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/*
* Copyright (C) 2006 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 org.elasticsearch.common.inject;
import org.elasticsearch.common.Classes;
import org.elasticsearch.common.inject.internal.Annotations;
import org.elasticsearch.common.inject.internal.BindingImpl;
import org.elasticsearch.common.inject.internal.Errors;
import org.elasticsearch.common.inject.internal.ErrorsException;
import org.elasticsearch.common.inject.internal.InstanceBindingImpl;
import org.elasticsearch.common.inject.internal.InternalContext;
import org.elasticsearch.common.inject.internal.InternalFactory;
import org.elasticsearch.common.inject.internal.LinkedBindingImpl;
import org.elasticsearch.common.inject.internal.LinkedProviderBindingImpl;
import org.elasticsearch.common.inject.internal.MatcherAndConverter;
import org.elasticsearch.common.inject.internal.Scoping;
import org.elasticsearch.common.inject.internal.SourceProvider;
import org.elasticsearch.common.inject.internal.ToStringBuilder;
import org.elasticsearch.common.inject.spi.BindingTargetVisitor;
import org.elasticsearch.common.inject.spi.ConvertedConstantBinding;
import org.elasticsearch.common.inject.spi.Dependency;
import org.elasticsearch.common.inject.spi.ProviderBinding;
import org.elasticsearch.common.inject.spi.ProviderKeyBinding;
import org.elasticsearch.common.inject.util.Providers;
import java.lang.annotation.Annotation;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import static java.util.Collections.emptySet;
import static org.elasticsearch.common.inject.internal.Annotations.findScopeAnnotation;
/**
* Default {@link Injector} implementation.
*
* @author [email protected] (Bob Lee)
* @see InjectorBuilder
*/
class InjectorImpl implements Injector, Lookups {
final State state;
BindingsMultimap bindingsMultimap = new BindingsMultimap();
/**
* Just-in-time binding cache. Guarded by state.lock()
*/
Map, BindingImpl> jitBindings = new HashMap<>();
Lookups lookups = new DeferredLookups(this);
InjectorImpl(State state) {
this.state = state;
localContext = new ThreadLocal<>();
}
/**
* Indexes bindings by type.
*/
void index() {
for (Binding binding : state.getExplicitBindingsThisLevel().values()) {
index(binding);
}
}
void index(Binding binding) {
bindingsMultimap.put(binding.getKey().getTypeLiteral(), binding);
}
@Override
public List> findBindingsByType(TypeLiteral type) {
return bindingsMultimap.getAll(type);
}
/**
* Gets a binding implementation. First, it check to see if the parent has a binding. If the
* parent has a binding and the binding is scoped, it will use that binding. Otherwise, this
* checks for an explicit binding. If no explicit binding is found, it looks for a just-in-time
* binding.
*/
public BindingImpl getBindingOrThrow(Key key, Errors errors) throws ErrorsException {
// Check explicit bindings, i.e. bindings created by modules.
BindingImpl binding = state.getExplicitBinding(key);
if (binding != null) {
return binding;
}
// Look for an on-demand binding.
return getJustInTimeBinding(key, errors);
}
/**
* Returns a just-in-time binding for {@code key}, creating it if necessary.
*
* @throws ErrorsException if the binding could not be created.
*/
private BindingImpl getJustInTimeBinding(Key key, Errors errors) throws ErrorsException {
synchronized (state.lock()) {
// first try to find a JIT binding that we've already created
@SuppressWarnings("unchecked") // we only store bindings that match their key
BindingImpl binding = (BindingImpl) jitBindings.get(key);
if (binding != null) {
return binding;
}
return createJustInTimeBindingRecursive(key, errors);
}
}
/**
* Returns true if the key type is Provider (but not a subclass of Provider).
*/
static boolean isProvider(Key key) {
return key.getTypeLiteral().getRawType().equals(Provider.class);
}
/**
* Returns true if the key type is MembersInjector (but not a subclass of MembersInjector).
