1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/jdk/internal/dynalink/beans/BeanLinker.java Thu Feb 14 13:22:26 2013 +0100
1.3 @@ -0,0 +1,493 @@
1.4 +/*
1.5 + * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +/*
1.30 + * This file is available under and governed by the GNU General Public
1.31 + * License version 2 only, as published by the Free Software Foundation.
1.32 + * However, the following notice accompanied the original version of this
1.33 + * file, and Oracle licenses the original version of this file under the BSD
1.34 + * license:
1.35 + */
1.36 +/*
1.37 + Copyright 2009-2013 Attila Szegedi
1.38 +
1.39 + Licensed under both the Apache License, Version 2.0 (the "Apache License")
1.40 + and the BSD License (the "BSD License"), with licensee being free to
1.41 + choose either of the two at their discretion.
1.42 +
1.43 + You may not use this file except in compliance with either the Apache
1.44 + License or the BSD License.
1.45 +
1.46 + If you choose to use this file in compliance with the Apache License, the
1.47 + following notice applies to you:
1.48 +
1.49 + You may obtain a copy of the Apache License at
1.50 +
1.51 + http://www.apache.org/licenses/LICENSE-2.0
1.52 +
1.53 + Unless required by applicable law or agreed to in writing, software
1.54 + distributed under the License is distributed on an "AS IS" BASIS,
1.55 + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
1.56 + implied. See the License for the specific language governing
1.57 + permissions and limitations under the License.
1.58 +
1.59 + If you choose to use this file in compliance with the BSD License, the
1.60 + following notice applies to you:
1.61 +
1.62 + Redistribution and use in source and binary forms, with or without
1.63 + modification, are permitted provided that the following conditions are
1.64 + met:
1.65 + * Redistributions of source code must retain the above copyright
1.66 + notice, this list of conditions and the following disclaimer.
1.67 + * Redistributions in binary form must reproduce the above copyright
1.68 + notice, this list of conditions and the following disclaimer in the
1.69 + documentation and/or other materials provided with the distribution.
1.70 + * Neither the name of the copyright holder nor the names of
1.71 + contributors may be used to endorse or promote products derived from
1.72 + this software without specific prior written permission.
1.73 +
1.74 + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
1.75 + IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
1.76 + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
1.77 + PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
1.78 + BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.79 + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.80 + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
1.81 + BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
1.82 + WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
1.83 + OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
1.84 + ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.85 +*/
1.86 +
1.87 +package jdk.internal.dynalink.beans;
1.88 +
1.89 +import java.lang.invoke.MethodHandle;
1.90 +import java.lang.invoke.MethodHandles;
1.91 +import java.lang.invoke.MethodType;
1.92 +import java.lang.reflect.Array;
1.93 +import java.util.Collection;
1.94 +import java.util.List;
1.95 +import java.util.Map;
1.96 +import jdk.internal.dynalink.CallSiteDescriptor;
1.97 +import jdk.internal.dynalink.beans.GuardedInvocationComponent.ValidationType;
1.98 +import jdk.internal.dynalink.linker.GuardedInvocation;
1.99 +import jdk.internal.dynalink.linker.LinkerServices;
1.100 +import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
1.101 +import jdk.internal.dynalink.support.Guards;
1.102 +import jdk.internal.dynalink.support.Lookup;
1.103 +import jdk.internal.dynalink.support.TypeUtilities;
1.104 +
1.105 +
1.106 +/**
1.107 + * A class that provides linking capabilities for a single POJO class. Normally not used directly, but managed by
1.108 + * {@link BeansLinker}.
1.109 + *
1.110 + * @author Attila Szegedi
1.111 + */
1.112 +class BeanLinker extends AbstractJavaLinker implements TypeBasedGuardingDynamicLinker {
1.113 + BeanLinker(Class<?> clazz) {
1.114 + super(clazz, Guards.getClassGuard(clazz), Guards.getInstanceOfGuard(clazz));
1.115 + if(clazz.isArray()) {
1.116 + // Some languages won't have a notion of manipulating collections. Exposing "length" on arrays as an
1.117 + // explicit property is beneficial for them.
1.118 + // REVISIT: is it maybe a code smell that "dyn:getLength" is not needed?
