Add Client Metadata Update Support.

driver-core/src/main/com/mongodb/internal/connection/ClientMetadata.java

@@ -20,23 +20,25 @@
 import com.mongodb.lang.Nullable;
 import org.bson.BsonDocument;
 
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import static com.mongodb.internal.Locks.withLock;
 import static com.mongodb.internal.connection.ClientMetadataHelper.createClientMetadataDocument;
-import static com.mongodb.internal.connection.ClientMetadataHelper.updateClientMedataDocument;
+import static com.mongodb.internal.connection.ClientMetadataHelper.updateClientMetadataDocument;
 
 /**
  * Represents metadata of the current MongoClient.
  *
  * <p>This class is not part of the public API and may be removed or changed at any time</p>
  */
 public class ClientMetadata {
-    private final ReentrantLock updateLock = new ReentrantLock();
-    private volatile BsonDocument clientMetadataBsonDocument;
+    private final ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock();
+    private BsonDocument clientMetadataBsonDocument;
 
     public ClientMetadata(@Nullable final String applicationName, final MongoDriverInformation mongoDriverInformation) {
-        this.clientMetadataBsonDocument = createClientMetadataDocument(applicationName, mongoDriverInformation);
+        withLock(readWriteLock.writeLock(), () -> {
+            this.clientMetadataBsonDocument = createClientMetadataDocument(applicationName, mongoDriverInformation);
+        });
     }
 
     /**
@@ -47,8 +49,8 @@ public BsonDocument getBsonDocument() {
     }
 
     public void append(final MongoDriverInformation mongoDriverInformation) {
-        withLock(updateLock, () ->
-                this.clientMetadataBsonDocument = updateClientMedataDocument(clientMetadataBsonDocument.clone(), mongoDriverInformation)
+        withLock(readWriteLock.writeLock(), () ->
+                this.clientMetadataBsonDocument = updateClientMetadataDocument(clientMetadataBsonDocument.clone(), mongoDriverInformation)
         );
     }
 }

driver-core/src/main/com/mongodb/internal/connection/ClientMetadataHelper.java

@@ -180,29 +180,30 @@ static boolean clientMetadataDocumentTooLarge(final BsonDocument document) {
         new BsonDocumentCodec().encode(new BsonBinaryWriter(buffer), document, EncoderContext.builder().build());
         return buffer.getPosition() > MAXIMUM_CLIENT_METADATA_ENCODED_SIZE;
     }
-/**
- * Modifies the given client metadata document by appending the driver information.
- * Driver name and version are appended atomically to the existing driver name and version if they do not exceed
- * {@value MAXIMUM_CLIENT_METADATA_ENCODED_SIZE} bytes.
- *
- * Platform is appended separately to the existing platform if it does not exceed {@value MAXIMUM_CLIENT_METADATA_ENCODED_SIZE} bytes.
- */
-    public static BsonDocument updateClientMedataDocument(final BsonDocument clientMetadataDocument,
-                                                          final MongoDriverInformation mongoDriverInformation) {
-        BsonDocument driverInformation = clientMetadataDocument.getDocument("driver");
 
-        List<String> driverNamesToAppend = mongoDriverInformation.getDriverNames();
-        List<String> driverVersionsToAppend = mongoDriverInformation.getDriverVersions();
-        List<String> driverPlatformsToAppend = mongoDriverInformation.getDriverPlatforms();
+    /**
+     * Modifies the given client metadata document by appending the driver information.
+     * Driver name and version are appended atomically to the existing driver name and version if they do not exceed
+     * {@value MAXIMUM_CLIENT_METADATA_ENCODED_SIZE} bytes.
+     * <p>
+     * Platform is appended separately to the existing platform if it does not exceed {@value MAXIMUM_CLIENT_METADATA_ENCODED_SIZE} bytes.
+     */
+    public static BsonDocument updateClientMetadataDocument(final BsonDocument clientMetadataDocument,
+                                                            final MongoDriverInformation driverInformationToAppend) {
+        BsonDocument currentDriverInformation = clientMetadataDocument.getDocument("driver");
+
+        List<String> driverNamesToAppend = driverInformationToAppend.getDriverNames();
+        List<String> driverVersionsToAppend = driverInformationToAppend.getDriverVersions();
+        List<String> driverPlatformsToAppend = driverInformationToAppend.getDriverPlatforms();
 
         List<String> updatedDriverNames = new ArrayList<>(driverNamesToAppend.size() + 1);
         List<String> updatedDriverVersions = new ArrayList<>(driverVersionsToAppend.size() + 1);
         List<String> updateDriverPlatforms = new ArrayList<>(driverPlatformsToAppend.size() + 1);
 
-        updatedDriverNames.add(driverInformation.getString("name").getValue());
+        updatedDriverNames.add(currentDriverInformation.getString("name").getValue());
         updatedDriverNames.addAll(driverNamesToAppend);
 
-        updatedDriverVersions.add(driverInformation.getString("version").getValue());
+        updatedDriverVersions.add(currentDriverInformation.getString("version").getValue());
         updatedDriverVersions.addAll(driverVersionsToAppend);
 
         updateDriverPlatforms.add(clientMetadataDocument.getString("platform").getValue());

driver-core/src/test/functional/com/mongodb/internal/connection/ClientMetadataHelperProseTest.java

@@ -43,7 +43,7 @@
 import static com.mongodb.client.WithWrapper.withWrapper;
 import static com.mongodb.internal.connection.ClientMetadataHelper.createClientMetadataDocument;
 import static com.mongodb.internal.connection.ClientMetadataHelper.getOperatingSystemType;
-import static com.mongodb.internal.connection.ClientMetadataHelper.updateClientMedataDocument;
+import static com.mongodb.internal.connection.ClientMetadataHelper.updateClientMetadataDocument;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -349,7 +349,7 @@ void testUpdateClientMetadataDocument() {
                 .build();
 
         //when
-        BsonDocument updatedClientMetadata = updateClientMedataDocument(initialClientMetadataDocument, metadataToAppend);
+        BsonDocument updatedClientMetadata = updateClientMetadataDocument(initialClientMetadataDocument, metadataToAppend);
 
         //then
         assertEquals(