com.google.cloud.trace.v1.util.TraceBuffer.java Source code

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Here is the source code for com.google.cloud.trace.v1.util.TraceBuffer.java

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// Copyright 2016 Google Inc. All rights reserved.
//
// 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.google.cloud.trace.v1.util;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.devtools.cloudtrace.v1.Trace;
import com.google.devtools.cloudtrace.v1.TraceSpan;
import java.util.HashMap;
import java.util.Map;

/**
 * A class that buffers trace messages. Trace messages added to this buffer are combined with
 * existing trace messages when they contain the same trace identifiers, by combining the spans of
 * the matching trace messages.
 *
 * @see Iterable
 * @see Trace
 */
public class TraceBuffer {
    private final HashMap<TraceKey, SpanBuffer> traceMap;

    /**
     * Creates a trace buffer.
     */
    public TraceBuffer() {
        this.traceMap = new HashMap<TraceKey, SpanBuffer>();
    }

    /**
     * Adds a trace message to this trace buffer.
     *
     * @param trace a trace message to add this trace buffer.
     */
    public void put(Trace trace) {
        TraceKey traceKey = new TraceKey(trace.getProjectId(), trace.getTraceId());
        SpanBuffer spans = traceMap.get(traceKey);
        if (spans == null) {
            spans = new SpanBuffer();
            traceMap.put(traceKey, spans);
        }
        for (TraceSpan span : trace.getSpansList()) {
            spans.put(span);
        }
    }

    /**
     * Returns all of the trace messages in this trace buffer.
     *
     * @return an iterable containing the trace messages in this trace buffer.
     */
    public Iterable<Trace> getTraces() {
        return Iterables.transform(traceMap.entrySet(), new Function<Map.Entry<TraceKey, SpanBuffer>, Trace>() {
            @Override
            public Trace apply(Map.Entry<TraceKey, SpanBuffer> entry) {
                Trace.Builder traceBuilder = Trace.newBuilder().setProjectId(entry.getKey().getProjectId())
                        .setTraceId(entry.getKey().getTraceId());
                for (TraceSpan.Builder spanBuilder : entry.getValue().getSpans()) {
                    traceBuilder.addSpans(spanBuilder);
                }
                return traceBuilder.build();
            }
        });
    }

    /**
     * Removes all of the trace messages from this trace buffer.
     */
    public void clear() {
        traceMap.clear();
    }
}