io.micrometer.tracing.http.HttpServerHandler Maven / Gradle / Ivy

/**
 * Copyright 2022 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
 *
 * https://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 io.micrometer.tracing.http;

import io.micrometer.tracing.http.HttpServerRequest;
import io.micrometer.tracing.http.HttpServerResponse;
import io.micrometer.tracing.Span;

/**
 * This API is taken from OpenZipkin Brave.
 * 
 * This standardizes a way to instrument http servers, particularly in a way that
 * encourages use of portable customizations via {@link HttpRequestParser} and
 * {@link HttpResponseParser}.
 *
 * @author OpenZipkin Brave Authors
 * @author Marcin Grzejszczak
 * @since 1.0.0
 */
public interface HttpServerHandler {

    /**
     * Conditionally joins a span, or starts a new trace, depending on if a trace context
     * was extracted from the request. Tags are added before the span is started.
     * @param request HTTP request
     * @return server side span (either joined or a new trace)
     */
    Span handleReceive(HttpServerRequest request);

    /**
     * Finishes the server span after assigning it tags according to the response or
     * error.
     * @param response HTTP response
     * @param span server side span to end
     */
    void handleSend(HttpServerResponse response, Span span);

}