| /* |
| * 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.commons.compress.archivers.sevenz; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.SeekableByteChannel; |
| |
| class BoundedSeekableByteChannelInputStream extends InputStream { |
| private static final int MAX_BUF_LEN = 8192; |
| private final ByteBuffer buffer; |
| private final SeekableByteChannel channel; |
| private long bytesRemaining; |
| |
| public BoundedSeekableByteChannelInputStream(final SeekableByteChannel channel, |
| final long size) { |
| this.channel = channel; |
| this.bytesRemaining = size; |
| if (size < MAX_BUF_LEN && size > 0) { |
| buffer = ByteBuffer.allocate((int) size); |
| } else { |
| buffer = ByteBuffer.allocate(MAX_BUF_LEN); |
| } |
| } |
| |
| @Override |
| public int read() throws IOException { |
| if (bytesRemaining > 0) { |
| --bytesRemaining; |
| int read = read(1); |
| if (read < 0) { |
| return read; |
| } |
| return buffer.get() & 0xff; |
| } |
| return -1; |
| } |
| |
| @Override |
| public int read(final byte[] b, final int off, final int len) throws IOException { |
| if (bytesRemaining == 0) { |
| return -1; |
| } |
| int bytesToRead = len; |
| if (bytesToRead > bytesRemaining) { |
| bytesToRead = (int) bytesRemaining; |
| } |
| int bytesRead; |
| ByteBuffer buf; |
| if (bytesToRead <= buffer.capacity()) { |
| buf = buffer; |
| bytesRead = read(bytesToRead); |
| } else { |
| buf = ByteBuffer.allocate(bytesToRead); |
| bytesRead = channel.read(buf); |
| buf.flip(); |
| } |
| if (bytesRead >= 0) { |
| buf.get(b, off, bytesRead); |
| bytesRemaining -= bytesRead; |
| } |
| return bytesRead; |
| } |
| |
| private int read(int len) throws IOException { |
| buffer.rewind().limit(len); |
| int read = channel.read(buffer); |
| buffer.flip(); |
| return read; |
| } |
| |
| @Override |
| public void close() { |
| // the nested channel is controlled externally |
| } |
| } |