greenplumn CParseHandlerValuesScan 源码

greenplumn CParseHandlerValuesScan 代码

文件路径：/src/backend/gporca/libnaucrates/src/parser/CParseHandlerValuesScan.cpp

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2017 VMware, Inc. or its affiliates.
//
//	@filename:
//		CParseHandlerValuesScan.cpp
//
//	@doc:
//
//		Implementation of the SAX parse handler class for parsing value scan
//		operator
//---------------------------------------------------------------------------

#include "naucrates/dxl/parser/CParseHandlerValuesScan.h"

#include "naucrates/dxl/CDXLUtils.h"
#include "naucrates/dxl/operators/CDXLOperatorFactory.h"
#include "naucrates/dxl/parser/CParseHandlerFactory.h"
#include "naucrates/dxl/parser/CParseHandlerPhysicalOp.h"
#include "naucrates/dxl/parser/CParseHandlerProjList.h"
#include "naucrates/dxl/parser/CParseHandlerProperties.h"
#include "naucrates/dxl/parser/CParseHandlerScalarValuesList.h"
#include "naucrates/dxl/parser/CParseHandlerUtils.h"

using namespace gpdxl;

XERCES_CPP_NAMESPACE_USE


//	ctor
CParseHandlerValuesScan::CParseHandlerValuesScan(
	CMemoryPool *mp, CParseHandlerManager *parse_handler_mgr,
	CParseHandlerBase *parse_handler_root)
	: CParseHandlerPhysicalOp(mp, parse_handler_mgr, parse_handler_root)
{
}


//	processes a Xerces start element event
void
CParseHandlerValuesScan::StartElement(const XMLCh *const element_uri,
									  const XMLCh *const element_local_name,
									  const XMLCh *const element_qname,
									  const Attributes &attrs)
{
	if (0 == XMLString::compareString(
				 CDXLTokens::XmlstrToken(EdxltokenPhysicalValuesScan),
				 element_local_name))
	{
		m_dxl_op = GPOS_NEW(m_mp) CDXLPhysicalValuesScan(m_mp);

		// parse handler for the proj list
		CParseHandlerBase *proj_list_parse_handler =
			CParseHandlerFactory::GetParseHandler(
				m_mp, CDXLTokens::XmlstrToken(EdxltokenScalarProjList),
				m_parse_handler_mgr, this);
		m_parse_handler_mgr->ActivateParseHandler(proj_list_parse_handler);

		//parse handler for the properties of the operator
		CParseHandlerBase *prop_parse_handler =
			CParseHandlerFactory::GetParseHandler(
				m_mp, CDXLTokens::XmlstrToken(EdxltokenProperties),
				m_parse_handler_mgr, this);
		m_parse_handler_mgr->ActivateParseHandler(prop_parse_handler);

		// store parse handlers
		this->Append(prop_parse_handler);
		this->Append(proj_list_parse_handler);
	}
	else
	{
		// parse scalar child
		CParseHandlerBase *child_parse_handler =
			CParseHandlerFactory::GetParseHandler(
				m_mp, CDXLTokens::XmlstrToken(EdxltokenScalarValuesList),
				m_parse_handler_mgr, this);
		m_parse_handler_mgr->ActivateParseHandler(child_parse_handler);

		// store parse handler
		this->Append(child_parse_handler);

		child_parse_handler->startElement(element_uri, element_local_name,
										  element_qname, attrs);
	}
}

//	processes a Xerces end element event
void
CParseHandlerValuesScan::EndElement(const XMLCh *const,	 // element_uri,
									const XMLCh *const element_local_name,
									const XMLCh *const	// element_qname
)
{
	if (0 != XMLString::compareString(
				 CDXLTokens::XmlstrToken(EdxltokenPhysicalValuesScan),
				 element_local_name))
	{
		CWStringDynamic *str = CDXLUtils::CreateDynamicStringFromXMLChArray(
			m_parse_handler_mgr->GetDXLMemoryManager(), element_local_name);
		GPOS_RAISE(gpdxl::ExmaDXL, gpdxl::ExmiDXLUnexpectedTag,
				   str->GetBuffer());
	}

	const ULONG arity = this->Length();
	GPOS_ASSERT(3 <= arity);

	m_dxl_node = GPOS_NEW(m_mp) CDXLNode(m_mp, m_dxl_op);

	// valuesscan has properties element as its first child
	CParseHandlerProperties *prop_parse_handler =
		dynamic_cast<CParseHandlerProperties *>((*this)[0]);

	// set statistics and physical properties
	CParseHandlerUtils::SetProperties(m_dxl_node, prop_parse_handler);

	// valuesscan has project list element as its second child
	CParseHandlerProjList *proj_list_parse_handler =
		dynamic_cast<CParseHandlerProjList *>((*this)[1]);
	AddChildFromParseHandler(proj_list_parse_handler);

	// valuesscan child value list begins with third child
	for (ULONG idx = 2; idx < arity; idx++)
	{
		CParseHandlerScalarValuesList *scalar_values_list_parse_handler =
			dynamic_cast<CParseHandlerScalarValuesList *>((*this)[idx]);
		AddChildFromParseHandler(scalar_values_list_parse_handler);
	}

	// deactivate handler
	m_parse_handler_mgr->DeactivateHandler();
}

// EOF

相关信息

greenplumn 源码目录

相关文章

greenplumn CParseHandlerAgg 源码

greenplumn CParseHandlerAppend 源码

greenplumn CParseHandlerArray 源码

greenplumn CParseHandlerAssert 源码

greenplumn CParseHandlerBase 源码

greenplumn CParseHandlerBroadcastMotion 源码

greenplumn CParseHandlerCTEConfig 源码

greenplumn CParseHandlerCTEList 源码

greenplumn CParseHandlerColDescr 源码

greenplumn CParseHandlerColStats 源码