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use ::std::cell::*;
#[derive(Debug,Clone, PartialEq)]
pub struct AppendOnlySet<T>{
slots: RefCell<Vec<Box<T>>>
}
impl<T> AppendOnlySet<T> {
pub fn with_capacity(slots: usize) -> AppendOnlySet<T> {
AppendOnlySet {
slots: RefCell::new(Vec::with_capacity(slots))
}
}
pub fn add(&self, value: T) -> &T {
let boxed = Box::new(value);
let ptr = &*boxed as *const T;
self.slots.borrow_mut().push(boxed);
unsafe { &*ptr }
}
pub fn get_reference(&self, ptr: *const T) -> Option<&T> {
for ref item in self.slots.borrow().iter() {
let item_ptr = &***item as *const T;
if ptr == item_ptr {
return Some(unsafe { &*item_ptr })
}
}
None
}
pub fn contains(&self, item: *const T) -> bool {
self.get_reference(item).is_some()
}
pub fn get_mut_vec(&mut self) -> &mut Vec<Box<T>>{
self.slots.get_mut()
}
pub fn iter(&self) -> IterAppendOnlySet<T>{
IterAppendOnlySet{
set: self,
index: 0
}
}
}
pub struct IterAppendOnlySet<'a, T: 'a>{
set: &'a AppendOnlySet<T>,
index: usize
}
impl<'a, T> Iterator for IterAppendOnlySet<'a, T> {
type Item = &'a T;
fn next(&mut self) -> Option<Self::Item> {
let vec_ref = self.set.slots.borrow();
let result = vec_ref.get(self.index).map(|b| {
unsafe{ &* (&**b as *const T)}
});
self.index += 1;
result
}
}
#[derive(Debug,Clone, PartialEq)]
pub struct AddRemoveSet<T>{
inner: AppendOnlySet<RefCell<Option<T>>>
}
impl<T> AddRemoveSet<T> {
pub fn with_capacity(slots: usize) -> AddRemoveSet<T> {
AddRemoveSet {
inner: AppendOnlySet::with_capacity(slots)
}
}
pub fn add(&self, value: T) -> Ref<T> {
Ref::map(self.inner.add(RefCell::new(Some(value))).borrow(), |t| t.as_ref().unwrap())
}
pub fn add_mut(&self, value: T) -> RefMut<T> {
RefMut::map(self.inner.add(RefCell::new(Some(value))).borrow_mut(), |t| t.as_mut().unwrap())
}
pub fn iter(&self) -> IterAddRemoveSet<T>{
IterAddRemoveSet{ inner: self.inner.iter() }
}
pub fn iter_mut(&self) -> IterMutAddRemoveSet<T>{
IterMutAddRemoveSet{ inner: self.inner.iter() }
}
pub fn mut_clear(&mut self){
self.inner.get_mut_vec().clear();
}
pub fn clear(&self) -> Result<(),BorrowMutError>{
for refcell in self.inner.iter() {
match refcell.try_borrow_mut() {
Ok(mut ref_obj) => {
*ref_obj = None
}
Err(e) => { return Err(e) }
}
}
Ok(())
}
pub fn try_remove(&self, v: *const T) -> Result<bool, BorrowMutError>{
match self.try_get_option_reference_mut(v){
Ok(Some(mut ref_obj)) => {
*ref_obj = None;
return Ok(true)
},
Ok(None) => Ok(false),
Err(e) => Err(e)
}
}
pub fn try_contains(&self, v: *const T) -> Result<bool, BorrowError>{
self.try_get_reference(v).map(|opt| opt.is_some())
}
pub fn try_get_reference(&self, v: *const T) -> Result<Option<Ref<T>>, BorrowError>{
let mut last_error = None;
for refcell in self.inner.iter() {
match refcell.try_borrow() {
Ok(ref_obj) => {
let other_ptr = ref_obj.as_ref().map(|v| v as *const T);
if Some(v) == other_ptr{
return Ok(Some(Ref::map(ref_obj, |r| r.as_ref().unwrap())));
}
}
Err(e) => { last_error = Some(e); }
}
}
if last_error.is_some(){
Err(last_error.unwrap())
}else{
Ok(None)
}
}
pub fn try_get_reference_mut(&self, v: *const T) -> Result<Option<RefMut<T>>, BorrowMutError>{
