This AO can be used instead of CreateReadableStream in cases where we
need to set up a newly allocated ReadableStream before initialization of
said ReadableStream, i.e. ReadableStream is captured by lambdas in an
uninitialized state.
We enqueue a microtask for this readable stream AO, and the methods that
we call from the chunk steps manipulate promises. As such, we need to
enable callbacks for the entire microtask's temporary execution
context.
ReadLoopReadRequest::on_chunk expects an UInt8Array, so make sure we
convert the passed in ByteBuffer to an UInt8Array before passing it to
the AO writable_stream_default_writer_write.
Co-authored-by: Timothy Flynn <trflynn89@pm.me>
The ReadableStreamPipeTo AO requires reading all chunks from a stream.
There actually isn't an AO defined to do that, so the "read all bytes"
implementation was changed to provide each chunk in a vector in commit
12cfa08a09.
This change makes reading all bytes a bit more uncomfortable in normal
use cases, as we now have to manually join the vector we receive. This
can also cause churn with huge allocations.
So instead, let's just provide an ad-hoc callback to receive each chunk
as they arrive.
There were several instances where the spec marks an AO invocation as
infallible, but we were propagating WebIDL::ExceptionOr. These mostly
cannot throw due to knowledge about the values they are provided. By
unwinding these, we can remove a decent amount of exception handling.
There are a number of script-provided stream callbacks for various
stream operations, such as `start`, `pull`, `cancel`, etc. Out of all of
these, only the `start` callback can actually throw. And when it does,
the exception is realized immediately in the corresponding stream
constructor.
All other callbacks have spec text of the form:
Throwing an exception is treated the same as returning a rejected
promise.
And indeed this is internally handled by the streams spec. Thus all of
those callbacks can be specified as returning only a promise, rather
than a WebIDL::ExceptionOr<Promise>.
This was resulting in a whole lot of rebuilding whenever a new IDL
interface was added.
Instead, just directly include the prototype in every C++ file which
needs it. While we only really need a forward declaration in each cpp
file; including the full prototype header (which itself only includes
LibJS/Object.h, which is already transitively brought in by
PlatformObject) - it seems like a small price to pay compared to what
feels like a full rebuild of LibWeb whenever a new IDL file is added.
Given all of these includes are only needed for the ::initialize
method, there is probably a smart way of avoiding this problem
altogether. I've considered both using some macro trickery or generating
these functions somehow instead.
This changes the signature of queue_a_microtask() from AK:Function to
JS::HeapFunction to be more clear to the user of the functions that this
is what is used internally.
Switching away from SafeFunction immediately backfired here, as we're
dealing with two layers of captures, not one.
Let's do the correct fix, which is to use HeapFunction. This makes the
API and its behavior explicit, and keeps captures alive as long as the
HeapFunction is alive.
Fixes#23819.
This commit introduces a WEB_SET_PROTOTYPE_FOR_INTERFACE macro that
caches the interface name in a local static FlyString. This means that
we only pay for FlyString-from-literal lookup once per browser lifetime
instead of every time the interface is instantiated.
This reduces the number of files needed to be recompiled when TypedArray
changes from ~1000 to ~600. The remaining ~600 are almost all generated
constructors and prototypes.
