDeque(null));
+    }
+
+}

oak-store-document/src/main/java/org/apache/jackrabbit/oak/plugins/document/NodeDocument.java

@@ -58,7 +58,7 @@
 import org.apache.jackrabbit.guava.common.collect.Ordering;
 import org.apache.jackrabbit.oak.api.PropertyState;
 import org.apache.jackrabbit.oak.commons.PathUtils;
-import org.apache.jackrabbit.oak.commons.collections.CollectionUtils;
+import org.apache.jackrabbit.oak.commons.collections.DequeUtils;
 import org.apache.jackrabbit.oak.commons.json.JsopBuilder;
 import org.apache.jackrabbit.oak.commons.json.JsopReader;
 import org.apache.jackrabbit.oak.commons.json.JsopTokenizer;
@@ -1434,7 +1434,7 @@ Iterator<NodeDocument> getAllPreviousDocs() {
         //on property that all prevDoc id would starts <depth+2>:p/path/to/node
         return new AbstractIterator<NodeDocument>(){
             private Queue<Map.Entry<Revision, Range>> previousRanges =
-                    CollectionUtils.toArrayDeque(getPreviousRanges().entrySet());
+                    DequeUtils.toArrayDeque(getPreviousRanges().entrySet());
             @Override
             protected NodeDocument computeNext() {
                 if(!previousRanges.isEmpty()){