import quincy 17.2.0

[ceph.git] / ceph / src / arrow / java / vector / src / main / java / org / apache / arrow / vector / complex / EmptyValuePopulator.java

diff --git a/ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/complex/EmptyValuePopulator.java b/ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/complex/EmptyValuePopulator.java
new file mode 100644 (file)
index 0000000..b32dce3
--- /dev/null
+++ b/ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/complex/EmptyValuePopulator.java
@@ -0,0 +1,51 @@
+/*
+ * 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.arrow.vector.complex;
+
+import org.apache.arrow.util.Preconditions;
+import org.apache.arrow.vector.UInt4Vector;
+
+/**
+ * A helper class that is used to track and populate empty values in repeated value vectors.
+ */
+public class EmptyValuePopulator {
+  private final UInt4Vector offsets;
+
+  public EmptyValuePopulator(UInt4Vector offsets) {
+    this.offsets = Preconditions.checkNotNull(offsets, "offsets cannot be null");
+  }
+
+  /**
+   * Marks all values since the last set as empty. The last set value is obtained from underlying offsets vector.
+   *
+   * @param lastIndex the last index (inclusive) in the offsets vector until which empty population takes place
+   * @throws java.lang.IndexOutOfBoundsException if lastIndex is negative or greater than offsets capacity.
+   */
+  public void populate(int lastIndex) {
+    if (lastIndex < 0) {
+      throw new IndexOutOfBoundsException("index cannot be negative");
+    }
+    final int lastSet = Math.max(offsets.getValueCount() - 1, 0);
+    final int previousEnd = offsets.get(lastSet); //0 ? 0 : accessor.get(lastSet);
+    for (int i = lastSet; i < lastIndex; i++) {
+      offsets.setSafe(i + 1, previousEnd);
+    }
+    offsets.setValueCount(lastIndex + 1);
+  }
+
+}