Implement batch queries for MSSQL Client

vertx-mssql-client/src/main/asciidoc/index.adoc

@@ -1,6 +1,5 @@
 = Reactive MSSQL Client
 :PREPARED_PARAMS: `@1`, `@2`, etc…​
-:batching-unsupported:
 
 The Reactive MSSQL Client is a client for Microsoft SQL Server with a straightforward API focusing on
 scalability and low overhead.
@@ -17,7 +16,7 @@ scalability and low overhead.
 *Not supported yet*
 
 * Prepared queries caching
-* Batch and cursor
+* Cursor
 * Row streaming
 * Some https://github.com/eclipse-vertx/vertx-sql-client/issues/608#issuecomment-629390027[data types] are not supported
 

vertx-mssql-client/src/main/java/io/vertx/mssqlclient/impl/codec/ExtendedBatchQueryCommandCodec.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2011-2021 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+ * which is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+ */
+
+package io.vertx.mssqlclient.impl.codec;
+
+import io.netty.buffer.ByteBuf;
+import io.vertx.sqlclient.Tuple;
+import io.vertx.sqlclient.impl.TupleInternal;
+import io.vertx.sqlclient.impl.command.CommandResponse;
+import io.vertx.sqlclient.impl.command.ExtendedQueryCommand;
+
+import java.util.List;
+
+class ExtendedBatchQueryCommandCodec<T> extends ExtendedQueryCommandBaseCodec<T> {
+
+  private final List<Tuple> paramsList;
+
+  private int paramsIdx;
+  private int messageDecoded;
+
+  ExtendedBatchQueryCommandCodec(ExtendedQueryCommand<T> cmd) {
+    super(cmd);
+    paramsList = cmd.paramsList();
+  }
+
+  @Override
+  void encode(TdsMessageEncoder encoder) {
+    if (paramsList.isEmpty()) {
+      completionHandler.handle(CommandResponse.failure("Can not execute batch query with 0 sets of batch parameters."));
+      return;
+    }
+    super.encode(encoder);
+  }
+
+  @Override
+  protected void handleMessageDecoded() {
+    if (paramsList.size() == 1 || ++messageDecoded == 2) {
+      complete();
+    } else {
+      sendExecRequest();
+    }
+  }
+
+  @Override
+  protected TupleInternal prepexecRequestParams() {
+    paramsIdx = 1;
+    return (TupleInternal) paramsList.get(0);
+  }
+
+  @Override
+  protected void writeRpcRequestBatch(ByteBuf packet) {
+    for (int initial = paramsIdx; paramsIdx < paramsList.size(); paramsIdx++) {
+      if (initial != paramsIdx) {
+        packet.writeByte(0xFF); // batch separator
+      }
+      super.writeRpcRequestBatch(packet);
+    }
+  }
+
+  @Override
+  protected TupleInternal execRequestParams() {
+    return (TupleInternal) paramsList.get(paramsIdx);
+  }
+}