readfuncs.c

关系型数据库 Postgresql 6.5.2

/*-------------------------------------------------------------------------
 *
 * readfuncs.c
 *	  Reader functions for Postgres tree nodes.
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /usr/local/cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.64 1999/05/25 16:09:11 momjian Exp $
 *
 * NOTES
 *	  Most of the read functions for plan nodes are tested. (In fact, they
 *	  pass the regression test as of 11/8/94.) The rest (for path selection)
 *	  are probably never used. No effort has been made to get them to work.
 *	  The simplest way to test these functions is by doing the following in
 *	  ProcessQuery (before executing the plan):
 *				plan = stringToNode(nodeToString(plan));
 *	  Then, run the regression test. Let's just say you'll notice if either
 *	  of the above function are not properly done.
 *														- ay 11/94
 *
 *-------------------------------------------------------------------------
 */
#include <stdio.h>
#include <math.h>
#include <string.h>

#include "postgres.h"

#include "access/heapam.h"
#include "access/htup.h"
#include "fmgr.h"
#include "utils/builtins.h"
#include "utils/elog.h"
#include "utils/palloc.h"

#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "catalog/pg_index.h"
#include "catalog/pg_type.h"

#include "nodes/primnodes.h"
#include "nodes/plannodes.h"
#include "nodes/parsenodes.h"
#include "nodes/execnodes.h"
#include "nodes/relation.h"
#include "nodes/readfuncs.h"

/* ----------------
 *		node creator declarations
 * ----------------
 */

static Datum readDatum(Oid type);

static List *
toIntList(List *list)
{
	List	   *l;

	foreach(l, list)
	{
		/* ugly manipulation, should probably free the Value node too */
		lfirst(l) = (void *) intVal(lfirst(l));
	}
	return list;
}

/* ----------------
 *		_readQuery
 * ----------------
 */
static Query *
_readQuery()
{
	Query	   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(Query);

	token = lsptok(NULL, &length);		/* skip the :command */
	token = lsptok(NULL, &length);		/* get the commandType */
	local_node->commandType = atoi(token);

	token = lsptok(NULL, &length);		/* skip :utility */
	/* we can't get create or index here, can we? */

	token = lsptok(NULL, &length);		/* get the notify name if any */
	if (length == 0)
		local_node->utilityStmt = NULL;
	else
	{
		NotifyStmt *n = makeNode(NotifyStmt);

		n->relname = palloc(length + 1);
		StrNCpy(n->relname, token, length + 1);
		local_node->utilityStmt = (Node *) n;
	}

	token = lsptok(NULL, &length);		/* skip the :resultRelation */
	token = lsptok(NULL, &length);		/* get the resultRelation */
	local_node->resultRelation = atoi(token);

	token = lsptok(NULL, &length);		/* skip :into */
	token = lsptok(NULL, &length);		/* get into */
	if (length == 0)
		local_node->into = NULL;
	else
	{
		local_node->into = palloc(length + 1);
		StrNCpy(local_node->into, token, length + 1);
	}

	token = lsptok(NULL, &length);		/* skip :isPortal */
	token = lsptok(NULL, &length);		/* get isPortal */
	local_node->isPortal = (token[0] == 't') ? true : false;

	token = lsptok(NULL, &length);		/* skip :isBinary */
	token = lsptok(NULL, &length);		/* get isBinary */
	local_node->isBinary = (token[0] == 't') ? true : false;

	token = lsptok(NULL, &length);		/* skip :isTemp */
	token = lsptok(NULL, &length);		/* get isTemp */
	local_node->isTemp = (token[0] == 't') ? true : false;

	token = lsptok(NULL, &length);		/* skip :unionall */
	token = lsptok(NULL, &length);		/* get unionall */
	local_node->unionall = (token[0] == 't') ? true : false;

	token = lsptok(NULL, &length);		/* skip :uniqueFlag */
	token = lsptok(NULL, &length);		/* get uniqueFlag */
	if (length == 0)
		local_node->uniqueFlag = NULL;
	else
	{
		local_node->uniqueFlag = palloc(length + 1);
		StrNCpy(local_node->uniqueFlag, token, length + 1);
	}

	token = lsptok(NULL, &length);		/* skip :sortClause */
	local_node->sortClause = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :rtable */
	local_node->rtable = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :targetlist */
	local_node->targetList = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :qual */
	local_node->qual = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :groupClause */
	local_node->groupClause = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :havingQual */
	local_node->havingQual = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip the :hasAggs */
	token = lsptok(NULL, &length);		/* get hasAggs */
	local_node->hasAggs = (token[0] == 't') ? true : false;

	token = lsptok(NULL, &length);		/* skip the :hasSubLinks */
	token = lsptok(NULL, &length);		/* get hasSubLinks */
	local_node->hasSubLinks = (token[0] == 't') ? true : false;

	token = lsptok(NULL, &length);		/* skip :unionClause */
	local_node->unionClause = nodeRead(true);

