XXX NOTE XXX: this is a heavily modified commit from the original
(ec226463) which was super out of date when rebased onto the current
branch. I went through a manual conflict rework and removed all the
legacy segments as well as rename-moved this original mod
`tractor.msg.py` -> `tractor.msg/_old_msg.py`. Further the
`NamespacePath` type def was discarded from this mod since it was from
a super old version which was already moved to a `.msg.ptr` submod.
As per original questions and discussion with `msgspec` author:
- https://github.com/jcrist/msgspec/issues/25
- https://github.com/jcrist/msgspec/issues/140
this prototypes a new (but very naive) `msgspec.Struct` codec
implementation which will be more filled out in the next commit.
Fitting in line with the issues outstanding:
- #36: (msg)spec-ing out our SCIPP (structured-con-inter-proc-prot).
(https://github.com/goodboy/tractor/issues/36)
- #196: adding strictly typed IPC msg dialog schemas, more or less
better described as "dialog/transaction scoped message specs"
using `msgspec`'s tagged unions and custom codecs.
(https://github.com/goodboy/tractor/issues/196)
- #365: using modern static type-annots to drive capability based
messaging and RPC.
(statically https://github.com/goodboy/tractor/issues/365)
This is a first draft of a new API for dynamically overriding IPC msg
codecs for a given interchange lib from any task in the runtime. Right
now we obviously only support `msgspec` but ideally this API holds
general enough to be used for other backends eventually (like
`capnproto`, and apache arrow).
Impl is in a new `tractor.msg._codec` with:
- a new `MsgCodec` type for encapsing `msgspec.msgpack.Encoder/Decoder`
pairs and configuring any custom enc/dec_hooks or typed decoding.
- factory `mk_codec()` for creating new codecs ad-hoc from a task.
- `contextvars` support for a new `trio.Task` scoped
`_ctxvar_MsgCodec: ContextVar[MsgCodec]` named 'msgspec_codec'.
- `apply_codec()` for temporarily modifying the above per task
as needed around `.open_context()` / `.open_stream()` operation.
A new test (suite) in `test_caps_msging.py`:
- verify a parent and its child can enable the same custom codec (in
this case to transmit `NamespacePath`s) with tons of pedantic ctx-vars
checks.
- ToDo: still need to implement #36 msg types in order to be able to get
decodes working (as in `MsgStream.receive()` will deliver an already
created `NamespacePath` obj) since currently all msgs come packed in `dict`-msg
wrapper packets..
-> use the proto from PR #35 to get nested `msgspec.Raw` processing up
and running Bo
Obviously we can't deterministic-ally call `.load_ref()` (since you'd
have to point to an `id()` or something and presume a particular
py-runtime + virt-mem space for it to exist?) but it at least helps with
the `str` formatting for logging purposes (like `._cancel_rpc_tasks()`)
when `repr`-ing ctxs and their specific "rpc signatures".
Maybe in the future getting this working at least for singleton types
per process (like `Actor` XD ) will be a thing we can support and make
some sense of.. Bo
Originally designed and used throughout `piker`, the subtype adds some
handy pprinting and field diffing extras often handy when viewing struct
types in logging or REPL console interfaces B)
Obvi this rejigs the `tractor.msg` mod into a sub-pkg and moves the
existing namespace obj-pointer stuff into a new `.msg.ptr` sub mod.