perf: small optimizations to reduce CPU overhead on hot paths

google-cloud-spanner-cassandra/src/main/java/com/google/cloud/spanner/adapter/AdapterClientWrapper.java

@@ -21,6 +21,7 @@
 import com.google.api.gax.rpc.ApiCallContext;
 import com.google.api.gax.rpc.ServerStream;
 import com.google.protobuf.ByteString;
+import com.google.protobuf.UnsafeByteOperations;
 import com.google.spanner.adapter.v1.AdaptMessageRequest;
 import com.google.spanner.adapter.v1.AdaptMessageResponse;
 import com.google.spanner.adapter.v1.AdapterClient;
@@ -71,7 +72,10 @@ ByteString sendGrpcRequest(
             .setName(sessionManager.getSession().getName())
             .setProtocol("cassandra")
             .putAllAttachments(attachments)
-            .setPayload(ByteString.copyFrom(payload))
+            // It is safe to use UnsafeByteOperations to wrap the payload without copying, as the
+            // underlying `payload` byte array is not modified after this point. This avoids an
+            // unnecessary memory copy for every request, which is a performance optimization.
+            .setPayload(UnsafeByteOperations.unsafeWrap(payload))
             .build();
 
     List<ByteString> collectedPayloads = new ArrayList<>();

google-cloud-spanner-cassandra/src/main/java/com/google/cloud/spanner/adapter/DriverConnectionHandler.java

@@ -63,7 +63,6 @@ final class DriverConnectionHandler implements Runnable {
   private static final char WRITE_ACTION_QUERY_ID_PREFIX = 'W';
   private static final String ROUTE_TO_LEADER_HEADER_KEY = "x-goog-spanner-route-to-leader";
   private static final String MAX_COMMIT_DELAY_ATTACHMENT_KEY = "max_commit_delay";
-  private static final String ADAPT_MESSAGE_METHOD = "Adapter.AdaptMessage";
   private static final ByteBufAllocator byteBufAllocator = ByteBufAllocator.DEFAULT;
   private static final FrameCodec<ByteBuf> serverFrameCodec =
       FrameCodec.defaultServer(new ByteBufPrimitiveCodec(byteBufAllocator), Compressor.none());
@@ -77,8 +76,6 @@ final class DriverConnectionHandler implements Runnable {
   private static final GrpcCallContext DEFAULT_CONTEXT = GrpcCallContext.createDefault();
   private static final Map<String, List<String>> ROUTE_TO_LEADER_HEADER_MAP =
       ImmutableMap.of(ROUTE_TO_LEADER_HEADER_KEY, Collections.singletonList("true"));
-  private static final Map<String, String> SUCCESS_METRIC_ATTRIBUTES =
-      ImmutableMap.of("method", ADAPT_MESSAGE_METHOD, "status", "OK");
   private static final GrpcCallContext DEFAULT_CONTEXT_WITH_LAR =
       GrpcCallContext.createDefault().withExtraHeaders(ROUTE_TO_LEADER_HEADER_MAP);
   private static final byte[] EMPTY_BYTES = new byte[0];
@@ -188,8 +185,8 @@ private void recordMetrics(Instant startTime) {
       return;
     }
     final long latency = Duration.between(startTime, Instant.now()).toMillis();
-    metricsRecorder.recordOperationCount(1, SUCCESS_METRIC_ATTRIBUTES);
-    metricsRecorder.recordOperationLatency(latency, SUCCESS_METRIC_ATTRIBUTES);
+    metricsRecorder.recordOperationCount(1);
+    metricsRecorder.recordOperationLatency(latency);
   }
 
   private static int readNBytesJava8(InputStream in, byte[] b, int off, int len)

google-cloud-spanner-cassandra/src/main/java/com/google/cloud/spanner/adapter/metrics/BuiltInMetricsProvider.java

@@ -23,7 +23,9 @@
 import static com.google.cloud.spanner.adapter.metrics.BuiltInMetricsConstant.INSTANCE_CONFIG_ID_KEY;
 import static com.google.cloud.spanner.adapter.metrics.BuiltInMetricsConstant.INSTANCE_ID_KEY;
 import static com.google.cloud.spanner.adapter.metrics.BuiltInMetricsConstant.LOCATION_ID_KEY;
+import static com.google.cloud.spanner.adapter.metrics.BuiltInMetricsConstant.METHOD_KEY;
 import static com.google.cloud.spanner.adapter.metrics.BuiltInMetricsConstant.PROJECT_ID_KEY;
+import static com.google.cloud.spanner.adapter.metrics.BuiltInMetricsConstant.STATUS_KEY;
 
 import com.google.api.gax.core.GaxProperties;
 import com.google.cloud.opentelemetry.detection.AttributeKeys;
@@ -48,8 +50,6 @@
 import java.lang.reflect.Method;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
-import java.util.HashMap;
-import java.util.Map;
 import java.util.UUID;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -117,18 +117,20 @@ Attributes createResourceAttributes(String projectId, String instanceId) {
             .put(INSTANCE_ID_KEY.getKey(), instanceId)
             .put(LOCATION_ID_KEY.getKey(), detectClientLocation())
             .put("gcp.resource_type", BuiltInMetricsConstant.SPANNER_RESOURCE_TYPE);
-
     return attributesBuilder.build();
   }
 