1.119 + setPropertyGetter("length", GET_ARRAY_LENGTH, ValidationType.IS_ARRAY);
1.120 + }
1.121 + }
1.122 +
1.123 + @Override
1.124 + public boolean canLinkType(Class<?> type) {
1.125 + return type == clazz;
1.126 + }
1.127 +
1.128 + @Override
1.129 + FacetIntrospector createFacetIntrospector() {
1.130 + return new BeanIntrospector(clazz);
1.131 + }
1.132 +
1.133 + @Override
1.134 + protected GuardedInvocationComponent getGuardedInvocationComponent(CallSiteDescriptor callSiteDescriptor,
1.135 + LinkerServices linkerServices, List<String> operations) throws Exception {
1.136 + final GuardedInvocationComponent superGic = super.getGuardedInvocationComponent(callSiteDescriptor,
1.137 + linkerServices, operations);
1.138 + if(superGic != null) {
1.139 + return superGic;
1.140 + }
1.141 + if(operations.isEmpty()) {
1.142 + return null;
1.143 + }
1.144 + final String op = operations.get(0);
1.145 + // dyn:getElem(this, id)
1.146 + // id is typically either an int (for arrays and lists) or an object (for maps). linkerServices can provide
1.147 + // conversion from call site argument type though.
1.148 + if("getElem".equals(op)) {
1.149 + return getElementGetter(callSiteDescriptor, linkerServices, pop(operations));
1.150 + }
1.151 + if("setElem".equals(op)) {
1.152 + return getElementSetter(callSiteDescriptor, linkerServices, pop(operations));
1.153 + }
1.154 + // dyn:getLength(this) (works on Java arrays, collections, and maps)
1.155 + if("getLength".equals(op)) {
1.156 + return getLengthGetter(callSiteDescriptor);
1.157 + }
1.158 + return null;
1.159 + }
1.160 +
1.161 + private static MethodHandle GET_LIST_ELEMENT = Lookup.PUBLIC.findVirtual(List.class, "get",
1.162 + MethodType.methodType(Object.class, int.class));
1.163 +
1.164 + private static MethodHandle GET_MAP_ELEMENT = Lookup.PUBLIC.findVirtual(Map.class, "get",
1.165 + MethodType.methodType(Object.class, Object.class));
1.166 +
1.167 + private static MethodHandle LIST_GUARD = Guards.getInstanceOfGuard(List.class);
1.168 + private static MethodHandle MAP_GUARD = Guards.getInstanceOfGuard(Map.class);
1.169 +
1.170 + private GuardedInvocationComponent getElementGetter(final CallSiteDescriptor callSiteDescriptor,
1.171 + final LinkerServices linkerServices, List<String> operations) throws Exception {
1.172 + final MethodType callSiteType = callSiteDescriptor.getMethodType();
1.173 + final Class<?> declaredType = callSiteType.parameterType(0);
1.174 + final GuardedInvocationComponent nextComponent = getGuardedInvocationComponent(callSiteDescriptor,
1.175 + linkerServices, operations);
1.176 +
1.177 + // If declared type of receiver at the call site is already an array, a list or map, bind without guard. Thing
1.178 + // is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance they're
1.179 + // dealing with an array, or a list or map, but hey...
1.180 + // Note that for arrays and lists, using LinkerServices.asType() will ensure that any language specific linkers
1.181 + // in use will get a chance to perform any (if there's any) implicit conversion to integer for the indices.
1.182 + final GuardedInvocationComponent gic;;
1.183 + final boolean isMap;
1.184 + if(declaredType.isArray()) {
1.185 + gic = new GuardedInvocationComponent(MethodHandles.arrayElementGetter(declaredType));
1.186 + isMap = false;
1.187 + } else if(List.class.isAssignableFrom(declaredType)) {
1.188 + gic = new GuardedInvocationComponent(GET_LIST_ELEMENT);
1.189 + isMap = false;
1.190 + } else if(Map.class.isAssignableFrom(declaredType)) {
1.191 + gic = new GuardedInvocationComponent(GET_MAP_ELEMENT);
1.192 + isMap = true;
1.193 + } else if(clazz.isArray()) {
1.194 + gic = getClassGuardedInvocationComponent(MethodHandles.arrayElementGetter(clazz), callSiteType);
1.195 + isMap = false;
1.196 + } else if(List.class.isAssignableFrom(clazz)) {
1.197 + gic = new GuardedInvocationComponent(GET_LIST_ELEMENT, Guards.asType(LIST_GUARD, callSiteType), List.class,
1.198 + ValidationType.INSTANCE_OF);
1.199 + isMap = false;
1.200 + } else if(Map.class.isAssignableFrom(clazz)) {
1.201 + gic = new GuardedInvocationComponent(GET_MAP_ELEMENT, Guards.asType(MAP_GUARD, callSiteType), Map.class,
1.202 + ValidationType.INSTANCE_OF);
1.203 + isMap = true;
1.204 + } else {
1.205 + // Can't retrieve elements for objects that are neither arrays, nor list, nor maps.
