Reduce allocation cost reporting spans

extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/exporter/otlp/VertxGrpcExporter.java

@@ -20,6 +20,7 @@
 import io.opentelemetry.sdk.internal.ThrottlingLogger;
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
+import io.quarkus.vertx.core.runtime.BufferOutputStream;
 import io.vertx.core.Handler;
 import io.vertx.core.Vertx;
 import io.vertx.core.buffer.Buffer;
@@ -194,10 +195,9 @@ public void handle(GrpcClientRequest<Buffer, Buffer> request) {
 
             try {
                 int messageSize = marshaler.getBinarySerializedSize();
-                var baos = new NonCopyingByteArrayOutputStream(messageSize); // TODO: we can probably use Vert.x / Netty buffering here
-                marshaler.writeBinaryTo(baos);
                 Buffer buffer = Buffer.buffer(messageSize);
-                buffer.appendBytes(baos.toByteArray());
+                var os = new BufferOutputStream(buffer);
+                marshaler.writeBinaryTo(os);
                 request.send(buffer).onSuccess(new Handler<>() {
                     @Override
                     public void handle(GrpcClientResponse<Buffer, Buffer> response) {

extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/exporter/otlp/VertxHttpExporter.java

@@ -2,7 +2,6 @@
 
 import static io.quarkus.opentelemetry.runtime.exporter.otlp.OtlpExporterUtil.getPort;
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.URI;
@@ -18,6 +17,7 @@
 import io.opentelemetry.sdk.common.CompletableResultCode;
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
+import io.quarkus.vertx.core.runtime.BufferOutputStream;
 import io.vertx.core.AsyncResult;
 import io.vertx.core.Handler;
 import io.vertx.core.Vertx;
@@ -129,17 +129,16 @@ public byte[] responseBody() {
                             })
                                     .putHeader("Content-Type", contentType);
 
-                            ByteArrayOutputStream os; // TODO: we can probably use Vert.x / Netty buffering here
+                            Buffer buffer = Buffer.buffer(contentLength);
+                            OutputStream os = new BufferOutputStream(buffer);
                             if (compressionEnabled) {
-                                os = new ByteArrayOutputStream(contentLength);
                                 clientRequest.putHeader("Content-Encoding", "gzip");
                                 try (var gzos = new GZIPOutputStream(os)) {
                                     marshaler.accept(gzos);
                                 } catch (IOException e) {
                                     throw new IllegalStateException(e);
                                 }
                             } else {
-                                os = new NonCopyingByteArrayOutputStream(contentLength);
                                 marshaler.accept(os);
                             }
 
@@ -149,7 +148,7 @@ public byte[] responseBody() {
                                 }
                             }
 
-                            clientRequest.send(Buffer.buffer(os.toByteArray()));
+                            clientRequest.send(buffer);
 
                         }
                     })

extensions/smallrye-health/runtime/src/main/java/io/quarkus/smallrye/health/runtime/SmallRyeHealthHandlerBase.java

@@ -1,12 +1,12 @@
 package io.quarkus.smallrye.health.runtime;
 
 import java.io.IOException;
-import java.io.OutputStream;
 import java.io.UncheckedIOException;
 
 import io.quarkus.arc.Arc;
 import io.quarkus.arc.ManagedContext;
 import io.quarkus.security.identity.CurrentIdentityAssociation;
+import io.quarkus.vertx.core.runtime.BufferOutputStream;
 import io.quarkus.vertx.http.runtime.security.QuarkusHttpUser;
 import io.smallrye.health.SmallRyeHealth;
 import io.smallrye.health.SmallRyeHealthReporter;
@@ -56,22 +56,4 @@ private void doHandle(RoutingContext ctx) {
         }
     }
 
-    private static class BufferOutputStream extends OutputStream {
-
-        private final Buffer buffer;
-
-        private BufferOutputStream(Buffer buffer) {
-            this.buffer = buffer;
-        }
-
-        @Override
-        public void write(byte[] b, int off, int len) throws IOException {
-            buffer.appendBytes(b, off, len);
-        }
-
-        @Override
-        public void write(int b) throws IOException {
-            buffer.appendInt(b);
-        }
-    }
 }

extensions/vertx/runtime/src/main/java/io/quarkus/vertx/core/runtime/BufferOutputStream.java

@@ -0,0 +1,29 @@
+package io.quarkus.vertx.core.runtime;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import io.vertx.core.buffer.Buffer;
+
+/**
+ * Simple {@link OutputStream} implementation that appends content
+ * written in given {@link Buffer} instance.
+ */
+public class BufferOutputStream extends OutputStream {
+
+    private final Buffer buffer;
+
+    public BufferOutputStream(Buffer buffer) {
+        this.buffer = buffer;
+    }
+
+    @Override
+    public void write(byte[] b, int off, int len) throws IOException {
+        buffer.appendBytes(b, off, len);
+    }
+
+    @Override
+    public void write(int b) throws IOException {
+        buffer.appendInt(b);
+    }
+}