*/
static boolean isMembersInjector(Key key) {
return key.getTypeLiteral().getRawType().equals(MembersInjector.class) && key.hasAnnotationType() == false;
}
private BindingImpl> createMembersInjectorBinding(Key> key, Errors errors)
throws ErrorsException {
Type membersInjectorType = key.getTypeLiteral().getType();
if ((membersInjectorType instanceof ParameterizedType) == false) {
throw errors.cannotInjectRawMembersInjector().toException();
}
@SuppressWarnings("unchecked") // safe because T came from Key>
TypeLiteral instanceType = (TypeLiteral) TypeLiteral.get(
((ParameterizedType) membersInjectorType).getActualTypeArguments()[0]
);
MembersInjector membersInjector = membersInjectorStore.get(instanceType, errors);
InternalFactory> factory = new ConstantFactory<>(Initializables.of(membersInjector));
return new InstanceBindingImpl<>(this, key, SourceProvider.UNKNOWN_SOURCE, factory, emptySet(), membersInjector);
}
/**
* Creates a synthetic binding to {@code Provider}, i.e. a binding to the provider from
* {@code Binding}.
*/
private BindingImpl> createProviderBinding(Key> key, Errors errors) throws ErrorsException {
Type providerType = key.getTypeLiteral().getType();
// If the Provider has no type parameter (raw Provider)...
if ((providerType instanceof ParameterizedType) == false) {
throw errors.cannotInjectRawProvider().toException();
}
Type entryType = ((ParameterizedType) providerType).getActualTypeArguments()[0];
@SuppressWarnings("unchecked") // safe because T came from Key>
Key providedKey = (Key) key.ofType(entryType);
BindingImpl delegate = getBindingOrThrow(providedKey, errors);
return new ProviderBindingImpl<>(this, key, delegate);
}
static class ProviderBindingImpl extends BindingImpl> implements ProviderBinding> {
final BindingImpl providedBinding;
ProviderBindingImpl(InjectorImpl injector, Key> key, Binding providedBinding) {
super(injector, key, providedBinding.getSource(), createInternalFactory(providedBinding), Scoping.UNSCOPED);
this.providedBinding = (BindingImpl) providedBinding;
}
static InternalFactory> createInternalFactory(Binding providedBinding) {
final Provider provider = providedBinding.getProvider();
return (errors, context, dependency) -> provider;
}
@Override
public V acceptTargetVisitor(BindingTargetVisitor, V> visitor) {
return visitor.visit();
}
@Override
public String toString() {
return new ToStringBuilder(ProviderKeyBinding.class).add("key", getKey())
.add("providedKey", providedBinding.getKey())
.toString();
}
}
/**
* Converts a constant string binding to the required type.
*
* @return the binding if it could be resolved, or null if the binding doesn't exist
* @throws org.elasticsearch.common.inject.internal.ErrorsException
* if there was an error resolving the binding
*/
private BindingImpl convertConstantStringBinding(Key key, Errors errors) throws ErrorsException {
// Find a constant string binding.
BindingImpl stringBinding = state.getExplicitBinding(key.ofStringType());
if (stringBinding == null || stringBinding.isConstant() == false) {
return null;
}
String stringValue = stringBinding.getProvider().get();
Object source = stringBinding.getSource();
// Find a matching type converter.
TypeLiteral type = key.getTypeLiteral();
MatcherAndConverter matchingConverter = state.getConverter(stringValue, type, errors, source);
if (matchingConverter == null) {
// No converter can handle the given type.
return null;
}
// Try to convert the string. A failed conversion results in an error.
try {
@SuppressWarnings("unchecked") // This cast is safe because we double check below.
