postgres/src/backend/nodes/equalfuncs.c

/*-------------------------------------------------------------------------
 *
 * equalfuncs.c--
 *	  equal functions to compare the nodes
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.18 1998/08/04 16:43:58 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#include <string.h>

#include "postgres.h"

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

#include "utils/builtins.h"		/* for namestrcmp() */
#include "utils/datum.h"
#include "utils/elog.h"
#include "storage/itemptr.h"

static bool equali(List *a, List *b);

/*
 *	Stuff from primnodes.h
 */

/*
 *	Resdom is a subclass of Node.
 */
static bool
_equalResdom(Resdom *a, Resdom *b)
{
	if (a->resno != b->resno)
		return (false);
	if (a->restype != b->restype)
		return (false);
	if (a->restypmod != b->restypmod)
		return (false);
	if (strcmp(a->resname, b->resname) != 0)
		return (false);
	if (a->reskey != b->reskey)
		return (false);
	if (a->reskeyop != b->reskeyop)
		return (false);

	return (true);
}

static bool
_equalFjoin(Fjoin *a, Fjoin *b)
{
	int			nNodes;

	if (a->fj_initialized != b->fj_initialized)
		return (false);
	if (a->fj_nNodes != b->fj_nNodes)
		return (false);
	if (!equal(a->fj_innerNode, b->fj_innerNode))
		return (false);

	nNodes = a->fj_nNodes;
	if (memcmp(a->fj_results, b->fj_results, nNodes * sizeof(Datum)) != 0)
		return (false);
	if (memcmp(a->fj_alwaysDone, b->fj_alwaysDone, nNodes * sizeof(bool)) != 0)
		return (false);

	return (true);
}

/*
 *	Expr is a subclass of Node.
 */
static bool
_equalExpr(Expr *a, Expr *b)
{
	if (a->opType != b->opType)
		return (false);
	if (!equal(a->oper, b->oper))
		return (false);
	if (!equal(a->args, b->args))
		return (false);

	return (true);
}

static bool
_equalIter(Iter *a, Iter *b)
{
	return (equal(a->iterexpr, b->iterexpr));
}

static bool
_equalStream(Stream *a, Stream *b)
{
	if (a->clausetype != b->clausetype)
		return (false);
	if (a->groupup != b->groupup)
		return (false);
	if (a->groupcost != b->groupcost)
		return (false);
	if (a->groupsel != b->groupsel)
		return (false);
	if (!equal(a->pathptr, b->pathptr))
		return (false);
	if (!equal(a->cinfo, b->cinfo))
		return (false);
	if (!equal(a->upstream, b->upstream))
		return (false);
	return (equal(a->downstream, b->downstream));
}

/*
 *	Var is a subclass of Expr.
 */
static bool
_equalVar(Var *a, Var *b)
{
	if (a->varno != b->varno)
		return (false);
	if (a->varattno != b->varattno)
		return (false);
	if (a->vartype != b->vartype)
		return (false);
	if (a->vartypmod != b->vartypmod)
		return (false);
	if (a->varlevelsup != b->varlevelsup)
		return (false);
	if (a->varnoold != b->varnoold)
		return (false);
	if (a->varoattno != b->varoattno)
		return (false);

	return (true);
}

static bool
_equalArray(Array *a, Array *b)
{
	if (a->arrayelemtype != b->arrayelemtype)
		return (false);
	if (a->arrayndim != b->arrayndim)
		return (false);
	if (a->arraylow.indx[0] != b->arraylow.indx[0])
		return (false);
	if (a->arrayhigh.indx[0] != b->arrayhigh.indx[0])
		return (false);
	if (a->arraylen != b->arraylen)
		return (false);
	return (TRUE);
}

static bool
_equalArrayRef(ArrayRef *a, ArrayRef *b)
{
	if (a->refelemtype != b->refelemtype)
		return (false);
	if (a->refattrlength != b->refattrlength)
		return (false);
	if (a->refelemlength != b->refelemlength)
		return (false);
	if (a->refelembyval != b->refelembyval)
		return (false);
	if (!equal(a->refupperindexpr, b->refupperindexpr))
		return (false);
	if (!equal(a->reflowerindexpr, b->reflowerindexpr))
		return (false);
	if (!equal(a->refexpr, b->refexpr))
		return (false);
	return (equal(a->refassgnexpr, b->refassgnexpr));
}

/*
 *	Oper is a subclass of Expr.
 */
static bool
_equalOper(Oper *a, Oper *b)
{
	if (a->opno != b->opno)
		return (false);
	if (a->opresulttype != b->opresulttype)
		return (false);

	return (true);
}

/*
 *	Const is a subclass of Expr.
 */
static bool
_equalConst(Const *a, Const *b)
{

