void push(StackItem item) {
if (item.getLevel() == -1) item.setLevel(stackLevel++);
stack.push(item);
stackSize += item.size;
if (stackMaxSize < stackSize) stackMaxSize = stackSize;
}
StackItem peek() {
return stack.peek();
}
void popAll() {
stackSize = 0;
stack.clear();
}
StackItem pop() {
StackItem item = stack.pop();
stackSize -= item.size;
return item;
}
int getStackCount() {
return stack.size();
}