/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.plugins;
import org.elasticsearch.action.ActionRequest;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.action.GenericAction;
import org.elasticsearch.action.support.ActionFilter;
import org.elasticsearch.action.support.TransportAction;
import org.elasticsearch.action.support.TransportActions;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.IndexScopedSettings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.settings.SettingsFilter;
import org.elasticsearch.common.util.concurrent.ThreadContext;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.rest.RestController;
import org.elasticsearch.rest.RestHandler;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.function.Supplier;
import java.util.function.UnaryOperator;
/**
* An additional extension point for {@link Plugin}s that extends Elasticsearch's scripting functionality. Implement it like this:
* <pre>{@code
* {@literal @}Override
* public List<ActionHandler<?, ?>> getActions() {
* return Arrays.asList(new ActionHandler<>(ReindexAction.INSTANCE, TransportReindexAction.class),
* new ActionHandler<>(UpdateByQueryAction.INSTANCE, TransportUpdateByQueryAction.class),
* new ActionHandler<>(DeleteByQueryAction.INSTANCE, TransportDeleteByQueryAction.class),
* new ActionHandler<>(RethrottleAction.INSTANCE, TransportRethrottleAction.class));
* }
* }</pre>
*/
public interface ActionPlugin {
/**
* Actions added by this plugin.
*/
default List<ActionHandler<? extends ActionRequest, ? extends ActionResponse>> getActions() {
return Collections.emptyList();
}
/**
* Action filters added by this plugin.
*/
default List<Class<? extends ActionFilter>> getActionFilters() {
return Collections.emptyList();
}
/**
* Rest handlers added by this plugin.
*/
default List<RestHandler> getRestHandlers(Settings settings, RestController restController, ClusterSettings clusterSettings,
IndexScopedSettings indexScopedSettings, SettingsFilter settingsFilter,
IndexNameExpressionResolver indexNameExpressionResolver, Supplier<DiscoveryNodes> nodesInCluster) {
return Collections.emptyList();
}
/**
* Returns headers which should be copied through rest requests on to internal requests.
*/
default Collection<String> getRestHeaders() {
return Collections.emptyList();
}
/**
* Returns a function used to wrap each rest request before handling the request.
*
* Note: Only one installed plugin may implement a rest wrapper.
*/
default UnaryOperator<RestHandler> getRestHandlerWrapper(ThreadContext threadContext) {
return null;
}
final class ActionHandler<Request extends ActionRequest, Response extends ActionResponse> {
private final GenericAction<Request, Response> action;
private final Class<? extends TransportAction<Request, Response>> transportAction;
private final Class<?>[] supportTransportActions;
/**
* Create a record of an action, the {@linkplain TransportAction} that handles it, and any supporting {@linkplain TransportActions}
* that are needed by that {@linkplain TransportAction}.
*/
public ActionHandler(GenericAction<Request, Response> action, Class<? extends TransportAction<Request, Response>> transportAction,
Class<?>... supportTransportActions) {
this.action = action;
this.transportAction = transportAction;
this.supportTransportActions = supportTransportActions;
}
public GenericAction<Request, Response> getAction() {
return action;
}
public Class<? extends TransportAction<Request, Response>> getTransportAction() {
return transportAction;
}
public Class<?>[] getSupportTransportActions() {
return supportTransportActions;
}
@Override
public String toString() {
StringBuilder b = new StringBuilder().append(action.name()).append(" is handled by ").append(transportAction.getName());
if (supportTransportActions.length > 0) {
b.append('[').append(Strings.arrayToCommaDelimitedString(supportTransportActions)).append(']');
}
return b.toString();
}
@Override
public boolean equals(Object obj) {
if (obj == null || obj.getClass() != ActionHandler.class) {
return false;
}
ActionHandler<?, ?> other = (ActionHandler<?, ?>) obj;
return Objects.equals(action, other.action)
&& Objects.equals(transportAction, other.transportAction)
&& Objects.deepEquals(supportTransportActions, other.supportTransportActions);
}
@Override
public int hashCode() {
return Objects.hash(action, transportAction, supportTransportActions);
}
}
}