copyfuncs.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

/*-------------------------------------------------------------------------
 *
 * copyfuncs.c
 *	  Copy functions for Postgres tree nodes.
 *
 * NOTE: we currently support copying all node types found in parse and
 * plan trees.	We do not support copying executor state trees; there
 * is no need for that, and no point in maintaining all the code that
 * would be needed.  We also do not support copying Path trees, mainly
 * because the circular linkages between RelOptInfo and Path nodes can't
 * be handled easily in a simple depth-first traversal.
 *
 *
 * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.316.2.1 2005/11/14 23:54:32 tgl Exp $
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include "nodes/parsenodes.h"
#include "nodes/plannodes.h"
#include "nodes/relation.h"
#include "utils/datum.h"


/*
 * Macros to simplify copying of different kinds of fields.  Use these
 * wherever possible to reduce the chance for silly typos.	Note that these
 * hard-wire the convention that the local variables in a Copy routine are
 * named 'newnode' and 'from'.
 */

/* Copy a simple scalar field (int, float, bool, enum, etc) */
#define COPY_SCALAR_FIELD(fldname) \
	(newnode->fldname = from->fldname)

/* Copy a field that is a pointer to some kind of Node or Node tree */
#define COPY_NODE_FIELD(fldname) \
	(newnode->fldname = copyObject(from->fldname))

/* Copy a field that is a pointer to a Bitmapset */
#define COPY_BITMAPSET_FIELD(fldname) \
	(newnode->fldname = bms_copy(from->fldname))

/* Copy a field that is a pointer to a C string, or perhaps NULL */
#define COPY_STRING_FIELD(fldname) \
	(newnode->fldname = from->fldname ? pstrdup(from->fldname) : (char *) NULL)

/* Copy a field that is a pointer to a simple palloc'd object of size sz */
#define COPY_POINTER_FIELD(fldname, sz) \
	do { \
		Size	_size = (sz); \
		newnode->fldname = palloc(_size); \
		memcpy(newnode->fldname, from->fldname, _size); \
	} while (0)


/* ****************************************************************
 *					 plannodes.h copy functions
 * ****************************************************************
 */

/*
 * CopyPlanFields
 *
 *		This function copies the fields of the Plan node.  It is used by
 *		all the copy functions for classes which inherit from Plan.
 */
static void
CopyPlanFields(Plan *from, Plan *newnode)
{
	COPY_SCALAR_FIELD(startup_cost);
	COPY_SCALAR_FIELD(total_cost);
	COPY_SCALAR_FIELD(plan_rows);
	COPY_SCALAR_FIELD(plan_width);
	COPY_NODE_FIELD(targetlist);
	COPY_NODE_FIELD(qual);
	COPY_NODE_FIELD(lefttree);
	COPY_NODE_FIELD(righttree);
	COPY_NODE_FIELD(initPlan);
	COPY_BITMAPSET_FIELD(extParam);
	COPY_BITMAPSET_FIELD(allParam);
	COPY_SCALAR_FIELD(nParamExec);
}

/*
 * _copyPlan
 */
static Plan *
_copyPlan(Plan *from)
{
	Plan	   *newnode = makeNode(Plan);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields(from, newnode);

	return newnode;
}


/*
 * _copyResult
 */
static Result *
_copyResult(Result *from)
{
	Result	   *newnode = makeNode(Result);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(resconstantqual);

	return newnode;
}

/*
 * _copyAppend
 */
static Append *
_copyAppend(Append *from)
{
	Append	   *newnode = makeNode(Append);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(appendplans);
	COPY_SCALAR_FIELD(isTarget);

	return newnode;
}

/*
 * _copyBitmapAnd
 */
static BitmapAnd *
_copyBitmapAnd(BitmapAnd *from)
{
	BitmapAnd  *newnode = makeNode(BitmapAnd);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(bitmapplans);

	return newnode;
}

/*
 * _copyBitmapOr
 */
static BitmapOr *
_copyBitmapOr(BitmapOr *from)
{
	BitmapOr   *newnode = makeNode(BitmapOr);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(bitmapplans);

	return newnode;
}


/*
 * CopyScanFields
 *
 *		This function copies the fields of the Scan node.  It is used by
 *		all the copy functions for classes which inherit from Scan.
 */
static void
CopyScanFields(Scan *from, Scan *newnode)
{
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	COPY_SCALAR_FIELD(scanrelid);
}

