algebraextensions.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 algebraExtensions
@v 2.0
@a M.L.Kersten, P. Boncz
@+ Algebra Extensions
The algebra extensions rely
on the MAL runtime setting, but logically belong to the kernel/algebra
module.
@mal

pattern algebra.project( b:bat[:any_1,:any_3], val:any_2) :bat[:any_1,:any_2] 	
address CMDBBPproject
comment "Fill the tail column with a newly typed constant.";
pattern algebra.project(b:bat[:any_1,:any_3], val:bat[:any_1,:any_2]) :bat[:any_1,:any_2]
address CMDBBPproject
comment "Fill the tail column with a constant.";
                                                                                
@{
@include prelude.mx
@+ Implementation section
In most cases we pass a BAT identifier, which should be unified
with a BAT descriptor. Upon failure we can simply abort the function.

@c
#include "mal_config.h"
#include "mal_box.h"
#include "mal_client.h"
#include "mal_interpreter.h"
#include "bat5.h"
#include "algebra.h"

#ifdef WIN32
#ifndef LIBALGEBRAEXTENSIONS
#define ae_export extern __declspec(dllimport)
#else
#define ae_export extern __declspec(dllexport)
#endif
#else
#define ae_export extern
#endif

ae_export str CMDBBPproject(MalBlkPtr mb, MalStkPtr stk, InstrPtr pci);
ae_export str CMDBBPprojectNil(int *ret, int *bid);

str
CMDBBPproject(MalBlkPtr mb, MalStkPtr stk, InstrPtr pci)
{
	int *result, *bid, tt;
	ptr *p;
	BAT *b, *bn;

	result = (int *) getArgReference(stk, pci, 0);
	bid = (int *) getArgReference(stk, pci, 1);
	p = (ptr *) getArgReference(stk, pci, 2);
	tt = getArgType(mb, pci, 2);
	if ((b = BATdescriptor(*bid)) == NULL) {
		throw(MAL, "bbp.project", "Cannot access descriptor");
	}

	if (ATOMvarsized(tt)) {
		if (p == 0 || *(str *) p == 0)
			p = (ptr *) str_nil;
		else
			p = *(ptr **) p;
	}
	bn = BATconst(b, tt, p);
	BBPunfix(b->batCacheid);
	if (bn) {
		*result = bn->batCacheid;
		BBPkeepref(bn->batCacheid);
		return MAL_SUCCEED;
	}
	throw(MAL, "bbp.project", "Cannot create the constant BAT");
}