1 /* 2 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package jdk.nashorn.internal.runtime; 26 27 import static jdk.nashorn.internal.lookup.Lookup.MH; 28 29 import java.io.Serializable; 30 import java.lang.invoke.MethodHandle; 31 import java.lang.invoke.MethodHandles; 32 import jdk.nashorn.internal.codegen.CompilerConstants; 33 34 /** 35 * Encapsulates the allocation strategy for a function when used as a constructor. 36 */ 37 final public class AllocationStrategy implements Serializable { 38 private static final long serialVersionUID = 1L; 39 40 private static final MethodHandles.Lookup LOOKUP = MethodHandles.lookup(); 41 42 /** Allocator map from allocator descriptor */ 43 private final PropertyMap allocatorMap; 44 45 /** Name of class where allocator function resides */ 46 private final String allocatorClassName; 47 48 /** lazily generated allocator */ 49 private transient MethodHandle allocator; 50 51 /** 52 * Construct an allocation strategy with the given map and class name. 53 * @param allocatorMap the property map 54 * @param className the class name 55 */ 56 public AllocationStrategy(final PropertyMap allocatorMap, final String className) { 57 this.allocatorMap = allocatorMap; 58 // These classes get loaded, so an interned variant of their name is most likely around anyway. 59 this.allocatorClassName = className.intern(); 60 } 61 62 PropertyMap getAllocatorMap() { 63 return allocatorMap; 64 } 65 66 ScriptObject allocate(final PropertyMap map) { 67 try { 68 if (allocator == null) { 69 allocator = MH.findStatic(LOOKUP, Context.forStructureClass(allocatorClassName), 70 CompilerConstants.ALLOCATE.symbolName(), MH.type(ScriptObject.class, PropertyMap.class)); 71 } 72 return (ScriptObject)allocator.invokeExact(map); 73 } catch (final RuntimeException | Error e) { 74 throw e; 75 } catch (final Throwable t) { 76 throw new RuntimeException(t); 77 } 78 } 79 80 @Override 81 public String toString() { 82 return "AllocationStrategy[allocatorClassName=" + allocatorClassName + ", allocatorMap.size=" + 83 allocatorMap.size() + "]"; 84 } 85 }