nullaway

Signed-off-by: Gregor Zeitlinger <[email protected]>

Author: zeitlinger

prometheus-metrics-exporter-httpserver/src/main/java/io/prometheus/metrics/exporter/httpserver/HTTPServer.java

@@ -21,6 +21,7 @@
 import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
 import javax.security.auth.Subject;
 
 /**
@@ -54,9 +55,9 @@ private HTTPServer(
       ExecutorService executorService,
       HttpServer httpServer,
       PrometheusRegistry registry,
-      Authenticator authenticator,
-      String authenticatedSubjectAttributeName,
-      HttpHandler defaultHandler) {
+      @Nullable Authenticator authenticator,
+      @Nullable String authenticatedSubjectAttributeName,
+      @Nullable HttpHandler defaultHandler) {
     if (httpServer.getAddress() == null) {
       throw new IllegalArgumentException("HttpServer hasn't been bound to an address");
     }
@@ -88,14 +89,17 @@ private HTTPServer(
   }
 
   private void registerHandler(
-      String path, HttpHandler handler, Authenticator authenticator, String subjectAttributeName) {
+      String path,
+      HttpHandler handler,
+      @Nullable Authenticator authenticator,
+      @Nullable String subjectAttributeName) {
     HttpContext context = server.createContext(path, wrapWithDoAs(handler, subjectAttributeName));
     if (authenticator != null) {
       context.setAuthenticator(authenticator);
     }
   }
 
-  private HttpHandler wrapWithDoAs(HttpHandler handler, String subjectAttributeName) {
+  private HttpHandler wrapWithDoAs(HttpHandler handler, @Nullable String subjectAttributeName) {
     if (subjectAttributeName == null) {
       return handler;
     }
@@ -169,15 +173,15 @@ public static Builder builder(PrometheusProperties config) {
   public static class Builder {
 
     private final PrometheusProperties config;
-    private Integer port = null;
-    private String hostname = null;
-    private InetAddress inetAddress = null;
-    private ExecutorService executorService = null;
-    private PrometheusRegistry registry = null;
-    private Authenticator authenticator = null;
-    private HttpsConfigurator httpsConfigurator = null;
-    private HttpHandler defaultHandler = null;
-    private String authenticatedSubjectAttributeName = null;
+    @Nullable private Integer port = null;
+    @Nullable private String hostname = null;
+    @Nullable private InetAddress inetAddress = null;
+    @Nullable private ExecutorService executorService = null;
+    @Nullable private PrometheusRegistry registry = null;
+    @Nullable private Authenticator authenticator = null;
+    @Nullable private HttpsConfigurator httpsConfigurator = null;
+    @Nullable private HttpHandler defaultHandler = null;
+    @Nullable private String authenticatedSubjectAttributeName = null;
 
     private Builder(PrometheusProperties config) {
       this.config = config;
@@ -313,7 +317,7 @@ private int findPort() {
       return 0; // random port will be selected
     }
 
-    private void assertNull(Object o, String msg) {
+    private void assertNull(@Nullable Object o, String msg) {
       if (o != null) {
         throw new IllegalStateException(msg);
       }

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/OpenTelemetryExporter.java

@@ -5,6 +5,7 @@
 import io.prometheus.metrics.model.registry.PrometheusRegistry;
 import java.util.HashMap;
 import java.util.Map;
+import javax.annotation.Nullable;
 
 public class OpenTelemetryExporter implements AutoCloseable {
   private final MetricReader reader;
@@ -29,16 +30,16 @@ public static Builder builder(PrometheusProperties config) {
   public static class Builder {
 
     private final PrometheusProperties config;
-    private PrometheusRegistry registry = null;
-    String protocol;
-    String endpoint;
+    @Nullable private PrometheusRegistry registry = null;
+    @Nullable String protocol;
+    @Nullable String endpoint;
     final Map<String, String> headers = new HashMap<>();
-    String interval;
-    String timeout;
-    String serviceName;
-    String serviceNamespace;
-    String serviceInstanceId;
-    String serviceVersion;
+    @Nullable String interval;
+    @Nullable String timeout;
+    @Nullable String serviceName;
+    @Nullable String serviceNamespace;
+    @Nullable String serviceInstanceId;
+    @Nullable String serviceVersion;
     final Map<String, String> resourceAttributes = new HashMap<>();
 
     private Builder(PrometheusProperties config) {

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/OtelAutoConfig.java

@@ -1,5 +1,7 @@
 package io.prometheus.metrics.exporter.opentelemetry;
 
+import static java.util.Objects.requireNonNull;
+
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
@@ -35,7 +37,7 @@ static MetricReader createReader(
             config.getExporterOpenTelemetryProperties(),
             instrumentationScopeInfo);
 
-    MetricReader reader = readerRef.get();
+    MetricReader reader = requireNonNull(readerRef.get());
     reader.register(
         new PrometheusMetricProducer(registry, instrumentationScopeInfo, getResourceField(sdk)));
     return reader;

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PrometheusMetricProducer.java

@@ -22,6 +22,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import javax.annotation.Nullable;
 
 class PrometheusMetricProducer implements CollectionRegistration {
 
@@ -93,6 +94,7 @@ private Resource resourceFromTargetInfo(MetricSnapshots snapshots) {
     return result.build();
   }
 
+  @Nullable
   private InstrumentationScopeInfo instrumentationScopeFromOtelScopeInfo(
       MetricSnapshots snapshots) {
     for (MetricSnapshot snapshot : snapshots) {
@@ -125,7 +127,7 @@ private InstrumentationScopeInfo instrumentationScopeFromOtelScopeInfo(
     return null;
   }
 
