--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ListAdapter.java 2020-04-15 18:49:55.000000000 +0530 +++ /dev/null 2020-04-15 18:49:55.000000000 +0530 @@ -1,411 +0,0 @@ -/* - * 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 - * or visit www.oracle.com if you need additional information or have any - * questions. - */ - -package jdk.nashorn.internal.runtime; - -import java.lang.invoke.MethodHandle; -import java.util.AbstractList; -import java.util.Deque; -import java.util.Iterator; -import java.util.ListIterator; -import java.util.NoSuchElementException; -import java.util.Objects; -import java.util.RandomAccess; -import java.util.concurrent.Callable; -import jdk.nashorn.api.scripting.JSObject; -import jdk.nashorn.api.scripting.ScriptObjectMirror; -import jdk.nashorn.internal.objects.Global; -import jdk.nashorn.internal.runtime.linker.Bootstrap; - -/** - * An adapter that can wrap any ECMAScript Array-like object (that adheres to the array rules for the property - * {@code length} and having conforming {@code push}, {@code pop}, {@code shift}, {@code unshift}, and {@code splice} - * methods) and expose it as both a Java list and double-ended queue. While script arrays aren't necessarily efficient - * as dequeues, it's still slightly more efficient to be able to translate dequeue operations into pushes, pops, shifts, - * and unshifts, than to blindly translate all list's add/remove operations into splices. Also, it is conceivable that a - * custom script object that implements an Array-like API can have a background data representation that is optimized - * for dequeue-like access. Note that with ECMAScript arrays, {@code push} and {@code pop} operate at the end of the - * array, while in Java {@code Deque} they operate on the front of the queue and as such the Java dequeue - * {@link #push(Object)} and {@link #pop()} operations will translate to {@code unshift} and {@code shift} script - * operations respectively, while {@link #addLast(Object)} and {@link #removeLast()} will translate to {@code push} and - * {@code pop}. - */ -public class ListAdapter extends AbstractList implements RandomAccess, Deque { - // Invoker creator for methods that add to the start or end of the list: PUSH and UNSHIFT. Takes fn, this, and value, returns void. - private static final Callable ADD_INVOKER_CREATOR = invokerCreator(void.class, Object.class, JSObject.class, Object.class); - - // PUSH adds to the start of the list - private static final Object PUSH = new Object(); - // UNSHIFT adds to the end of the list - private static final Object UNSHIFT = new Object(); - - // Invoker creator for methods that remove from the tail or head of the list: POP and SHIFT. Takes fn, this, returns Object. - private static final Callable REMOVE_INVOKER_CREATOR = invokerCreator(Object.class, Object.class, JSObject.class); - - // POP removes from the start of the list - private static final Object POP = new Object(); - // SHIFT removes from the end of the list - private static final Object SHIFT = new Object(); - - // SPLICE can be used to add a value in the middle of the list. - private static final Object SPLICE_ADD = new Object(); - private static final Callable SPLICE_ADD_INVOKER_CREATOR = invokerCreator(void.class, Object.class, JSObject.class, int.class, int.class, Object.class); - - // SPLICE can also be used to remove values from the middle of the list. - private static final Object SPLICE_REMOVE = new Object(); - private static final Callable SPLICE_REMOVE_INVOKER_CREATOR = invokerCreator(void.class, Object.class, JSObject.class, int.class, int.class); - - /** wrapped object */ - final JSObject obj; - private final Global global; - - // allow subclasses only in this package - ListAdapter(final JSObject obj, final Global global) { - if (global == null) { - throw new IllegalStateException(ECMAErrors.getMessage("list.adapter.null.global")); - } - - this.obj = obj; - this.global = global; - } - - /** - * Factory to create a ListAdapter for a given script object. - * - * @param obj script object to wrap as a ListAdapter - * @return A ListAdapter wrapper object - */ - public static ListAdapter create(final Object obj) { - final Global global = Context.getGlobal(); - return new ListAdapter(getJSObject(obj, global), global); - } - - private static JSObject getJSObject(final Object obj, final Global global) { - if (obj instanceof ScriptObject) { - return (JSObject)ScriptObjectMirror.wrap(obj, global); - } else if (obj instanceof JSObject) { - return (JSObject)obj; - } - throw new IllegalArgumentException("ScriptObject or JSObject expected"); - } - - @Override - public final Object get(final int index) { - checkRange(index); - return getAt(index); - } - - private Object getAt(final int index) { - return obj.getSlot(index); - } - - @Override - public Object set(final int index, final Object element) { - checkRange(index); - final Object prevValue = getAt(index); - obj.setSlot(index, element); - return prevValue; - } - - private void checkRange(final int index) { - if(index < 0 || index >= size()) { - throw invalidIndex(index); - } - } - - @Override - public int size() { - return JSType.toInt32(obj.getMember("length")); - } - - @Override - public final void push(final Object e) { - addFirst(e); - } - - @Override - public final boolean add(final Object e) { - addLast(e); - return true; - } - - @Override - public final void addFirst(final Object e) { - try { - getDynamicInvoker(UNSHIFT, ADD_INVOKER_CREATOR).invokeExact(getFunction("unshift"), obj, e); - } catch(RuntimeException | Error ex) { - throw ex; - } catch(final Throwable t) { - throw new RuntimeException(t); - } - } - - @Override - public final void addLast(final Object e) { - try { - getDynamicInvoker(PUSH, ADD_INVOKER_CREATOR).invokeExact(getFunction("push"), obj, e); - } catch(RuntimeException | Error ex) { - throw ex; - } catch(final Throwable t) { - throw new RuntimeException(t); - } - } - - @Override - public final void add(final int index, final Object e) { - try { - if(index < 0) { - throw invalidIndex(index); - } else if(index == 0) { - addFirst(e); - } else { - final int size = size(); - if(index < size) { - getDynamicInvoker(SPLICE_ADD, SPLICE_ADD_INVOKER_CREATOR).invokeExact(obj.getMember("splice"), obj, index, 0, e); - } else if(index == size) { - addLast(e); - } else { - throw invalidIndex(index); - } - } - } catch(final RuntimeException | Error ex) { - throw ex; - } catch(final Throwable t) { - throw new RuntimeException(t); - } - } - private Object getFunction(final String name) { - final Object fn = obj.getMember(name); - if(!(Bootstrap.isCallable(fn))) { - throw new UnsupportedOperationException("The script object doesn't have a function named " + name); - } - return fn; - } - - private static IndexOutOfBoundsException invalidIndex(final int index) { - return new IndexOutOfBoundsException(String.valueOf(index)); - } - - @Override - public final boolean offer(final Object e) { - return offerLast(e); - } - - @Override - public final boolean offerFirst(final Object e) { - addFirst(e); - return true; - } - - @Override - public final boolean offerLast(final Object e) { - addLast(e); - return true; - } - - @Override - public final Object pop() { - return removeFirst(); - } - - @Override - public final Object remove() { - return removeFirst(); - } - - @Override - public final Object removeFirst() { - checkNonEmpty(); - return invokeShift(); - } - - @Override - public final Object removeLast() { - checkNonEmpty(); - return invokePop(); - } - - private void checkNonEmpty() { - if(isEmpty()) { - throw new NoSuchElementException(); - } - } - - @Override - public final Object remove(final int index) { - if(index < 0) { - throw invalidIndex(index); - } else if (index == 0) { - return invokeShift(); - } else { - final int maxIndex = size() - 1; - if(index < maxIndex) { - final Object prevValue = get(index); - invokeSpliceRemove(index, 1); - return prevValue; - } else if(index == maxIndex) { - return invokePop(); - } else { - throw invalidIndex(index); - } - } - } - - private Object invokeShift() { - try { - return getDynamicInvoker(SHIFT, REMOVE_INVOKER_CREATOR).invokeExact(getFunction("shift"), obj); - } catch(RuntimeException | Error ex) { - throw ex; - } catch(final Throwable t) { - throw new RuntimeException(t); - } - } - - private Object invokePop() { - try { - return getDynamicInvoker(POP, REMOVE_INVOKER_CREATOR).invokeExact(getFunction("pop"), obj); - } catch(RuntimeException | Error ex) { - throw ex; - } catch(final Throwable t) { - throw new RuntimeException(t); - } - } - - @Override - protected final void removeRange(final int fromIndex, final int toIndex) { - invokeSpliceRemove(fromIndex, toIndex - fromIndex); - } - - private void invokeSpliceRemove(final int fromIndex, final int count) { - try { - getDynamicInvoker(SPLICE_REMOVE, SPLICE_REMOVE_INVOKER_CREATOR).invokeExact(getFunction("splice"), obj, fromIndex, count); - } catch(RuntimeException | Error ex) { - throw ex; - } catch(final Throwable t) { - throw new RuntimeException(t); - } - } - - @Override - public final Object poll() { - return pollFirst(); - } - - @Override - public final Object pollFirst() { - return isEmpty() ? null : invokeShift(); - } - - @Override - public final Object pollLast() { - return isEmpty() ? null : invokePop(); - } - - @Override - public final Object peek() { - return peekFirst(); - } - - @Override - public final Object peekFirst() { - return isEmpty() ? null : get(0); - } - - @Override - public final Object peekLast() { - return isEmpty() ? null : get(size() - 1); - } - - @Override - public final Object element() { - return getFirst(); - } - - @Override - public final Object getFirst() { - checkNonEmpty(); - return get(0); - } - - @Override - public final Object getLast() { - checkNonEmpty(); - return get(size() - 1); - } - - @Override - public final Iterator descendingIterator() { - final ListIterator it = listIterator(size()); - return new Iterator() { - @Override - public boolean hasNext() { - return it.hasPrevious(); - } - - @Override - public Object next() { - return it.previous(); - } - - @Override - public void remove() { - it.remove(); - } - }; - } - - @Override - public final boolean removeFirstOccurrence(final Object o) { - return removeOccurrence(o, iterator()); - } - - @Override - public final boolean removeLastOccurrence(final Object o) { - return removeOccurrence(o, descendingIterator()); - } - - private static boolean removeOccurrence(final Object o, final Iterator it) { - while(it.hasNext()) { - if(Objects.equals(o, it.next())) { - it.remove(); - return true; - } - } - return false; - } - - private static Callable invokerCreator(final Class rtype, final Class... ptypes) { - return new Callable() { - @Override - public MethodHandle call() { - return Bootstrap.createDynamicCallInvoker(rtype, ptypes); - } - }; - } - - private MethodHandle getDynamicInvoker(final Object key, final Callable creator) { - return global.getDynamicInvoker(key, creator); - } -}