com.google.template.soy.jbcsrc.restricted.ConstructorRef.java Source code

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Here is the source code for com.google.template.soy.jbcsrc.restricted.ConstructorRef.java

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/*
 * Copyright 2015 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.template.soy.jbcsrc.restricted;

import static com.google.common.base.Preconditions.checkArgument;

import com.google.auto.value.AutoValue;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.google.template.soy.data.SoyRecord;
import com.google.template.soy.data.internal.AugmentedParamStore;
import com.google.template.soy.data.internal.BasicParamStore;
import com.google.template.soy.jbcsrc.restricted.Expression.Feature;
import com.google.template.soy.jbcsrc.runtime.JbcSrcRuntime;
import com.ibm.icu.util.ULocale;
import java.lang.reflect.Constructor;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedHashMap;
import org.objectweb.asm.Type;
import org.objectweb.asm.commons.Method;

/** A reference to a type that can be constructed at runtime. */
@AutoValue
public abstract class ConstructorRef {
    /**
     * Returns a new {@link ConstructorRef} that refers to a constructor on the given type with the
     * given parameter types.
     */
    public static ConstructorRef create(TypeInfo type, Method init) {
        checkArgument(init.getName().equals("<init>") && init.getReturnType().equals(Type.VOID_TYPE),
                "'%s' is not a valid constructor", init);
        return new AutoValue_ConstructorRef(type, init, ImmutableList.copyOf(init.getArgumentTypes()));
    }

    /**
     * Returns a new {@link ConstructorRef} that refers to a constructor on the given type with the
     * given parameter types.
     */
    public static ConstructorRef create(TypeInfo type, Iterable<Type> argTypes) {
        return create(type, new Method("<init>", Type.VOID_TYPE, Iterables.toArray(argTypes, Type.class)));
    }

    public static ConstructorRef create(Class<?> clazz, Class<?>... argTypes) {
        TypeInfo type = TypeInfo.create(clazz);
        Constructor<?> c;
        try {
            c = clazz.getConstructor(argTypes);
        } catch (NoSuchMethodException | SecurityException e) {
            throw new RuntimeException(e);
        }
        Type constructorType = Type.getType(c);

        return new AutoValue_ConstructorRef(type, Method.getMethod(c),
                ImmutableList.copyOf(constructorType.getArgumentTypes()));
    }

    public static final ConstructorRef ARRAY_LIST_SIZE = create(ArrayList.class, int.class);
    public static final ConstructorRef HASH_MAP_CAPACITY = create(HashMap.class, int.class);
    public static final ConstructorRef LINKED_HASH_MAP_CAPACITY = create(LinkedHashMap.class, int.class);
    public static final ConstructorRef AUGMENTED_PARAM_STORE = create(AugmentedParamStore.class, SoyRecord.class,
            int.class);
    public static final ConstructorRef BASIC_PARAM_STORE = create(BasicParamStore.class, int.class);

    public static final ConstructorRef MSG_RENDERER = create(JbcSrcRuntime.MsgRenderer.class, long.class,
            ImmutableList.class, ULocale.class, int.class);
    public static final ConstructorRef PLRSEL_MSG_RENDERER = create(JbcSrcRuntime.PlrSelMsgRenderer.class,
            long.class, ImmutableList.class, ULocale.class, int.class);

    public abstract TypeInfo instanceClass();

    public abstract Method method();

    public abstract ImmutableList<Type> argTypes();

    /**
     * Returns an expression that constructs a new instance of {@link #instanceClass()} by calling
     * this constructor.
     */
    public Expression construct(final Expression... args) {
        return construct(Arrays.asList(args));
    }

    /**
     * Returns an expression that constructs a new instance of {@link #instanceClass()} by calling
     * this constructor.
     */
    public Expression construct(final Iterable<? extends Expression> args) {
        Expression.checkTypes(argTypes(), args);
        return new Expression(instanceClass().type(), Feature.NON_NULLABLE) {
            @Override
            protected void doGen(CodeBuilder mv) {
                mv.newInstance(instanceClass().type());
                // push a second reference onto the stack so there is still a reference to the new object
                // after invoking the constructor (constructors are void methods)
                mv.dup();
                for (Expression arg : args) {
                    arg.gen(mv);
                }
                mv.invokeConstructor(instanceClass().type(), method());
            }
        };
    }
}