/*
 * _copyScan
 */
static Scan *
_copyScan(Scan *from)
{
	Scan	   *newnode = makeNode(Scan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	return newnode;
}

/*
 * _copySeqScan
 */
static SeqScan *
_copySeqScan(SeqScan *from)
{
	SeqScan    *newnode = makeNode(SeqScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	return newnode;
}

/*
 * _copyIndexScan
 */
static IndexScan *
_copyIndexScan(IndexScan *from)
{
	IndexScan  *newnode = makeNode(IndexScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_SCALAR_FIELD(indexid);
	COPY_NODE_FIELD(indexqual);
	COPY_NODE_FIELD(indexqualorig);
	COPY_NODE_FIELD(indexstrategy);
	COPY_NODE_FIELD(indexsubtype);
	COPY_SCALAR_FIELD(indexorderdir);

	return newnode;
}

/*
 * _copyBitmapIndexScan
 */
static BitmapIndexScan *
_copyBitmapIndexScan(BitmapIndexScan *from)
{
	BitmapIndexScan *newnode = makeNode(BitmapIndexScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_SCALAR_FIELD(indexid);
	COPY_NODE_FIELD(indexqual);
	COPY_NODE_FIELD(indexqualorig);
	COPY_NODE_FIELD(indexstrategy);
	COPY_NODE_FIELD(indexsubtype);

	return newnode;
}

/*
 * _copyBitmapHeapScan
 */
static BitmapHeapScan *
_copyBitmapHeapScan(BitmapHeapScan *from)
{
	BitmapHeapScan *newnode = makeNode(BitmapHeapScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(bitmapqualorig);

	return newnode;
}

/*
 * _copyTidScan
 */
static TidScan *
_copyTidScan(TidScan *from)
{
	TidScan    *newnode = makeNode(TidScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(tideval);

	return newnode;
}

/*
 * _copySubqueryScan
 */
static SubqueryScan *
_copySubqueryScan(SubqueryScan *from)
{
	SubqueryScan *newnode = makeNode(SubqueryScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(subplan);

	return newnode;
}

/*
 * _copyFunctionScan
 */
static FunctionScan *
_copyFunctionScan(FunctionScan *from)
{
	FunctionScan *newnode = makeNode(FunctionScan);

	/*
	 * copy node superclass fields
	 */
	CopyScanFields((Scan *) from, (Scan *) newnode);

	return newnode;
}

/*
 * CopyJoinFields
 *
 *		This function copies the fields of the Join node.  It is used by
 *		all the copy functions for classes which inherit from Join.
 */
static void
CopyJoinFields(Join *from, Join *newnode)
{
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	COPY_SCALAR_FIELD(jointype);
	COPY_NODE_FIELD(joinqual);
}


/*
 * _copyJoin
 */
static Join *
_copyJoin(Join *from)
{
	Join	   *newnode = makeNode(Join);

	/*
	 * copy node superclass fields
	 */
	CopyJoinFields(from, newnode);

	return newnode;
}


/*
 * _copyNestLoop
 */
static NestLoop *
_copyNestLoop(NestLoop *from)
{
	NestLoop   *newnode = makeNode(NestLoop);

	/*
	 * copy node superclass fields
	 */
	CopyJoinFields((Join *) from, (Join *) newnode);

	return newnode;
}


/*
 * _copyMergeJoin
 */
static MergeJoin *
_copyMergeJoin(MergeJoin *from)
{
	MergeJoin  *newnode = makeNode(MergeJoin);

