/*
* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package jdk.nashorn.internal.objects;
import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
import java.nio.ByteBuffer;
import jdk.nashorn.internal.objects.annotations.Attribute;
import jdk.nashorn.internal.objects.annotations.Constructor;
import jdk.nashorn.internal.objects.annotations.Function;
import jdk.nashorn.internal.objects.annotations.Getter;
import jdk.nashorn.internal.objects.annotations.ScriptClass;
import jdk.nashorn.internal.objects.annotations.SpecializedFunction;
import jdk.nashorn.internal.objects.annotations.Where;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.PropertyMap;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.ScriptRuntime;
/**
* NativeArrayBuffer - ArrayBuffer as described in the JS typed
* array spec
*/
@ScriptClass("ArrayBuffer")
public final class NativeArrayBuffer extends ScriptObject {
private final ByteBuffer nb;
// initialized by nasgen
private static PropertyMap $nasgenmap$;
/**
* Constructor
* @param nb native byte buffer to wrap
* @param global global instance
*/
protected NativeArrayBuffer(final ByteBuffer nb, final Global global) {
super(global.getArrayBufferPrototype(), $nasgenmap$);
this.nb = nb;
}
/**
* Constructor
* @param nb native byte buffer to wrap
*/
protected NativeArrayBuffer(final ByteBuffer nb) {
this(nb, Global.instance());
}
/**
* Constructor
* @param byteLength byteLength for buffer
*/
protected NativeArrayBuffer(final int byteLength) {
this(ByteBuffer.allocateDirect(byteLength));
}
/**
* Clone constructor
* Used only for slice
* @param other original buffer
* @param begin begin byte index
* @param end end byte index
*/
protected NativeArrayBuffer(final NativeArrayBuffer other, final int begin, final int end) {
this(cloneBuffer(other.getNioBuffer(), begin, end));
}
/**
* Constructor
* @param newObj is this invoked with new
* @param self self reference
* @param args arguments to constructor
* @return new NativeArrayBuffer
*/
@Constructor(arity = 1)
public static NativeArrayBuffer constructor(final boolean newObj, final Object self, final Object... args) {
if (!newObj) {
throw typeError("constructor.requires.new", "ArrayBuffer");
}
if (args.length == 0) {
return new NativeArrayBuffer(0);
}
final Object arg0 = args[0];
if (arg0 instanceof ByteBuffer) {
return new NativeArrayBuffer((ByteBuffer)arg0);
} else {
return new NativeArrayBuffer(JSType.toInt32(arg0));
}
}
private static ByteBuffer cloneBuffer(final ByteBuffer original, final int begin, final int end) {
final ByteBuffer clone = ByteBuffer.allocateDirect(original.capacity());
original.rewind();//copy from the beginning
clone.put(original);
original.rewind();
clone.flip();
clone.position(begin);
clone.limit(end);
return clone.slice();
}
ByteBuffer getNioBuffer() {
return nb;
}
@Override
public String getClassName() {
return "ArrayBuffer";
}
/**
* Byte length for native array buffer
* @param self native array buffer
* @return byte length
*/
@Getter(attributes = Attribute.NOT_ENUMERABLE | Attribute.NOT_WRITABLE | Attribute.NOT_CONFIGURABLE)
public static int byteLength(final Object self) {
return ((NativeArrayBuffer)self).getByteLength();
}
/**
* Returns true if an object is an ArrayBufferView
*
* @param self self
* @param obj object to check
*
* @return true if obj is an ArrayBufferView
*/
@Function(attributes = Attribute.NOT_ENUMERABLE, where = Where.CONSTRUCTOR)
public static boolean isView(final Object self, final Object obj) {
return obj instanceof ArrayBufferView;
}
/**
* Slice function
* @param self native array buffer
* @param begin0 start byte index
* @param end0 end byte index
* @return new array buffer, sliced
*/
@Function(attributes = Attribute.NOT_ENUMERABLE)
public static NativeArrayBuffer slice(final Object self, final Object begin0, final Object end0) {
final NativeArrayBuffer arrayBuffer = (NativeArrayBuffer)self;
final int byteLength = arrayBuffer.getByteLength();
final int begin = adjustIndex(JSType.toInt32(begin0), byteLength);
final int end = adjustIndex(end0 != ScriptRuntime.UNDEFINED ? JSType.toInt32(end0) : byteLength, byteLength);
return new NativeArrayBuffer(arrayBuffer, begin, Math.max(end, begin));
}
/**
* Specialized slice function
* @param self native array buffer
* @param begin start byte index
* @param end end byte index
* @return new array buffer, sliced
*/
@SpecializedFunction
public static Object slice(final Object self, final int begin, final int end) {
final NativeArrayBuffer arrayBuffer = (NativeArrayBuffer)self;
final int byteLength = arrayBuffer.getByteLength();
return new NativeArrayBuffer(arrayBuffer, adjustIndex(begin, byteLength), Math.max(adjustIndex(end, byteLength), begin));
}
/**
* Specialized slice function
* @param self native array buffer
* @param begin start byte index
* @return new array buffer, sliced
*/
@SpecializedFunction
public static Object slice(final Object self, final int begin) {
return slice(self, begin, ((NativeArrayBuffer)self).getByteLength());
}
/**
* If index is negative, it refers to an index from the end of the array, as
* opposed to from the beginning. The index is clamped to the valid index
* range for the array.
*
* @param index The index.
* @param length The length of the array.
* @return valid index index in the range [0, length).
*/
static int adjustIndex(final int index, final int length) {
return index < 0 ? clamp(index + length, length) : clamp(index, length);
}
/**
* Clamp index into the range [0, length).
*/
private static int clamp(final int index, final int length) {
if (index < 0) {
return 0;
} else if (index > length) {
return length;
}
return index;
}
int getByteLength() {
return nb.limit();
}
ByteBuffer getBuffer() {
return nb;
}
ByteBuffer getBuffer(final int offset) {
return nb.duplicate().position(offset);
}
ByteBuffer getBuffer(final int offset, final int length) {
return getBuffer(offset).limit(length);
}
}