	/***S*I***/
	token = lsptok(NULL, &length);		/* skip :intersectClause */
	local_node->intersectClause = nodeRead(true);


	token = lsptok(NULL, &length);		/* skip :limitOffset */
	local_node->limitOffset = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :limitCount */
	local_node->limitCount = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :rowMark */
	local_node->rowMark = nodeRead(true);

	return local_node;
}

/* ----------------
 *		_readSortClause
 * ----------------
 */
static SortClause *
_readSortClause()
{
	SortClause *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(SortClause);

	token = lsptok(NULL, &length);		/* skip the :resdom */
	local_node->resdom = nodeRead(true);

	token = lsptok(NULL, &length);		/* skip :opoid */
	token = lsptok(NULL, &length);		/* get opoid */
	local_node->opoid = strtoul(token, NULL, 10);

	return local_node;
}

/* ----------------
 *		_readGroupClause
 * ----------------
 */
static GroupClause *
_readGroupClause()
{
	GroupClause *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(GroupClause);

	token = lsptok(NULL, &length);		/* skip :grpOpoid */
	token = lsptok(NULL, &length);		/* get grpOpoid */
	local_node->grpOpoid = strtoul(token, NULL, 10);

	token = lsptok(NULL, &length);		/* skip :tleGroupref */
	token = lsptok(NULL, &length);		/* get tleGroupref */
	local_node->tleGroupref = strtoul(token, NULL, 10);

	return local_node;
}

/* ----------------
 *		_getPlan
 * ----------------
 */
static void
_getPlan(Plan *node)
{
	char	   *token;
	int			length;

	token = lsptok(NULL, &length);		/* first token is :cost */
	token = lsptok(NULL, &length);		/* next is the actual cost */
	node->cost = (Cost) atof(token);

	token = lsptok(NULL, &length);		/* skip the :size */
	token = lsptok(NULL, &length);		/* get the plan_size */
	node->plan_size = atoi(token);

	token = lsptok(NULL, &length);		/* skip the :width */
	token = lsptok(NULL, &length);		/* get the plan_width */
	node->plan_width = atoi(token);

	token = lsptok(NULL, &length);		/* eat the :state stuff */
	token = lsptok(NULL, &length);		/* now get the state */

	if (length == 0)
		node->state = (EState *) NULL;
	else
	{							/* Disgusting hack until I figure out what
								 * to do here */
		node->state = (EState *) !NULL;
	}

	token = lsptok(NULL, &length);		/* eat :qptargetlist */
	node->targetlist = nodeRead(true);

	token = lsptok(NULL, &length);		/* eat :qpqual */
	node->qual = nodeRead(true);

	token = lsptok(NULL, &length);		/* eat :lefttree */
	node->lefttree = (Plan *) nodeRead(true);

	token = lsptok(NULL, &length);		/* eat :righttree */
	node->righttree = (Plan *) nodeRead(true);

	return;
}

/*
 *	Stuff from plannodes.h
 */

/* ----------------
 *		_readPlan
 * ----------------
 */
static Plan *
_readPlan()
{
	Plan	   *local_node;

	local_node = makeNode(Plan);

	_getPlan(local_node);

	return local_node;
}

/* ----------------
 *		_readResult
 *
 *		Does some obscene, possibly unportable, magic with
 *		sizes of things.
 * ----------------
 */
static Result *
_readResult()
{
	Result	   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(Result);

	_getPlan((Plan *) local_node);

	token = lsptok(NULL, &length);		/* eat :resconstantqual */
	local_node->resconstantqual = nodeRead(true);		/* now read it */

	return local_node;
}

/* ----------------
 *		_readAppend
 *
 *	Append is a subclass of Plan.
 * ----------------
 */

static Append *
_readAppend()
{
	Append	   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(Append);