	/*
	 * * this function used to do a pointer compare on a and b.  That's *
	 * ridiculous.	-- JMH, 7/11/92
	 */
	if (a->consttype != b->consttype)
		return (false);
	if (a->constlen != b->constlen)
		return (false);
	if (a->constisnull != b->constisnull)
		return (false);
	if (a->constbyval != b->constbyval)
		return (false);
	return (datumIsEqual(a->constvalue, b->constvalue,
						 a->consttype, a->constbyval, a->constlen));
}

/*
 *	Param is a subclass of Expr.
 */
static bool
_equalParam(Param *a, Param *b)
{
	if (a->paramkind != b->paramkind)
		return (false);
	if (a->paramtype != b->paramtype)
		return (false);
	if (!equal(a->param_tlist, b->param_tlist))
		return (false);

	switch (a->paramkind)
	{
		case PARAM_NAMED:
		case PARAM_NEW:
		case PARAM_OLD:
			if (strcmp(a->paramname, b->paramname) != 0)
				return (false);
			break;
		case PARAM_NUM:
		case PARAM_EXEC:
			if (a->paramid != b->paramid)
				return (false);
			break;
		case PARAM_INVALID:

			/*
			 * XXX: Hmmm... What are we supposed to return in this case ??
			 */
			return (true);
			break;
		default:
			elog(ERROR, "_equalParam: Invalid paramkind value: %d",
				 a->paramkind);
	}

	return (true);
}

/*
 *	Func is a subclass of Expr.
 */
static bool
_equalFunc(Func *a, Func *b)
{
	if (a->funcid != b->funcid)
		return (false);
	if (a->functype != b->functype)
		return (false);
	if (a->funcisindex != b->funcisindex)
		return (false);
	if (a->funcsize != b->funcsize)
		return (false);
	if (!equal(a->func_tlist, b->func_tlist))
		return (false);
	if (!equal(a->func_planlist, b->func_planlist))
		return (false);

	return (true);
}

/*
 * CInfo is a subclass of Node.
 */
static bool
_equalCInfo(CInfo *a, CInfo *b)
{
	Assert(IsA(a, CInfo));
	Assert(IsA(b, CInfo));

	if (!equal(a->clause, b->clause))
		return (false);
	if (a->selectivity != b->selectivity)
		return (false);
	if (a->notclause != b->notclause)
		return (false);
#ifdef EqualMergeOrderExists
	if (!EqualMergeOrder(a->mergejoinorder, b->mergejoinorder))
		return (false);
#endif
	if (a->hashjoinoperator != b->hashjoinoperator)
		return (false);
	return (equal((a->indexids),
				  (b->indexids)));
}

/*
 * RelOptInfo is a subclass of Node.
 */
static bool
_equalRelOptInfo(RelOptInfo *a, RelOptInfo *b)
{
	Assert(IsA(a, RelOptInfo));
	Assert(IsA(b, RelOptInfo));

	return (equal((a->relids),
				  (b->relids)));
}

static bool
_equalJoinMethod(JoinMethod *a, JoinMethod *b)
{
	Assert(IsA(a, JoinMethod));
	Assert(IsA(b, JoinMethod));

	if (!equal((a->jmkeys),
			   (b->jmkeys)))
		return (false);
	if (!equal((a->clauses),
			   (b->clauses)))
		return (false);
	return (true);
}

static bool
_equalPath(Path *a, Path *b)
{
	if (a->pathtype != b->pathtype)
		return (false);
	if (a->parent != b->parent)
		return (false);

	/*
	 * if (a->path_cost != b->path_cost) return(false);
	 */
	if (a->p_ordering.ordtype == SORTOP_ORDER)
	{
		int			i = 0;

		if (a->p_ordering.ord.sortop == NULL ||
			b->p_ordering.ord.sortop == NULL)
		{

			if (a->p_ordering.ord.sortop != b->p_ordering.ord.sortop)
				return false;
		}
		else
		{
			while (a->p_ordering.ord.sortop[i] != 0 &&
				   b->p_ordering.ord.sortop[i] != 0)
			{
				if (a->p_ordering.ord.sortop[i] != b->p_ordering.ord.sortop[i])
					return false;
				i++;
			}
			if (a->p_ordering.ord.sortop[i] != 0 ||
				b->p_ordering.ord.sortop[i] != 0)
				return false;
		}
	}
	else
	{
		if (!equal((a->p_ordering.ord.merge),
				   (b->p_ordering.ord.merge)))
			return (false);
	}
	if (!equal((a->keys),
			   (b->keys)))
		return (false);

