Make shared array buffer incrementer a message pub

Drop ctx manager api and use `tractor.msg.pub`.

piker/data/_buffer.py

@@ -1,18 +1,19 @@
 """
 Data buffers for fast shared humpy.
 """
+from typing import Tuple, Callable
 import time
 
 import tractor
 import trio
 
-from ._sharedmem import attach_shared_array
+from ._sharedmem import attach_shm_array
 
 
-@tractor.stream
+@tractor.msg.pub
 async def incr_buffer(
-    ctx: tractor.Context,
-    shm_token: str,
+    shm_token: dict,
+    get_topics: Callable[..., Tuple[str]],
     # delay_s: Optional[float] = None,
 ):
     """Task which inserts new bars into the provide shared memory array
@@ -23,10 +24,10 @@ async def incr_buffer(
     # Likely the best way to solve this is to make this task
     # aware of the instrument's tradable hours?
 
-    with attach_shared_array(
+    shm = attach_shm_array(
         token=shm_token,
         readonly=False,
-    ) as shm:
+    )
 
     # determine ohlc delay between bars
     # to determine time step between datums
@@ -39,10 +40,10 @@ async def incr_buffer(
     async def sleep():
         """Sleep until next time frames worth has passed from last bar.
         """
-            last_ts = shm.array[-1]['time']
-            delay = max((last_ts + ad) - time.time(), 0)
-            await trio.sleep(delay)
-            # await trio.sleep(ad)
+        # last_ts = shm.array[-1]['time']
+        # delay = max((last_ts + ad) - time.time(), 0)
+        # await trio.sleep(delay)
+        await trio.sleep(ad)
 
     while True:
         # sleep for duration of current bar
@@ -67,5 +68,7 @@ async def incr_buffer(
         shm.push(last)
         # print('incrementing array')
 
-            # yield the new buffer index value
-            await ctx.send_yield(shm._i.value)
+        # print(get_topics())
+
+        # broadcast the buffer index step
+        yield {'index': shm._i.value}