SimpleEmitter.java

/*
 * Copyright (c) 2015 Snowplow Analytics Ltd. All rights reserved.
 *
 * This program is licensed to you under the Apache License Version 2.0,
 * and you may not use this file except in compliance with the Apache License Version 2.0.
 * You may obtain a copy of the Apache License Version 2.0 at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the Apache License Version 2.0 is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
 */
package com.snowplowanalytics.snowplow.tracker.emitter;

// Java
import java.util.ArrayList;
import java.util.List;

// Slf4j
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

// This library
import com.snowplowanalytics.snowplow.tracker.payload.TrackerPayload;

/**
 * An emitter which sends events as soon as they are received via
 * GET requests.
 */
public class SimpleEmitter extends AbstractEmitter {

    private static final Logger LOGGER = LoggerFactory.getLogger(BatchEmitter.class);

    public static abstract class Builder<T extends Builder<T>> extends AbstractEmitter.Builder<T> {
        public SimpleEmitter build() {
            return new SimpleEmitter(this);
        }
    }

    private static class Builder2 extends Builder<Builder2> {
        @Override
        protected Builder2 self() {
            return this;
        }
    }

    public static Builder<?> builder() {
        return new Builder2();
    }

    protected SimpleEmitter(Builder<?> builder) {
        super(builder);
    }

    /**
     * Adds a payload to the buffer and instantly sends it
     *
     * @param payload an event payload
     */
    @Override
    public void emit(TrackerPayload payload) {
        execute(getRequestRunnable(payload));
    }

    /**
     * When the buffer limit is reached sending of the buffer is
     * initiated.
     */
    public void flushBuffer() {
        // Do nothing!
    }

    /**
     * Returns a Runnable GET Request operation
     *
     * @param payload the event to be sent
     * @return the new Callable object
     */
    private Runnable getRequestRunnable(final TrackerPayload payload) {
        return new Runnable() {
            @Override
            public void run() {
                int code = httpClientAdapter.get(payload);

                // Process results
                int success = 0;
                int failure = 0;
                if (!isSuccessfulSend(code)) {
                    LOGGER.error("SimpleEmitter failed to send {} events: code: {}", 1, code);
                    failure += 1;
                } else {
                    LOGGER.info("SimpleEmitter successfully sent {} events: code: {}", 1, code);
                    success += 1;
                }

                // Send the callback if available
                if (requestCallback != null) {
                    if (failure != 0) {
                        List<TrackerPayload> buffer = new ArrayList<>();
                        buffer.add(payload);
                        requestCallback.onFailure(success, buffer);
                    } else {
                        requestCallback.onSuccess(success);
                    }
                }
            }
        };
    }
}