-  public Map<String, String> createDefaultAttributes(String databaseId) {
-    Map<String, String> defaultAttributes = new HashMap<>();
-    defaultAttributes.put(DATABASE_KEY.getKey(), databaseId);
-    defaultAttributes.put(
-        CLIENT_NAME_KEY.getKey(),
-        "spanner-cassandra-java/" + GaxProperties.getLibraryVersion(getClass()));
-    defaultAttributes.put(CLIENT_UID_KEY.getKey(), getDefaultTaskValue());
-    return defaultAttributes;
+  public Attributes createDefaultAttributes(String databaseId) {
+    AttributesBuilder defaultAttributesBuilder =
+        Attributes.builder()
+            .put(DATABASE_KEY.getKey(), databaseId)
+            .put(
+                CLIENT_NAME_KEY.getKey(),
+                "spanner-cassandra-java/" + GaxProperties.getLibraryVersion(getClass()))
+            .put(CLIENT_UID_KEY.getKey(), getDefaultTaskValue())
+            .put(METHOD_KEY.getKey(), "Adapter.AdaptMessage")
+            .put(STATUS_KEY.getKey(), "OK");
+    return defaultAttributesBuilder.build();
   }
 
   /**

google-cloud-spanner-cassandra/src/main/java/com/google/cloud/spanner/adapter/metrics/BuiltInMetricsRecorder.java

@@ -16,21 +16,18 @@
 package com.google.cloud.spanner.adapter.metrics;
 
 import com.google.api.gax.core.GaxProperties;
-import com.google.common.base.Preconditions;
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.api.metrics.DoubleHistogram;
 import io.opentelemetry.api.metrics.LongCounter;
 import io.opentelemetry.api.metrics.Meter;
-import java.util.Map;
 
 /** Implementation for recording built in metrics. */
 public final class BuiltInMetricsRecorder {
 
   private final LongCounter operationCountRecorder;
   private final DoubleHistogram operationLatencyRecorder;
-  private final Map<String, String> defaultAttr;
+  private final Attributes defaultAttr;
 
   /**
    * Creates the following instruments for the following metrics:
@@ -43,7 +40,7 @@ public final class BuiltInMetricsRecorder {
    * @param openTelemetry OpenTelemetry instance
    * @param defaultAttr Default attibutes
    */
-  public BuiltInMetricsRecorder(OpenTelemetry openTelemetry, Map<String, String> defaultAttr) {
+  public BuiltInMetricsRecorder(OpenTelemetry openTelemetry, Attributes defaultAttr) {
     Meter meter =
         openTelemetry
             .meterBuilder(BuiltInMetricsConstant.SPANNER_METER_NAME)
@@ -72,19 +69,11 @@ public BuiltInMetricsRecorder(OpenTelemetry openTelemetry, Map<String, String> d
     this.defaultAttr = defaultAttr;
   }
 
-  public void recordOperationLatency(double operationLatency, Map<String, String> attributes) {
-    operationLatencyRecorder.record(operationLatency, toOtelAttributes(attributes));
+  public void recordOperationLatency(double operationLatency) {
+    operationLatencyRecorder.record(operationLatency, defaultAttr);
   }
 
-  public void recordOperationCount(long count, Map<String, String> attributes) {
-    operationCountRecorder.add(count, toOtelAttributes(attributes));
-  }
-
-  Attributes toOtelAttributes(Map<String, String> attributes) {
-    Preconditions.checkNotNull(attributes, "Attributes map cannot be null");
-    AttributesBuilder attributesBuilder = Attributes.builder();
-    attributes.forEach(attributesBuilder::put);
-    this.defaultAttr.forEach(attributesBuilder::put);
-    return attributesBuilder.build();
+  public void recordOperationCount(long count) {
+    operationCountRecorder.add(count, defaultAttr);
   }
 }

google-cloud-spanner-cassandra/src/test/java/com/google/cloud/spanner/adapter/DriverConnectionHandlerTest.java

@@ -73,8 +73,6 @@ public final class DriverConnectionHandlerTest {
   private AdapterClientWrapper mockAdapterClient;
   private Socket mockSocket;
   private ByteArrayOutputStream outputStream;
-  private static final Map<String, String> expectedAttributes =
-      ImmutableMap.of("method", "Adapter.AdaptMessage", "status", "OK");
 
   public DriverConnectionHandlerTest() {}
 
@@ -206,7 +204,7 @@ public void successfulDmlExecuteMessage() throws IOException {
         .containsExactly("x-goog-spanner-route-to-leader", ImmutableList.of("true"));
     assertThat(attachmentsCaptor.getValue())
         .containsExactly(preparedQueryKey, "query", "max_commit_delay", "100");
-    verify(mockMetricsRecorder).recordOperationCount(1L, expectedAttributes);
+    verify(mockMetricsRecorder).recordOperationCount(1L);
   }
 
