From ff0cfb7b1dade03d9e883a14b218fc2172fae88d Mon Sep 17 00:00:00 2001
From: "Ware, Joseph (DLSLtd,RAL,LSCI)" <joseph.ware@diamond.ac.uk>
Date: Mon, 11 Mar 2024 15:08:52 +0000
Subject: [PATCH] Simplify metadata handling

---
 src/ophyd_async/epics/_backend/_aioca.py | 30 +++++++++---------------
 tests/epics/test_signals.py              | 10 ++++----
 2 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/src/ophyd_async/epics/_backend/_aioca.py b/src/ophyd_async/epics/_backend/_aioca.py
index fe95397350..da5a0bca50 100644
--- a/src/ophyd_async/epics/_backend/_aioca.py
+++ b/src/ophyd_async/epics/_backend/_aioca.py
@@ -38,9 +38,7 @@
     dbr.DBR_DOUBLE: "number",
     dbr.DBR_ENUM: "string",
 }
-_number_dbr = {dbr.DBR_SHORT, dbr.DBR_CHAR, dbr.DBR_LONG, dbr.DBR_FLOAT, dbr.DBR_DOUBLE}
-_floating_dbr = {dbr.DBR_FLOAT, dbr.DBR_DOUBLE}
-_number_meta = {
+_common_meta = {
     "units",
     "lower_alarm_limit",
     "upper_alarm_limit",
@@ -50,20 +48,18 @@
     "upper_disp_limit",
     "lower_warning_limit",
     "upper_warning_limit",
+    "precision",
+    "timestamp",
 }
 
 
-def _if_has_meta_add_meta(
-    d: Dict[str, Any], value: AugmentedValue, key: Union[str, Set[str]]
-):
-    if isinstance(key, str):
-        key = {key}
-    for k in key:
-        if not hasattr(value, k):
+def _if_has_meta_add_meta(d: Dict[str, Any], value: AugmentedValue, keys: Set[str]):
+    for key in keys:
+        if not hasattr(value, key):
             continue
-        attr = getattr(value, k)
+        attr = getattr(value, key)
         if isinstance(attr, str) or not isnan(attr):
-            d[k] = attr
+            d[key] = attr
 
 
 def _data_key_from_augmented_value(value: AugmentedValue, **kwargs) -> Descriptor:
@@ -83,22 +79,18 @@ def _data_key_from_augmented_value(value: AugmentedValue, **kwargs) -> Descripto
     assert value.ok, f"Error reading {source}: {value}"
 
     scalar = value.element_count == 1
+    dtype = dbr_to_dtype[value.datatype]
 
     d = Descriptor(
         source=source,
-        dtype=dbr_to_dtype[value.datatype] if scalar else "array",
+        dtype=dtype if scalar else "array",
         # strictly value.element_count >= len(value)
         shape=[] if scalar else [len(value)],
     )
 
-    if value.datatype in _number_dbr:
-        _if_has_meta_add_meta(d, value, _number_meta)
-    if value.datatype in _floating_dbr:
-        _if_has_meta_add_meta(d, value, "precision")
+    _if_has_meta_add_meta(d, value, _common_meta)
     if value.datatype is dbr.DBR_ENUM:
         d["choices"] = value.enums
-    if value.datatype is dbr.DBR_STRING:
-        _if_has_meta_add_meta(d, value, "timestamp")
     d.update(kwargs)
 
     return d
diff --git a/tests/epics/test_signals.py b/tests/epics/test_signals.py
index e6455e7e5b..18e9de6dff 100644
--- a/tests/epics/test_signals.py
+++ b/tests/epics/test_signals.py
@@ -155,10 +155,10 @@ class MyEnum(str, Enum):
 }
 
 _int_metadata = {
-    "lower_alarm_limit": 0,
-    "lower_warning_limit": 0,
-    "upper_alarm_limit": 0,
-    "upper_warning_limit": 0,
+    "lower_alarm_limit": ANY,
+    "lower_warning_limit": ANY,
+    "upper_alarm_limit": ANY,
+    "upper_warning_limit": ANY,
 }
 
 _metadata: Dict[str, Dict[str, Any]] = {
@@ -171,7 +171,7 @@ class MyEnum(str, Enum):
 
 def descriptor(protocol: str, suffix: str, value=None) -> Descriptor:
     def get_internal_dtype(suffix: str) -> str:
-        # uint32, int64, uint64 all backed by DBR_DOUBLE which has precision
+        # uint32, [u]int64 backed by DBR_DOUBLE, have precision
         if "float" in suffix or "uint32" in suffix or "int64" in suffix:
             return "number"
         if "int" in suffix or "bool" in suffix: