add checkstyle

zeitlinger · zeitlinger · commit ab2a2c3cfa67 · 2024-11-11T18:16:29.000+01:00
Signed-off-by: Gregor Zeitlinger &lt;gregor.zeitlinger@grafana.com&gt;
diff --git a/.editorconfig b/.editorconfig
@@ -0,0 +1,4 @@
+root = true
+
+[*]
+max_line_length = 100
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -27,6 +27,7 @@ If you're getting errors when running tests:
 
 - Use `-Dspotless.check.skip=true` to skip the formatting check during development.
 - Use `-Dcoverage.skip=true` to skip the coverage check during development.
+- Use `-Dcheckstyle.skip=true` to skip the checkstyle check during development.
 - Use `-Dwarnings=-nowarn` to skip the warnings during development.
 
 ## Updating the Protobuf Java Classes
diff --git a/checkstyle-suppressions.xml b/checkstyle-suppressions.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+  "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+  "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<suppressions>
+    <suppress checks="Javadoc" files="."/>
+</suppressions>
diff --git a/examples/example-exemplars-tail-sampling/example-greeting-service/pom.xml b/examples/example-exemplars-tail-sampling/example-greeting-service/pom.xml
@@ -57,7 +57,7 @@
                         <configuration>
                             <transformers>
                                 <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
-                                    <mainClass>io.prometheus.metrics.examples.otel_exemplars.greeting.Main</mainClass>
+                                    <mainClass>io.prometheus.metrics.examples.otel.exemplars.greeting.Main</mainClass>
                                 </transformer>
                             </transformers>
                         </configuration>
diff --git a/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel/exemplars/greeting/GreetingServlet.java b/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel/exemplars/greeting/GreetingServlet.java
@@ -1,15 +1,16 @@
-package io.prometheus.metrics.examples.otel_exemplars.greeting;
-
-import static io.prometheus.metrics.model.snapshots.Unit.nanosToSeconds;
+package io.prometheus.metrics.examples.otel.exemplars.greeting;
 
 import io.prometheus.metrics.core.metrics.Histogram;
 import io.prometheus.metrics.model.snapshots.Unit;
 import jakarta.servlet.http.HttpServlet;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+
 import java.io.IOException;
 import java.util.Random;
 
+import static io.prometheus.metrics.model.snapshots.Unit.nanosToSeconds;
+
 /** Hello World REST servlet, with an example counter and an example histogram. */
 public class GreetingServlet extends HttpServlet {
 
diff --git a/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel/exemplars/greeting/Main.java b/examples/example-exemplars-tail-sampling/example-greeting-service/src/main/java/io/prometheus/metrics/examples/otel/exemplars/greeting/Main.java
@@ -1,4 +1,4 @@
-package io.prometheus.metrics.examples.otel_exemplars.greeting;
+package io.prometheus.metrics.examples.otel.exemplars.greeting;
 
 import io.prometheus.metrics.exporter.servlet.jakarta.PrometheusMetricsServlet;
 import io.prometheus.metrics.instrumentation.jvm.JvmMetrics;
diff --git a/examples/example-exemplars-tail-sampling/example-hello-world-app/pom.xml b/examples/example-exemplars-tail-sampling/example-hello-world-app/pom.xml
@@ -57,7 +57,7 @@
                         <configuration>
                             <transformers>
                                 <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
-                                    <mainClass>io.prometheus.metrics.examples.otel_exemplars.app.Main</mainClass>
+                                    <mainClass>io.prometheus.metrics.examples.otel.exemplars.app.Main</mainClass>
                                 </transformer>
                             </transformers>
                         </configuration>
diff --git a/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel/exemplars/app/HelloWorldServlet.java b/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel/exemplars/app/HelloWorldServlet.java
@@ -1,4 +1,4 @@
-package io.prometheus.metrics.examples.otel_exemplars.app;
+package io.prometheus.metrics.examples.otel.exemplars.app;
 