   @Test
@@ -249,7 +247,7 @@ public void successfulBatchMessage() throws IOException {
         .sendGrpcRequest(any(), any(), contextCaptor.capture(), any(int.class));
     assertThat(contextCaptor.getValue().getExtraHeaders())
         .containsExactly("x-goog-spanner-route-to-leader", ImmutableList.of("true"));
-    verify(mockMetricsRecorder).recordOperationCount(1L, expectedAttributes);
+    verify(mockMetricsRecorder).recordOperationCount(1L);
   }
 
   @Test

google-cloud-spanner-cassandra/src/test/java/com/google/cloud/spanner/adapter/metrics/BuiltInMetricsRecorderTest.java

@@ -15,8 +15,6 @@
 */
 package com.google.cloud.spanner.adapter.metrics;
 
-import static com.google.common.truth.Truth.assertThat;
-import static org.junit.Assert.assertThrows;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -30,9 +28,6 @@
 import io.opentelemetry.api.metrics.LongCounterBuilder;
 import io.opentelemetry.api.metrics.Meter;
 import io.opentelemetry.api.metrics.MeterBuilder;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -47,7 +42,7 @@ public class BuiltInMetricsRecorderTest {
   private LongCounter mockOperationCounter;
 
   private BuiltInMetricsRecorder metricsRecorder;
-  private Map<String, String> defaultAttributes;
+  private Attributes defaultAttributes;
 
   @Before
   public void setUp() {
@@ -78,74 +73,43 @@ public void setUp() {
     when(mockCounterBuilder.build()).thenReturn(mockOperationCounter);
 
     // 5. Setup default attributes and create the recorder instance
-    defaultAttributes = new HashMap<>();
-    defaultAttributes.put("db", "test-db");
-    defaultAttributes.put("client_id", "test-client");
-    metricsRecorder = new BuiltInMetricsRecorder(mockOpenTelemetry, defaultAttributes);
-  }
-
-  @Test
-  public void toOtelAttributes_withNull_throwsException() {
-    assertThrows(NullPointerException.class, () -> metricsRecorder.toOtelAttributes(null));
-  }
-
-  @Test
-  public void toOtelAttributes_mergesAttributesCorrectly() {
-    Map<String, String> specificAttributes = new HashMap<>();
-    specificAttributes.put("method", "testMethod");
-    specificAttributes.put("status", "OK");
-
-    Attributes result = metricsRecorder.toOtelAttributes(specificAttributes);
-
-    Attributes expected =
+    defaultAttributes =
         Attributes.builder()
             .put("db", "test-db")
             .put("client_id", "test-client")
-            .put("method", "testMethod")
+            .put("method", "myMethod")
             .put("status", "OK")
             .build();
-
-    assertThat(result).isEqualTo(expected);
-  }
-
-  @Test
-  public void toOtelAttributes_withEmptySpecificAttributes_returnsDefaults() {
-    Attributes result = metricsRecorder.toOtelAttributes(Collections.emptyMap());
-
-    Attributes expected =
-        Attributes.builder().put("db", "test-db").put("client_id", "test-client").build();
-
-    assertThat(result).isEqualTo(expected);
+    metricsRecorder = new BuiltInMetricsRecorder(mockOpenTelemetry, defaultAttributes);
   }
 
   @Test
   public void recordOperationLatency_callsRecordWithCorrectValues() {
     double latency = 123.45;
-    Map<String, String> attributes = Collections.singletonMap("status", "ERROR");
 
-    metricsRecorder.recordOperationLatency(latency, attributes);
+    metricsRecorder.recordOperationLatency(latency);
 
     Attributes expectedAttributes =
         Attributes.builder()
             .put("db", "test-db")
             .put("client_id", "test-client")
-            .put("status", "ERROR")
+            .put("method", "myMethod")
+            .put("status", "OK")
             .build();
     verify(mockLatencyRecorder).record(latency, expectedAttributes);
   }
 
   @Test
   public void recordOperationCount_callsAddWithCorrectValues() {
     long count = 5L;
-    Map<String, String> attributes = Collections.singletonMap("method", "myMethod");
-
-    metricsRecorder.recordOperationCount(count, attributes);
+    metricsRecorder.recordOperationCount(count);
 
     Attributes expectedAttributes =
         Attributes.builder()
             .put("db", "test-db")
             .put("client_id", "test-client")
             .put("method", "myMethod")
+            .put("status", "OK")
             .build();
     verify(mockOperationCounter).add(count, expectedAttributes);
   }