Moving default callback to constants

Author: LikeTheSalad

disk-buffering/src/main/java/io/opentelemetry/contrib/disk/buffering/exporters/LogRecordToDiskExporter.java

@@ -7,6 +7,7 @@
 
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import io.opentelemetry.contrib.disk.buffering.exporters.callback.ExporterCallback;
+import io.opentelemetry.contrib.disk.buffering.exporters.callback.NoopExporterCallback;
 import io.opentelemetry.contrib.disk.buffering.internal.exporters.SignalStorageExporter;
 import io.opentelemetry.contrib.disk.buffering.storage.SignalStorage;
 import io.opentelemetry.sdk.common.CompletableResultCode;
@@ -19,6 +20,8 @@
 public final class LogRecordToDiskExporter implements LogRecordExporter {
   private final SignalStorageExporter<LogRecordData> storageExporter;
   private final ExporterCallback<LogRecordData> callback;
+  private static final ExporterCallback<LogRecordData> DEFAULT_CALLBACK =
+      new NoopExporterCallback<>();
   private static final Duration DEFAULT_EXPORT_TIMEOUT = Duration.ofSeconds(10);
 
   private LogRecordToDiskExporter(
@@ -50,7 +53,7 @@ public CompletableResultCode shutdown() {
 
   public static final class Builder {
     private final SignalStorage.LogRecord storage;
-    private ExporterCallback<LogRecordData> callback = ExporterCallback.noop();
+    private ExporterCallback<LogRecordData> callback = DEFAULT_CALLBACK;
     private Duration writeTimeout = DEFAULT_EXPORT_TIMEOUT;
 
     @CanIgnoreReturnValue

disk-buffering/src/main/java/io/opentelemetry/contrib/disk/buffering/exporters/MetricToDiskExporter.java

@@ -7,6 +7,7 @@
 
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import io.opentelemetry.contrib.disk.buffering.exporters.callback.ExporterCallback;
+import io.opentelemetry.contrib.disk.buffering.exporters.callback.NoopExporterCallback;
 import io.opentelemetry.contrib.disk.buffering.internal.exporters.SignalStorageExporter;
 import io.opentelemetry.contrib.disk.buffering.storage.SignalStorage;
 import io.opentelemetry.sdk.common.CompletableResultCode;
@@ -23,6 +24,7 @@ public final class MetricToDiskExporter implements MetricExporter {
   private final SignalStorageExporter<MetricData> storageExporter;
   private final AggregationTemporalitySelector aggregationTemporalitySelector;
   private final ExporterCallback<MetricData> callback;
+  private static final ExporterCallback<MetricData> DEFAULT_CALLBACK = new NoopExporterCallback<>();
   private static final Duration DEFAULT_EXPORT_TIMEOUT = Duration.ofSeconds(10);
 
   private MetricToDiskExporter(
@@ -63,7 +65,7 @@ public static final class Builder {
     private final SignalStorage.Metric storage;
     private AggregationTemporalitySelector aggregationTemporalitySelector =
         AggregationTemporalitySelector.alwaysCumulative();
-    private ExporterCallback<MetricData> callback = ExporterCallback.noop();
+    private ExporterCallback<MetricData> callback = DEFAULT_CALLBACK;
     private Duration writeTimeout = DEFAULT_EXPORT_TIMEOUT;
 
     @CanIgnoreReturnValue

disk-buffering/src/main/java/io/opentelemetry/contrib/disk/buffering/exporters/SpanToDiskExporter.java

@@ -7,6 +7,7 @@
 
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import io.opentelemetry.contrib.disk.buffering.exporters.callback.ExporterCallback;
+import io.opentelemetry.contrib.disk.buffering.exporters.callback.NoopExporterCallback;
 import io.opentelemetry.contrib.disk.buffering.internal.exporters.SignalStorageExporter;
 import io.opentelemetry.contrib.disk.buffering.storage.SignalStorage;
 import io.opentelemetry.sdk.common.CompletableResultCode;
@@ -19,6 +20,7 @@
 public final class SpanToDiskExporter implements SpanExporter {
   private final SignalStorageExporter<SpanData> storageExporter;
   private final ExporterCallback<SpanData> callback;
+  private static final ExporterCallback<SpanData> DEFAULT_CALLBACK = new NoopExporterCallback<>();
   private static final Duration DEFAULT_EXPORT_TIMEOUT = Duration.ofSeconds(10);
 
   private SpanToDiskExporter(
@@ -49,7 +51,7 @@ public CompletableResultCode shutdown() {
 
   public static final class Builder {
     private final SignalStorage.Span storage;
-    private ExporterCallback<SpanData> callback = ExporterCallback.noop();
+    private ExporterCallback<SpanData> callback = DEFAULT_CALLBACK;
     private Duration writeTimeout = DEFAULT_EXPORT_TIMEOUT;
 
     private Builder(SignalStorage.Span storage) {

disk-buffering/src/main/java/io/opentelemetry/contrib/disk/buffering/exporters/callback/ExporterCallback.java

@@ -27,8 +27,4 @@ public interface ExporterCallback<T> {
 
   /** Called when the exporter is closed. */
   void onShutdown();
-
-  static <T> ExporterCallback<T> noop() {
-    return new NoopExporterCallback<>();
-  }
 }

disk-buffering/src/main/java/io/opentelemetry/contrib/disk/buffering/exporters/callback/NoopExporterCallback.java

@@ -8,9 +8,7 @@
 import java.util.Collection;
 import javax.annotation.Nullable;
 
-final class NoopExporterCallback<T> implements ExporterCallback<T> {
-
-  NoopExporterCallback() {}
+public final class NoopExporterCallback<T> implements ExporterCallback<T> {
 
   @Override
   public void onExportSuccess(Collection<T> items) {}