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package org.jruby.runtime.opto;

import org.jruby.Ruby;
import org.jruby.RubyModule;
import org.jruby.runtime.ThreadContext;
import org.jruby.util.cli.Options;

import java.lang.invoke.MethodHandles;

A set of factory methods to construct optimizing utilities for compilation,
cache invalidation, and so on.
/**
 * A set of factory methods to construct optimizing utilities for compilation,
 * cache invalidation, and so on.
 */
public class OptoFactory {

    
Create a new "constant" representation for this object, conforming to the given concrete type. This is currently
only used by invokedynamic to cache "constant" method handle wrappers for common literal fixnums and symbols.
Params:
type – the class to which the constant should conform
Returns:
a "constant" representation of this object appropriate to the current JVM and runtime modes/**
     * Create a new "constant" representation for this object, conforming to the given concrete type. This is currently
     * only used by invokedynamic to cache "constant" method handle wrappers for common literal fixnums and symbols.
     * @param type the class to which the constant should conform
     * @return a "constant" representation of this object appropriate to the current JVM and runtime modes
     */
    public static final Object newConstantWrapper(Class type, Object object) {
        return OptoFactory.CONSTANT_FACTORY.create(type, object);
    }

    public static Invalidator newConstantInvalidator(Ruby runtime) {
        return new ConstantInvalidator(runtime.getCaches());
    }

    private static Boolean indyEnabled() {
        return Options.COMPILE_INVOKEDYNAMIC.load();
    }

    public static Invalidator newGlobalInvalidator(int maxFailures) {
        return new FailoverSwitchPointInvalidator(maxFailures);
    }

    public static Invalidator newMethodInvalidator(RubyModule module) {
        if (indyEnabled()) {
            try {
                return new GenerationAndSwitchPointInvalidator(module);
            } catch (Error e) {
                disableIndy();
                throw e;
            } catch (Throwable t) {
                disableIndy();
            }
        }
        return new GenerationInvalidator(module);
    }

    private static void disableIndy() {
        Options.COMPILE_INVOKEDYNAMIC.force("false");
    }

    
A factory for abstract "constant" representations of objects. This is currently only used by our invokedynamic
support to cache the "constant" handles that wrap common literal fixnums and symbols. See #2058.
/**
     * A factory for abstract "constant" representations of objects. This is currently only used by our invokedynamic
     * support to cache the "constant" handles that wrap common literal fixnums and symbols. See #2058.
     */
    public static interface ConstantFactory {
        
Return a representation of a "constant" suitable for optimization in the current runtime. For invokedynamic,
this produces a MethodHandles.constant wrapper around the given object, typed with the given type.
Params:
type – the type to which the constant should conform
object – the object which represents the constant's value
Returns:
a constant representation suitable for optimization/**
         * Return a representation of a "constant" suitable for optimization in the current runtime. For invokedynamic,
         * this produces a MethodHandles.constant wrapper around the given object, typed with the given type.
         *
         * @param type the type to which the constant should conform
         * @param object the object which represents the constant's value
         * @return a constant representation suitable for optimization
         */
        public Object create(Class type, Object object);
    }

    
A constant factory that produces MethodHandle constants that drop an initial ThreadContext argument.
/**
     * A constant factory that produces MethodHandle constants that drop an initial ThreadContext argument.
     */
    private static class MethodHandleConstantFactory implements ConstantFactory {
        public Object create(Class type, Object object) {
            return MethodHandles.dropArguments(
                    MethodHandles.constant(type, object),
                    0,
                    ThreadContext.class);
        }
    }

    
The constant factory we'll be using for this run.
/**
     * The constant factory we'll be using for this run.
     */
    private static final ConstantFactory CONSTANT_FACTORY = new MethodHandleConstantFactory();
}