This is part of the future work of implementing LazyDOMString as
outlined in https://github.com/servo/servo/issues/39479.
We use str() method or direct implementations on DOMString for these
methods. We also change some types.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
Testing: This is essentially just renaming a method and a type and
should not change functionality.
Signed-off-by: Narfinger <Narfinger@users.noreply.github.com>
This PR **removes** `ScriptToConstellationMessage::ForwardToEmbedder`,
and replaces it with an explicit `ScriptToEmbedderChannel`. This new
channel is based on `GenericCallback` and in single-process mode will
directly send the message the to the embedder and wake it. In
multi-process mode, the message is routed via the ROUTER, since waking
is only possible from the same process currently. This means in
multi-process mode there are likely no direct perf benefits, since we
still need to hop the message over the ROUTER (instead of over the
constellation).
In single-process mode we can directly send the message to the embedder,
which should provide a noticable latency improvement in all cases where
script is blocked waiting on the embedder to reply.
This does not change the way the embedder receives messages - the
receiving end is unchanged.
## How was sending messages to the embedder working before?
1. Script wraps it's message to the embedder in
`ScriptToConstellationMessage::ForwardToEmbedder` and sends it to
constellation.
2. The [constellation event loop] receives the message in
[handle_request]
3. If deserialization fails, [an error is logged and the message is
ignored]
4. Since our message came from script, it is handle in
[handle_request_from_script]
5. The message is logged with trace log level
6. If the pipeline is closed, [a warning is logged and the message
ignored]
7. The wrapped `EmbedderMsg` [is forwarded to the embedder]. Sending the
message also invokes `wake()` on the embedder eventloop waker.
[constellation event loop]:
2e1b2e7260/components/constellation/constellation.rs (L755)
[handle request]:
2e1b2e7260/components/constellation/constellation.rs (L1182)
[an error is logged and the message is ignored]:
2e1b2e7260/components/constellation/constellation.rs (L1252)
[handle_request_from_script]:
https://github.com/servo/servo/blob/main/components/constellation/constellation.rs#L1590
[a warning is logged and the message ignored]:
2e1b2e7260/components/constellation/constellation.rs (L1599)
[is forwarded to the embedder]:
2e1b2e7260/components/constellation/constellation.rs (L1701)
Testing: Communication between Script and Embedder is extensive, so this
should be covered by existing tests.
Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