self.try_get_option_reference_mut(v).map(|opt| opt.and_then(|ref_obj| {
if ref_obj.is_some() { Some(RefMut::map(ref_obj, |r| r.as_mut().unwrap())) } else {None}
}))
}
fn try_get_option_reference_mut(&self, v: *const T) -> Result<Option<RefMut<Option<T>>>, BorrowMutError>{
let mut last_error = None;
for refcell in self.inner.iter() {
match refcell.try_borrow_mut() {
Ok(ref_obj) => {
if ref_obj.is_some() && ref_obj.as_ref().unwrap() as *const T == v {
return Ok(Some(ref_obj));
}
}
Err(e) => { last_error = Some(e); }
}
}
if last_error.is_some(){
Err(last_error.unwrap())
}else{
Ok(None)
}
}
}
pub struct IterAddRemoveSet<'a, T: 'a>{
inner: IterAppendOnlySet<'a, RefCell<Option<T>>>
}
impl<'a, T> Iterator for IterAddRemoveSet<'a, T> {
type Item = Result<Ref<'a,T>, BorrowError>;
fn next(&mut self) -> Option<Self::Item> {
match self.inner.next(){
None => None,
Some(cell) => {
match cell.try_borrow(){
Ok(ref_obj) => {
if ref_obj.is_none(){
None
}else{
Some(Ok(Ref::map(ref_obj, |r| r.as_ref().unwrap())))
}
}
Err(e) => Some(Err(e))
}
}
}
}
}
pub struct IterMutAddRemoveSet<'a, T: 'a>{
inner: IterAppendOnlySet<'a, RefCell<Option<T>>>
}
impl<'a, T> Iterator for IterMutAddRemoveSet<'a, T> {
type Item = Result<RefMut<'a,T>, BorrowMutError>;
fn next(&mut self) -> Option<Self::Item> {
match self.inner.next(){
None => None,
Some(cell) => {
match cell.try_borrow_mut(){
Ok(ref_obj) => {
if ref_obj.is_none(){
None
}else{
Some(Ok(RefMut::map(ref_obj, |r| r.as_mut().unwrap())))
}
}
Err(e) => Some(Err(e))
}
}
}
}
}
#[cfg(test)]
mod tests{
use ::std::cell::*;
use super::*;
#[derive(Clone, PartialEq,Debug)]
struct Container{
objects: AppendOnlySet<RefCell<Option<Child>>>,
b: AddRemoveSet<Child>
}
impl Container{
pub fn new() -> Container{
Container{
objects: AppendOnlySet::with_capacity(4),
b: AddRemoveSet::with_capacity(1)
}
}
pub fn add_child_get_cell(&self) -> &RefCell<Option<Child>>{
self.objects.add(RefCell::new(Some(Child{})))
}
pub fn add_child_get_ref(&self) -> RefMut<Option<Child>>{
self.objects.add(RefCell::new(Some(Child{}))).borrow_mut()
}
}
#[derive(Clone, PartialEq,Debug)]
struct Child{
}
impl Child{
pub fn do_a_thing(&mut self, _: &Container){
}
}
#[test]
fn test_sets_with_interior_mutability(){
let g = Container::new();
let child = g.add_child_get_cell();
child.borrow_mut().as_mut().unwrap().do_a_thing(&g);
assert_eq!(g.objects.get_reference(child as *const RefCell<Option<Child>>), Some(child));
assert!(g.objects.contains(&*child));
let mut c2 = g.add_child_get_ref();
assert!(g.objects.contains(&*child));
c2.as_mut().unwrap().do_a_thing(&g);
let c3_ptr;
{
let c3 = g.b.add(Child {});
c3_ptr = &*c3 as *const Child;
g.b.add_mut(Child {}).do_a_thing(&g);
for _ in 0..30 {
let addl_ptr;
{
let mut addl = g.b.add_mut(Child {});
addl.do_a_thing(&g);
addl_ptr = &*addl as *const Child;
}
assert!(g.b.try_contains(&*c3).unwrap());
assert!(g.b.try_remove(addl_ptr).unwrap());
assert!(!g.b.try_contains(addl_ptr).unwrap());
}
}
assert!(g.b.try_remove(c3_ptr).unwrap());
assert!(!g.b.try_contains(c3_ptr).unwrap());
}
}