 import static io.prometheus.metrics.model.snapshots.Unit.nanosToSeconds;
 import static java.net.http.HttpResponse.BodyHandlers.ofString;
diff --git a/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel/exemplars/app/Main.java b/examples/example-exemplars-tail-sampling/example-hello-world-app/src/main/java/io/prometheus/metrics/examples/otel/exemplars/app/Main.java
@@ -1,4 +1,4 @@
-package io.prometheus.metrics.examples.otel_exemplars.app;
+package io.prometheus.metrics.examples.otel.exemplars.app;
 
 import io.prometheus.metrics.exporter.servlet.jakarta.PrometheusMetricsServlet;
 import io.prometheus.metrics.instrumentation.jvm.JvmMetrics;
diff --git a/integration-tests/it-exporter/it-exporter-servlet-jetty-sample/src/main/java/io/prometheus/metrics/it/exporter/servlet/jetty/ExporterServletJettySample.java b/integration-tests/it-exporter/it-exporter-servlet-jetty-sample/src/main/java/io/prometheus/metrics/it/exporter/servlet/jetty/ExporterServletJettySample.java
@@ -27,7 +27,9 @@ public static void main(String[] args) throws Exception {
       System.exit(1);
     }
 
+    //noinspection CheckStyle
     int port = parsePortOrExit(args[0]);
+    //noinspection CheckStyle
     Mode mode = parseModeOrExit(args[1]);
 
     Counter counter =
diff --git a/integration-tests/it-exporter/it-exporter-servlet-tomcat-sample/src/main/java/io/prometheus/metrics/it/exporter/servlet/tomcat/ExporterServletTomcatSample.java b/integration-tests/it-exporter/it-exporter-servlet-tomcat-sample/src/main/java/io/prometheus/metrics/it/exporter/servlet/tomcat/ExporterServletTomcatSample.java
@@ -7,13 +7,14 @@
 import io.prometheus.metrics.model.registry.Collector;
 import io.prometheus.metrics.model.registry.PrometheusRegistry;
 import io.prometheus.metrics.model.snapshots.Unit;
+import org.apache.catalina.Context;
+import org.apache.catalina.LifecycleException;
+import org.apache.catalina.startup.Tomcat;
+
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import org.apache.catalina.Context;
-import org.apache.catalina.LifecycleException;
-import org.apache.catalina.startup.Tomcat;
 
 /** Sample application using the {@link PrometheusMetricsServlet} in Tomcat. */
 public class ExporterServletTomcatSample {
@@ -30,7 +31,9 @@ public static void main(String[] args) throws LifecycleException, IOException {
       System.exit(1);
     }
 
+    //noinspection CheckStyle
     int port = parsePortOrExit(args[0]);
+    //noinspection CheckStyle
     Mode mode = parseModeOrExit(args[1]);
 
     Counter counter =
diff --git a/pom.xml b/pom.xml
@@ -21,6 +21,7 @@
         <otel.instrumentation.version>2.9.0-alpha</otel.instrumentation.version>
         <java.version>8</java.version>
         <jacoco.line-coverage>0.70</jacoco.line-coverage>
+        <checkstyle.skip>false</checkstyle.skip>
         <coverage.skip>false</coverage.skip>
         <warnings>-Werror</warnings>
     </properties>
@@ -224,6 +225,27 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-checkstyle-plugin</artifactId>
+                <version>3.5.0</version>
+                <configuration>
+                    <consoleOutput>true</consoleOutput>
+                    <configLocation>google_checks.xml</configLocation>
+                    <violationSeverity>warning</violationSeverity>
+                    <failOnViolation>true</failOnViolation>
+                    <skip>${checkstyle.skip}</skip>
+                    <suppressionsLocation>checkstyle-suppressions.xml</suppressionsLocation>
+                    <excludes>**/generated/**,**CkmsQuantiles</excludes>
+                </configuration>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
             <plugin>
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/exemplars/ExemplarSampler.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/exemplars/ExemplarSampler.java
@@ -130,6 +130,16 @@ private long doObserveSingleExemplar(double value) {
     return 0;
   }
 
+  private long doObserveSingleExemplar(double amount, Labels labels) {
+    long now = System.currentTimeMillis();
+    Exemplar current = customExemplars[0];
+    if (current == null
+        || now - current.getTimestampMillis() > config.getMinRetentionPeriodMillis()) {
+      return updateCustomExemplar(0, amount, labels, now);
+    }
+    return 0;
+  }
+
   private long doObserveWithUpperBounds(double value) {
     long now = System.currentTimeMillis();
     double[] upperBounds = config.getHistogramClassicUpperBounds();
@@ -212,16 +222,6 @@ private long doObserveWithExemplar(double amount, Labels labels) {
     }
   }
 
-  private long doObserveSingleExemplar(double amount, Labels labels) {
-    long now = System.currentTimeMillis();
-    Exemplar current = customExemplars[0];
-    if (current == null
-        || now - current.getTimestampMillis() > config.getMinRetentionPeriodMillis()) {
-      return updateCustomExemplar(0, amount, labels, now);
-    }
-    return 0;
-  }
-
   private long doObserveWithExemplarWithUpperBounds(double value, Labels labels) {
     long now = System.currentTimeMillis();
     double[] upperBounds = config.getHistogramClassicUpperBounds();
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CallbackMetric.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CallbackMetric.java
@@ -28,7 +28,8 @@ protected Labels makeLabels(String... labelValues) {
       if (labelValues == null) {
         throw new IllegalArgumentException(
             this.getClass().getSimpleName()
-                + " was created with label names, but the callback was called without label values.");
+                + " was created with label names, "
+                + "but the callback was called without label values.");
       }
       if (labelValues.length != labelNames.length) {
         throw new IllegalArgumentException(
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Counter.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/Counter.java
@@ -82,6 +82,15 @@ public CounterSnapshot collect() {
     return (CounterSnapshot) super.collect();
   }
 
+  @Override
+  protected CounterSnapshot collect(List<Labels> labels, List<DataPoint> metricData) {
+    List<CounterSnapshot.CounterDataPointSnapshot> data = new ArrayList<>(labels.size());
+    for (int i = 0; i < labels.size(); i++) {
+      data.add(metricData.get(i).collect(labels.get(i)));
+    }
+    return new CounterSnapshot(getMetadata(), data);
+  }
+
   @Override
   protected boolean isExemplarsEnabled() {
     return exemplarsEnabled;
@@ -96,15 +105,6 @@ protected DataPoint newDataPoint() {
     }
   }
 