	_getPlan((Plan *) local_node);

	token = lsptok(NULL, &length);		/* eat :appendplans */
	local_node->appendplans = nodeRead(true);	/* now read it */

	token = lsptok(NULL, &length);		/* eat :unionrtables */
	local_node->unionrtables = nodeRead(true);	/* now read it */

	token = lsptok(NULL, &length);		/* eat :inheritrelid */
	token = lsptok(NULL, &length);		/* get inheritrelid */
	local_node->inheritrelid = strtoul(token, NULL, 10);

	token = lsptok(NULL, &length);		/* eat :inheritrtable */
	local_node->inheritrtable = nodeRead(true); /* now read it */

	return local_node;
}

/* ----------------
 *		_getJoin
 *
 * In case Join is not the same structure as Plan someday.
 * ----------------
 */
static void
_getJoin(Join *node)
{
	_getPlan((Plan *) node);
}


/* ----------------
 *		_readJoin
 *
 *	Join is a subclass of Plan
 * ----------------
 */
static Join *
_readJoin()
{
	Join	   *local_node;

	local_node = makeNode(Join);

	_getJoin(local_node);

	return local_node;
}

/* ----------------
 *		_readNestLoop
 *
 *	NestLoop is a subclass of Join
 * ----------------
 */

static NestLoop *
_readNestLoop()
{
	NestLoop   *local_node;

	local_node = makeNode(NestLoop);

	_getJoin((Join *) local_node);

	return local_node;
}

/* ----------------
 *		_readMergeJoin
 *
 *	MergeJoin is a subclass of Join
 * ----------------
 */
static MergeJoin *
_readMergeJoin()
{
	MergeJoin  *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(MergeJoin);

	_getJoin((Join *) local_node);
	token = lsptok(NULL, &length);		/* eat :mergeclauses */
	local_node->mergeclauses = nodeRead(true);	/* now read it */

	return local_node;
}

/* ----------------
 *		_readHashJoin
 *
 *	HashJoin is a subclass of Join.
 * ----------------
 */
static HashJoin *
_readHashJoin()
{
	HashJoin   *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(HashJoin);

	_getJoin((Join *) local_node);

	token = lsptok(NULL, &length);		/* eat :hashclauses */
	local_node->hashclauses = nodeRead(true);	/* now read it */

	token = lsptok(NULL, &length);		/* eat :hashjoinop */
	token = lsptok(NULL, &length);		/* get hashjoinop */
	local_node->hashjoinop = strtoul(token, NULL, 10);

	token = lsptok(NULL, &length);		/* eat :hashdone */
	token = lsptok(NULL, &length);		/* eat hashdone */
	local_node->hashdone = false;

	return local_node;
}

/* ----------------
 *		_getScan
 *
 *	Scan is a subclass of Node
 *	(Actually, according to the plannodes.h include file, it is a
 *	subclass of Plan.  This is why _getPlan is used here.)
 *
 *	Scan gets its own get function since stuff inherits it.
 * ----------------
 */
static void
_getScan(Scan *node)
{
	char	   *token;
	int			length;

	_getPlan((Plan *) node);

	token = lsptok(NULL, &length);		/* eat :scanrelid */
	token = lsptok(NULL, &length);		/* get scanrelid */
	node->scanrelid = strtoul(token, NULL, 10);
}

/* ----------------
 *		_readScan
 *
 * Scan is a subclass of Plan (Not Node, see above).
 * ----------------
 */
static Scan *
_readScan()
{
	Scan	   *local_node;

	local_node = makeNode(Scan);

	_getScan(local_node);

	return local_node;
}

/* ----------------
 *		_readSeqScan
 *
 *	SeqScan is a subclass of Scan
 * ----------------
 */
static SeqScan *
_readSeqScan()
{
	SeqScan    *local_node;

	local_node = makeNode(SeqScan);

	_getScan((Scan *) local_node);

	return local_node;
}

/* ----------------
 *		_readIndexScan
 *
 *	IndexScan is a subclass of Scan
 * ----------------
 */
static IndexScan *
_readIndexScan()
{
	IndexScan  *local_node;
	char	   *token;
	int			length;

	local_node = makeNode(IndexScan);

	_getScan((Scan *) local_node);

	token = lsptok(NULL, &length);		/* eat :indxid */
	local_node->indxid = toIntList(nodeRead(true));		/* now read it */

	token = lsptok(NULL, &length);		/* eat :indxqual */
	local_node->indxqual = nodeRead(true);		/* now read it */

	token = lsptok(NULL, &length);		/* eat :indxqualorig */
	local_node->indxqualorig = nodeRead(true);	/* now read it */