From 90bc9b9730439974a68f5f147c6d8046a23bfe15 Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Fri, 15 Jul 2022 16:27:06 -0400
Subject: [PATCH 1/2] Only 4k seconds of 1s ohlc when no tsdb

---
 piker/data/feed.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/piker/data/feed.py b/piker/data/feed.py
index 2795535d..dfd47852 100644
--- a/piker/data/feed.py
+++ b/piker/data/feed.py
@@ -309,7 +309,7 @@ async def start_backfill(
             # when no tsdb "last datum" is provided, we just load
             # some near-term history.
             periods = {
-                1: {'days': 1},
+                1: {'seconds': 4000},
                 60: {'days': 14},
             }
 

From e0491cf2e77edd110cb3a2093fa7b4150c634b6c Mon Sep 17 00:00:00 2001
From: Tyler Goodlet <jgbt@protonmail.com>
Date: Fri, 15 Jul 2022 17:10:09 -0400
Subject: [PATCH 2/2] Cache fsp ``ShmArrays`` where possible

Minimize calling `.data._shmarray.attach_shm_array()` as much as is
possible to avoid the crash from #332. This is the suggested hack from
issue #359.

Resolves https://github.com/pikers/piker/issues/359
---
 piker/fsp/_api.py    | 25 ++++++++++++++++++++-----
 piker/fsp/_engine.py |  7 ++++---
 piker/ui/_fsp.py     |  7 ++++---
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/piker/fsp/_api.py b/piker/fsp/_api.py
index a332ec5f..f4e42bc1 100644
--- a/piker/fsp/_api.py
+++ b/piker/fsp/_api.py
@@ -78,7 +78,8 @@ class Fsp:
     # + the consuming fsp *to* the consumers output
     # shm flow.
     _flow_registry: dict[
-        tuple[_Token, str], _Token,
+        tuple[_Token, str],
+        tuple[_Token, Optional[ShmArray]],
     ] = {}
 
     def __init__(
@@ -120,7 +121,6 @@ class Fsp:
     ):
         return self.func(*args, **kwargs)
 
-    # TODO: lru_cache this? prettty sure it'll work?
     def get_shm(
         self,
         src_shm: ShmArray,
@@ -131,12 +131,27 @@ class Fsp:
         for this "instance" of a signal processor for
         the given ``key``.
 
+        The destination shm "token" and array are cached if possible to
+        minimize multiple stdlib/system calls.
+
         '''
-        dst_token = self._flow_registry[
+        dst_token, maybe_array = self._flow_registry[
             (src_shm._token, self.name)
         ]
-        shm = attach_shm_array(dst_token)
-        return shm
+        if maybe_array is None:
+            self._flow_registry[
+                (src_shm._token, self.name)
+            ] = (
+                dst_token,
+                # "cache" the ``ShmArray`` such that
+                # we call the underlying "attach" code as few
+                # times as possible as per:
+                # - https://github.com/pikers/piker/issues/359
+                # - https://github.com/pikers/piker/issues/332
+                maybe_array := attach_shm_array(dst_token)
+            )
+
+        return maybe_array
 
 
 def fsp(
diff --git a/piker/fsp/_engine.py b/piker/fsp/_engine.py
index 94d9bfa1..d9f3af26 100644
--- a/piker/fsp/_engine.py
+++ b/piker/fsp/_engine.py
@@ -284,9 +284,10 @@ async def cascade(
     # TODO: ugh i hate this wind/unwind to list over the wire
     # but not sure how else to do it.
     for (token, fsp_name, dst_token) in shm_registry:
-        Fsp._flow_registry[
-            (_Token.from_msg(token), fsp_name)
-        ] = _Token.from_msg(dst_token)
+        Fsp._flow_registry[(
+            _Token.from_msg(token),
+            fsp_name,
+        )] = _Token.from_msg(dst_token), None
 
     fsp: Fsp = reg.get(
         NamespacePath(ns_path)
diff --git a/piker/ui/_fsp.py b/piker/ui/_fsp.py
index 5301db6a..f3165667 100644
--- a/piker/ui/_fsp.py
+++ b/piker/ui/_fsp.py
@@ -469,9 +469,10 @@ class FspAdmin:
             target=target,
             readonly=True,
         )
-        self._flow_registry[
-            (self.src_shm._token, target.name)
-        ] = dst_shm._token
+        self._flow_registry[(
+            self.src_shm._token,
+            target.name
+        )] = dst_shm._token
 
         # if not opened:
         #     raise RuntimeError(