greenplumn CParseHandlerMetadataColumns 源码

greenplumn CParseHandlerMetadataColumns 代码

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

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2011 Greenplum, Inc.
//
//	@filename:
//		CParseHandlerMetadataColumns.cpp
//
//	@doc:
//		Implementation of the SAX parse handler class for parsing a list of
//		columns in a relation's metadata.
//---------------------------------------------------------------------------

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

#include "naucrates/dxl/operators/CDXLOperatorFactory.h"
#include "naucrates/dxl/parser/CParseHandlerFactory.h"
#include "naucrates/dxl/parser/CParseHandlerManager.h"
#include "naucrates/dxl/parser/CParseHandlerMetadataColumn.h"

using namespace gpdxl;


XERCES_CPP_NAMESPACE_USE

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerMetadataColumns::CParseHandlerMetadataColumns
//
//	@doc:
//		Constructor
//
//---------------------------------------------------------------------------
CParseHandlerMetadataColumns::CParseHandlerMetadataColumns(
	CMemoryPool *mp, CParseHandlerManager *parse_handler_mgr,
	CParseHandlerBase *parse_handler_root)
	: CParseHandlerBase(mp, parse_handler_mgr, parse_handler_root),
	  m_md_col_array(nullptr)
{
}

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerMetadataColumns::~CParseHandlerMetadataColumns
//
//	@doc:
//		Destructor
//
//---------------------------------------------------------------------------
CParseHandlerMetadataColumns::~CParseHandlerMetadataColumns()
{
	CRefCount::SafeRelease(m_md_col_array);
}

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerMetadataColumns::StartElement
//
//	@doc:
//		Invoked by Xerces to process an opening tag
//
//---------------------------------------------------------------------------
void
CParseHandlerMetadataColumns::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(EdxltokenColumns),
									  element_local_name))
	{
		// start of a columns' list
		GPOS_ASSERT(nullptr == m_md_col_array);

		m_md_col_array = GPOS_NEW(m_mp) CMDColumnArray(m_mp);
	}
	else if (0 ==
			 XMLString::compareString(CDXLTokens::XmlstrToken(EdxltokenColumn),
									  element_local_name))
	{
		// column list must be initialized already
		GPOS_ASSERT(nullptr != m_md_col_array);

		// activate parse handler to parse the column info
		CParseHandlerBase *col_parse_handler =
			CParseHandlerFactory::GetParseHandler(
				m_mp, CDXLTokens::XmlstrToken(EdxltokenMetadataColumn),
				m_parse_handler_mgr, this);

		m_parse_handler_mgr->ActivateParseHandler(col_parse_handler);
		this->Append(col_parse_handler);

		col_parse_handler->startElement(element_uri, element_local_name,
										element_qname, attrs);
	}
	else
	{
		CWStringDynamic *str = CDXLUtils::CreateDynamicStringFromXMLChArray(
			m_parse_handler_mgr->GetDXLMemoryManager(), element_local_name);
		GPOS_RAISE(gpdxl::ExmaDXL, gpdxl::ExmiDXLUnexpectedTag,
				   str->GetBuffer());
	}
}

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerMetadataColumns::EndElement
//
//	@doc:
//		Invoked by Xerces to process a closing tag
//
//---------------------------------------------------------------------------
void
CParseHandlerMetadataColumns::EndElement(const XMLCh *const,  // element_uri,
										 const XMLCh *const element_local_name,
										 const XMLCh *const	 // element_qname
)
{
	if (0 == XMLString::compareString(CDXLTokens::XmlstrToken(EdxltokenColumns),
									  element_local_name))
	{
		// end of the columns' list
		GPOS_ASSERT(nullptr != m_md_col_array);

		const ULONG size = this->Length();
		// add parsed columns to the list
		for (ULONG ul = 0; ul < size; ul++)
		{
			CParseHandlerMetadataColumn *md_col_parse_handler =
				dynamic_cast<CParseHandlerMetadataColumn *>((*this)[ul]);

			GPOS_ASSERT(nullptr != md_col_parse_handler->GetMdCol());

			CMDColumn *md_col = md_col_parse_handler->GetMdCol();
			md_col->AddRef();

			m_md_col_array->Append(md_col);
		}
		// deactivate handler
		m_parse_handler_mgr->DeactivateHandler();
	}
	else
	{
		CWStringDynamic *str = CDXLUtils::CreateDynamicStringFromXMLChArray(
			m_parse_handler_mgr->GetDXLMemoryManager(), element_local_name);
		GPOS_RAISE(gpdxl::ExmaDXL, gpdxl::ExmiDXLUnexpectedTag,
				   str->GetBuffer());
	}
}

//---------------------------------------------------------------------------
//	@function:
//		CParseHandlerMetadataColumns::GetMdColArray
//
//	@doc:
//		Return the constructed list of metadata columns
//
//---------------------------------------------------------------------------
CMDColumnArray *
CParseHandlerMetadataColumns::GetMdColArray()
{
	return m_md_col_array;
}

// 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