io.airlift.drift.protocol.TMemoryBuffer Maven / Gradle / Ivy
/*
* Copyright (C) 2017 Facebook, Inc.
*
* Licensed 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 io.airlift.drift.protocol;
import static java.lang.Math.max;
public class TMemoryBuffer
implements TTransport
{
private byte[] data;
private int head;
private int tail;
public TMemoryBuffer(int initialSize)
{
data = new byte[max(initialSize, 16)];
}
@Override
public void read(byte[] buf, int off, int len)
throws TTransportException
{
if (head - tail < len) {
throw new TTransportException("Too few bytes in buffer");
}
System.arraycopy(data, tail, buf, off, len);
tail += len;
}
@Override
public void write(byte[] buf, int off, int len)
{
int available = data.length - head;
if (available < len) {
int need = len - available - tail;
byte[] temp = new byte[max(data.length * 2, need)];
System.arraycopy(data, tail, temp, 0, head - tail);
data = temp;
head -= tail;
tail = 0;
}
System.arraycopy(buf, off, data, head, len);
head += len;
}
}