Java Guards.asType方法代码示例

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private GuardedInvocationComponent getLengthGetter(final CallSiteDescriptor callSiteDescriptor) {
    assertParameterCount(callSiteDescriptor, 1);
    final MethodType callSiteType = callSiteDescriptor.getMethodType();
    final Class<?> declaredType = callSiteType.parameterType(0);
    // If declared type of receiver at the call site is already an array, collection, or map, bind without guard.
    // Thing is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance
    // they're dealing with an array, collection, or map, but hey...
    if(declaredType.isArray()) {
        return new GuardedInvocationComponent(GET_ARRAY_LENGTH.asType(callSiteType));
    } else if(Collection.class.isAssignableFrom(declaredType)) {
        return new GuardedInvocationComponent(GET_COLLECTION_LENGTH.asType(callSiteType));
    } else if(Map.class.isAssignableFrom(declaredType)) {
        return new GuardedInvocationComponent(GET_MAP_LENGTH.asType(callSiteType));
    }

    // Otherwise, create a binding based on the actual type of the argument with an appropriate guard.
    if(clazz.isArray()) {
        return new GuardedInvocationComponent(GET_ARRAY_LENGTH.asType(callSiteType), Guards.isArray(0,
                callSiteType), ValidationType.IS_ARRAY);
    } if(Collection.class.isAssignableFrom(clazz)) {
        return new GuardedInvocationComponent(GET_COLLECTION_LENGTH.asType(callSiteType), Guards.asType(
                COLLECTION_GUARD, callSiteType), Collection.class, ValidationType.INSTANCE_OF);
    } if(Map.class.isAssignableFrom(clazz)) {
        return new GuardedInvocationComponent(GET_MAP_LENGTH.asType(callSiteType), Guards.asType(MAP_GUARD,
                callSiteType), Map.class, ValidationType.INSTANCE_OF);
    }
    // Can't retrieve length for objects that are neither arrays, nor collections, nor maps.
    return null;
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private GuardedInvocationComponent getLengthGetter(CallSiteDescriptor callSiteDescriptor) {
    assertParameterCount(callSiteDescriptor, 1);
    final MethodType callSiteType = callSiteDescriptor.getMethodType();
    final Class<?> declaredType = callSiteType.parameterType(0);
    // If declared type of receiver at the call site is already an array, collection, or map, bind without guard.
    // Thing is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance
    // they're dealing with an array, collection, or map, but hey...
    if(declaredType.isArray()) {
        return new GuardedInvocationComponent(GET_ARRAY_LENGTH.asType(callSiteType));
    } else if(Collection.class.isAssignableFrom(declaredType)) {
        return new GuardedInvocationComponent(GET_COLLECTION_LENGTH.asType(callSiteType));
    } else if(Map.class.isAssignableFrom(declaredType)) {
        return new GuardedInvocationComponent(GET_MAP_LENGTH.asType(callSiteType));
    }

    // Otherwise, create a binding based on the actual type of the argument with an appropriate guard.
    if(clazz.isArray()) {
        return new GuardedInvocationComponent(GET_ARRAY_LENGTH.asType(callSiteType), Guards.isArray(0,
                callSiteType), ValidationType.IS_ARRAY);
    } if(Collection.class.isAssignableFrom(clazz)) {
        return new GuardedInvocationComponent(GET_COLLECTION_LENGTH.asType(callSiteType), Guards.asType(
                COLLECTION_GUARD, callSiteType), Collection.class, ValidationType.INSTANCE_OF);
    } if(Map.class.isAssignableFrom(clazz)) {
        return new GuardedInvocationComponent(GET_MAP_LENGTH.asType(callSiteType), Guards.asType(MAP_GUARD,
                callSiteType), Map.class, ValidationType.INSTANCE_OF);
    }
    // Can't retrieve length for objects that are neither arrays, nor collections, nor maps.
    return null;
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
MethodHandle getClassGuard(final MethodType type) {
    return Guards.asType(classGuard, type);
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private MethodHandle getAssignableGuard(final MethodType type) {
    return Guards.asType(assignableGuard, type);
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private GuardedInvocationComponent getElementGetter(final CallSiteDescriptor callSiteDescriptor,
        final LinkerServices linkerServices, final List<String> operations) throws Exception {
    final MethodType callSiteType = callSiteDescriptor.getMethodType();
    final Class<?> declaredType = callSiteType.parameterType(0);
    final GuardedInvocationComponent nextComponent = getGuardedInvocationComponent(callSiteDescriptor,
            linkerServices, operations);

