libthrift091.transport.AutoExpandingBuffer Maven / Gradle / Ivy
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* 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 libthrift091.transport;
/**
* Helper class that wraps a byte[] so that it can expand and be reused. Users
* should call resizeIfNecessary to make sure the buffer has suitable capacity,
* and then use the array as needed. Note that the internal array will grow at a
* rate slightly faster than the requested capacity with the (untested)
* objective of avoiding expensive buffer allocations and copies.
*/
public class AutoExpandingBuffer {
private byte[] array;
private final double growthCoefficient;
public AutoExpandingBuffer(int initialCapacity, double growthCoefficient) {
if (growthCoefficient < 1.0) {
throw new IllegalArgumentException("Growth coefficient must be >= 1.0");
}
array = new byte[initialCapacity];
this.growthCoefficient = growthCoefficient;
}
public void resizeIfNecessary(int size) {
if (array.length < size) {
byte[] newBuf = new byte[(int)(size * growthCoefficient)];
System.arraycopy(array, 0, newBuf, 0, array.length);
array = newBuf;
}
}
public byte[] array() {
return array;
}
}