com.google.inject.internal.MembersInjectorStore Maven / Gradle / Ivy

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package com.google.inject.internal;

import static com.google.common.collect.ImmutableListMultimap.flatteningToImmutableListMultimap;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableListMultimap;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.inject.ConfigurationException;
import com.google.inject.TypeLiteral;
import com.google.inject.spi.InjectionPoint;
import com.google.inject.spi.TypeListener;
import com.google.inject.spi.TypeListenerBinding;

import java.lang.reflect.Field;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Members injectors by type.
 */
final class MembersInjectorStore {

    private final InjectorImpl injector;

    private final ImmutableList typeListenerBindings;

    private final FailableCache, MembersInjectorImpl> cache = new FailableCache<>() {
                @Override
                protected MembersInjectorImpl create(TypeLiteral type, Errors errors)
                        throws ErrorsException {
                    return createWithListeners(type, errors);
                }
            };
    MembersInjectorStore(InjectorImpl injector,
                         List typeListenerBindings) {
        this.injector = injector;
        this.typeListenerBindings = ImmutableList.copyOf(typeListenerBindings);
    }

    /**
     * Returns true if any type listeners are installed. Other code may take shortcuts when there
     * aren't any type listeners.
     */
    boolean hasTypeListeners() {
        return !typeListenerBindings.isEmpty();
    }

    /**
     * Returns a new complete members injector with injection listeners registered.
     */
    @SuppressWarnings("unchecked") // the MembersInjector type always agrees with the passed type
    public  MembersInjectorImpl get(TypeLiteral key, Errors errors) throws ErrorsException {
        return (MembersInjectorImpl) cache.get(key, errors);
    }

    /**
     * Purges a type literal from the cache. Use this only if the type is not actually valid for
     * binding and needs to be purged. (See issue 319 and
     * ImplicitBindingTest#testCircularJitBindingsLeaveNoResidue and
     * #testInstancesRequestingProvidersForThemselvesWithChildInjectors for examples of when this is
     * necessary.)
     *
     * Returns true if the type was stored in the cache, false otherwise.
     */
    boolean remove(TypeLiteral type) {
        return cache.remove(type);
    }

    /**
     * Creates a new members injector and attaches both injection listeners and method aspects.
     */
    private  MembersInjectorImpl createWithListeners(TypeLiteral type, Errors errors)
            throws ErrorsException {
        int numErrorsBefore = errors.size();

        Set injectionPoints;
        try {
            injectionPoints = InjectionPoint.forInstanceMethodsAndFields(type);
        } catch (ConfigurationException e) {
            errors.merge(e.getErrorMessages());
            injectionPoints = e.getPartialValue();
        }
        ImmutableList injectors = getInjectors(injectionPoints, errors);
        errors.throwIfNewErrors(numErrorsBefore);

        EncounterImpl encounter = new EncounterImpl<>(errors, injector.lookups);
        Set alreadySeenListeners = Sets.newHashSet();
        for (TypeListenerBinding binding : typeListenerBindings) {
            TypeListener typeListener = binding.getListener();
            if (!alreadySeenListeners.contains(typeListener) && binding.getTypeMatcher().matches(type)) {
                alreadySeenListeners.add(typeListener);
                try {
                    typeListener.hear(type, encounter);
                } catch (RuntimeException e) {
                    errors.errorNotifyingTypeListener(binding, type, e);
                }
            }
        }
        encounter.invalidate();
        errors.throwIfNewErrors(numErrorsBefore);

        return new MembersInjectorImpl<>(injector, type, encounter, injectors);
    }

    /**
     * Returns the injectors for the specified injection points.
     */
    ImmutableList getInjectors(
            Set injectionPoints, Errors errors) {
        List injectors = Lists.newArrayList();
        for (InjectionPoint injectionPoint : injectionPoints) {
            try {
                Errors errorsForMember = injectionPoint.isOptional()
                        ? new Errors(injectionPoint)
                        : errors.withSource(injectionPoint);
                SingleMemberInjector injector = injectionPoint.getMember() instanceof Field
                        ? new SingleFieldInjector(this.injector, injectionPoint, errorsForMember)
                        : new SingleMethodInjector(this.injector, injectionPoint, errorsForMember);
                injectors.add(injector);
            } catch (ErrorsException ignoredForNow) {
                // ignored for now
            }
        }
        return ImmutableList.copyOf(injectors);
    }

    ImmutableListMultimap, InjectionPoint> getAllInjectionPoints() {
        return cache.asMap().entrySet().stream()
                .collect(
                        flatteningToImmutableListMultimap(
                                Map.Entry::getKey, entry -> entry.getValue().getInjectionPoints().stream()));
    }
}