    // If declared type of receiver at the call site is already an array, a list or map, bind without guard. Thing
    // is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance they're
    // dealing with an array, or a list or map, but hey...
    // Note that for arrays and lists, using LinkerServices.asType() will ensure that any language specific linkers
    // in use will get a chance to perform any (if there's any) implicit conversion to integer for the indices.
    final GuardedInvocationComponent gic;
    final boolean isMap;
    if(declaredType.isArray()) {
        gic = new GuardedInvocationComponent(MethodHandles.arrayElementGetter(declaredType));
        isMap = false;
    } else if(List.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(GET_LIST_ELEMENT);
        isMap = false;
    } else if(Map.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(GET_MAP_ELEMENT);
        isMap = true;
    } else if(clazz.isArray()) {
        gic = getClassGuardedInvocationComponent(MethodHandles.arrayElementGetter(clazz), callSiteType);
        isMap = false;
    } else if(List.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(GET_LIST_ELEMENT, Guards.asType(LIST_GUARD, callSiteType), List.class,
                ValidationType.INSTANCE_OF);
        isMap = false;
    } else if(Map.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(GET_MAP_ELEMENT, Guards.asType(MAP_GUARD, callSiteType), Map.class,
                ValidationType.INSTANCE_OF);
        isMap = true;
    } else {
        // Can't retrieve elements for objects that are neither arrays, nor list, nor maps.
        return nextComponent;
    }

    // We can have "dyn:getElem:foo", especially in composites, i.e. "dyn:getElem|getProp|getMethod:foo"
    final String fixedKey = getFixedKey(callSiteDescriptor);
    // Convert the key to a number if we're working with a list or array
    final Object typedFixedKey;
    if(!isMap && fixedKey != null) {
        typedFixedKey = convertKeyToInteger(fixedKey, linkerServices);
        if(typedFixedKey == null) {
            // key is not numeric, it can never succeed
            return nextComponent;
        }
    } else {
        typedFixedKey = fixedKey;
    }

    final GuardedInvocation gi = gic.getGuardedInvocation();
    final Binder binder = new Binder(linkerServices, callSiteType, typedFixedKey);
    final MethodHandle invocation = gi.getInvocation();

    if(nextComponent == null) {
        return gic.replaceInvocation(binder.bind(invocation));
    }

    final MethodHandle checkGuard;
    if(invocation == GET_LIST_ELEMENT) {
        checkGuard = convertArgToInt(RANGE_CHECK_LIST, linkerServices, callSiteDescriptor);
    } else if(invocation == GET_MAP_ELEMENT) {
        // TODO: A more complex solution could be devised for maps, one where we do a get() first, and fold it
        // into a GWT that tests if it returned null, and if it did, do another GWT with containsKey()
        // that returns constant null (on true), or falls back to next component (on false)
        checkGuard = CONTAINS_MAP;
    } else {
        checkGuard = convertArgToInt(RANGE_CHECK_ARRAY, linkerServices, callSiteDescriptor);
    }
    final MethodPair matchedInvocations = matchReturnTypes(binder.bind(invocation),
            nextComponent.getGuardedInvocation().getInvocation());
    return nextComponent.compose(matchedInvocations.guardWithTest(binder.bindTest(checkGuard)), gi.getGuard(),
            gic.getValidatorClass(), gic.getValidationType());
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private GuardedInvocationComponent getElementSetter(final CallSiteDescriptor callSiteDescriptor,
        final LinkerServices linkerServices, final List<String> operations) throws Exception {
    final MethodType callSiteType = callSiteDescriptor.getMethodType();
    final Class<?> declaredType = callSiteType.parameterType(0);

    final GuardedInvocationComponent gic;
    // If declared type of receiver at the call site is already an array, a list or map, bind without guard. Thing
    // is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance they're
    // dealing with an array, or a list or map, but hey...
    // Note that for arrays and lists, using LinkerServices.asType() will ensure that any language specific linkers
    // in use will get a chance to perform any (if there's any) implicit conversion to integer for the indices.
    final boolean isMap;
    if(declaredType.isArray()) {
        gic = new GuardedInvocationComponent(MethodHandles.arrayElementSetter(declaredType));
        isMap = false;
    } else if(List.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(SET_LIST_ELEMENT);
        isMap = false;
    } else if(Map.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(PUT_MAP_ELEMENT);
        isMap = true;
    } else if(clazz.isArray()) {
        gic = getClassGuardedInvocationComponent(MethodHandles.arrayElementSetter(clazz), callSiteType);
        isMap = false;
    } else if(List.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(SET_LIST_ELEMENT, Guards.asType(LIST_GUARD, callSiteType), List.class,
                ValidationType.INSTANCE_OF);
        isMap = false;
    } else if(Map.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(PUT_MAP_ELEMENT, Guards.asType(MAP_GUARD, callSiteType), Map.class,
                ValidationType.INSTANCE_OF);
        isMap = true;
    } else {
        // Can't set elements for objects that are neither arrays, nor list, nor maps.
        gic = null;
        isMap = false;
    }

