| /* |
| * 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 |
| * |
| * https://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.avro.util; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.Buffer; |
| import java.nio.ByteBuffer; |
| |
| public class ReusableByteBufferInputStream extends InputStream { |
| |
| private static final ByteBuffer EMPTY_BUFFER = ByteBuffer.allocate(0); |
| |
| // work around issues compiling with Java11 but running with 8 |
| // due to ByteBuffer overriding several methods |
| private ByteBuffer byteBuffer = EMPTY_BUFFER; |
| private Buffer buffer = byteBuffer; |
| private int mark = 0; |
| |
| public void setByteBuffer(ByteBuffer buf) { |
| // do not modify the buffer that is passed in |
| this.byteBuffer = buf.duplicate(); |
| this.buffer = byteBuffer; |
| this.mark = buf.position(); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| if (buffer.hasRemaining()) { |
| return byteBuffer.get() & 0xff; |
| } else { |
| return -1; |
| } |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| if (buffer.remaining() <= 0) { |
| return -1; |
| } |
| // allow IndexOutOfBoundsException to be thrown by ByteBuffer#get |
| int bytesToRead = Math.min(len, buffer.remaining()); |
| byteBuffer.get(b, off, bytesToRead); |
| return bytesToRead; |
| } |
| |
| @Override |
| public long skip(long n) throws IOException { |
| if (n <= 0) { |
| // n may be negative and results in skipping 0 bytes, according to javadoc |
| return 0; |
| } |
| |
| // this catches n > Integer.MAX_VALUE |
| int bytesToSkip = n > buffer.remaining() ? buffer.remaining() : (int) n; |
| buffer.position(buffer.position() + bytesToSkip); |
| return bytesToSkip; |
| } |
| |
| @Override |
| public synchronized void mark(int readLimit) { |
| // readLimit is ignored. there is no requirement to implement readLimit, it |
| // is a way for implementations to avoid buffering too much. since all data |
| // for this stream is held in memory, this has no need for such a limit. |
| this.mark = buffer.position(); |
| } |
| |
| @Override |
| public synchronized void reset() throws IOException { |
| buffer.position(mark); |
| } |
| |
| @Override |
| public boolean markSupported() { |
| return true; |
| } |
| } |