| /* ==================================================================== |
| 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.poi.util; |
| |
| import java.io.ByteArrayInputStream; |
| |
| /** |
| * Adapts a plain byte array to {@link LittleEndianInput} |
| */ |
| public class LittleEndianByteArrayInputStream extends ByteArrayInputStream implements LittleEndianInput { |
| /** |
| * Creates <code>LittleEndianByteArrayInputStream</code> |
| * that uses <code>buf</code> as its |
| * buffer array. The initial value of <code>pos</code> |
| * is <code>offset</code> and the initial value |
| * of <code>count</code> is the minimum of <code>offset+length</code> |
| * and <code>buf.length</code>. |
| * The buffer array is not copied. The buffer's mark is |
| * set to the specified offset. |
| * |
| * @param buf the input buffer. |
| * @param offset the offset in the buffer of the first byte to read. |
| * @param length the maximum number of bytes to read from the buffer. |
| */ |
| public LittleEndianByteArrayInputStream(byte[] buf, int offset, int length) { // NOSONAR |
| super(buf, offset, length); |
| } |
| |
| /** |
| * Creates <code>LittleEndianByteArrayInputStream</code> |
| * that uses <code>buf</code> as its |
| * buffer array. The initial value of <code>pos</code> |
| * is <code>offset</code> and the initial value |
| * of <code>count</code> is the minimum of <code>offset+buf.length</code> |
| * and <code>buf.length</code>. |
| * The buffer array is not copied. The buffer's mark is |
| * set to the specified offset. |
| * |
| * @param buf the input buffer. |
| * @param offset the offset in the buffer of the first byte to read. |
| */ |
| public LittleEndianByteArrayInputStream(byte[] buf, int offset) { |
| this(buf, offset, buf.length - offset); |
| } |
| |
| /** |
| * Creates a <code>LittleEndianByteArrayInputStream</code> |
| * so that it uses <code>buf</code> as its |
| * buffer array. |
| * The buffer array is not copied. |
| * The initial value of <code>pos</code> |
| * is <code>0</code> and the initial value |
| * of <code>count</code> is the length of |
| * <code>buf</code>. |
| * |
| * @param buf the input buffer. |
| */ |
| public LittleEndianByteArrayInputStream(byte[] buf) { |
| super(buf); |
| } |
| |
| protected void checkPosition(int i) { |
| if (i > count - pos) { |
| throw new RuntimeException("Buffer overrun, having " + count + " bytes in the stream and position is at " + pos + |
| ", but trying to increment position by " + i); |
| } |
| } |
| |
| public int getReadIndex() { |
| return pos; |
| } |
| |
| public void setReadIndex(int pos) { |
| if (pos < 0 || pos >= count) { |
| throw new IndexOutOfBoundsException(); |
| } |
| this.pos = pos; |
| } |
| |
| |
| @Override |
| public byte readByte() { |
| checkPosition(1); |
| return (byte)read(); |
| } |
| |
| @Override |
| public int readInt() { |
| final int size = LittleEndianConsts.INT_SIZE; |
| checkPosition(size); |
| int le = LittleEndian.getInt(buf, pos); |
| long skipped = super.skip(size); |
| assert skipped == size : "Buffer overrun"; |
| return le; |
| } |
| |
| @Override |
| public long readLong() { |
| final int size = LittleEndianConsts.LONG_SIZE; |
| checkPosition(size); |
| long le = LittleEndian.getLong(buf, pos); |
| long skipped = super.skip(size); |
| assert skipped == size : "Buffer overrun"; |
| return le; |
| } |
| |
| @Override |
| public short readShort() { |
| final int size = LittleEndianConsts.SHORT_SIZE; |
| checkPosition(size); |
| short le = LittleEndian.getShort(buf, pos); |
| long skipped = super.skip(size); |
| assert skipped == size : "Buffer overrun"; |
| return le; |
| } |
| |
| @Override |
| public int readUByte() { |
| return readByte() & 0x00FF; |
| } |
| |
| @Override |
| public int readUShort() { |
| return readShort() & 0x00FFFF; |
| } |
| |
| public long readUInt() { |
| return readInt() & 0x00FFFFFFFFL; |
| } |
| |
| @Override |
| public double readDouble() { |
| return Double.longBitsToDouble(readLong()); |
| } |
| |
| @Override |
| public void readFully(byte[] buffer, int off, int len) { |
| checkPosition(len); |
| read(buffer, off, len); |
| } |
| |
| @Override |
| public void readFully(byte[] buffer) { |
| checkPosition(buffer.length); |
| read(buffer, 0, buffer.length); |
| } |
| |
| @Override |
| public void readPlain(byte[] buf, int off, int len) { |
| readFully(buf, off, len); |
| } |
| |
| /** |
| * Change the limit of the ByteArrayInputStream |
| * @param size the new limit - is truncated to length of internal buffer |
| */ |
| public void limit(int size) { |
| count = Math.min(size, buf.length); |
| } |
| } |