constraints.mx

一个内存数据库的源代码这是服务器端还有客户端

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@f constraints
@a Niels Nes
@* constraints 

@mal
module constraints;

command emptySet(b:bat[:oid,:any_2]):void
address CemptySet
comment "Check if the bat is empty";

@h
#ifndef _CONSTRAINTS_H
#define _CONSTRAINTS_H


#ifdef WIN32
#ifndef LIBCONSTRAINTS
#define constraints_export extern __declspec(dllimport)
#else
#define constraints_export extern __declspec(dllexport)
#endif
#else
#define constraints_export extern
#endif

constraints_export str CemptySet(int *k, int *bid);

#endif /* _CONSTRAINTS_H */

@c
#include "mal_config.h"
#include "mal.h"
#include "mal_exception.h"
#include "constraints.h"


str 
CemptySet(int *k, int *bid)
{
	BAT *b = BATdescriptor(*bid);
	int cnt = 0;

	(void)k;
	if (b)
		cnt = BATcount(b);
	BBPunfix(b->batCacheid);
	if (cnt) 
		throw(OPTIMIZER, "mal.assert", "emptySet");
        return MAL_SUCCEED;
}