1.206 + return nextComponent;
1.207 + }
1.208 +
1.209 + // We can have "dyn:getElem:foo", especially in composites, i.e. "dyn:getElem|getProp|getMethod:foo"
1.210 + final String fixedKey = getFixedKey(callSiteDescriptor);
1.211 + // Convert the key to a number if we're working with a list or array
1.212 + final Object typedFixedKey;
1.213 + if(!isMap && fixedKey != null) {
1.214 + typedFixedKey = convertKeyToInteger(fixedKey, linkerServices);
1.215 + if(typedFixedKey == null) {
1.216 + // key is not numeric, it can never succeed
1.217 + return nextComponent;
1.218 + }
1.219 + } else {
1.220 + typedFixedKey = fixedKey;
1.221 + }
1.222 +
1.223 + final GuardedInvocation gi = gic.getGuardedInvocation();
1.224 + final Binder binder = new Binder(linkerServices, callSiteType, typedFixedKey);
1.225 + final MethodHandle invocation = gi.getInvocation();
1.226 +
1.227 + if(nextComponent == null) {
1.228 + return gic.replaceInvocation(binder.bind(invocation));
1.229 + } else {
1.230 + final MethodHandle checkGuard;
1.231 + if(invocation == GET_LIST_ELEMENT) {
1.232 + checkGuard = convertArgToInt(RANGE_CHECK_LIST, linkerServices, callSiteDescriptor);
1.233 + } else if(invocation == GET_MAP_ELEMENT) {
1.234 + // TODO: A more complex solution could be devised for maps, one where we do a get() first, and fold it
1.235 + // into a GWT that tests if it returned null, and if it did, do another GWT with containsKey()
1.236 + // that returns constant null (on true), or falls back to next component (on false)
1.237 + checkGuard = CONTAINS_MAP;
1.238 + } else {
1.239 + checkGuard = convertArgToInt(RANGE_CHECK_ARRAY, linkerServices, callSiteDescriptor);
1.240 + }
1.241 + return nextComponent.compose(MethodHandles.guardWithTest(binder.bindTest(checkGuard),
1.242 + binder.bind(invocation), nextComponent.getGuardedInvocation().getInvocation()), gi.getGuard(),
1.243 + gic.getValidatorClass(), gic.getValidationType());
1.244 + }
1.245 + }
1.246 +
1.247 + private static String getFixedKey(final CallSiteDescriptor callSiteDescriptor) {
1.248 + return callSiteDescriptor.getNameTokenCount() == 2 ? null : callSiteDescriptor.getNameToken(
1.249 + CallSiteDescriptor.NAME_OPERAND);
1.250 + }
1.251 +
1.252 + private static Object convertKeyToInteger(String fixedKey, LinkerServices linkerServices) throws Exception {
1.253 + try {
1.254 + if(linkerServices.canConvert(String.class, Number.class)) {
1.255 + try {
1.256 + final Object val = linkerServices.getTypeConverter(String.class, Number.class).invoke(fixedKey);
1.257 + if(!(val instanceof Number)) {
1.258 + return null; // not a number
1.259 + }
1.260 + final Number n = (Number)val;
1.261 + if(n instanceof Integer) {
1.262 + return n;
1.263 + }
1.264 + final int intIndex = n.intValue();
1.265 + final double doubleValue = n.doubleValue();
1.266 + if(intIndex != doubleValue && !Double.isInfinite(doubleValue)) { // let infinites trigger IOOBE
1.267 + return null; // not an exact integer
1.268 + }
1.269 + return Integer.valueOf(intIndex);
1.270 + } catch(Exception|Error e) {
1.271 + throw e;
1.272 + } catch(Throwable t) {
1.273 + throw new RuntimeException(t);
1.274 + }
1.275 + }
1.276 + return Integer.valueOf(fixedKey);
1.277 + } catch(NumberFormatException e) {
1.278 + // key is not a number
1.279 + return null;
1.280 + }
1.281 + }
1.282 +
1.283 + private static MethodHandle convertArgToInt(MethodHandle mh, LinkerServices ls, CallSiteDescriptor desc) {
1.284 + final Class<?> sourceType = desc.getMethodType().parameterType(1);
1.285 + if(TypeUtilities.isMethodInvocationConvertible(sourceType, Number.class)) {
1.286 + return mh;
1.287 + } else if(ls.canConvert(sourceType, Number.class)) {
1.288 + final MethodHandle converter = ls.getTypeConverter(sourceType, Number.class);
1.289 + return MethodHandles.filterArguments(mh, 1, converter.asType(converter.type().changeReturnType(
1.290 + mh.type().parameterType(1))));
1.291 + }
1.292 + return mh;
1.293 + }
1.294 +
1.295 + /**
1.296 + * Contains methods to adapt an item getter/setter method handle to the requested type, optionally binding it to a
1.297 + * fixed key first.
