m-trieu commented on code in PR #30796: URL: https://github.com/apache/beam/pull/30796#discussion_r1560067189
########## sdks/java/core/src/main/java/org/apache/beam/sdk/metrics/LabeledMetricNameUtils.java: ########## @@ -0,0 +1,122 @@ +/* + * 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.beam.sdk.metrics; + +import com.google.auto.value.AutoValue; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.base.Splitter; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableMap; + +/** Util class for building/parsing labeled {@link MetricName}. */ +public class LabeledMetricNameUtils { + // Delimiters. Avoid using delimeters that can be used in metric labels. + // E.g. Since we support BigQuery TableIds as labels we avoid using delimiters that can be used in + // TableIds. + // ref: https://cloud.google.com/bigquery/docs/tables#table_naming + private static final char LABEL_DELIMITER = ';'; + private static final char METRIC_KV_DELIMITER = ':'; + private static final char METRIC_NAME_DELIMITER = '*'; + + /** + * Builder class for a labeled {@code MetricName}. Returned {@link MetricName#getName} will be + * formatted as: + * + * <p>'{baseName}-{metricLabelKey1}:{metricLabelVal1};...{metricLabelKeyN}:{metricLabelValN};' + */ + public static class MetricNameBuilder { + private final StringBuilder labeledNameBuilder; + + private MetricNameBuilder(String baseName) { + this.labeledNameBuilder = new StringBuilder(baseName + METRIC_NAME_DELIMITER); + } + + public static MetricNameBuilder baseNameBuilder(String baseName) { + return new MetricNameBuilder(baseName); + } + + /** + * Add a metric label KV pair to the metric name. Calling {@code addLabel} multiple times with + * the same {@code key} will lead to unexpected results when parsing metric names. + */ + public void addLabel(String key, String value) { + this.labeledNameBuilder + .append(key) + .append(METRIC_KV_DELIMITER) + .append(value) + .append(LABEL_DELIMITER); + } + + public MetricName build(String metricNamespace) { + return MetricName.named(metricNamespace, labeledNameBuilder.toString()); + } + } + + @AutoValue + public abstract static class ParsedMetricName { + public abstract String getBaseName(); + + public abstract Map<String, String> getMetricLabels(); + + public static ParsedMetricName create(String baseName, Map<String, String> metricLabels) { + return new AutoValue_LabeledMetricNameUtils_ParsedMetricName(baseName, metricLabels); + } + + public static ParsedMetricName create(String baseName) { + ImmutableMap<String, String> emptyMap = ImmutableMap.of(); + return new AutoValue_LabeledMetricNameUtils_ParsedMetricName(baseName, emptyMap); + } + } + + /** + * Parse a 'metric name' String that was created with 'MetricNameBuilder'. The input string should + * be formatted as. + * + * <p>'{baseName}*{metricLabelKey1}:{metricLabelVal1};...{metricLabelKeyN}:{metricLabelValN};' + * + * @param metricName + * @return Returns a ParsedMetricName object if the input string is properly formatted. If the + * input string is empty or malformed, returns an empty value. + */ + public static Optional<ParsedMetricName> parseMetricName(String metricName) { + if (metricName.isEmpty()) { + return Optional.empty(); + } + + List<String> metricNameSplit = + Splitter.on(METRIC_NAME_DELIMITER).limit(2).splitToList(metricName); + + if (metricNameSplit.size() == 0) { + return Optional.empty(); + } + + if (metricNameSplit.size() == 1) { + return Optional.of(ParsedMetricName.create(metricNameSplit.get(0))); + } + + Splitter.MapSplitter splitter = + Splitter.on(LABEL_DELIMITER).omitEmptyStrings().withKeyValueSeparator(METRIC_KV_DELIMITER); + try { + Map<String, String> labels = splitter.split(metricNameSplit.get(1)); + return Optional.of(ParsedMetricName.create(metricNameSplit.get(0), labels)); + } catch (IllegalArgumentException e) { Review Comment: should we log something here? -- 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]
