From 62d4824c68821c879785bd3bd231a80483ae34a3 Mon Sep 17 00:00:00 2001
From: Allen Porter <allen.porter@gmail.com>
Date: Sun, 30 Jun 2024 08:49:28 -0700
Subject: [PATCH 1/2] Pre-load all timezone disk reads on import

---
 ical/tzif/timezoneinfo.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/ical/tzif/timezoneinfo.py b/ical/tzif/timezoneinfo.py
index 93e8d2c..c15eb1b 100644
--- a/ical/tzif/timezoneinfo.py
+++ b/ical/tzif/timezoneinfo.py
@@ -22,6 +22,11 @@
 _LOGGER = logging.getLogger(__name__)
 
 
+_IGNORED_TIMEZONES = {
+    "Asia/Hanoi",  # Not in tzdata
+}
+
+
 class TimezoneInfoError(Exception):
     """Raised on error working with timezone information."""
 
@@ -32,6 +37,7 @@ def _read_system_timezones() -> set[str]:
     return zoneinfo.available_timezones()
 
 
+@cache
 def _find_tzfile(key: str) -> str | None:
     """Retrieve the path to a TZif file from a key."""
     for search_path in zoneinfo.TZPATH:
@@ -63,6 +69,7 @@ def _iana_key_to_resource(key: str) -> tuple[str, str]:
     return package, resource
 
 
+@cache
 def read(key: str) -> TimezoneInfo:
     """Read the TZif file from the tzdata package and return timezone records."""
     if key not in _read_system_timezones() and key not in _read_tzdata_timezones():
@@ -167,3 +174,12 @@ def read_tzinfo(key: str) -> TzInfo:
         return TzInfo.from_timezoneinfo(timezoneinfo)
     except ValueError as err:
         raise TimezoneInfoError(f"Unable create TzInfo: {key}") from err
+
+
+
+# Avoid blocking disk reads in async function by pre-loading all timezone reads
+for key in _read_system_timezones():
+    try:
+        read_tzinfo(key)
+    except TimezoneInfoError:
+        pass

From f9b828fe9f2de9d04860e2478ff6c3ac71807805 Mon Sep 17 00:00:00 2001
From: Allen Porter <allen.porter@gmail.com>
Date: Sun, 30 Jun 2024 08:50:42 -0700
Subject: [PATCH 2/2] Remove dead code

---
 ical/tzif/timezoneinfo.py | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/ical/tzif/timezoneinfo.py b/ical/tzif/timezoneinfo.py
index c15eb1b..0d8577b 100644
--- a/ical/tzif/timezoneinfo.py
+++ b/ical/tzif/timezoneinfo.py
@@ -22,11 +22,6 @@
 _LOGGER = logging.getLogger(__name__)
 
 
-_IGNORED_TIMEZONES = {
-    "Asia/Hanoi",  # Not in tzdata
-}
-
-
 class TimezoneInfoError(Exception):
     """Raised on error working with timezone information."""
 
@@ -176,7 +171,6 @@ def read_tzinfo(key: str) -> TzInfo:
         raise TimezoneInfoError(f"Unable create TzInfo: {key}") from err
 
 
-
 # Avoid blocking disk reads in async function by pre-loading all timezone reads
 for key in _read_system_timezones():
     try: