scummvm/engines/glk/alan3/memory.cpp
2021-12-26 18:48:43 +01:00

116 lines
3.0 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "glk/alan3/memory.h"
#include "glk/alan3/types.h"
#include "glk/alan3/syserr.h"
namespace Glk {
namespace Alan3 {
/* PUBLIC DATA */
Aword *memory = nullptr;
static ACodeHeader dummyHeader; /* Dummy to use until memory allocated */
ACodeHeader *header = &dummyHeader;
int memTop = 0; /* Top of load memory */
/*======================================================================*/
void *allocate(unsigned long lengthInBytes) {
void *p = (void *)calloc((size_t)lengthInBytes, 1);
if (p == nullptr)
syserr("Out of memory.");
return p;
}
/*======================================================================*/
void deallocate(void *ptr) {
free(ptr);
}
/*======================================================================*/
void *duplicate(void *original, unsigned long len) {
void *p = allocate(len + 1);
memcpy(p, original, len);
return p;
}
typedef struct {
Aptr aptr;
void *voidp;
} PointerMapEntry;
static PointerMapEntry *pointerMap = nullptr;
static int pointerMapSize = 0;
static int nextAptr = 1;
/*======================================================================*/
void resetPointerMap(void) {
if (pointerMap != nullptr) free(pointerMap);
pointerMap = nullptr;
pointerMapSize = 0;
}
/*======================================================================*/
void *fromAptr(Aptr aptr) {
int index;
for (index = 0; index < pointerMapSize && pointerMap[index].aptr != aptr; index++)
;
if (index == pointerMapSize)
syserr("No pointerMap entry for Aptr");
return pointerMap[index].voidp;
}
/*======================================================================*/
Aptr toAptr(void *ptr) {
int index;
if (pointerMap == nullptr) {
pointerMap = (PointerMapEntry *)allocate(sizeof(PointerMapEntry));
pointerMapSize = 1;
}
for (index = 0; index < pointerMapSize && pointerMap[index].voidp != nullptr; index++)
;
if (index == pointerMapSize) {
pointerMap = (PointerMapEntry *)realloc(pointerMap, (index + 1) * sizeof(PointerMapEntry));
pointerMapSize++;
}
pointerMap[index].voidp = ptr;
pointerMap[index].aptr = nextAptr++;
return pointerMap[index].aptr;
}
} // End of namespace Alan3
} // End of namespace Glk