    // In contrast to, say, getElementGetter, we only compute the nextComponent if the target object is not a map,
    // as maps will always succeed in setting the element and will never need to fall back to the next component
    // operation.
    final GuardedInvocationComponent nextComponent = isMap ? null : getGuardedInvocationComponent(
            callSiteDescriptor, linkerServices, operations);
    if(gic == null) {
        return nextComponent;
    }

    // We can have "dyn:setElem:foo", especially in composites, i.e. "dyn:setElem|setProp:foo"
    final String fixedKey = getFixedKey(callSiteDescriptor);
    // Convert the key to a number if we're working with a list or array
    final Object typedFixedKey;
    if(!isMap && fixedKey != null) {
        typedFixedKey = convertKeyToInteger(fixedKey, linkerServices);
        if(typedFixedKey == null) {
            // key is not numeric, it can never succeed
            return nextComponent;
        }
    } else {
        typedFixedKey = fixedKey;
    }

    final GuardedInvocation gi = gic.getGuardedInvocation();
    final Binder binder = new Binder(linkerServices, callSiteType, typedFixedKey);
    final MethodHandle invocation = gi.getInvocation();

    if(nextComponent == null) {
        return gic.replaceInvocation(binder.bind(invocation));
    }

    final MethodHandle checkGuard = convertArgToInt(invocation == SET_LIST_ELEMENT ? RANGE_CHECK_LIST :
        RANGE_CHECK_ARRAY, linkerServices, callSiteDescriptor);
    final MethodPair matchedInvocations = matchReturnTypes(binder.bind(invocation),
            nextComponent.getGuardedInvocation().getInvocation());
    return nextComponent.compose(matchedInvocations.guardWithTest(binder.bindTest(checkGuard)), gi.getGuard(),
            gic.getValidatorClass(), gic.getValidationType());
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
MethodHandle getClassGuard(MethodType type) {
    return Guards.asType(classGuard, type);
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private MethodHandle getAssignableGuard(MethodType type) {
    return Guards.asType(assignableGuard, type);
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private GuardedInvocationComponent getElementGetter(final CallSiteDescriptor callSiteDescriptor,
        final LinkerServices linkerServices, List<String> operations) throws Exception {
    final MethodType callSiteType = callSiteDescriptor.getMethodType();
    final Class<?> declaredType = callSiteType.parameterType(0);
    final GuardedInvocationComponent nextComponent = getGuardedInvocationComponent(callSiteDescriptor,
            linkerServices, operations);

    // If declared type of receiver at the call site is already an array, a list or map, bind without guard. Thing
    // is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance they're
    // dealing with an array, or a list or map, but hey...
    // Note that for arrays and lists, using LinkerServices.asType() will ensure that any language specific linkers
    // in use will get a chance to perform any (if there's any) implicit conversion to integer for the indices.
    final GuardedInvocationComponent gic;
    final boolean isMap;
    if(declaredType.isArray()) {
        gic = new GuardedInvocationComponent(MethodHandles.arrayElementGetter(declaredType));
        isMap = false;
    } else if(List.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(GET_LIST_ELEMENT);
        isMap = false;
    } else if(Map.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(GET_MAP_ELEMENT);
        isMap = true;
    } else if(clazz.isArray()) {
        gic = getClassGuardedInvocationComponent(MethodHandles.arrayElementGetter(clazz), callSiteType);
        isMap = false;
    } else if(List.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(GET_LIST_ELEMENT, Guards.asType(LIST_GUARD, callSiteType), List.class,
                ValidationType.INSTANCE_OF);
        isMap = false;
    } else if(Map.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(GET_MAP_ELEMENT, Guards.asType(MAP_GUARD, callSiteType), Map.class,
                ValidationType.INSTANCE_OF);
        isMap = true;
    } else {
        // Can't retrieve elements for objects that are neither arrays, nor list, nor maps.
        return nextComponent;
    }

    // We can have "dyn:getElem:foo", especially in composites, i.e. "dyn:getElem|getProp|getMethod:foo"
    final String fixedKey = getFixedKey(callSiteDescriptor);
    // Convert the key to a number if we're working with a list or array
    final Object typedFixedKey;
    if(!isMap && fixedKey != null) {
        typedFixedKey = convertKeyToInteger(fixedKey, linkerServices);
        if(typedFixedKey == null) {
            // key is not numeric, it can never succeed
            return nextComponent;
        }
    } else {
        typedFixedKey = fixedKey;
    }

    final GuardedInvocation gi = gic.getGuardedInvocation();
    final Binder binder = new Binder(linkerServices, callSiteType, typedFixedKey);
    final MethodHandle invocation = gi.getInvocation();

    if(nextComponent == null) {
        return gic.replaceInvocation(binder.bind(invocation));
    }

