refactor(wildcard): optimize and add caching (#1634)

* fix(wildcard): avoid excessive allocations every loop

* are you going to Scarborough Fair?

* ruby ruby ruby ruby

* ride on, little murphy

* shirley?

* to the moon

* reggie are you there?

* code 99

* my doctorate is in Art History

* helps to be consistent

* tidy

* slow and steady gets the clam

* oysters were better anyway

* DIAL TONE

pkg/regexcache/regex.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2021 - 2024, Ludvig Lundgren and the autobrr contributors.
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package regexcache
+
+import (
+	"regexp"
+	"time"
+
+	"github.com/jellydator/ttlcache/v3"
+)
+
+var cache = ttlcache.New[string, *regexp.Regexp](
+	ttlcache.WithTTL[string, *regexp.Regexp](5 * time.Minute),
+)
+
+func init() {
+	go cache.Start()
+}
+
+func MustCompilePOSIX(pattern string) *regexp.Regexp {
+	item := cache.Get(pattern)
+	if item != nil {
+		return item.Value()
+	}
+
+	reg := regexp.MustCompilePOSIX(pattern)
+	cache.Set(pattern, reg, ttlcache.NoTTL)
+	return reg
+}
+
+func MustCompile(pattern string) *regexp.Regexp {
+	item := cache.Get(pattern)
+	if item != nil {
+		return item.Value()
+	}
+
+	reg := regexp.MustCompile(pattern)
+	cache.Set(pattern, reg, ttlcache.NoTTL)
+	return reg
+}
+
+func CompilePOSIX(pattern string) (*regexp.Regexp, error) {
+	item := cache.Get(pattern)
+	if item != nil {
+		return item.Value(), nil
+	}
+
+	reg, err := regexp.CompilePOSIX(pattern)
+	if err != nil {
+		return nil, err
+	}
+
+	cache.Set(pattern, reg, ttlcache.DefaultTTL)
+	return reg, nil
+}
+
+func Compile(pattern string) (*regexp.Regexp, error) {
+	item := cache.Get(pattern)
+	if item != nil {
+		return item.Value(), nil
+	}
+
+	reg, err := regexp.Compile(pattern)
+	if err != nil {
+		return nil, err
+	}
+
+	cache.Set(pattern, reg, ttlcache.DefaultTTL)
+	return reg, nil
+}