EventResource.java

/*
 * Copyright 2011-2014 Proofpoint, 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 com.proofpoint.event.collector;

import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import com.google.inject.Inject;
import com.proofpoint.event.collector.EventCollectorStats.ProcessType;

import javax.ws.rs.Consumes;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import java.io.IOException;
import java.util.List;
import java.util.Set;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.proofpoint.event.collector.EventCollectorStats.EventStatus.UNSUPPORTED;
import static com.proofpoint.event.collector.EventCollectorStats.EventStatus.VALID;
import static com.proofpoint.event.collector.EventCollectorStats.ProcessType.DISTRIBUTE;
import static com.proofpoint.event.collector.EventCollectorStats.ProcessType.WRITE;
import static com.proofpoint.event.collector.EventResource.EventProcessor.DISTRIBUTOR;
import static com.proofpoint.event.collector.EventResource.EventProcessor.WRITER;

@Path("/v2/event")
public class EventResource
{
    private final Set<EventWriter> writers;
    private final Set<String> acceptedEventTypes;

    private final EventCollectorStats eventCollectorStats;

    @Inject
    public EventResource(Set<EventWriter> writers, ServerConfig config, EventCollectorStats eventCollectorStats)
    {
        this.eventCollectorStats = checkNotNull(eventCollectorStats, "eventCollectorStats is null");
        this.writers = checkNotNull(writers, "writers are null");
        this.acceptedEventTypes = ImmutableSet.copyOf(checkNotNull(config, "config is null").getAcceptedEventTypes());
    }

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    public Response write(List<Event> events)
            throws IOException
    {
        return processEvents(WRITER, events, WRITE);
    }

    @POST
    @Path("/distribute")
    @Consumes(MediaType.APPLICATION_JSON)
    public Response distribute(List<Event> events)
            throws IOException
    {
        return processEvents(DISTRIBUTOR, events, DISTRIBUTE);
    }

    private Response processEvents(EventProcessor processor, List<Event> events, ProcessType processType)
            throws IOException
    {
        Set<String> badEvents = Sets.newHashSet();
        for (Event event : events) {
            if (acceptedEventType(event.getType())) {

                for (EventWriter writer : writers) {
                    processor.process(writer, event);
                }

                eventCollectorStats.inboundEvents(event.getType(), VALID, processType).add(1);
            }
            else {
                badEvents.add(event.getType());

                eventCollectorStats.inboundEvents(event.getType(), UNSUPPORTED, processType).add(1);
            }
        }

        if (!badEvents.isEmpty()) {
            String errorMessage = "Unsupported event type(s): " + Joiner.on(", ").join(badEvents);
            return Response.status(Status.BAD_REQUEST).entity(errorMessage).build();
        }

        return Response.status(Response.Status.ACCEPTED).build();
    }

    private boolean acceptedEventType(String type)
    {
        return acceptedEventTypes.isEmpty() || acceptedEventTypes.contains(type);
    }

    public enum EventProcessor
    {
        WRITER
                {
                    @Override
                    void process(EventWriter writer, Event event)
                            throws IOException
                    {
                        writer.write(event);
                    }
                },
        DISTRIBUTOR
                {
                    @Override
                    void process(EventWriter writer, Event event)
                            throws IOException
                    {
                        writer.distribute(event);
                    }
                };

        abstract void process(EventWriter writer, Event event)
                throws IOException;
    }
}