init push

src/sql/engine/expr/ob_expr_empty_lob.cpp

@@ -0,0 +1,113 @@
+/**
+ * Copyright (c) 2021 OceanBase
+ * OceanBase CE is licensed under Mulan PubL v2.
+ * You can use this software according to the terms and conditions of the Mulan PubL v2.
+ * You may obtain a copy of Mulan PubL v2 at:
+ *          http://license.coscl.org.cn/MulanPubL-2.0
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PubL v2 for more details.
+ */
+
+#define USING_LOG_PREFIX SQL_ENG
+#include <string.h>
+#include "sql/engine/expr/ob_expr_empty_lob.h"
+#include "sql/session/ob_sql_session_info.h"
+#include "sql/parser/ob_item_type.h"
+#include "lib/oblog/ob_log.h"
+
+namespace oceanbase {
+using namespace common;
+namespace sql {
+
+// empty_clob
+ObExprEmptyClob::ObExprEmptyClob(ObIAllocator& alloc)
+    : ObFuncExprOperator(alloc, T_FUN_EMPTY_CLOB, N_EMPTY_CLOB, 0, NOT_ROW_DIMENSION)
+{}
+ObExprEmptyClob::~ObExprEmptyClob()
+{}
+
+int ObExprEmptyClob::calc_result_type0(ObExprResType& type, ObExprTypeCtx& type_ctx) const
+{
+  UNUSED(type_ctx);
+  ObSessionNLSParams nls_param = type_ctx.get_session()->get_session_nls_params();
+  type.set_clob();
+  type.set_collation_level(CS_LEVEL_IMPLICIT);
+  type.set_collation_type(nls_param.nls_collation_);
+  return OB_SUCCESS;
+}
+
+int ObExprEmptyClob::calc_result0(ObObj& result, ObExprCtx& expr_ctx) const
+{
+  int ret = OB_SUCCESS;
+  UNUSED(expr_ctx);
+
+  result.set_lob_value(ObLongTextType, ObString().ptr(), ObString().length());
+  result.set_collation(result_type_);
+
+  return ret;
+}
+
+int ObExprEmptyClob::eval_empty_clob(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum)
+{
+  int ret = OB_SUCCESS;
+  UNUSED(expr);
+  UNUSED(ctx);
+  expr_datum.set_string(NULL, 0);
+  return ret;
+}
+
+int ObExprEmptyClob::cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const
+{
+  UNUSED(op_cg_ctx);
+  UNUSED(raw_expr);
+  rt_expr.eval_func_ = ObExprEmptyClob::eval_empty_clob;
+  return OB_SUCCESS;
+}
+
+// empty_blob
+ObExprEmptyBlob::ObExprEmptyBlob(ObIAllocator& alloc)
+    : ObFuncExprOperator(alloc, T_FUN_EMPTY_BLOB, N_EMPTY_BLOB, 0, NOT_ROW_DIMENSION)
+{}
+ObExprEmptyBlob::~ObExprEmptyBlob()
+{}
+
+int ObExprEmptyBlob::calc_result_type0(ObExprResType& type, ObExprTypeCtx& type_ctx) const
+{
+  UNUSED(type_ctx);
+  type.set_blob();
+  type.set_collation_type(CS_TYPE_BINARY);
+  return OB_SUCCESS;
+}
+
+int ObExprEmptyBlob::calc_result0(ObObj& result, ObExprCtx& expr_ctx) const
+{
+  int ret = OB_SUCCESS;
+  UNUSED(expr_ctx);
+
+  result.set_lob_value(ObLongTextType, ObString().ptr(), ObString().length());
+  result.set_collation_type(CS_TYPE_BINARY);
+
+  return ret;
+}
+
+int ObExprEmptyBlob::eval_empty_blob(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum)
+{
+  int ret = OB_SUCCESS;
+  UNUSED(expr);
+  UNUSED(ctx);
+  expr_datum.set_string(NULL, 0);
+  return ret;
+}
+
+int ObExprEmptyBlob::cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const
+{
+  UNUSED(op_cg_ctx);
+  UNUSED(raw_expr);
+  rt_expr.eval_func_ = ObExprEmptyBlob::eval_empty_blob;
+  return OB_SUCCESS;
+}
+
+}  // namespace sql
+}  // namespace oceanbase