Initial commit

engines/glk/alan3/memory.cpp

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+/* 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