-  private void addUnlessNull(List<MetricData> result, MetricData data) {
+  private void addUnlessNull(List<MetricData> result, @Nullable MetricData data) {
     if (data != null) {
       result.add(data);
     }

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PropertiesResourceProvider.java

@@ -5,15 +5,16 @@
 import io.opentelemetry.sdk.resources.Resource;
 import java.util.HashMap;
 import java.util.Map;
+import javax.annotation.Nullable;
 
 final class PropertiesResourceProvider {
 
   static Resource mergeResource(
       Map<String, String> resourceAttributes,
-      String serviceName,
-      String serviceNamespace,
-      String serviceInstanceId,
-      String serviceVersion) {
+      @Nullable String serviceName,
+      @Nullable String serviceNamespace,
+      @Nullable String serviceInstanceId,
+      @Nullable String serviceVersion) {
     Map<String, String> resource = new HashMap<>(resourceAttributes);
     if (serviceName != null) {
       resource.put("service.name", serviceName);

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/PropertyMapper.java

@@ -6,6 +6,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Function;
+import javax.annotation.Nullable;
 
 class PropertyMapper {
 
@@ -29,7 +30,8 @@ static PropertyMapper create(
         .addString(builder.serviceName, properties.getServiceName(), "otel.service.name");
   }
 
-  PropertyMapper addString(String builderValue, String propertyValue, String otelKey) {
+  PropertyMapper addString(
+      @Nullable String builderValue, @Nullable String propertyValue, String otelKey) {
     if (builderValue != null) {
       // the low priority config should not be used for the metrics settings, so that both general
       // and metrics settings
@@ -42,6 +44,7 @@ PropertyMapper addString(String builderValue, String propertyValue, String otelK
     return this;
   }
 
+  @Nullable
   private static String mapToOtelString(Map<String, String> map) {
     if (map.isEmpty()) {
       return null;

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/MetricDataFactory.java

@@ -10,6 +10,7 @@
 import io.prometheus.metrics.model.snapshots.StateSetSnapshot;
 import io.prometheus.metrics.model.snapshots.SummarySnapshot;
 import io.prometheus.metrics.model.snapshots.UnknownSnapshot;
+import javax.annotation.Nullable;
 
 public class MetricDataFactory {
 
@@ -42,6 +43,7 @@ public MetricData create(GaugeSnapshot snapshot) {
         resource);
   }
 
+  @Nullable
   public MetricData create(HistogramSnapshot snapshot) {
     if (!snapshot.getDataPoints().isEmpty()) {
       HistogramSnapshot.HistogramDataPointSnapshot firstDataPoint = snapshot.getDataPoints().get(0);

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/PrometheusClassicHistogram.java

@@ -11,6 +11,7 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.stream.Collectors;
+import javax.annotation.Nullable;
 
 class PrometheusClassicHistogram extends PrometheusData<HistogramPointData>
     implements HistogramData {
@@ -36,6 +37,7 @@ public Collection<HistogramPointData> getPoints() {
     return points;
   }
 
+  @Nullable
   private HistogramPointData toOtelDataPoint(
       HistogramSnapshot.HistogramDataPointSnapshot dataPoint, long currentTimeMillis) {
     if (!dataPoint.hasClassicHistogramData()) {

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/PrometheusData.java

@@ -20,6 +20,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
+import javax.annotation.Nullable;
 
 abstract class PrometheusData<T extends PointData> implements Data<T> {
 
@@ -45,7 +46,7 @@ protected Attributes labelsToAttributes(Labels labels) {
     }
   }
 
-  protected List<DoubleExemplarData> convertExemplar(Exemplar exemplar) {
+  protected List<DoubleExemplarData> convertExemplar(@Nullable Exemplar exemplar) {
     if (exemplar == null) {
       return Collections.emptyList();
     }
@@ -58,7 +59,8 @@ protected List<DoubleExemplarData> convertExemplars(Exemplars exemplars) {
         .collect(Collectors.toList());
   }
 
-  protected DoubleExemplarData toDoubleExemplarData(Exemplar exemplar) {
+  @Nullable
+  protected DoubleExemplarData toDoubleExemplarData(@Nullable Exemplar exemplar) {
     if (exemplar == null) {
       return null;
     }

prometheus-metrics-exporter-opentelemetry/src/main/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/PrometheusMetricData.java

@@ -8,14 +8,15 @@
 import io.opentelemetry.sdk.resources.Resource;
 import io.prometheus.metrics.model.snapshots.MetricMetadata;
 import io.prometheus.metrics.model.snapshots.Unit;
+import javax.annotation.Nullable;
 
 class PrometheusMetricData<T extends PrometheusData<?>> implements MetricData {
 
   private final Resource resource;
   private final InstrumentationScopeInfo instrumentationScopeInfo;
   private final String name;
-  private final String description;
-  private final String unit;
+  @Nullable private final String description;
+  @Nullable private final String unit;
   T data;
 
   PrometheusMetricData(
@@ -48,7 +49,8 @@ private String getNameWithoutUnit(MetricMetadata metricMetadata) {
 
   // See
   // https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/6cf4dec6cb42d87d8840e9f67d4acf66d4eb8fda/pkg/translator/prometheus/normalize_name.go#L19
-  static String convertUnit(Unit unit) {
+  @Nullable
+  static String convertUnit(@Nullable Unit unit) {
     if (unit == null) {
       return null;
     }
@@ -129,11 +131,13 @@ public String getName() {
   }
 
   @Override
+  @Nullable
   public String getDescription() {
     return description;
   }
 
   @Override
+  @Nullable
   public String getUnit() {
     return unit;
   }