-  @Override
-  protected CounterSnapshot collect(List<Labels> labels, List<DataPoint> metricData) {
-    List<CounterSnapshot.CounterDataPointSnapshot> data = new ArrayList<>(labels.size());
-    for (int i = 0; i < labels.size(); i++) {
-      data.add(metricData.get(i).collect(labels.get(i)));
-    }
-    return new CounterSnapshot(getMetadata(), data);
-  }
-
   static String stripTotalSuffix(String name) {
     if (name != null && (name.endsWith("_total") || name.endsWith(".total"))) {
       name = name.substring(0, name.length() - 6);
diff --git a/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CounterWithCallback.java b/prometheus-metrics-core/src/main/java/io/prometheus/metrics/core/metrics/CounterWithCallback.java
@@ -15,7 +15,7 @@
  *
  * CounterWithCallback.builder()
  *         .name("classes_loaded_total")
- *         .help("The total number of classes that have been loaded since the JVM has started execution")
+ *         .help("The total number of classes since the JVM has started execution")
  *         .callback(callback -> callback.call(classLoadingMXBean.getLoadedClassCount()))
  *         .register();
  * }</pre>
diff --git a/prometheus-metrics-exporter-httpserver/src/main/java/io/prometheus/metrics/exporter/httpserver/DefaultHandler.java b/prometheus-metrics-exporter-httpserver/src/main/java/io/prometheus/metrics/exporter/httpserver/DefaultHandler.java
@@ -21,15 +21,19 @@ public DefaultHandler() {
             + "<h2>Metrics Path</h2>\n"
             + "The metrics path is <a href=\"metrics\">/metrics</a>.\n"
             + "<h2>Name Filter</h2>\n"
-            + "If you want to scrape only specific metrics, use the <tt>name[]</tt> parameter like this:\n"
+            + "If you want to scrape only specific metrics, "
+            + "use the <tt>name[]</tt> parameter like this:\n"
             + "<ul>\n"
             + "<li><a href=\"metrics?name[]=my_metric\">/metrics?name[]=my_metric</a></li>\n"
             + "</ul>\n"
             + "You can also use multiple <tt>name[]</tt> parameters to query multiple metrics:\n"
             + "<ul>\n"
-            + "<li><a href=\"metrics?name[]=my_metric_a&name=my_metrics_b\">/metrics?name[]=my_metric_a&amp;name=[]=my_metric_b</a></li>\n"
+            + "<li><a href=\"metrics?name[]=my_metric_a&name=my_metrics_b\">"
+            + "/metrics?name[]=my_metric_a&amp;name=[]=my_metric_b</a></li>\n"
             + "</ul>\n"
-            + "The <tt>name[]</tt> parameter can be used by the Prometheus server for scraping. Add the following snippet to your scrape job configuration in <tt>prometheus.yaml</tt>:\n"
+            + "The <tt>name[]</tt> parameter can be used by the Prometheus server for scraping. "
+            + "Add the following snippet to your scrape job configuration in "
+            + "<tt>prometheus.yaml</tt>:\n"
             + "<pre>\n"
             + "params:\n"
             + "    name[]:\n"
@@ -38,16 +42,28 @@ public DefaultHandler() {
             + "</pre>\n"
             + "<h2>Debug Parameter</h2>\n"
             + "The Prometheus Java metrics library supports multiple exposition formats.\n"
-            + "The Prometheus server sends the <tt>Accept</tt> header to indicate which format it accepts.\n"
-            + "By default, the Prometheus server accepts OpenMetrics text format, unless the Prometheus server is started with feature flag <tt>--enable-feature=native-histograms</tt>,\n"
+            + "The Prometheus server sends the <tt>Accept</tt> header "
+            + "to indicate which format it accepts.\n"
+            + "By default, the Prometheus server accepts OpenMetrics text format, "
+            + "unless the Prometheus server is started with feature flag "
+            + "<tt>--enable-feature=native-histograms</tt>,\n"
             + "in which case the default is Prometheus protobuf.\n"
-            + "The Prometheus Java metrics library supports a <tt>debug</tt> query parameter for viewing the different formats in a Web browser:\n"
+            + "The Prometheus Java metrics library supports a <tt>debug</tt> query parameter "
+            + "for viewing the different formats in a Web browser:\n"
             + "<ul>\n"
-            + "<li><a href=\"metrics?debug=openmetrics\">/metrics?debug=openmetrics</a>: View OpenMetrics text format.</li>\n"
-            + "<li><a href=\"metrics?debug=text\">/metrics?debug=text</a>: View Prometheus text format (this is the default when accessing the <a href=\"metrics\">/metrics</a> endpoint with a Web browser).</li>\n"
-            + "<li><a href=\"metrics?debug=prometheus-protobuf\">/metrics?debug=prometheus-protobuf</a>: View a text representation of the Prometheus protobuf format.</li>\n"
+            + "<li><a href=\"metrics?debug=openmetrics\">/metrics?debug=openmetrics</a>: "
+            + "View OpenMetrics text format.</li>\n"
+            + "<li><a href=\"metrics?debug=text\">/metrics?debug=text</a>: "
+            + "View Prometheus text format (this is the default when accessing the "
+            + "<a href=\"metrics\">/metrics</a> endpoint with a Web browser).</li>\n"
+            + "<li><a href=\"metrics?debug=prometheus-protobuf\">"
+            + "/metrics?debug=prometheus-protobuf</a>: "
+            + "View a text representation of the Prometheus protobuf format.</li>\n"
             + "</ul>\n"
-            + "Note that the <tt>debug</tt> parameter is only for viewing different formats in a Web browser, it should not be used by the Prometheus server for scraping. The Prometheus server uses the <tt>Accept</tt> header for indicating which format it accepts.\n"
+            + "Note that the <tt>debug</tt> parameter is only for viewing different formats in a "
+            + "Web browser, it should not be used by the Prometheus server for scraping. "
+            + "The Prometheus server uses the <tt>Accept</tt> "
+            + "header for indicating which format it accepts.\n"
             + "</body>\n"
             + "</html>\n";
     this.responseBytes = responseString.getBytes(StandardCharsets.UTF_8);
diff --git a/prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java b/prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java
@@ -1,12 +1,29 @@
 package io.prometheus.metrics.instrumentation.dropwizard5;
 