T converted = (T) matchingConverter.getTypeConverter().convert(stringValue, type);
if (converted == null) {
throw errors.converterReturnedNull(stringValue, source, type, matchingConverter).toException();
}
if (type.getRawType().isInstance(converted) == false) {
throw errors.conversionTypeError(stringValue, source, type, matchingConverter, converted).toException();
}
return new ConvertedConstantBindingImpl<>(this, key, converted, stringBinding);
} catch (RuntimeException e) {
throw errors.conversionError(stringValue, source, type, matchingConverter, e).toException();
}
}
private static class ConvertedConstantBindingImpl extends BindingImpl implements ConvertedConstantBinding {
final T value;
final Provider provider;
final Binding originalBinding;
ConvertedConstantBindingImpl(Injector injector, Key key, T value, Binding originalBinding) {
super(injector, key, originalBinding.getSource(), new ConstantFactory<>(Initializables.of(value)), Scoping.UNSCOPED);
this.value = value;
provider = Providers.of(value);
this.originalBinding = originalBinding;
}
@Override
public Provider getProvider() {
return provider;
}
@Override
public V acceptTargetVisitor(BindingTargetVisitor visitor) {
return visitor.visit();
}
@Override
public String toString() {
return new ToStringBuilder(ConvertedConstantBinding.class).add("key", getKey())
.add("sourceKey", originalBinding.getKey())
.add("value", value)
.toString();
}
}
void initializeBinding(BindingImpl binding, Errors errors) throws ErrorsException {
// Put the partially constructed binding in the map a little early. This enables us to handle
// circular dependencies. Example: FooImpl -> BarImpl -> FooImpl.
// Note: We don't need to synchronize on state.lock() during injector creation.
// TODO: for the above example, remove the binding for BarImpl if the binding for FooImpl fails
if (binding instanceof ConstructorBindingImpl) {
Key key = binding.getKey();
jitBindings.put(key, binding);
boolean successful = false;
try {
((ConstructorBindingImpl) binding).initialize(this, errors);
successful = true;
} finally {
if (successful == false) {
jitBindings.remove(key);
}
}
}
}
/**
* Creates a binding for an injectable type with the given scope. Looks for a scope on the type if
* none is specified.
*/
BindingImpl createUnitializedBinding(Key key, Scoping scoping, Object source, Errors errors) throws ErrorsException {
Class rawType = key.getTypeLiteral().getRawType();
// Don't try to inject arrays, or enums.
if (rawType.isArray() || rawType.isEnum()) {
throw errors.missingImplementation(key).toException();
}
// Handle TypeLiteral by binding the inner type
if (rawType == TypeLiteral.class) {
@SuppressWarnings("unchecked") // we have to fudge the inner type as Object
BindingImpl binding = (BindingImpl) createTypeLiteralBinding((Key>) key, errors);
return binding;
}
// Handle @ImplementedBy
ImplementedBy implementedBy = rawType.getAnnotation(ImplementedBy.class);
if (implementedBy != null) {
Annotations.checkForMisplacedScopeAnnotations(rawType, source, errors);
return createImplementedByBinding(key, scoping, implementedBy, errors);
}
// Handle @ProvidedBy.
ProvidedBy providedBy = rawType.getAnnotation(ProvidedBy.class);
if (providedBy != null) {
Annotations.checkForMisplacedScopeAnnotations(rawType, source, errors);
return createProvidedByBinding(key, scoping, providedBy, errors);
}
// We can't inject abstract classes.
// TODO: Method interceptors could actually enable us to implement
// abstract types. Should we remove this restriction?
if (Modifier.isAbstract(rawType.getModifiers())) {
throw errors.missingImplementation(key).toException();
}
// Error: Inner class.
if (Classes.isInnerClass(rawType)) {
throw errors.cannotInjectInnerClass(rawType).toException();
}
if (scoping.isExplicitlyScoped() == false) {
Class scopeAnnotation = findScopeAnnotation(errors, rawType);
if (scopeAnnotation != null) {
scoping = Scopes.makeInjectable(Scoping.forAnnotation(scopeAnnotation), this, errors.withSource(rawType));
}
}
return ConstructorBindingImpl.create(this, key, source, scoping);
}
/**
* Converts a binding for a {@code Key>} to the value {@code TypeLiteral}. It's
* a bit awkward because we have to pull out the inner type in the type literal.
