this makes using the zero-copy pipes a lot more ergonomic. error
handling is unfortunately not trivial and duplicating it for all
pipe users would thus be a bad idea. we're also not oblivious to
the fact that this is a `sourceToSink`, but it's async this time
around. (at least we don't need terrible stackful coroutines..?)
Change-Id: I1ba59f27183988ad68e7f88d102935d005690f43
rpc will often need to transfer data received on push-bashed interfaces
to consumers that expect input stream sources, which are pull-based. we
want to avoid copies for performance reasons (since kj overhead as kind
of on the high side for us already), so we'll use a shared-buffer class
that behaves much like a mutex. we *don't* use mutexes because ours are
cross-thread-capable and thus require syscalls for all wakeups they do.
Change-Id: I3b14925f5d9f5e07ea2cafdf00a88a64f79e4742
this is an equivalent of the regular kj read interface which also takes
a min/max pair. we do not need this very often though, so we'll keep it
as a separate method for now. if we do find we use it more than read we
can still rename read to readSingle and readRange to read. we will see.
Change-Id: Ib04ca146911adae7081cf4b2df097217ea5fe9f8
the old protocols are largely untested, mostly unused, and have design
problems that make the RPC transition a lot harder, if not impossible.
in theory we could ship a transparent protocol-converting proxy that'd
isolate the daemon itself from old protocol versions, but that's a lot
of code to maintain for presumably little gain or even no gain at all.
Change-Id: I4c3f3bb34d39044f6aeb07c10caaf13b8340a220
eldritch horrors