[FLINK-21759][metrics][tests] Add TestMetricGroup

flink-metrics/flink-metrics-core/src/test/java/org/apache/flink/metrics/util/TestMetricGroup.java

@@ -0,0 +1,159 @@
+/*
+ * 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: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 org.apache.flink.metrics.util;
+
+import org.apache.flink.metrics.CharacterFilter;
+import org.apache.flink.metrics.Counter;
+import org.apache.flink.metrics.Gauge;
+import org.apache.flink.metrics.Histogram;
+import org.apache.flink.metrics.LogicalScopeProvider;
+import org.apache.flink.metrics.Meter;
+import org.apache.flink.metrics.MetricGroup;
+import org.apache.flink.metrics.SimpleCounter;
+
+import java.util.Collections;
+import java.util.Map;
+import java.util.Optional;
+import java.util.function.BiFunction;
+
+/** A customizable test {@link MetricGroup} implementation. */
+public class TestMetricGroup implements MetricGroup, LogicalScopeProvider {
+
+ private final String[] scopeComponents;
+ private final Map<String, String> variables;
+ private final BiFunction<String, Optional<CharacterFilter>, String> metricIdentifierFunction;
+ private final BiFunction<CharacterFilter, Optional<Character>, String> logicalScopeFunction;
+
+ public TestMetricGroup(
+ String[] scopeComponents,
+ Map<String, String> variables,
+ BiFunction<String, Optional<CharacterFilter>, String> metricIdentifierFunction,
+ BiFunction<CharacterFilter, Optional<Character>, String> logicalScopeFunction) {
+ this.scopeComponents = scopeComponents;
+ this.variables = variables;
+ this.metricIdentifierFunction = metricIdentifierFunction;
+ this.logicalScopeFunction = logicalScopeFunction;
+ }
+
+ public static TestMetricGroupBuilder newBuilder() {
+ return new TestMetricGroupBuilder();
+ }
+
+ @Override
+ public Counter counter(String name) {
+ return new SimpleCounter();
+ }
+
+ @Override
+ public <C extends Counter> C counter(String name, C counter) {
+ return counter;
+ }
+
+ @Override
+ public <T, G extends Gauge<T>> G gauge(String name, G gauge) {
+ return gauge;
+ }
+
+ @Override
+ public <H extends Histogram> H histogram(String name, H histogram) {
+ return histogram;
+ }
+
+ @Override
+ public <M extends Meter> M meter(String name, M meter) {
+ return meter;
+ }
+
+ @Override
+ public MetricGroup addGroup(String name) {
+ return this;
+ }
+
+ @Override
+ public MetricGroup addGroup(String key, String value) {
+ return this;
+ }
+
+ @Override
+ public String[] getScopeComponents() {
+ return scopeComponents;
+ }
+
+ @Override
+ public Map<String, String> getAllVariables() {
+ return variables;
+ }
+
+ @Override
+ public String getMetricIdentifier(String metricName) {
+ return metricIdentifierFunction.apply(metricName, Optional.empty());
+ }
+
+ @Override
+ public String getMetricIdentifier(String metricName, CharacterFilter filter) {
+ return metricIdentifierFunction.apply(metricName, Optional.of(filter));
+ }
+
+ @Override
+ public String getLogicalScope(CharacterFilter filter) {
+ return logicalScopeFunction.apply(filter, Optional.empty());
+ }
+
+ @Override
+ public String getLogicalScope(CharacterFilter filter, char delimiter) {
+ return logicalScopeFunction.apply(filter, Optional.of(delimiter));
+ }
+
+ /** Builder for {@link TestMetricGroup}. */
+ public static final class TestMetricGroupBuilder {
+ private String[] scopeComponents = new String[] {};
+ private Map<String, String> variables = Collections.emptyMap();
+ private BiFunction<String, Optional<CharacterFilter>, String> metricIdentifierFunction =
+ (name, filter) -> filter.map(f -> f.filterCharacters(name)).orElse(name);
+
+ private BiFunction<CharacterFilter, Optional<Character>, String> logicalScopeFunction =
+ (characterFilter, character) -> "logicalScope";
+
+ public TestMetricGroupBuilder setScopeComponents(String[] scopeComponents) {
+ this.scopeComponents = scopeComponents;
+ return this;
+ }
+
+ public TestMetricGroupBuilder setVariables(Map<String, String> variables) {
+ this.variables = variables;
+ return this;
+ }
+
+ public TestMetricGroupBuilder setMetricIdentifierFunction(
+ BiFunction<String, Optional<CharacterFilter>, String> metricIdentifierFunction) {
+ this.metricIdentifierFunction = metricIdentifierFunction;
+ return this;
+ }
+
+ public TestMetricGroupBuilder setLogicalScopeFunction(
+ BiFunction<CharacterFilter, Optional<Character>, String> logicalScopeFunction) {
+ this.logicalScopeFunction = logicalScopeFunction;
+ return this;
+ }
+
+ public TestMetricGroup build() {
+ return new TestMetricGroup(
+ scopeComponents, variables, metricIdentifierFunction, logicalScopeFunction);
+ }
+ }
+}