asafm commented on code in PR #15558: URL: https://github.com/apache/pulsar/pull/15558#discussion_r938022919
########## pulsar-broker/src/main/java/org/apache/pulsar/broker/stats/prometheus/PrometheusMetricStreams.java: ########## @@ -0,0 +1,75 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.pulsar.broker.stats.prometheus; + +import io.netty.buffer.ByteBufAllocator; +import java.util.HashMap; +import java.util.Map; +import org.apache.pulsar.common.util.SimpleTextOutputStream; + +/** + * Helper class to ensure that metrics of the same name are grouped together under the same TYPE header when written. + * Those are the requirements of the + * <a href="https://github.com/prometheus/docs/blob/master/content/docs/instrumenting/exposition_formats.md#grouping-and-sorting";>Prometheus Exposition Format</a>. + */ +public class PrometheusMetricStreams { + private final Map<String, SimpleTextOutputStream> metricStreamMap = new HashMap<>(); + + /** + * Write the given metric and sample value to the stream. Will write #TYPE header if metric not seen before. + * @param metricName name of the metric. + * @param value value of the sample + * @param labelsAndValuesArray varargs of label and label value + */ + void writeSample(String metricName, Number value, String... labelsAndValuesArray) { + SimpleTextOutputStream stream = initGaugeType(metricName); + stream.write(metricName).write('{'); + for (int i = 0; i < labelsAndValuesArray.length; i += 2) { + stream.write(labelsAndValuesArray[i]).write("=\"").write(labelsAndValuesArray[i + 1]).write('\"'); + if (i + 2 != labelsAndValuesArray.length) { + stream.write(','); + } + } + stream.write("} ").write(value).write(' ').write(System.currentTimeMillis()).write('\n'); + } + + /** + * Flush all the stored metrics to the supplied stream. + * @param stream the stream to write to. + */ + void flushAllToStream(SimpleTextOutputStream stream) { + metricStreamMap.values().forEach(s -> stream.write(s.getBuffer())); + } + + /** + * Release all the streams to clean up resources. + */ + void releaseAll() { + metricStreamMap.values().forEach(s -> s.getBuffer().release()); + metricStreamMap.clear(); + } + + private SimpleTextOutputStream initGaugeType(String metricName) { + return metricStreamMap.computeIfAbsent(metricName, s -> { + SimpleTextOutputStream stream = new SimpleTextOutputStream(ByteBufAllocator.DEFAULT.directBuffer()); Review Comment: It seems that needs fixing, and use `PulsarByteBufAllocator` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
