From 49358630495fc7b6e91b630be6a5975e1e55ab80 Mon Sep 17 00:00:00 2001
From: Oleksandr Yakushev <alex@bytopia.org>
Date: Fri, 23 Aug 2024 08:55:31 +0300
Subject: [PATCH] perf: [date-2.parse] Add a fastpath for timestamps that are
likely ISO instants (#47143)
---
src/metabase/util/date_2/parse.clj | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/src/metabase/util/date_2/parse.clj b/src/metabase/util/date_2/parse.clj
index 563b68784ce..5e9f8354aeb 100644
--- a/src/metabase/util/date_2/parse.clj
+++ b/src/metabase/util/date_2/parse.clj
@@ -7,8 +7,8 @@
[metabase.util.i18n :refer [tru]]
[metabase.util.malli :as mu])
(:import
- (java.time LocalDateTime OffsetDateTime OffsetTime ZonedDateTime ZoneOffset)
- (java.time.format DateTimeFormatter)
+ (java.time Instant LocalDateTime OffsetDateTime OffsetTime ZonedDateTime ZoneOffset)
+ (java.time.format DateTimeFormatter DateTimeParseException)
(java.time.temporal Temporal TemporalAccessor TemporalField TemporalQueries)))
(set! *warn-on-reflection* true)
@@ -49,6 +49,15 @@
(def ^:private utc-zone-region (t/zone-id "UTC"))
+(defn- try-parse-as-iso-timestamp
+ "Fastpath for parsing ISO Instant timestamp if it matches the required length. Return nil if the length doesn't match
+ or the parsing fails, otherwise return a ZonedDateTime instance at UTC."
+ [^String s]
+ (when (and s (= (.length s) (.length "1970-01-01T00:00:00Z")))
+ (try (let [temporal-accessor (.parse DateTimeFormatter/ISO_INSTANT s)]
+ (.atZone (Instant/from temporal-accessor) utc-zone-region))
+ (catch DateTimeParseException _))))
+
(mu/defn parse-with-formatter :- [:maybe InstanceOfTemporal]
"Parse a String with a DateTimeFormatter, returning an appropriate instance of an `java.time` temporal class."
[formattr
@@ -137,4 +146,5 @@
(defn parse
"Parse a string into a `java.time` object."
[^String s]
- (parse-with-formatter formatter s))
+ (or (try-parse-as-iso-timestamp s) ;; Try the fastpath first.
+ (parse-with-formatter formatter s)))
--
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