Servo currently uses `heapsize`, but Stylo/Gecko use `malloc_size_of`.
`malloc_size_of` is better -- it handles various cases that `heapsize` does not
-- so this patch changes Servo to use `malloc_size_of`.
This patch makes the following changes to the `malloc_size_of` crate.
- Adds `MallocSizeOf` trait implementations for numerous types, some built-in
(e.g. `VecDeque`), some external and Servo-only (e.g. `string_cache`).
- Makes `enclosing_size_of_op` optional, because vanilla jemalloc doesn't
support that operation.
- For `HashSet`/`HashMap`, falls back to a computed estimate when
`enclosing_size_of_op` isn't available.
- Adds an extern "C" `malloc_size_of` function that does the actual heap
measurement; this is based on the same functions from the `heapsize` crate.
This patch makes the following changes elsewhere.
- Converts all the uses of `heapsize` to instead use `malloc_size_of`.
- Disables the "heapsize"/"heap_size" feature for the external crates that
provide it.
- Removes the `HeapSizeOf` implementation from `hashglobe`.
- Adds `ignore` annotations to a few `Rc`/`Arc`, because `malloc_size_of`
doesn't derive those types, unlike `heapsize`.
I don't want to do such a gratuitous rename, but with all the other types
now having "Dom" as part of their name, and especially with "DomOnceCell",
I feel like the other cell type that we already have should also follow
the convention. That argument loses weight though when we realise there
is still DOMString and other things.
This adds some overhead, but also provides the small performance benefit of
avoiding dirtying in the case where an event state is toggled an even
number of times between reflows.
The main benefit here though is that it sets us up to be smarter about
what we mark as dirty using restyle hints.
This method returned the result of `RefCell<T>.try_borrow().is_some()`.
But it meant whether the state **is not** BorrowState::Writing.
This wrong is introduced by [1], Before it revision, this method had
returned whether the state is BorrowState::Writing or not.
This doesn't change callers of this method because git blames ([3], [4]) says
that the caller is introduced by [2] and [2] is introduced before [1].
[1]: 86d609abaf
[2]: 49234484d6
[3]: 2cc08f289a/components/script/dom/servohtmlparser.rs
[4]: a7e29939a1/components/script/dom/bindings/cell.rs
It also removes LiveDOMReferences destructor that it's a no-op but it contains an assert that was being violated causing an endless cycle of destructor calls ending up in a stack overflow.
This used to conflict with the util crate from the standard library, which
has long since been removed.
The import in layout has not been changed because of a conflict with the
util mod there.
This gets rid of a dubious transmute:
let val = mem::transmute::<&RefCell<T>, &T>(&self.base);
The code duplication will be reduced once rust-lang/rust#18131 is fixed.
This type simply wraps `RefCell<T>` to add the special method,
and introduce the method to return the pointer of the value contained in
itself, for used in layout task.
