Use array.clone(), which should be faster than System.arraycopy

h2/src/main/org/h2/mvstore/Page.java

@@ -471,14 +471,18 @@ public class Page {
     public void setChild(int index, Page c) {
         if (c == null) {
             long oldCount = children[index].count;
-            children = Arrays.copyOf(children, children.length);
+            // this is slightly slower:
+            // children = Arrays.copyOf(children, children.length);
+            children = children.clone();
             PageReference ref = new PageReference(null, 0, 0);
             children[index] = ref;
             totalCount -= oldCount;
         } else if (c != children[index].page ||
                 c.getPos() != children[index].pos) {
             long oldCount = children[index].count;
-            children = Arrays.copyOf(children, children.length);
+            // this is slightly slower:
+            // children = Arrays.copyOf(children, children.length);
+            children = children.clone();
             PageReference ref = new PageReference(c, c.pos, c.totalCount);
             children[index] = ref;
             totalCount += c.totalCount - oldCount;
@@ -492,7 +496,9 @@ public class Page {
      * @param key the new key
      */
     public void setKey(int index, Object key) {
-        keys = Arrays.copyOf(keys, keys.length);
+        // this is slightly slower:
+        // keys = Arrays.copyOf(keys, keys.length);
+        keys = keys.clone();
         Object old = keys[index];
         DataType keyType = map.getKeyType();
         int mem = keyType.getMemory(key);
@@ -512,7 +518,9 @@ public class Page {
      */
     public Object setValue(int index, Object value) {
         Object old = values[index];
-        values = Arrays.copyOf(values, values.length);
+        // this is slightly slower:
+        // values = Arrays.copyOf(values, values.length);
+        values = values.clone();
         DataType valueType = map.getValueType();
         addMemory(valueType.getMemory(value) -
                 valueType.getMemory(old));

h2/src/main/org/h2/mvstore/db/MVSecondaryIndex.java

@@ -125,7 +125,7 @@ public class MVSecondaryIndex extends BaseIndex implements MVIndex {
                 if (indexType.isUnique()) {
                     Value[] array = ((ValueArray) v).getList();
                     // don't change the original value
-                    array = Arrays.copyOf(array, array.length);
+                    array = array.clone();
                     array[keyColumns - 1] = ValueLong.get(Long.MIN_VALUE);
                     ValueArray unique = ValueArray.get(array);
                     SearchRow row = convertToSearchRow((ValueArray) v);

h2/src/main/org/h2/store/LobStorageMap.java

@@ -246,7 +246,7 @@ public class LobStorageMap implements LobStorageInterface {
             throw DbException.throwInternalError("Length is different");
         }
         Object[] value = lobMap.get(oldLobId);
-        value = Arrays.copyOf(value, value.length);
+        value = value.clone();
         byte[] streamStoreId = (byte[]) value[0];
         long lobId = generateLobId();
         value[1] = tableId;

h2/src/main/org/h2/store/fs/FilePathEncrypt.java

@@ -474,7 +474,7 @@ public class FilePathEncrypt extends FilePathWrapper {
                     updateTweak(tweak);
                     if (i + CIPHER_BLOCK_SIZE + CIPHER_BLOCK_SIZE > len &&
                             i + CIPHER_BLOCK_SIZE < len) {
-                        tweakEnd = Arrays.copyOf(tweak, CIPHER_BLOCK_SIZE);
+                        tweakEnd = tweak.clone();
                         updateTweak(tweak);
                     }
                 }