// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package com.google.protobuf;
import java.util.NoSuchElementException;
/**
* This class is used to represent the substring of a {@link ByteString} over a
* single byte array. In terms of the public API of {@link ByteString}, you end
* up here by calling {@link ByteString#copyFrom(byte[])} followed by {@link
* ByteString#substring(int, int)}.
*
* <p>This class contains most of the overhead involved in creating a substring
* from a {@link LiteralByteString}. The overhead involves some range-checking
* and two extra fields.
*
* @author carlanton@google.com (Carl Haverl)
*/
class BoundedByteString extends LiteralByteString {
private final int bytesOffset;
private final int bytesLength;
/**
* Creates a {@code BoundedByteString} backed by the sub-range of given array,
* without copying.
*
* @param bytes array to wrap
* @param offset index to first byte to use in bytes
* @param length number of bytes to use from bytes
* @throws IllegalArgumentException if {@code offset < 0}, {@code length < 0},
* or if {@code offset + length >
* bytes.length}.
*/
BoundedByteString(byte[] bytes, int offset, int length) {
super(bytes);
if (offset < 0) {
throw new IllegalArgumentException("Offset too small: " + offset);
}
if (length < 0) {
throw new IllegalArgumentException("Length too small: " + offset);
}
if ((long) offset + length > bytes.length) {
throw new IllegalArgumentException(
"Offset+Length too large: " + offset + "+" + length);
}
this.bytesOffset = offset;
this.bytesLength = length;
}
/**
* Gets the byte at the given index.
* Throws {@link ArrayIndexOutOfBoundsException}
* for backwards-compatibility reasons although it would more properly be
* {@link IndexOutOfBoundsException}.
*
* @param index index of byte
* @return the value
* @throws ArrayIndexOutOfBoundsException {@code index} is < 0 or >= size
*/
@Override
public byte byteAt(int index) {
// We must check the index ourselves as we cannot rely on Java array index
// checking for substrings.
if (index < 0) {
throw new ArrayIndexOutOfBoundsException("Index too small: " + index);
}
if (index >= size()) {
throw new ArrayIndexOutOfBoundsException(
"Index too large: " + index + ", " + size());
}
return bytes[bytesOffset + index];
}
@Override
public int size() {
return bytesLength;
}
@Override
protected int getOffsetIntoBytes() {
return bytesOffset;
}
// =================================================================
// ByteString -> byte[]
@Override
protected void copyToInternal(byte[] target, int sourceOffset,
int targetOffset, int numberToCopy) {
System.arraycopy(bytes, getOffsetIntoBytes() + sourceOffset, target,
targetOffset, numberToCopy);
}
// =================================================================
// ByteIterator
@Override
public ByteIterator iterator() {
return new BoundedByteIterator();
}
private class BoundedByteIterator implements ByteIterator {
private int position;
private final int limit;
private BoundedByteIterator() {
position = getOffsetIntoBytes();
limit = position + size();
}
public boolean hasNext() {
return (position < limit);
}
public Byte next() {
// Boxing calls Byte.valueOf(byte), which does not instantiate.
return nextByte();
}
public byte nextByte() {
if (position >= limit) {
throw new NoSuchElementException();
}
return bytes[position++];
}
public void remove() {
throw new UnsupportedOperationException();
}
}
}