greenplumn CParseHandlerBase 源码

greenplumn CParseHandlerBase 代码

文件路径：/src/backend/gporca/libnaucrates/include/naucrates/dxl/parser/CParseHandlerBase.h

//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2010 Greenplum, Inc.
//
//	@filename:
//		CParseHandlerBase.h
//
//	@doc:
//		Base SAX parse handler class for DXL documents
//---------------------------------------------------------------------------

#ifndef GPDXL_CParseHandlerBase_H
#define GPDXL_CParseHandlerBase_H

#include <xercesc/sax2/DefaultHandler.hpp>

#include "gpos/base.h"

#include "naucrates/dxl/CDXLUtils.h"
#include "naucrates/dxl/operators/CDXLNode.h"
#include "naucrates/exception.h"

namespace gpdxl
{
using namespace gpos;

// fwd decl
class CParseHandlerManager;
class CParseHandlerBase;

// dynamic arrays of parse handlers
using CParseHandlerBaseArray =
	CDynamicPtrArray<CParseHandlerBase, CleanupDelete>;

XERCES_CPP_NAMESPACE_USE

// DXL parse handler type. Currently we only annotate the top-level parse handlers
// for the top-level DXL elements such as Plan, Query and Metadata
enum EDxlParseHandlerType
{
	EdxlphOptConfig,
	EdxlphEnumeratorConfig,
	EdxlphStatisticsConfig,
	EdxlphCTEConfig,
	EdxlphHint,
	EdxlphWindowOids,
	EdxlphTraceFlags,
	EdxlphPlan,
	EdxlphQuery,
	EdxlphMetadata,
	EdxlphMetadataRequest,
	EdxlphStatistics,
	EdxlphSearchStrategy,
	EdxlphCostParams,
	EdxlphCostParam,
	EdxlphScalarExpr,
	EdxlphOther
};
//---------------------------------------------------------------------------
//	@class:
//		CParseHandlerBase
//
//	@doc:
//		Base SAX parse handler class for parsing DXL documents.
//		Implements Xerces required interface for SAX parse handlers.
//
//---------------------------------------------------------------------------
class CParseHandlerBase : public DefaultHandler
{
private:
	// array of parse handlers for child elements
	CParseHandlerBaseArray *m_parse_handler_base_array;

protected:
	// memory pool to create DXL objects in
	CMemoryPool *m_mp;

	// manager for transitions between parse handlers
	CParseHandlerManager *m_parse_handler_mgr;

	// add child parse handler
	inline void
	Append(CParseHandlerBase *parse_handler_base)
	{
		GPOS_ASSERT(nullptr != parse_handler_base);
		m_parse_handler_base_array->Append(parse_handler_base);
	};

	// number of children
	inline ULONG
	Length() const
	{
		return m_parse_handler_base_array->Size();
	}

	// shorthand to access children
	inline CParseHandlerBase *
	operator[](ULONG idx) const
	{
		return (*m_parse_handler_base_array)[idx];
	};

	// parse handler for root element
	CParseHandlerBase *m_parse_handler_root;

	// process the start of an element
	virtual void StartElement(
		const XMLCh *const element_uri,			// URI of element's namespace
		const XMLCh *const element_local_name,	// local part of element's name
		const XMLCh *const element_qname,		// element's qname
		const Attributes &attr					// element's attributes
		) = 0;

	// process the end of an element
	virtual void EndElement(
		const XMLCh *const element_uri,			// URI of element's namespace
		const XMLCh *const element_local_name,	// local part of element's name
		const XMLCh *const element_qname		// element's qname
		) = 0;

public:
	CParseHandlerBase(const CParseHandlerBase &) = delete;

	// ctor
	CParseHandlerBase(CMemoryPool *mp, CParseHandlerManager *parse_handler_mgr,
					  CParseHandlerBase *parse_handler_root);

	//dtor
	~CParseHandlerBase() override;

	virtual EDxlParseHandlerType GetParseHandlerType() const;

	// replaces a parse handler in the parse handler array with a new one
	void ReplaceParseHandler(CParseHandlerBase *parse_handler_base_old,
							 CParseHandlerBase *parse_handler_base_new);

	// Xerces parse handler interface method to eceive notification of the beginning of an element.
	void startElement(
		const XMLCh *const element_uri,			// URI of element's namespace
		const XMLCh *const element_local_name,	// local part of element's name
		const XMLCh *const element_qname,		// element's qname
		const Attributes &attr					// element's attributes
		) override;

	// Xerces parse handler interface method to eceive notification of the end of an element.
	void endElement(
		const XMLCh *const element_uri,			// URI of element's namespace
		const XMLCh *const element_local_name,	// local part of element's name
		const XMLCh *const element_qname		// element's qname
		) override;

	// process a parsing ProcessError
	void error(const SAXParseException &) override;
};
}  // namespace gpdxl

#endif	// !GPDXL_CParseHandlerBase_H

// 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 CParseHandlerBroadcastMotion 源码

greenplumn CParseHandlerCTEConfig 源码

greenplumn CParseHandlerCTEList 源码

greenplumn CParseHandlerColDescr 源码

greenplumn CParseHandlerColStats 源码

greenplumn CParseHandlerColStatsBucket 源码