*/
private BindingImpl> createTypeLiteralBinding(Key> key, Errors errors) throws ErrorsException {
Type typeLiteralType = key.getTypeLiteral().getType();
if ((typeLiteralType instanceof ParameterizedType) == false) {
throw errors.cannotInjectRawTypeLiteral().toException();
}
ParameterizedType parameterizedType = (ParameterizedType) typeLiteralType;
Type innerType = parameterizedType.getActualTypeArguments()[0];
// this is unfortunate. We don't support building TypeLiterals for type variable like 'T'. If
// this proves problematic, we can probably fix TypeLiteral to support type variables
if ((innerType instanceof Class) == false
&& (innerType instanceof GenericArrayType) == false
&& (innerType instanceof ParameterizedType) == false) {
throw errors.cannotInjectTypeLiteralOf(innerType).toException();
}
@SuppressWarnings("unchecked") // by definition, innerType == T, so this is safe
TypeLiteral value = (TypeLiteral) TypeLiteral.get(innerType);
InternalFactory> factory = new ConstantFactory<>(Initializables.of(value));
return new InstanceBindingImpl<>(this, key, SourceProvider.UNKNOWN_SOURCE, factory, emptySet(), value);
}
/**
* Creates a binding for a type annotated with @ProvidedBy.
*/
BindingImpl createProvidedByBinding(Key key, Scoping scoping, ProvidedBy providedBy, Errors errors) throws ErrorsException {
final Class rawType = key.getTypeLiteral().getRawType();
final Class> providerType = providedBy.value();
// Make sure it's not the same type. TODO: Can we check for deeper loops?
if (providerType == rawType) {
throw errors.recursiveProviderType().toException();
}
// Assume the provider provides an appropriate type. We double check at runtime.
@SuppressWarnings("unchecked")
final Key> providerKey = (Key>) Key.get(providerType);
final BindingImpl> providerBinding = getBindingOrThrow(providerKey, errors);
InternalFactory internalFactory = (errors1, context, dependency) -> {
errors1 = errors1.withSource(providerKey);
Provider provider = providerBinding.getInternalFactory().get(errors1, context, dependency);
try {
Object o = provider.get();
if (o != null && rawType.isInstance(o) == false) {
throw errors1.subtypeNotProvided(providerType, rawType).toException();
}
@SuppressWarnings("unchecked") // protected by isInstance() check above
T t = (T) o;
return t;
} catch (RuntimeException e) {
throw errors1.errorInProvider(e).toException();
}
};
return new LinkedProviderBindingImpl<>(
this,
key,
rawType /* source */,
Scopes.scope(this, internalFactory, scoping),
scoping,
providerKey
);
}
/**
* Creates a binding for a type annotated with @ImplementedBy.
*/
BindingImpl createImplementedByBinding(Key key, Scoping scoping, ImplementedBy implementedBy, Errors errors)
throws ErrorsException {
Class rawType = key.getTypeLiteral().getRawType();
Class implementationType = implementedBy.value();
// Make sure it's not the same type. TODO: Can we check for deeper cycles?
if (implementationType == rawType) {
throw errors.recursiveImplementationType().toException();
}
// Make sure implementationType extends type.
if (rawType.isAssignableFrom(implementationType) == false) {
throw errors.notASubtype(implementationType, rawType).toException();
}
@SuppressWarnings("unchecked") // After the preceding check, this cast is safe.
