Partial support of SSVARIANTTYPE (#1314)

Fixes #1312

Partial implementation of SSVARIANTTYPE decoding, just enough to support querying metadata about integer MSSQL sequences.

Signed-off-by: Thomas Segismont <tsegismont@gmail.com>

Author: tsegismont

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

@@ -968,7 +968,30 @@ public Object decodeValue(ByteBuf byteBuf, TypeInfo typeInfo) {
       return result;
     }
   },
-  SSVARIANT(0x62);
+  SSVARIANT(0x62) {
+    @Override
+    public TypeInfo decodeTypeInfo(ByteBuf byteBuf) {
+      byteBuf.skipBytes(4);
+      return new TypeInfo().maxLength(8009);
+    }
+
+    @Override
+    public Object decodeValue(ByteBuf byteBuf, TypeInfo typeInfo) {
+      int length = byteBuf.readIntLE();
+      if (length == 0) return null;
+      DataType actualType = DataType.forId(byteBuf.readUnsignedByte());
+      switch (actualType) {
+        case INT1:
+        case INT2:
+        case INT4:
+        case INT8:
+          byteBuf.skipBytes(1); // prop bytes
+          return actualType.decodeValue(byteBuf, null);
+        default:
+          throw new UnsupportedOperationException("Unsupported variant type: " + actualType);
+      }
+    }
+  };
 
   public final int id;
 

vertx-mssql-client/src/test/java/io/vertx/mssqlclient/MSSQLQueriesTest.java

@@ -11,6 +11,8 @@
 
 package io.vertx.mssqlclient;
 
+import io.vertx.core.CompositeFuture;
+import io.vertx.core.Future;
 import io.vertx.core.Vertx;
 import io.vertx.ext.unit.Async;
 import io.vertx.ext.unit.TestContext;
@@ -30,8 +32,10 @@
 import java.time.LocalDateTime;
 import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.stream.Stream;
 
 import static org.hamcrest.CoreMatchers.instanceOf;
 import static org.hamcrest.CoreMatchers.is;
@@ -158,4 +162,25 @@ public void testExecuteStoredProcedure(TestContext ctx) {
         });
     }));
   }
+
+  @Test
+  public void testQuerySequences(TestContext ctx) {
+    Future[] futures = Stream.of("tinyint", "smallint", "int", "bigint")
+      .flatMap(type -> Stream.of(
+        String.format("DROP SEQUENCE IF EXISTS seq_%s", type),
+        String.format("CREATE SEQUENCE seq_%s AS %s", type, type)
+      ))
+      .map(sql -> connection.query(sql).execute())
+      .toArray(Future[]::new);
+    CompositeFuture.all(Arrays.asList(futures)).onComplete(ctx.asyncAssertSuccess(cf -> {
+      connection
+        .query("SELECT * FROM INFORMATION_SCHEMA.SEQUENCES WHERE SEQUENCE_NAME LIKE 'seq_%'")
+        .execute()
+        .onComplete(ctx.asyncAssertSuccess(rows -> {
+          for (Row row : rows) {
+            ctx.assertEquals(row.getString("SEQUENCE_NAME"), "seq_" + row.getString("DECLARED_DATA_TYPE"));
+          }
+        }));
+    }));
+  }
 }

vertx-mssql-client/src/test/resources/init.sql

@@ -307,4 +307,6 @@ VALUES (1, 32767, 2147483647, 9223372036854775807, 123.456, 1.234567, 'HELLO,WOR
 INSERT INTO collector_test
 VALUES (2, 32767, 2147483647, 9223372036854775807, 123.456, 1.234567, 'hello,world');
 
+GO
+
 -- TCK usage --