We are often forced to convert numbers to strings inside LibJS, e.g when
iterating over the property names of an array, but it's also just a very
common operation in general.
This patch adds a 1000-entry string cache for the numbers 0-999 since
those appear to be by far the most common ones we convert.
This reverts commit c14173f651. We
should only annotate the minimum number of symbols that external
consumers actually use, so I am starting from scratch to do that
I was investigating an optimization in this area, and while it
didn't seem to have a noticable improvement, it still seems
useful to apply this change.
If we have two PrimitiveString objects that are both backed by UTF-16
data, we don't have to convert them to UTF-8 for equality checking.
Just compare the underlying UTF-16 data. :^)
By moving the LHS and RHS pointers used by rope strings into a
RopeString subclass, we shrink PrimitiveString by 16 bytes. Most strings
are not rope strings, so this ends up saving quite a bit of memory.
PrimitiveString is now internally either UTF-8, UTF-16, or both.
We no longer convert them to/from ByteString anywhere, nor does VM have
a ByteString cache.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
More work on decoupling the general runtime from Interpreter. The goal
is becoming clearer. Interpreter should be one possible way to execute
code inside a VM. In the future we might have other ways :^)