Class subclass = (Class) implementationType;
// Look up the target binding.
final Key targetKey = Key.get(subclass);
final BindingImpl targetBinding = getBindingOrThrow(targetKey, errors);
InternalFactory internalFactory = (errors1, context, dependency) -> targetBinding.getInternalFactory()
.get(errors1.withSource(targetKey), context, dependency);
return new LinkedBindingImpl<>(this, key, rawType /* source */, Scopes.scope(this, internalFactory, scoping), scoping, targetKey);
}
/**
* Attempts to create a just-in-time binding for {@code key} in the root injector, falling back to
* other ancestor injectors until this injector is tried.
*/
private BindingImpl createJustInTimeBindingRecursive(Key key, Errors errors) throws ErrorsException {
if (state.isBlacklisted(key)) {
throw errors.childBindingAlreadySet(key).toException();
}
BindingImpl binding = createJustInTimeBinding(key, errors);
state.parent().blacklist(key);
jitBindings.put(key, binding);
return binding;
}
/**
* Returns a new just-in-time binding created by resolving {@code key}. The strategies used to
* create just-in-time bindings are:
*
* - Internalizing Providers. If the requested binding is for {@code Provider
}, we delegate
* to the binding for {@code T}.
* - Converting constants.
*
- ImplementedBy and ProvidedBy annotations. Only for unannotated keys.
*
- The constructor of the raw type. Only for unannotated keys.
*
*
* @throws org.elasticsearch.common.inject.internal.ErrorsException
* if the binding cannot be created.
*/
BindingImpl createJustInTimeBinding(Key key, Errors errors) throws ErrorsException {
if (state.isBlacklisted(key)) {
throw errors.childBindingAlreadySet(key).toException();
}
// Handle cases where T is a Provider.
if (isProvider(key)) {
// These casts are safe. We know T extends Provider and that given Key>,
// createProviderBinding() will return BindingImpl>.
@SuppressWarnings("unchecked")
BindingImpl binding = (BindingImpl) createProviderBinding((Key>) key, errors);
return binding;
}
// Handle cases where T is a MembersInjector
if (isMembersInjector(key)) {
// These casts are safe. T extends MembersInjector and that given Key>,
// createMembersInjectorBinding() will return BindingImpl>.
@SuppressWarnings("unchecked")
BindingImpl binding = (BindingImpl) createMembersInjectorBinding((Key>) key, errors);
return binding;
}
// Try to convert a constant string binding to the requested type.
BindingImpl convertedBinding = convertConstantStringBinding(key, errors);
if (convertedBinding != null) {
return convertedBinding;
}
// If the key has an annotation...
if (key.hasAnnotationType()) {
// Look for a binding without annotation attributes or return null.
if (key.hasAttributes()) {
try {
Errors ignored = new Errors();
return getBindingOrThrow(key.withoutAttributes(), ignored);
} catch (ErrorsException ignored) {
// throw with a more appropriate message below
}
}
throw errors.missingImplementation(key).toException();
}
Object source = key.getTypeLiteral().getRawType();
BindingImpl binding = createUnitializedBinding(key, Scoping.UNSCOPED, source, errors);
initializeBinding(binding, errors);
return binding;
}
InternalFactory getInternalFactory(Key key, Errors errors) throws ErrorsException {
return getBindingOrThrow(key, errors).getInternalFactory();
}
private static class BindingsMultimap {
final Map, List>> multimap = new HashMap<>();
void put(TypeLiteral type, Binding binding) {
multimap.computeIfAbsent(type, k -> new ArrayList<>()).add(binding);
}
@SuppressWarnings("unchecked")
// safe because we only put matching entries into the map
List> getAll(TypeLiteral type) {
List> bindings = multimap.get(type);
return bindings != null ? Collections.>unmodifiableList((List) multimap.get(type)) : Collections.emptyList();
}
}
/**
* Returns parameter injectors, or {@code null} if there are no parameters.
