Fix divide-by-zero when quote read is too fast in throttle task

piker/data/_sampling.py

@@ -172,6 +172,7 @@ async def sample_and_broadcast(
 
     # iterate stream delivered by broker
     async for quotes in quote_stream:
+
         # TODO: ``numba`` this!
         for sym, quote in quotes.items():
 
@@ -184,12 +185,8 @@ async def sample_and_broadcast(
 
             # start writing the shm buffer with appropriate
             # trade data
+            for tick in quote['ticks']:
 
-            # TODO: we should probably not write every single
-            # value to an OHLC sample stream XD
-            # for a tick stream sure.. but this is excessive..
-            ticks = quote['ticks']
-            for tick in ticks:
                 ticktype = tick['type']
 
                 # write trade events to shm last OHLC sample
@@ -261,8 +258,7 @@ async def sample_and_broadcast(
 
                 except (
                     trio.BrokenResourceError,
-                    trio.ClosedResourceError,
-                    trio.EndOfChannel,
+                    trio.ClosedResourceError
                 ):
                     # XXX: do we need to deregister here
                     # if it's done in the fee bus code?
@@ -272,10 +268,6 @@ async def sample_and_broadcast(
                         f'{stream._ctx.chan.uid} dropped  '
                         '`brokerd`-quotes-feed connection'
                     )
-                    if tick_throttle:
-                        assert stream.closed()
-                        # await stream.aclose()
-
                     subs.remove((stream, tick_throttle))
 
 
@@ -291,8 +283,12 @@ async def uniform_rate_send(
 
 ) -> None:
 
-    sleep_period = 1/rate - 0.0001  # 100us
+    sleep_period = 1/rate - 0.000616
     last_send = time.time()
+    aname = stream._ctx.chan.uid[0]
+    fsp = False
+    if 'fsp' in aname:
+        fsp = True
 
     while True:
 
@@ -312,33 +308,21 @@ async def uniform_rate_send(
                 sym, next_quote = quote_stream.receive_nowait()
                 ticks = next_quote.get('ticks')
 
-                # XXX: idea for frame type data structure we could use on the
-                # wire instead of a simple list?
-                # frames = {
-                #     'index': ['type_a', 'type_c', 'type_n', 'type_n'],
-
-                #     'type_a': [tick0, tick1, tick2, .., tickn],
-                #     'type_b': [tick0, tick1, tick2, .., tickn],
-                #     'type_c': [tick0, tick1, tick2, .., tickn],
-                #     ...
-                #     'type_n': [tick0, tick1, tick2, .., tickn],
-                # }
                 if ticks:
                     first_quote['ticks'].extend(ticks)
 
             except trio.WouldBlock:
                 now = time.time()
-                rate = 1 / (now - last_send)
+                diff = now - last_send
+                rate = 1 / diff if diff else float('inf')
+                last_send = now
 
-                log.debug(
-                    f'`{sym}` throttled send hz: {round(rate, ndigits=1)}'
-                )
+                # log.info(f'{rate} Hz sending quotes')  # \n{first_quote}')
 
                 # TODO: now if only we could sync this to the display
                 # rate timing exactly lul
                 try:
                     await stream.send({sym: first_quote})
-                    last_send = now
                     break
                 except trio.ClosedResourceError:
                     # if the feed consumer goes down then drop