    final MethodHandle checkGuard;
    if(invocation == GET_LIST_ELEMENT) {
        checkGuard = convertArgToInt(RANGE_CHECK_LIST, linkerServices, callSiteDescriptor);
    } else if(invocation == GET_MAP_ELEMENT) {
        // TODO: A more complex solution could be devised for maps, one where we do a get() first, and fold it
        // into a GWT that tests if it returned null, and if it did, do another GWT with containsKey()
        // that returns constant null (on true), or falls back to next component (on false)
        checkGuard = CONTAINS_MAP;
    } else {
        checkGuard = convertArgToInt(RANGE_CHECK_ARRAY, linkerServices, callSiteDescriptor);
    }
    return nextComponent.compose(MethodHandles.guardWithTest(binder.bindTest(checkGuard),
            binder.bind(invocation), nextComponent.getGuardedInvocation().getInvocation()), gi.getGuard(),
            gic.getValidatorClass(), gic.getValidationType());
}
 

import jdk.internal.dynalink.support.Guards; //导入方法依赖的package包/类
private GuardedInvocationComponent getElementSetter(CallSiteDescriptor callSiteDescriptor,
        LinkerServices linkerServices, List<String> operations) throws Exception {
    final MethodType callSiteType = callSiteDescriptor.getMethodType();
    final Class<?> declaredType = callSiteType.parameterType(0);

    final GuardedInvocationComponent gic;
    // If declared type of receiver at the call site is already an array, a list or map, bind without guard. Thing
    // is, it'd be quite stupid of a call site creator to go though invokedynamic when it knows in advance they're
    // dealing with an array, or a list or map, but hey...
    // Note that for arrays and lists, using LinkerServices.asType() will ensure that any language specific linkers
    // in use will get a chance to perform any (if there's any) implicit conversion to integer for the indices.
    final boolean isMap;
    if(declaredType.isArray()) {
        gic = new GuardedInvocationComponent(MethodHandles.arrayElementSetter(declaredType));
        isMap = false;
    } else if(List.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(SET_LIST_ELEMENT);
        isMap = false;
    } else if(Map.class.isAssignableFrom(declaredType)) {
        gic = new GuardedInvocationComponent(PUT_MAP_ELEMENT);
        isMap = true;
    } else if(clazz.isArray()) {
        gic = getClassGuardedInvocationComponent(MethodHandles.arrayElementSetter(clazz), callSiteType);
        isMap = false;
    } else if(List.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(SET_LIST_ELEMENT, Guards.asType(LIST_GUARD, callSiteType), List.class,
                ValidationType.INSTANCE_OF);
        isMap = false;
    } else if(Map.class.isAssignableFrom(clazz)) {
        gic = new GuardedInvocationComponent(PUT_MAP_ELEMENT, Guards.asType(MAP_GUARD, callSiteType), Map.class,
                ValidationType.INSTANCE_OF);
        isMap = true;
    } else {
        // Can't set elements for objects that are neither arrays, nor list, nor maps.
        gic = null;
        isMap = false;
    }

    // In contrast to, say, getElementGetter, we only compute the nextComponent if the target object is not a map,
    // as maps will always succeed in setting the element and will never need to fall back to the next component
    // operation.
    final GuardedInvocationComponent nextComponent = isMap ? null : getGuardedInvocationComponent(
            callSiteDescriptor, linkerServices, operations);
    if(gic == null) {
        return nextComponent;
    }

    // We can have "dyn:setElem:foo", especially in composites, i.e. "dyn:setElem|setProp:foo"
    final String fixedKey = getFixedKey(callSiteDescriptor);
    // Convert the key to a number if we're working with a list or array
    final Object typedFixedKey;
    if(!isMap && fixedKey != null) {
        typedFixedKey = convertKeyToInteger(fixedKey, linkerServices);
        if(typedFixedKey == null) {
            // key is not numeric, it can never succeed
            return nextComponent;
        }
    } else {
        typedFixedKey = fixedKey;
    }

    final GuardedInvocation gi = gic.getGuardedInvocation();
    final Binder binder = new Binder(linkerServices, callSiteType, typedFixedKey);
    final MethodHandle invocation = gi.getInvocation();

    if(nextComponent == null) {
        return gic.replaceInvocation(binder.bind(invocation));
    }

    final MethodHandle checkGuard = convertArgToInt(invocation == SET_LIST_ELEMENT ? RANGE_CHECK_LIST :
        RANGE_CHECK_ARRAY, linkerServices, callSiteDescriptor);
    return nextComponent.compose(MethodHandles.guardWithTest(binder.bindTest(checkGuard),
            binder.bind(invocation), nextComponent.getGuardedInvocation().getInvocation()), gi.getGuard(),
            gic.getValidatorClass(), gic.getValidationType());
}