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secondo/Algebras/MainMemory2/MemoryStack.h
2026-01-23 17:03:45 +08:00

151 lines
3.6 KiB
C++

/*
----
This file is part of SECONDO.
Copyright (C) 2017,
University in Hagen,
Faculty of Mathematics and Computer Science,
Database Systems for New Applications.
SECONDO is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
SECONDO is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with SECONDO; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
----
*/
#ifndef MEMORYSTACK_H
#define MEMORYSTACK_H
#include "MainMemoryExt.h"
#include <stack>
#include "Attribute.h"
#include "PointerWrapper.h"
namespace mm2algebra{
class MemoryStackObject : public MemoryObject {
public:
typedef PointerWrap<Tuple> mstackentry;
MemoryStackObject(bool _flob,
const std::string& db,
const std::string& _type ):
MemoryObject(_flob, db, _type) {
flob = _flob;
ListExpr tl;
if(!nl->ReadFromString(_type,tl)){
assert(false);
}
ListExpr tln = SecondoSystem::GetCatalog()->NumericType(
nl->Second( nl->Second(tl)));
tt = new TupleType(tln);
}
~MemoryStackObject() {
while(!s.empty()){
s.pop();
}
if(tt){
tt->DeleteIfAllowed();
}
}
static const std::string BasicType() { return "mstack"; }
static bool checkType(ListExpr t){
return nl->HasLength(t,2)
&& listutils::isSymbol(nl->First(t),BasicType())
&& Tuple::checkType(nl->Second(t));
}
size_t size() const{
return s.size();
}
const Tuple* top(){
Tuple* t = s.top().getPointer();
t->IncReference();
return t;
}
Tuple* pop(){
Tuple* t = s.top().getPointer();
t->IncReference();
s.pop();
return t;
}
void push(Tuple* t){
if(flob){
t->bringToMemory();
}
s.push(mstackentry(t));
}
bool empty() const{
return s.empty();
}
TupleType* getTupleType(){
return tt;
}
MemoryObject* clone(){
MemoryStackObject* res = new MemoryStackObject(flob, database,
objectTypeExpr);
std::stack<mstackentry> tmp;
while(!s.empty()){
mstackentry e = s.top();
s.pop();
tmp.push(e);
}
while(!tmp.empty()){
mstackentry e = tmp.top();
tmp.pop();
Tuple* t = e()->Clone();
s.push(e);
res->s.push(mstackentry(t));
}
return res;
}
static ListExpr wrapType(ListExpr tupleType){
assert(Tuple::checkType(tupleType));
return nl->TwoElemList( nl->SymbolAtom(BasicType()),
tupleType);
}
private:
std::stack<mstackentry> s;
TupleType* tt;
};
}
#endif