org.springframework.cloud.consul.binder.EventService.java Source code

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Here is the source code for org.springframework.cloud.consul.binder.EventService.java

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/*
 * Copyright 2013-2016 the original author or authors.
 *
 * 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.springframework.cloud.consul.binder;

import java.util.List;
import java.util.concurrent.atomic.AtomicReference;

import javax.annotation.PostConstruct;

import org.springframework.cloud.consul.binder.config.ConsulBinderProperties;

import com.ecwid.consul.v1.ConsulClient;
import com.ecwid.consul.v1.QueryParams;
import com.ecwid.consul.v1.Response;
import com.ecwid.consul.v1.event.model.Event;
import com.ecwid.consul.v1.event.model.EventParams;
import com.fasterxml.jackson.databind.ObjectMapper;

/**
 * @author Spencer Gibb
 */
public class EventService {

    protected ConsulBinderProperties properties;

    protected ConsulClient consul;

    protected ObjectMapper objectMapper = new ObjectMapper();

    private AtomicReference<Long> lastIndex = new AtomicReference<>();

    public EventService(ConsulBinderProperties properties, ConsulClient consul, ObjectMapper objectMapper) {
        this.properties = properties;
        this.consul = consul;
        this.objectMapper = objectMapper;
    }

    public ConsulClient getConsulClient() {
        return consul;
    }

    @PostConstruct
    public void init() {
        setLastIndex(getEventsResponse());
    }

    private void setLastIndex(Response<?> response) {
        Long consulIndex = response.getConsulIndex();
        if (consulIndex != null) {
            lastIndex.set(response.getConsulIndex());
        }
    }

    public Long getLastIndex() {
        return lastIndex.get();
    }

    public Event fire(String name, String payload) {
        Response<Event> response = consul.eventFire(name, payload, new EventParams(), QueryParams.DEFAULT);
        return response.getValue();
    }

    public Response<List<Event>> getEventsResponse() {
        return consul.eventList(QueryParams.DEFAULT);
    }

    public List<Event> getEvents() {
        return getEventsResponse().getValue();
    }

    public List<Event> getEvents(Long lastIndex) {
        return filterEvents(readEvents(getEventsResponse()), lastIndex);
    }

    public List<Event> watch() {
        return watch(lastIndex.get());
    }

    public List<Event> watch(Long lastIndex) {
        // TODO: parameterized or configurable watch time
        long index = -1;
        if (lastIndex != null) {
            index = lastIndex;
        }
        Response<List<Event>> watch = consul.eventList(new QueryParams(properties.getEventTimeout(), index));
        return filterEvents(readEvents(watch), lastIndex);
    }

    protected List<Event> readEvents(Response<List<Event>> response) {
        setLastIndex(response);
        return response.getValue();
    }

    /**
     * from https://github.com/hashicorp/consul/blob/master/watch/funcs.go#L169-L194
     */
    protected List<Event> filterEvents(List<Event> toFilter, Long lastIndex) {
        List<Event> events = toFilter;
        if (lastIndex != null) {
            for (int i = 0; i < events.size(); i++) {
                Event event = events.get(i);
                Long eventIndex = event.getWaitIndex();
                if (lastIndex.equals(eventIndex)) {
                    events = events.subList(i + 1, events.size());
                    break;
                }
            }
        }
        return events;
    }

}