An upcoming commit will migrate the contents of Headers.h/cpp to LibHTTP
for use outside of LibWeb. These CORS and MIME helpers depend on other
LibWeb facilities, however, so they cannot be moved.
The spec declares these as a byte sequence, which we then implemented as
a ByteBuffer. This has become pretty awkward to deal with, as evidenced
by the plethora of `MUST(ByteBuffer::copy(...))` and `.bytes()` calls
everywhere inside Fetch. We would then treat the bytes as a string
anyways by wrapping them in StringView everywhere.
We now store these as a ByteString. This is more comfortable to deal
with, and we no longer need to continually copy underlying storage (as
ByteString is ref-counted).
This work is largely preparatory for an upcoming HTTP header refactor.
Generally just define things in the order they are declared (will make a
change to use ByteString in this file a bit easier to follow). Also make
a couple of free functions be class methods on Header / HeaderList.
We have a couple of ways to designate spec notes and (our) developer
notes in comments, but we never really settled on a single approach. As
a result, we have a bit of a mixed bag of note comments on our hands.
To the extent that I could find them, I changed developer notes to
`// NB: ...` and changed spec notes to `// NOTE: ...`. The rationale for
this is that in most web specs, notes are prefixed by `NOTE: ...` so
this makes it easier to copy paste verbatim. The choice for `NB: ...` is
pretty arbitrary, but it makes it stand out from the regular spec notes
and it was already in wide use in our codebase.
The spec language specifies 'Set maxScopeString to "/", followed by the
strings in XXXX’s path (including empty strings), separated from each
other by "/"': That is, adjacent components are separated by a '/', but
the last component does not get a trailing '/'.
This resulted in the generated scope string ending with '//' in some
cases, incorrectly tripping the 'Service-Worker-Allowed' security check
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
Now that the heap has no knowledge about a JavaScript realm and is
purely for managing the memory of the heap, it does not make sense
to name this function to say that it is a non-realm variant.