*/
SingleParameterInjector[] getParametersInjectors(List> parameters, Errors errors) throws ErrorsException {
if (parameters.isEmpty()) {
return null;
}
int numErrorsBefore = errors.size();
SingleParameterInjector[] result = new SingleParameterInjector[parameters.size()];
int i = 0;
for (Dependency parameter : parameters) {
try {
result[i++] = createParameterInjector(parameter, errors.withSource(parameter));
} catch (ErrorsException rethrownBelow) {
// rethrown below
}
}
errors.throwIfNewErrors(numErrorsBefore);
return result;
}
SingleParameterInjector createParameterInjector(final Dependency dependency, final Errors errors) throws ErrorsException {
InternalFactory factory = getInternalFactory(dependency.getKey(), errors);
return new SingleParameterInjector<>(dependency, factory);
}
/**
* Invokes a method.
*/
interface MethodInvoker {
Object invoke(Object target, Object... parameters) throws IllegalAccessException, InvocationTargetException;
}
/**
* Cached constructor injectors for each type
*/
ConstructorInjectorStore constructors = new ConstructorInjectorStore(this);
/**
* Cached field and method injectors for each type.
*/
MembersInjectorStore membersInjectorStore;
private Provider getProvider(Class type) {
return getProvider(Key.get(type));
}
Provider getProviderOrThrow(final Key key, Errors errors) throws ErrorsException {
final InternalFactory factory = getInternalFactory(key, errors);
// ES: optimize for a common case of read only instance getting from the parent...
if (factory instanceof InternalFactory.Instance) {
return () -> {
try {
return factory.get(null, null, null);
} catch (ErrorsException e) {
// ignore
}
// should never happen...
assert false;
return null;
};
}
final Dependency dependency = Dependency.get(key);
return new Provider<>() {
@Override
public T get() {
final Errors errors = new Errors(dependency);
try {
T t = callInContext((ContextualCallable) context -> {
context.setDependency(dependency);
try {
return factory.get(errors, context, dependency);
} finally {
context.setDependency(null);
}
});
errors.throwIfNewErrors(0);
return t;
} catch (ErrorsException e) {
throw new ProvisionException(errors.merge(e.getErrors()).getMessages());
}
}
@Override
public String toString() {
return factory.toString();
}
};
}
@Override
public Provider getProvider(final Key key) {
Errors errors = new Errors(key);
try {
Provider result = getProviderOrThrow(key, errors);
errors.throwIfNewErrors(0);
return result;
} catch (ErrorsException e) {
throw new ConfigurationException(errors.merge(e.getErrors()).getMessages());
}
}
@Override
public T getInstance(Key key) {
return getProvider(key).get();
}
@Override
public T getInstance(Class type) {
return getProvider(type).get();
}
private final ThreadLocal localContext;
/**
* Looks up thread local context. Creates (and removes) a new context if necessary.
*/
T callInContext(ContextualCallable callable) throws ErrorsException {
Object[] reference = localContext.get();
if (reference == null) {
reference = new Object[1];
localContext.set(reference);
}
if (reference[0] == null) {
reference[0] = new InternalContext();
try {
return callable.call((InternalContext) reference[0]);
} finally {
// Only clear the context if this call created it.
reference[0] = null;
}
} else {
// Someone else will clean up this context.
return callable.call((InternalContext) reference[0]);
}
}
@Override
public String toString() {
return new ToStringBuilder(Injector.class).add("bindings", state.getExplicitBindingsThisLevel().values()).toString();
}
// ES_GUICE: clear caches
public void clearCache() {
state.clearBlacklisted();
constructors = new ConstructorInjectorStore(this);
membersInjectorStore = new MembersInjectorStore(this);
jitBindings = new HashMap<>();
}
// ES_GUICE: make all registered bindings act as eager singletons
public void readOnlyAllSingletons() {
state.makeAllBindingsToEagerSingletons(this);
bindingsMultimap = new BindingsMultimap();
// reindex the bindings
index();
}
}