1.298 + * @author Attila Szegedi
1.299 + * @version $Id: $
1.300 + */
1.301 + private static class Binder {
1.302 + private final LinkerServices linkerServices;
1.303 + private final MethodType methodType;
1.304 + private final Object fixedKey;
1.305 +
1.306 + Binder(LinkerServices linkerServices, MethodType methodType, Object fixedKey) {
1.307 + this.linkerServices = linkerServices;
1.308 + this.methodType = fixedKey == null ? methodType : methodType.insertParameterTypes(1, fixedKey.getClass());
1.309 + this.fixedKey = fixedKey;
1.310 + }
1.311 +
1.312 + /*private*/ MethodHandle bind(MethodHandle handle) {
1.313 + return bindToFixedKey(linkerServices.asType(handle, methodType));
1.314 + }
1.315 +
1.316 + /*private*/ MethodHandle bindTest(MethodHandle handle) {
1.317 + return bindToFixedKey(Guards.asType(handle, methodType));
1.318 + }
1.319 +
1.320 + private MethodHandle bindToFixedKey(MethodHandle handle) {
1.321 + return fixedKey == null ? handle : MethodHandles.insertArguments(handle, 1, fixedKey);
1.322 + }
1.323 + }
1.324 +
1.325 + private static MethodHandle RANGE_CHECK_ARRAY = findRangeCheck(Object.class);
1.326 + private static MethodHandle RANGE_CHECK_LIST = findRangeCheck(List.class);
1.327 + private static MethodHandle CONTAINS_MAP = Lookup.PUBLIC.findVirtual(Map.class, "containsKey",
1.328 + MethodType.methodType(boolean.class, Object.class));
1.329 +
1.330 + private static MethodHandle findRangeCheck(Class<?> collectionType) {
1.331 + return Lookup.findOwnStatic(MethodHandles.lookup(), "rangeCheck", boolean.class, collectionType, Object.class);
1.332 + }
1.333 +
1.334 + @SuppressWarnings("unused")
1.335 + private static final boolean rangeCheck(Object array, Object index) {
1.336 + if(!(index instanceof Number)) {
1.337 + return false;
1.338 + }
1.339 + final Number n = (Number)index;
1.340 + final int intIndex = n.intValue();
1.341 + final double doubleValue = n.doubleValue();
1.342 + if(intIndex != doubleValue && !Double.isInfinite(doubleValue)) { // let infinite trigger IOOBE
1.343 + return false;
1.344 + }
1.345 + if(0 <= intIndex && intIndex < Array.getLength(array)) {
1.346 + return true;
1.347 + }
1.348 + throw new ArrayIndexOutOfBoundsException("Array index out of range: " + n);
1.349 + }
1.350 +
1.351 + @SuppressWarnings("unused")
1.352 + private static final boolean rangeCheck(List<?> list, Object index) {
1.353 + if(!(index instanceof Number)) {
1.354 + return false;
1.355 + }
1.356 + final Number n = (Number)index;
1.357 + final int intIndex = n.intValue();
1.358 + final double doubleValue = n.doubleValue();
1.359 + if(intIndex != doubleValue && !Double.isInfinite(doubleValue)) { // let infinite trigger IOOBE
1.360 + return false;
1.361 + }
1.362 + if(0 <= intIndex && intIndex < list.size()) {
1.363 + return true;
1.364 + }
1.365 + throw new IndexOutOfBoundsException("Index: " + n + ", Size: " + list.size());
1.366 + }
1.367 +
1.368 + private static MethodHandle SET_LIST_ELEMENT = Lookup.PUBLIC.findVirtual(List.class, "set",
1.369 + MethodType.methodType(Object.class, int.class, Object.class));
1.370 +
1.371 + private static MethodHandle PUT_MAP_ELEMENT = Lookup.PUBLIC.findVirtual(Map.class, "put",
1.372 + MethodType.methodType(Object.class, Object.class, Object.class));
1.373 +
1.374 + private GuardedInvocationComponent getElementSetter(CallSiteDescriptor callSiteDescriptor,
1.375 + LinkerServices linkerServices, List<String> operations) throws Exception {
1.376 + final MethodType callSiteType = callSiteDescriptor.getMethodType();
1.377 + final Class<?> declaredType = callSiteType.parameterType(0);
1.378 +
1.379 + final GuardedInvocationComponent gic;
1.380 + // If declared type of receiver at the call site is already an array, a list or map, bind without guard. Thing
1.381 + // is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance they're
1.382 + // dealing with an array, or a list or map, but hey...
