import quincy 17.2.0

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

diff --git a/ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/AllocationHelper.java b/ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/AllocationHelper.java
new file mode 100644 (file)
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--- /dev/null
+++ b/ceph/src/arrow/java/vector/src/main/java/org/apache/arrow/vector/AllocationHelper.java
@@ -0,0 +1,95 @@
+/*
+ * 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;
+
+import org.apache.arrow.vector.complex.RepeatedFixedWidthVectorLike;
+import org.apache.arrow.vector.complex.RepeatedVariableWidthVectorLike;
+
+/** Helper utility methods for allocating storage for Vectors. */
+public class AllocationHelper {
+  private AllocationHelper() {}
+
+  /**
+   * Allocates the vector.
+   *
+   * @param v The vector to allocate.
+   * @param valueCount Number of values to allocate.
+   * @param bytesPerValue bytes per value.
+   * @throws org.apache.arrow.memory.OutOfMemoryException if it can't allocate the memory.
+   */
+  public static void allocate(ValueVector v, int valueCount, int bytesPerValue) {
+    allocate(v, valueCount, bytesPerValue, 5);
+  }
+
+  /**
+   * Allocates memory for a vector assuming given number of values and their width.
+   *
+   * @param v The vector the allocate.
+   * @param valueCount The number of elements to allocate.
+   * @param bytesPerValue The bytes per value to use for allocating underlying storage
+   * @param childValCount  If <code>v</code> is a repeated vector, this is number of child elements to allocate.
+   * @throws org.apache.arrow.memory.OutOfMemoryException if it can't allocate the memory.
+   */
+  public static void allocatePrecomputedChildCount(
+      ValueVector v,
+      int valueCount,
+      int bytesPerValue,
+      int childValCount) {
+    if (v instanceof FixedWidthVector) {
+      ((FixedWidthVector) v).allocateNew(valueCount);
+    } else if (v instanceof VariableWidthVector) {
+      ((VariableWidthVector) v).allocateNew(valueCount * bytesPerValue, valueCount);
+    } else if (v instanceof RepeatedFixedWidthVectorLike) {
+      ((RepeatedFixedWidthVectorLike) v).allocateNew(valueCount, childValCount);
+    } else if (v instanceof RepeatedVariableWidthVectorLike) {
+      ((RepeatedVariableWidthVectorLike) v).allocateNew(childValCount * bytesPerValue, valueCount, childValCount);
+    } else {
+      v.allocateNew();
+    }
+  }
+
+  /**
+   * Allocates memory for a vector assuming given number of values and their width.
+   *
+   * @param v The vector the allocate.
+   * @param valueCount The number of elements to allocate.
+   * @param bytesPerValue The bytes per value to use for allocating underlying storage
+   * @param repeatedPerTop  If <code>v</code> is a repeated vector, this is assumed number of elements per child.
+   * @throws org.apache.arrow.memory.OutOfMemoryException if it can't allocate the memory
+   */
+  public static void allocate(ValueVector v, int valueCount, int bytesPerValue, int repeatedPerTop) {
+    allocatePrecomputedChildCount(v, valueCount, bytesPerValue, repeatedPerTop * valueCount);
+  }
+
+  /**
+   * Allocates the exact amount if v is fixed width, otherwise falls back to dynamic allocation.
+   *
+   * @param v          value vector we are trying to allocate
+   * @param valueCount size we are trying to allocate
+   * @throws org.apache.arrow.memory.OutOfMemoryException if it can't allocate the memory
+   */
+  public static void allocateNew(ValueVector v, int valueCount) {
+    if (v instanceof FixedWidthVector) {
+      ((FixedWidthVector) v).allocateNew(valueCount);
+    } else if (v instanceof VariableWidthVector) {
+      ((VariableWidthVector) v).allocateNew(valueCount);
+    } else {
+      v.allocateNew();
+    }
+  }
+}