	/*
	 * if (a->outerjoincost != b->outerjoincost) return(false);
	 */
	if (!equali((a->joinid),
				(b->joinid)))
		return (false);
	return (true);
}

static bool
_equalIndexPath(IndexPath *a, IndexPath *b)
{
	if (!_equalPath((Path *) a, (Path *) b))
		return (false);
	if (!equali((a->indexid), (b->indexid)))
		return (false);
	if (!equal((a->indexqual), (b->indexqual)))
		return (false);
	return (true);
}

static bool
_equalJoinPath(JoinPath *a, JoinPath *b)
{
	Assert(IsA_JoinPath(a));
	Assert(IsA_JoinPath(b));

	if (!_equalPath((Path *) a, (Path *) b))
		return (false);
	if (!equal((a->pathclauseinfo), (b->pathclauseinfo)))
		return (false);
	if (!equal((a->outerjoinpath), (b->outerjoinpath)))
		return (false);
	if (!equal((a->innerjoinpath), (b->innerjoinpath)))
		return (false);
	return (true);
}

static bool
_equalMergePath(MergePath *a, MergePath *b)
{
	Assert(IsA(a, MergePath));
	Assert(IsA(b, MergePath));

	if (!_equalJoinPath((JoinPath *) a, (JoinPath *) b))
		return (false);
	if (!equal((a->path_mergeclauses), (b->path_mergeclauses)))
		return (false);
	if (!equal((a->outersortkeys), (b->outersortkeys)))
		return (false);
	if (!equal((a->innersortkeys), (b->innersortkeys)))
		return (false);
	return (true);
}

static bool
_equalHashPath(HashPath *a, HashPath *b)
{
	Assert(IsA(a, HashPath));
	Assert(IsA(b, HashPath));

	if (!_equalJoinPath((JoinPath *) a, (JoinPath *) b))
		return (false);
	if (!equal((a->path_hashclauses), (b->path_hashclauses)))
		return (false);
	if (!equal((a->outerhashkeys), (b->outerhashkeys)))
		return (false);
	if (!equal((a->innerhashkeys), (b->innerhashkeys)))
		return (false);
	return (true);
}

static bool
_equalJoinKey(JoinKey *a, JoinKey *b)
{
	Assert(IsA(a, JoinKey));
	Assert(IsA(b, JoinKey));

	if (!equal((a->outer), (b->outer)))
		return (false);
	if (!equal((a->inner), (b->inner)))
		return (false);
	return (true);
}

static bool
_equalMergeOrder(MergeOrder *a, MergeOrder *b)
{
	if (a == (MergeOrder *) NULL && b == (MergeOrder *) NULL)
		return (true);
	Assert(IsA(a, MergeOrder));
	Assert(IsA(b, MergeOrder));

	if (a->join_operator != b->join_operator)
		return (false);
	if (a->left_operator != b->left_operator)
		return (false);
	if (a->right_operator != b->right_operator)
		return (false);
	if (a->left_type != b->left_type)
		return (false);
	if (a->right_type != b->right_type)
		return (false);
	return (true);
}

static bool
_equalHInfo(HInfo *a, HInfo *b)
{
	Assert(IsA(a, HInfo));
	Assert(IsA(b, HInfo));

	if (a->hashop != b->hashop)
		return (false);
	return (true);
}

/* XXX	This equality function is a quick hack, should be
 *		fixed to compare all fields.
 */
static bool
_equalIndexScan(IndexScan *a, IndexScan *b)
{
	Assert(IsA(a, IndexScan));
	Assert(IsA(b, IndexScan));

	/*
	 * if(a->scan.plan.cost != b->scan.plan.cost) return(false);
	 */

	if (!equal((a->indxqual), (b->indxqual)))
		return (false);

	if (a->scan.scanrelid != b->scan.scanrelid)
		return (false);

	if (!equali((a->indxid), (b->indxid)))
		return (false);
	return (true);
}

static bool
_equalSubPlan(SubPlan *a, SubPlan *b)
{
	if (a->plan_id != b->plan_id)
		return (false);

	if (!equal((a->sublink->oper), (b->sublink->oper)))
		return (false);

	return (true);
}

static bool
_equalJInfo(JInfo *a, JInfo *b)
{
	Assert(IsA(a, JInfo));
	Assert(IsA(b, JInfo));
	if (!equal((a->otherrels), (b->otherrels)))
		return (false);
	if (!equal((a->jinfoclauseinfo), (b->jinfoclauseinfo)))
		return (false);
	if (a->mergejoinable != b->mergejoinable)
		return (false);
	if (a->hashjoinable != b->hashjoinable)
		return (false);
	return (true);
}