1.383 + // Note that for arrays and lists, using LinkerServices.asType() will ensure that any language specific linkers
1.384 + // in use will get a chance to perform any (if there's any) implicit conversion to integer for the indices.
1.385 + final boolean isMap;
1.386 + if(declaredType.isArray()) {
1.387 + gic = new GuardedInvocationComponent(MethodHandles.arrayElementSetter(declaredType));
1.388 + isMap = false;
1.389 + } else if(List.class.isAssignableFrom(declaredType)) {
1.390 + gic = new GuardedInvocationComponent(SET_LIST_ELEMENT);
1.391 + isMap = false;
1.392 + } else if(Map.class.isAssignableFrom(declaredType)) {
1.393 + gic = new GuardedInvocationComponent(PUT_MAP_ELEMENT);
1.394 + isMap = true;
1.395 + } else if(clazz.isArray()) {
1.396 + gic = getClassGuardedInvocationComponent(MethodHandles.arrayElementSetter(clazz), callSiteType);
1.397 + isMap = false;
1.398 + } else if(List.class.isAssignableFrom(clazz)) {
1.399 + gic = new GuardedInvocationComponent(SET_LIST_ELEMENT, Guards.asType(LIST_GUARD, callSiteType), List.class,
1.400 + ValidationType.INSTANCE_OF);
1.401 + isMap = false;
1.402 + } else if(Map.class.isAssignableFrom(clazz)) {
1.403 + gic = new GuardedInvocationComponent(PUT_MAP_ELEMENT, Guards.asType(MAP_GUARD, callSiteType), Map.class,
1.404 + ValidationType.INSTANCE_OF);
1.405 + isMap = true;
1.406 + } else {
1.407 + // Can't set elements for objects that are neither arrays, nor list, nor maps.
1.408 + gic = null;
1.409 + isMap = false;
1.410 + }
1.411 +
1.412 + // In contrast to, say, getElementGetter, we only compute the nextComponent if the target object is not a map,
1.413 + // as maps will always succeed in setting the element and will never need to fall back to the next component
1.414 + // operation.
