/*
* 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 java.nio;
import com.google.gwt.corp.compatibility.Endianness;
import com.google.gwt.corp.compatibility.Numbers;
/** HeapByteBuffer, ReadWriteHeapByteBuffer and ReadOnlyHeapByteBuffer compose the implementation of array based byte buffers.
* <p>
* HeapByteBuffer implements all the shared readonly methods and is extended by the other two classes.
* </p>
* <p>
* All methods are marked final for runtime performance.
* </p> */
abstract class HeapByteBuffer extends BaseByteBuffer {
protected final byte[] backingArray;
protected final int offset;
HeapByteBuffer (byte[] backingArray) {
this(backingArray, backingArray.length, 0);
}
HeapByteBuffer (int capacity) {
this(new byte[capacity], capacity, 0);
}
HeapByteBuffer (byte[] backingArray, int capacity, int offset) {
super(capacity);
this.backingArray = backingArray;
this.offset = offset;
if (offset + capacity > backingArray.length) {
throw new IndexOutOfBoundsException();
}
}
/*
* Override ByteBuffer.get(byte[], int, int) to improve performance.
*
* (non-Javadoc)
*
* @see java.nio.ByteBuffer#get(byte[], int, int)
*/
public final ByteBuffer get (byte[] dest, int off, int len) {
int length = dest.length;
if (off < 0 || len < 0 || (long)off + (long)len > length) {
throw new IndexOutOfBoundsException();
}
if (len > remaining()) {
throw new BufferUnderflowException();
}
System.arraycopy(backingArray, offset + position, dest, off, len);
position += len;
return this;
}
public final byte get () {
if (position == limit) {
throw new BufferUnderflowException();
}
return backingArray[offset + position++];
}
public final byte get (int index) {
if (index < 0 || index >= limit) {
throw new IndexOutOfBoundsException();
}
return backingArray[offset + index];
}
public final double getDouble () {
return Numbers.longBitsToDouble(getLong());
}
public final double getDouble (int index) {
return Numbers.longBitsToDouble(getLong(index));
}
public final float getFloat () {
return Numbers.intBitsToFloat(getInt());
}
public final float getFloat (int index) {
return Numbers.intBitsToFloat(getInt(index));
}
public final int getInt () {
int newPosition = position + 4;
if (newPosition > limit) {
throw new BufferUnderflowException();
}
int result = loadInt(position);
position = newPosition;
return result;
}
public final int getInt (int index) {
if (index < 0 || index + 4 > limit) {
throw new IndexOutOfBoundsException();
}
return loadInt(index);
}
public final long getLong () {
int newPosition = position + 8;
if (newPosition > limit) {
throw new BufferUnderflowException();
}
long result = loadLong(position);
position = newPosition;
return result;
}
public final long getLong (int index) {
if (index < 0 || index + 8 > limit) {
throw new IndexOutOfBoundsException();
}
return loadLong(index);
}
public final short getShort () {
int newPosition = position + 2;
if (newPosition > limit) {
throw new BufferUnderflowException();
}
short result = loadShort(position);
position = newPosition;
return result;
}
public final short getShort (int index) {
if (index < 0 || index + 2 > limit) {
throw new IndexOutOfBoundsException();
}
return loadShort(index);
}
public final boolean isDirect () {
return false;
}
protected final int loadInt (int index) {
int baseOffset = offset + index;
int bytes = 0;
if (order == Endianness.BIG_ENDIAN) {
for (int i = 0; i < 4; i++) {
bytes = bytes << 8;
bytes = bytes | (backingArray[baseOffset + i] & 0xFF);
}
} else {
for (int i = 3; i >= 0; i--) {
bytes = bytes << 8;
bytes = bytes | (backingArray[baseOffset + i] & 0xFF);
}
}
return bytes;
}
protected final long loadLong (int index) {
int baseOffset = offset + index;
long bytes = 0;
if (order == Endianness.BIG_ENDIAN) {
for (int i = 0; i < 8; i++) {
bytes = bytes << 8;
bytes = bytes | (backingArray[baseOffset + i] & 0xFF);
}
} else {
for (int i = 7; i >= 0; i--) {
bytes = bytes << 8;
bytes = bytes | (backingArray[baseOffset + i] & 0xFF);
}
}
return bytes;
}
protected final short loadShort (int index) {
int baseOffset = offset + index;
short bytes = 0;
if (order == Endianness.BIG_ENDIAN) {
bytes = (short)(backingArray[baseOffset] << 8);
bytes |= (backingArray[baseOffset + 1] & 0xFF);
} else {
bytes = (short)(backingArray[baseOffset + 1] << 8);
bytes |= (backingArray[baseOffset] & 0xFF);
}
return bytes;
}
protected final void store (int index, int value) {
int baseOffset = offset + index;
if (order == Endianness.BIG_ENDIAN) {
for (int i = 3; i >= 0; i--) {
backingArray[baseOffset + i] = (byte)(value & 0xFF);
value = value >> 8;
}
} else {
for (int i = 0; i <= 3; i++) {
backingArray[baseOffset + i] = (byte)(value & 0xFF);
value = value >> 8;
}
}
}
protected final void store (int index, long value) {
int baseOffset = offset + index;
if (order == Endianness.BIG_ENDIAN) {
for (int i = 7; i >= 0; i--) {
backingArray[baseOffset + i] = (byte)(value & 0xFF);
value = value >> 8;
}
} else {
for (int i = 0; i <= 7; i++) {
backingArray[baseOffset + i] = (byte)(value & 0xFF);
value = value >> 8;
}
}
}
protected final void store (int index, short value) {
int baseOffset = offset + index;
if (order == Endianness.BIG_ENDIAN) {
backingArray[baseOffset] = (byte)((value >> 8) & 0xFF);
backingArray[baseOffset + 1] = (byte)(value & 0xFF);
} else {
backingArray[baseOffset + 1] = (byte)((value >> 8) & 0xFF);
backingArray[baseOffset] = (byte)(value & 0xFF);
}
}
}