me.j360.trace.storage.elasticsearch.ElasticsearchSpanConsumer.java Source code

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Here is the source code for me.j360.trace.storage.elasticsearch.ElasticsearchSpanConsumer.java

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/**
 * Copyright 2015-2016 The OpenZipkin 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 me.j360.trace.storage.elasticsearch;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Function;
import com.google.common.base.Functions;
import com.google.common.util.concurrent.AsyncFunction;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import me.j360.trace.core.Codec;
import me.j360.trace.core.Span;
import me.j360.trace.core.internal.ApplyTimestampAndDuration;
import me.j360.trace.storage.core.guava.GuavaSpanConsumer;
import org.elasticsearch.action.bulk.BulkRequestBuilder;
import org.elasticsearch.action.index.IndexRequestBuilder;
import org.elasticsearch.client.Client;

import java.util.List;
import java.util.concurrent.TimeUnit;

import static com.google.common.util.concurrent.Futures.transform;
import static me.j360.trace.storage.elasticsearch.ElasticFutures.toGuava;

final class ElasticsearchSpanConsumer implements GuavaSpanConsumer {
    private static final byte[] TIMESTAMP_MILLIS_PREFIX = "{\"timestamp_millis\":".getBytes();
    private static final Function<Object, Void> TO_VOID = Functions.<Void>constant(null);

    private final Client client;
    private final IndexNameFormatter indexNameFormatter;

    ElasticsearchSpanConsumer(Client client, IndexNameFormatter indexNameFormatter) {
        this.client = client;
        this.indexNameFormatter = indexNameFormatter;
    }

    @Override
    public ListenableFuture<Void> accept(List<Span> spans) {
        if (spans.isEmpty())
            return Futures.immediateFuture(null);

        // Create a bulk request when there is more than one span to store
        ListenableFuture<?> future;
        if (spans.size() == 1) {
            future = toGuava(createSpanIndexRequest(spans.get(0)).execute());
        } else {
            BulkRequestBuilder request = client.prepareBulk();
            for (Span span : spans) {
                request.add(createSpanIndexRequest(span));
            }
            future = toGuava(request.execute());
        }

        if (ElasticsearchStorage.FLUSH_ON_WRITES) {
            future = transform(future, new AsyncFunction() {
                @Override
                public ListenableFuture apply(Object input) {
                    return toGuava(client.admin().indices().prepareFlush(indexNameFormatter.catchAll()).execute());
                }
            });
        }

        return transform(future, TO_VOID);
    }

    private IndexRequestBuilder createSpanIndexRequest(Span input) {
        Span span = ApplyTimestampAndDuration.apply(input);
        long timestampMillis;
        final byte[] spanBytes;
        if (span.timestamp != null) {
            timestampMillis = TimeUnit.MICROSECONDS.toMillis(span.timestamp);
            spanBytes = prefixWithTimestampMillis(Codec.JSON.writeSpan(span), timestampMillis);
        } else {
            timestampMillis = System.currentTimeMillis();
            spanBytes = Codec.JSON.writeSpan(span);
        }
        String spanIndex = indexNameFormatter.indexNameForTimestamp(timestampMillis);
        return client.prepareIndex(spanIndex, ElasticsearchConstants.SPAN).setSource(spanBytes);
    }

    /**
     * In order to allow systems like Kibana to search by timestamp, we add a field "timestamp_millis"
     * when storing. The cheapest way to do this without changing the codec is prefixing it to the
     * json. For example. {"traceId":"... becomes {"timestamp_millis":12345,"traceId":"...
     */
    @VisibleForTesting
    static byte[] prefixWithTimestampMillis(byte[] input, long timestampMillis) {
        String dateAsString = Long.toString(timestampMillis);
        byte[] newSpanBytes = new byte[TIMESTAMP_MILLIS_PREFIX.length + dateAsString.length() + input.length];
        int pos = 0;
        System.arraycopy(TIMESTAMP_MILLIS_PREFIX, 0, newSpanBytes, pos, TIMESTAMP_MILLIS_PREFIX.length);
        pos += TIMESTAMP_MILLIS_PREFIX.length;
        for (int i = 0, length = dateAsString.length(); i < length; i++) {
            newSpanBytes[pos++] = (byte) dateAsString.charAt(i);
        }
        newSpanBytes[pos++] = ',';
        // starting at position 1 discards the old head of '{'
        System.arraycopy(input, 1, newSpanBytes, pos, input.length - 1);
        return newSpanBytes;
    }
}