1.415 + final GuardedInvocationComponent nextComponent = isMap ? null : getGuardedInvocationComponent(
1.416 + callSiteDescriptor, linkerServices, operations);
1.417 + if(gic == null) {
1.418 + return nextComponent;
1.419 + }
1.420 +
1.421 + // We can have "dyn:setElem:foo", especially in composites, i.e. "dyn:setElem|setProp:foo"
1.422 + final String fixedKey = getFixedKey(callSiteDescriptor);
1.423 + // Convert the key to a number if we're working with a list or array
1.424 + final Object typedFixedKey;
1.425 + if(!isMap && fixedKey != null) {
1.426 + typedFixedKey = convertKeyToInteger(fixedKey, linkerServices);
1.427 + if(typedFixedKey == null) {
1.428 + // key is not numeric, it can never succeed
1.429 + return nextComponent;
1.430 + }
1.431 + } else {
1.432 + typedFixedKey = fixedKey;
1.433 + }
1.434 +
1.435 + final GuardedInvocation gi = gic.getGuardedInvocation();
1.436 + final Binder binder = new Binder(linkerServices, callSiteType, typedFixedKey);
1.437 + final MethodHandle invocation = gi.getInvocation();
1.438 +
1.439 + if(nextComponent == null) {
1.440 + return gic.replaceInvocation(binder.bind(invocation));
1.441 + } else {
1.442 + final MethodHandle checkGuard = convertArgToInt(invocation == SET_LIST_ELEMENT ? RANGE_CHECK_LIST :
1.443 + RANGE_CHECK_ARRAY, linkerServices, callSiteDescriptor);
1.444 + return nextComponent.compose(MethodHandles.guardWithTest(binder.bindTest(checkGuard),
1.445 + binder.bind(invocation), nextComponent.getGuardedInvocation().getInvocation()), gi.getGuard(),
1.446 + gic.getValidatorClass(), gic.getValidationType());
1.447 + }
1.448 + }
1.449 +
1.450 + private static MethodHandle GET_ARRAY_LENGTH = Lookup.PUBLIC.findStatic(Array.class, "getLength",
1.451 + MethodType.methodType(int.class, Object.class));
1.452 +
1.453 + private static MethodHandle GET_COLLECTION_LENGTH = Lookup.PUBLIC.findVirtual(Collection.class, "size",
1.454 + MethodType.methodType(int.class));
1.455 +
1.456 + private static MethodHandle GET_MAP_LENGTH = Lookup.PUBLIC.findVirtual(Map.class, "size",
1.457 + MethodType.methodType(int.class));
1.458 +
1.459 + private static MethodHandle COLLECTION_GUARD = Guards.getInstanceOfGuard(Collection.class);
1.460 +
1.461 + private GuardedInvocationComponent getLengthGetter(CallSiteDescriptor callSiteDescriptor) {
1.462 + assertParameterCount(callSiteDescriptor, 1);
1.463 + final MethodType callSiteType = callSiteDescriptor.getMethodType();
1.464 + final Class<?> declaredType = callSiteType.parameterType(0);
1.465 + // If declared type of receiver at the call site is already an array, collection, or map, bind without guard.
1.466 + // Thing is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance
1.467 + // they're dealing with an array, collection, or map, but hey...
1.468 + if(declaredType.isArray()) {
1.469 + return new GuardedInvocationComponent(GET_ARRAY_LENGTH.asType(callSiteType));
1.470 + } else if(Collection.class.isAssignableFrom(declaredType)) {
1.471 + return new GuardedInvocationComponent(GET_COLLECTION_LENGTH.asType(callSiteType));
1.472 + } else if(Map.class.isAssignableFrom(declaredType)) {
1.473 + return new GuardedInvocationComponent(GET_MAP_LENGTH.asType(callSiteType));
1.474 + }
1.475 +
1.476 + // Otherwise, create a binding based on the actual type of the argument with an appropriate guard.
1.477 + if(clazz.isArray()) {
1.478 + return new GuardedInvocationComponent(GET_ARRAY_LENGTH.asType(callSiteType), Guards.isArray(0,
1.479 + callSiteType), ValidationType.IS_ARRAY);
1.480 + } if(Collection.class.isAssignableFrom(clazz)) {
1.481 + return new GuardedInvocationComponent(GET_COLLECTION_LENGTH.asType(callSiteType), Guards.asType(
1.482 + COLLECTION_GUARD, callSiteType), Collection.class, ValidationType.INSTANCE_OF);
1.483 + } if(Map.class.isAssignableFrom(clazz)) {
1.484 + return new GuardedInvocationComponent(GET_MAP_LENGTH.asType(callSiteType), Guards.asType(MAP_GUARD,
1.485 + callSiteType), Map.class, ValidationType.INSTANCE_OF);
1.486 + }
1.487 + // Can't retrieve length for objects that are neither arrays, nor collections, nor maps.
1.488 + return null;
1.489 + }
1.490 +
1.491 + private static void assertParameterCount(CallSiteDescriptor descriptor, int paramCount) {
1.492 + if(descriptor.getMethodType().parameterCount() != paramCount) {
1.493 + throw new BootstrapMethodError(descriptor.getName() + " must have exactly " + paramCount + " parameters.");
1.494 + }
1.495 + }
1.496 +}
1.497 \ No newline at end of file
