This patch makes the MallocSizeOf stuff in Stylo work more like the HeapSizeOf
stuff already in Servo, except better. In particular, it adds deriving support
for MallocSizeOf, which will make it easier to improve coverage.
The patch does the following.
- Combines servo/components/style/stylesheets/memory.rs and the heapsize crate
into a new crate, malloc_size_of.
- Forks the heapsize_derive crate, calling it malloc_size_of, so that
MallocSizeOf can be derived.
- Both the new crates have MIT/Apache licenses, like heapsize, in case they are
incorporated into heapsize in the future.
- Renames the methods within MallocSizeOf and the related traits so they are
more concise.
- Removes MallocSizeOfWithGuard.
- Adds `derive(MallocSizeOf)` to a lot of types, in some cases replacing an
equivalent or almost-equivalent hand-written implementation.
- Adds stuff so that Rc/Arc can be handled properly.
This patch doesn't modify any of the code because making a few things pub. I
did this first to make the next patch easier to audit.
MozReview-Commit-ID: 7PYxoS5bVGN
This improves cache locality and reduces allocations during parsing.
Note that this reverses the iteration order within a sequence of simple selectors,
but that shouldn't matter.
