piker/data/_sampling.py

@@ -95,6 +95,12 @@ class Sampler:
     # history loading.
     incr_task_cs: trio.CancelScope | None = None
 
+    bcast_errors: tuple[Exception] = (
+        trio.BrokenResourceError,
+        trio.ClosedResourceError,
+        trio.EndOfChannel,
+    )
+
     # holds all the ``tractor.Context`` remote subscriptions for
     # a particular sample period increment event: all subscribers are
     # notified on a step.
@@ -258,14 +264,15 @@ class Sampler:
         subs: set
         last_ts, subs = pair
 
-        task = trio.lowlevel.current_task()
+        # NOTE, for debugging pub-sub issues
-        log.debug(
+        # task = trio.lowlevel.current_task()
-            f'SUBS {self.subscribers}\n'
+        # log.debug(
-            f'PAIR {pair}\n'
+        #     f'AlL-SUBS@{period_s!r}: {self.subscribers}\n'
-            f'TASK: {task}: {id(task)}\n'
+        #     f'PAIR: {pair}\n'
-            f'broadcasting {period_s} -> {last_ts}\n'
+        #     f'TASK: {task}: {id(task)}\n'
-            # f'consumers: {subs}'
+        #     f'broadcasting {period_s} -> {last_ts}\n'
-        )
+        #     f'consumers: {subs}'
+        # )
         borked: set[MsgStream] = set()
         sent: set[MsgStream] = set()
         while True:
@@ -282,12 +289,11 @@ class Sampler:
                         await stream.send(msg)
                         sent.add(stream)
 
-                    except (
+                    except self.bcast_errors as err:
-                        trio.BrokenResourceError,
-                        trio.ClosedResourceError
-                    ):
                         log.error(
-                            f'{stream._ctx.chan.uid} dropped connection'
+                            f'Connection dropped for IPC ctx\n'
+                            f'{stream._ctx}\n\n'
+                            f'Due to {type(err)}'
                         )
                         borked.add(stream)
                 else:
@@ -394,7 +400,8 @@ async def register_with_sampler(
                 finally:
                     if (
                         sub_for_broadcasts
-                        and subs
+                        and
+                        subs
                     ):
                         try:
                             subs.remove(stream)
@@ -561,8 +568,7 @@ async def open_sample_stream(
 
 
 async def sample_and_broadcast(
-
+    bus: _FeedsBus,
-    bus: _FeedsBus,  # noqa
     rt_shm: ShmArray,
     hist_shm: ShmArray,
     quote_stream: trio.abc.ReceiveChannel,
@@ -582,11 +588,33 @@ async def sample_and_broadcast(
 
     overruns = Counter()
 
+    # NOTE, only used for debugging live-data-feed issues, though
+    # this should be resolved more correctly in the future using the
+    # new typed-msgspec feats of `tractor`!
+    #
+    # XXX, a multiline nested `dict` formatter (since rn quote-msgs
+    # are just that).
+    # pfmt: Callable[[str], str] = mk_repr()
+
     # iterate stream delivered by broker
     async for quotes in quote_stream:
         # print(quotes)
 
-        # TODO: ``numba`` this!
+        # XXX WARNING XXX only enable for debugging bc ow can cost
+        # ALOT of perf with HF-feedz!!!
+        #
+        # log.info(
+        #     'Rx live quotes:\n'
+        #     f'{pfmt(quotes)}'
+        # )
+
+        # TODO,
+        # -[ ] `numba` or `cython`-nize this loop possibly?
+        #  |_alternatively could we do it in rust somehow by upacking
+        #    arrow msgs instead of using `msgspec`?
+        # -[ ] use `msgspec.Struct` support in new typed-msging from
+        #     `tractor` to ensure only allowed msgs are transmitted?
+        #
         for broker_symbol, quote in quotes.items():
             # TODO: in theory you can send the IPC msg *before* writing
             # to the sharedmem array to decrease latency, however, that
@@ -659,6 +687,21 @@ async def sample_and_broadcast(
             sub_key: str = broker_symbol.lower()
             subs: set[Sub] = bus.get_subs(sub_key)
 
+            # TODO, figure out how to make this useful whilst
+            # incoporating feed "pausing" ..
+            #
+            # if not subs:
+            #     all_bs_fqmes: list[str] = list(
+            #         bus._subscribers.keys()
+            #     )
+            #     log.warning(
+            #         f'No subscribers for {brokername!r} live-quote ??\n'
+            #         f'broker_symbol: {broker_symbol}\n\n'
+
+            #         f'Maybe the backend-sys symbol does not match one of,\n'
+            #         f'{pfmt(all_bs_fqmes)}\n'
+            #     )
+
             # NOTE: by default the broker backend doesn't append
             # it's own "name" into the fqme schema (but maybe it
             # should?) so we have to manually generate the correct
@@ -728,18 +771,14 @@ async def sample_and_broadcast(
                         if lags > 10:
                             await tractor.pause()
 
-                except (
+                except Sampler.bcast_errors as ipc_err:
-                    trio.BrokenResourceError,
-                    trio.ClosedResourceError,
-                    trio.EndOfChannel,
-                ):
                     ctx: Context = ipc._ctx
                     chan: Channel = ctx.chan
                     if ctx:
                         log.warning(
-                            'Dropped `brokerd`-quotes-feed connection:\n'
+                            f'Dropped `brokerd`-feed for {broker_symbol!r} due to,\n'
-                            f'{broker_symbol}:'
+                            f'x>) {ctx.cid}@{chan.uid}'
-                            f'{ctx.cid}@{chan.uid}'
+                            f'|_{ipc_err!r}\n\n'
                         )
                     if sub.throttle_rate:
                         assert ipc._closed
@@ -756,12 +795,11 @@ async def sample_and_broadcast(
 
 
 async def uniform_rate_send(
-
     rate: float,
     quote_stream: trio.abc.ReceiveChannel,
     stream: MsgStream,
 
-    task_status: TaskStatus = trio.TASK_STATUS_IGNORED,
+    task_status: TaskStatus[None] = trio.TASK_STATUS_IGNORED,
 
 ) -> None:
     '''
@@ -779,13 +817,16 @@ async def uniform_rate_send(
     https://gist.github.com/njsmith/7ea44ec07e901cb78ebe1dd8dd846cb9
 
     '''
-    # TODO: compute the approx overhead latency per cycle
+    # ?TODO? dynamically compute the **actual** approx overhead latency per cycle
-    left_to_sleep = throttle_period = 1/rate - 0.000616
+    # instead of this magic # bidinezz?
+    throttle_period: float = 1/rate - 0.000616
+    left_to_sleep: float = throttle_period
 
     # send cycle state
+    first_quote: dict|None
     first_quote = last_quote = None
-    last_send = time.time()
+    last_send: float = time.time()
-    diff = 0
+    diff: float = 0
 
     task_status.started()
     ticks_by_type: dict[
@@ -796,22 +837,28 @@ async def uniform_rate_send(
     clear_types = _tick_groups['clears']
 
     while True:
-
         # compute the remaining time to sleep for this throttled cycle
-        left_to_sleep = throttle_period - diff
+        left_to_sleep: float = throttle_period - diff
 
         if left_to_sleep > 0:
+            cs: trio.CancelScope
             with trio.move_on_after(left_to_sleep) as cs:
+                sym: str
+                last_quote: dict
                 try:
                     sym, last_quote = await quote_stream.receive()
                 except trio.EndOfChannel:
-                    log.exception(f"feed for {stream} ended?")
+                    log.exception(
+                        f'Live stream for feed for ended?\n'
+                        f'<=c\n'
+                        f'  |_[{stream!r}\n'
+                    )
                     break
 
-                diff = time.time() - last_send
+                diff: float = time.time() - last_send
 
                 if not first_quote:
-                    first_quote = last_quote
+                    first_quote: float = last_quote
                     # first_quote['tbt'] = ticks_by_type
 
                 if (throttle_period - diff) > 0:
@@ -872,7 +919,9 @@ async def uniform_rate_send(
         # TODO: now if only we could sync this to the display
         # rate timing exactly lul
         try:
-            await stream.send({sym: first_quote})
+            await stream.send({
+                sym: first_quote
+            })
         except tractor.RemoteActorError as rme:
             if rme.type is not tractor._exceptions.StreamOverrun:
                 raise
@@ -883,19 +932,28 @@ async def uniform_rate_send(
                 f'{sym}:{ctx.cid}@{chan.uid}'
             )
 
+        # NOTE: any of these can be raised by `tractor`'s IPC
+        # transport-layer and we want to be highly resilient
+        # to consumers which crash or lose network connection.
+        # I.e. we **DO NOT** want to crash and propagate up to
+        # ``pikerd`` these kinds of errors!
         except (
-            # NOTE: any of these can be raised by ``tractor``'s IPC
-            # transport-layer and we want to be highly resilient
-            # to consumers which crash or lose network connection.
-            # I.e. we **DO NOT** want to crash and propagate up to
-            # ``pikerd`` these kinds of errors!
-            trio.ClosedResourceError,
-            trio.BrokenResourceError,
             ConnectionResetError,
-        ):
+        ) + Sampler.bcast_errors as ipc_err:
-            # if the feed consumer goes down then drop
+            match ipc_err:
-            # out of this rate limiter
+                case trio.EndOfChannel():
-            log.warning(f'{stream} closed')
+                    log.info(
+                        f'{stream} terminated by peer,\n'
+                        f'{ipc_err!r}'
+                    )
+                case _:
+                    # if the feed consumer goes down then drop
+                    # out of this rate limiter
+                    log.warning(
+                        f'{stream} closed due to,\n'
+                        f'{ipc_err!r}'
+                    )
+
             await stream.aclose()
             return
 

piker/log.py

@@ -19,6 +19,10 @@ Log like a forester!
 """
 import logging
 import json
+import reprlib
+from typing import (
+    Callable,
+)
 
 import tractor
 from pygments import (
@@ -84,3 +88,29 @@ def colorize_json(
         # likeable styles: algol_nu, tango, monokai
         formatters.TerminalTrueColorFormatter(style=style)
     )
+
+
+# TODO, eventually defer to the version in `modden` once
+# it becomes a dep!
+def mk_repr(
+    **repr_kws,
+) -> Callable[[str], str]:
+    '''
+    Allocate and deliver a `repr.Repr` instance with provided input
+    settings using the std-lib's `reprlib` mod,
+     * https://docs.python.org/3/library/reprlib.html
+
+    ------ Ex. ------
+    An up to 6-layer-nested `dict` as multi-line:
+    - https://stackoverflow.com/a/79102479
+    - https://docs.python.org/3/library/reprlib.html#reprlib.Repr.maxlevel
+
+    '''
+    def_kws: dict[str, int] = dict(
+        indent=2,
+        maxlevel=6,  # recursion levels
+        maxstring=66,  # match editor line-len limit
+    )
+    def_kws |= repr_kws
+    reprr = reprlib.Repr(**def_kws)
+    return reprr.repr