-import io.dropwizard.metrics5.*;
+import io.dropwizard.metrics5.Counter;
+import io.dropwizard.metrics5.Gauge;
+import io.dropwizard.metrics5.Histogram;
+import io.dropwizard.metrics5.Meter;
+import io.dropwizard.metrics5.Metric;
+import io.dropwizard.metrics5.MetricFilter;
+import io.dropwizard.metrics5.MetricName;
+import io.dropwizard.metrics5.MetricRegistry;
+import io.dropwizard.metrics5.Snapshot;
 import io.dropwizard.metrics5.Timer;
 import io.prometheus.metrics.instrumentation.dropwizard5.labels.CustomLabelMapper;
 import io.prometheus.metrics.model.registry.MultiCollector;
 import io.prometheus.metrics.model.registry.PrometheusRegistry;
-import io.prometheus.metrics.model.snapshots.*;
-import java.util.*;
+import io.prometheus.metrics.model.snapshots.CounterSnapshot;
+import io.prometheus.metrics.model.snapshots.GaugeSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricMetadata;
+import io.prometheus.metrics.model.snapshots.MetricSnapshot;
+import io.prometheus.metrics.model.snapshots.MetricSnapshots;
+import io.prometheus.metrics.model.snapshots.PrometheusNaming;
+import io.prometheus.metrics.model.snapshots.Quantiles;
+import io.prometheus.metrics.model.snapshots.SummarySnapshot;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/DataPointSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/DataPointSnapshot.java
@@ -21,11 +21,13 @@ private void validate() {
     }
     if (createdTimestampMillis < 0) {
       throw new IllegalArgumentException(
-          "Created timestamp cannot be negative. Use 0 if the metric doesn't have a created timestamp.");
+          "Created timestamp cannot be negative. "
+              + "Use 0 if the metric doesn't have a created timestamp.");
     }
     if (scrapeTimestampMillis < 0) {
       throw new IllegalArgumentException(
-          "Scrape timestamp cannot be negative. Use 0 to indicate that the Prometheus server should set the scrape timestamp.");
+          "Scrape timestamp cannot be negative. "
+              + "Use 0 to indicate that the Prometheus server should set the scrape timestamp.");
     }
     if (hasCreatedTimestamp() && hasScrapeTimestamp()) {
       if (scrapeTimestampMillis < createdTimestampMillis) {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/HistogramSnapshot.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/HistogramSnapshot.java
@@ -270,7 +270,8 @@ private static long calculateCount(
                 nativeZeroCount, nativeBucketsForPositiveValues, nativeBucketsForNegativeValues);
         if (classicCount != nativeCount) {
           throw new IllegalArgumentException(
-              "Inconsistent observation count: If a histogram has both classic and native data the observation count must be the same. Classic count is "
+              "Inconsistent observation count: If a histogram has both classic and native "
+                  + "data the observation count must be the same. Classic count is "
                   + classicCount
                   + " but native count is "
                   + nativeCount

-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +root = true
++
 +[*]
 +max_line_length = 100
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package io.prometheus.metrics.examples.otel_exemplars.greeting;`
	`1`	`+package io.prometheus.metrics.examples.otel.exemplars.greeting;`
`2`	`2`
`3`	`3`	`import io.prometheus.metrics.exporter.servlet.jakarta.PrometheusMetricsServlet;`
`4`	`4`	`import io.prometheus.metrics.instrumentation.jvm.JvmMetrics;`
Original file line number	Diff line number	Diff line change
`@@ -27,7 +27,9 @@ public static void main(String[] args) throws Exception {`
`27`	`27`	`System.exit(1);`
`28`	`28`	`}`
`29`	`29`
	`30`	`+ //noinspection CheckStyle`
`30`	`31`	`int port = parsePortOrExit(args[0]);`
	`32`	`+ //noinspection CheckStyle`
`31`	`33`	`Mode mode = parseModeOrExit(args[1]);`
`32`	`34`
`33`	`35`	`Counter counter =`