	/*
	 * copy node superclass fields
	 */
	CopyJoinFields((Join *) from, (Join *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(mergeclauses);

	return newnode;
}

/*
 * _copyHashJoin
 */
static HashJoin *
_copyHashJoin(HashJoin *from)
{
	HashJoin   *newnode = makeNode(HashJoin);

	/*
	 * copy node superclass fields
	 */
	CopyJoinFields((Join *) from, (Join *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(hashclauses);

	return newnode;
}


/*
 * _copyMaterial
 */
static Material *
_copyMaterial(Material *from)
{
	Material   *newnode = makeNode(Material);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	return newnode;
}


/*
 * _copySort
 */
static Sort *
_copySort(Sort *from)
{
	Sort	   *newnode = makeNode(Sort);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	COPY_SCALAR_FIELD(numCols);
	COPY_POINTER_FIELD(sortColIdx, from->numCols * sizeof(AttrNumber));
	COPY_POINTER_FIELD(sortOperators, from->numCols * sizeof(Oid));

	return newnode;
}


/*
 * _copyGroup
 */
static Group *
_copyGroup(Group *from)
{
	Group	   *newnode = makeNode(Group);

	CopyPlanFields((Plan *) from, (Plan *) newnode);

	COPY_SCALAR_FIELD(numCols);
	COPY_POINTER_FIELD(grpColIdx, from->numCols * sizeof(AttrNumber));

	return newnode;
}

/*
 * _copyAgg
 */
static Agg *
_copyAgg(Agg *from)
{
	Agg		   *newnode = makeNode(Agg);

	CopyPlanFields((Plan *) from, (Plan *) newnode);

	COPY_SCALAR_FIELD(aggstrategy);
	COPY_SCALAR_FIELD(numCols);
	if (from->numCols > 0)
		COPY_POINTER_FIELD(grpColIdx, from->numCols * sizeof(AttrNumber));
	COPY_SCALAR_FIELD(numGroups);

	return newnode;
}

/*
 * _copyUnique
 */
static Unique *
_copyUnique(Unique *from)
{
	Unique	   *newnode = makeNode(Unique);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_SCALAR_FIELD(numCols);
	COPY_POINTER_FIELD(uniqColIdx, from->numCols * sizeof(AttrNumber));

	return newnode;
}

/*
 * _copyHash
 */
static Hash *
_copyHash(Hash *from)
{
	Hash	   *newnode = makeNode(Hash);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */

	return newnode;
}

/*
 * _copySetOp
 */
static SetOp *
_copySetOp(SetOp *from)
{
	SetOp	   *newnode = makeNode(SetOp);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_SCALAR_FIELD(cmd);
	COPY_SCALAR_FIELD(numCols);
	COPY_POINTER_FIELD(dupColIdx, from->numCols * sizeof(AttrNumber));
	COPY_SCALAR_FIELD(flagColIdx);

	return newnode;
}

/*
 * _copyLimit
 */
static Limit *
_copyLimit(Limit *from)
{
	Limit	   *newnode = makeNode(Limit);

	/*
	 * copy node superclass fields
	 */
	CopyPlanFields((Plan *) from, (Plan *) newnode);

	/*
	 * copy remainder of node
	 */
	COPY_NODE_FIELD(limitOffset);
	COPY_NODE_FIELD(limitCount);

	return newnode;
}

/* ****************************************************************
 *					   primnodes.h copy functions
 * ****************************************************************
 */

/*
 * _copyAlias
 */
static Alias *
_copyAlias(Alias *from)
{
	Alias	   *newnode = makeNode(Alias);

	COPY_STRING_FIELD(aliasname);
	COPY_NODE_FIELD(colnames);

	return newnode;
}

/*
 * _copyRangeVar
 */
static RangeVar *