| /* |
| * 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.ignite.internal.util; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * Input stream wrapper which allows to read exactly expected number of bytes. |
| */ |
| public class GridFixedSizeInputStream extends InputStream { |
| /** */ |
| private final InputStream in; |
| |
| /** */ |
| private long size; |
| |
| /** |
| * @param in Input stream. |
| * @param size Size of available data. |
| */ |
| public GridFixedSizeInputStream(InputStream in, long size) { |
| this.in = in; |
| this.size = size; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public int read(byte[] b, int off, int len) throws IOException { |
| assert len <= b.length; |
| |
| if (size == 0) |
| return -1; |
| |
| if (len > size) |
| // Assignment is ok because size < len <= Integer.MAX_VALUE |
| len = (int)size; |
| |
| int res = in.read(b, off, len); |
| |
| if (res == -1) |
| throw new IOException("Expected " + size + " more bytes to read."); |
| |
| assert res >= 0 : res; |
| |
| size -= res; |
| |
| assert size >= 0 : size; |
| |
| return res; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public int available() throws IOException { |
| return size > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int)size; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public int read() throws IOException { |
| if (size == 0) |
| return -1; |
| |
| int res = in.read(); |
| |
| if (res == -1) |
| throw new IOException("Expected " + size + " more bytes to read."); |
| |
| size--; |
| |
| return res; |
| } |
| } |