summaryrefslogtreecommitdiff
path: root/core/src/main/java/org/elasticsearch/action/support/TransportAction.java
blob: 07ddff3348c3038b1ad0e5770550b28d4c7af994 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
/*
 * 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.action.support;

import org.elasticsearch.action.ActionFuture;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.ActionRequest;
import org.elasticsearch.action.ActionRequestValidationException;
import org.elasticsearch.action.ActionResponse;
import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
import org.elasticsearch.common.ParseFieldMatcher;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.logging.ESLogger;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.threadpool.ThreadPool;

import java.util.concurrent.atomic.AtomicInteger;

import static org.elasticsearch.action.support.PlainActionFuture.newFuture;

/**
 *
 */
public abstract class TransportAction<Request extends ActionRequest, Response extends ActionResponse> extends AbstractComponent {

    protected final ThreadPool threadPool;
    protected final String actionName;
    private final ActionFilter[] filters;
    protected final ParseFieldMatcher parseFieldMatcher;
    protected final IndexNameExpressionResolver indexNameExpressionResolver;

    protected TransportAction(Settings settings, String actionName, ThreadPool threadPool, ActionFilters actionFilters,
                              IndexNameExpressionResolver indexNameExpressionResolver) {
        super(settings);
        this.threadPool = threadPool;
        this.actionName = actionName;
        this.filters = actionFilters.filters();
        this.parseFieldMatcher = new ParseFieldMatcher(settings);
        this.indexNameExpressionResolver = indexNameExpressionResolver;
    }

    public final ActionFuture<Response> execute(Request request) {
        PlainActionFuture<Response> future = newFuture();
        execute(request, future);
        return future;
    }

    public final void execute(Request request, ActionListener<Response> listener) {
        ActionRequestValidationException validationException = request.validate();
        if (validationException != null) {
            listener.onFailure(validationException);
            return;
        }

        if (filters.length == 0) {
            try {
                doExecute(request, listener);
            } catch(Throwable t) {
                logger.trace("Error during transport action execution.", t);
                listener.onFailure(t);
            }
        } else {
            RequestFilterChain requestFilterChain = new RequestFilterChain<>(this, logger);
            requestFilterChain.proceed(actionName, request, listener);
        }
    }

    protected abstract void doExecute(Request request, ActionListener<Response> listener);

    private static class RequestFilterChain<Request extends ActionRequest, Response extends ActionResponse> implements ActionFilterChain {

        private final TransportAction<Request, Response> action;
        private final AtomicInteger index = new AtomicInteger();
        private final ESLogger logger;

        private RequestFilterChain(TransportAction<Request, Response> action, ESLogger logger) {
            this.action = action;
            this.logger = logger;
        }

        @Override @SuppressWarnings("unchecked")
        public void proceed(String actionName, ActionRequest request, ActionListener listener) {
            int i = index.getAndIncrement();
            try {
                if (i < this.action.filters.length) {
                    this.action.filters[i].apply(actionName, request, listener, this);
                } else if (i == this.action.filters.length) {
                    this.action.doExecute((Request) request, new FilteredActionListener<Response>(actionName, listener, new ResponseFilterChain(this.action.filters, logger)));
                } else {
                    listener.onFailure(new IllegalStateException("proceed was called too many times"));
                }
            } catch(Throwable t) {
                logger.trace("Error during transport action execution.", t);
                listener.onFailure(t);
            }
        }

        @Override
        public void proceed(String action, ActionResponse response, ActionListener listener) {
            assert false : "request filter chain should never be called on the response side";
        }
    }

    private static class ResponseFilterChain implements ActionFilterChain {

        private final ActionFilter[] filters;
        private final AtomicInteger index;
        private final ESLogger logger;

        private ResponseFilterChain(ActionFilter[] filters, ESLogger logger) {
            this.filters = filters;
            this.index = new AtomicInteger(filters.length);
            this.logger = logger;
        }

        @Override
        public void proceed(String action, ActionRequest request, ActionListener listener) {
            assert false : "response filter chain should never be called on the request side";
        }

        @Override @SuppressWarnings("unchecked")
        public void proceed(String action, ActionResponse response, ActionListener listener) {
            int i = index.decrementAndGet();
            try {
                if (i >= 0) {
                    filters[i].apply(action, response, listener, this);
                } else if (i == -1) {
                    listener.onResponse(response);
                } else {
                    listener.onFailure(new IllegalStateException("proceed was called too many times"));
                }
            } catch (Throwable t) {
                logger.trace("Error during transport action execution.", t);
                listener.onFailure(t);
            }
        }
    }

    private static class FilteredActionListener<Response extends ActionResponse> implements ActionListener<Response> {

        private final String actionName;
        private final ActionListener listener;
        private final ResponseFilterChain chain;

        private FilteredActionListener(String actionName, ActionListener listener, ResponseFilterChain chain) {
            this.actionName = actionName;
            this.listener = listener;
            this.chain = chain;
        }

        @Override
        public void onResponse(Response response) {
            chain.proceed(actionName, response, listener);
        }

        @Override
        public void onFailure(Throwable e) {
            listener.onFailure(e);
        }
    }
}