/*
 *	Stuff from execnodes.h
 */

/*
 *	EState is a subclass of Node.
 */
static bool
_equalEState(EState *a, EState *b)
{
	if (a->es_direction != b->es_direction)
		return (false);

	if (!equal(a->es_range_table, b->es_range_table))
		return (false);

	if (a->es_result_relation_info != b->es_result_relation_info)
		return (false);

	return (true);
}

static bool
_equalTargetEntry(TargetEntry *a, TargetEntry *b)
{
	if (!equal(a->resdom, b->resdom))
		return (false);
	if (!equal(a->fjoin, b->fjoin))
		return (false);
	if (!equal(a->expr, b->expr))
		return (false);

	return (true);
}


/*
 *	equal -- are two lists equal?
 *
 *		This is a comparison by value.	It would be simpler to write it
 *		to be recursive, but it should run faster if we iterate.
 */
static bool
_equalValue(Value *a, Value *b)
{
	if (a->type != b->type)
		return (false);

	switch (a->type)
	{
		case T_String:
			return strcmp(a->val.str, b->val.str);
		case T_Integer:
			return (a->val.ival == b->val.ival);
		case T_Float:
			return (a->val.dval == b->val.dval);
		default:
			break;
	}

	return (true);
}

/*
 * equal--
 *	  returns whether two nodes are equal
 */
bool
equal(void *a, void *b)
{
	bool		retval = false;

	if (a == b)
		return (true);

	/*
	 * note that a!=b, so only one of them can be NULL
	 */
	if (a == NULL || b == NULL)
		return (false);

	/*
	 * are they the same type of nodes?
	 */
	if (nodeTag(a) != nodeTag(b))
		return (false);

	switch (nodeTag(a))
	{
		case T_Resdom:
			retval = _equalResdom(a, b);
			break;
		case T_Fjoin:
			retval = _equalFjoin(a, b);
			break;
		case T_Expr:
			retval = _equalExpr(a, b);
			break;
		case T_TargetEntry:
			retval = _equalTargetEntry(a, b);
			break;
		case T_Iter:
			retval = _equalIter(a, b);
			break;
		case T_Stream:
			retval = _equalStream(a, b);
			break;
		case T_Var:
			retval = _equalVar(a, b);
			break;
		case T_Array:
			retval = _equalArray(a, b);
			break;
		case T_ArrayRef:
			retval = _equalArrayRef(a, b);
			break;
		case T_Oper:
			retval = _equalOper(a, b);
			break;
		case T_Const:
			retval = _equalConst(a, b);
			break;
		case T_Param:
			retval = _equalParam(a, b);
			break;
		case T_Func:
			retval = _equalFunc(a, b);
			break;
		case T_CInfo:
			retval = _equalCInfo(a, b);
			break;
		case T_RelOptInfo:
			retval = _equalRelOptInfo(a, b);
			break;
		case T_JoinMethod:
			retval = _equalJoinMethod(a, b);
			break;
		case T_Path:
			retval = _equalPath(a, b);
			break;
		case T_IndexPath:
			retval = _equalIndexPath(a, b);
			break;
		case T_JoinPath:
			retval = _equalJoinPath(a, b);
			break;
		case T_MergePath:
			retval = _equalMergePath(a, b);
			break;
		case T_HashPath:
			retval = _equalHashPath(a, b);
			break;
		case T_JoinKey:
			retval = _equalJoinKey(a, b);
			break;
		case T_MergeOrder:
			retval = _equalMergeOrder(a, b);
			break;
		case T_HInfo:
			retval = _equalHInfo(a, b);
			break;
		case T_IndexScan:
			retval = _equalIndexScan(a, b);
			break;
		case T_SubPlan:
			retval = _equalSubPlan(a, b);
			break;
		case T_JInfo:
			retval = _equalJInfo(a, b);
			break;
		case T_EState:
			retval = _equalEState(a, b);
			break;
		case T_Integer:
		case T_String:
		case T_Float:
			retval = _equalValue(a, b);
			break;
		case T_List:
			{
				List	   *la = (List *) a;
				List	   *lb = (List *) b;
				List	   *l;

				if (a == NULL && b == NULL)
					return (true);
				if (length(a) != length(b))
					return (false);
				foreach(l, la)
				{
					if (!equal(lfirst(l), lfirst(lb)))
						return (false);
					lb = lnext(lb);
				}
				retval = true;
			}
			break;
		default:
			elog(NOTICE, "equal: don't know whether nodes of type %d are equal",
				 nodeTag(a));
			break;
	}

	return retval;
}

/*
 * equali--
 *	  compares two lists of integers
 *
 * XXX temp hack. needs something like T_IntList
 */
static bool
equali(List *a, List *b)
{
	List	   *la = (List *) a;
	List	   *lb = (List *) b;
	List	   *l;

	if (a == NULL && b == NULL)
		return (true);
	if (length(a) != length(b))
		return (false);
	foreach(l, la)
	{
		if (lfirsti(l) != lfirsti(lb))
			return (false);
		lb = lnext(lb);
	}
	return true;
}