Add redis support for distributed caching

vendor/github.com/alicebob/miniredis/v2/keys.go

@@ -0,0 +1,83 @@
+package miniredis
+
+// Translate the 'KEYS' or 'PSUBSCRIBE' argument ('foo*', 'f??', &c.) into a regexp.
+
+import (
+	"bytes"
+	"regexp"
+)
+
+// patternRE compiles a glob to a regexp. Returns nil if the given
+// pattern will never match anything.
+// The general strategy is to sandwich all non-meta characters between \Q...\E.
+func patternRE(k string) *regexp.Regexp {
+	re := bytes.Buffer{}
+	re.WriteString(`(?s)^\Q`)
+	for i := 0; i < len(k); i++ {
+		p := k[i]
+		switch p {
+		case '*':
+			re.WriteString(`\E.*\Q`)
+		case '?':
+			re.WriteString(`\E.\Q`)
+		case '[':
+			charClass := bytes.Buffer{}
+			i++
+			for ; i < len(k); i++ {
+				if k[i] == ']' {
+					break
+				}
+				if k[i] == '\\' {
+					if i == len(k)-1 {
+						// Ends with a '\'. U-huh.
+						return nil
+					}
+					charClass.WriteByte(k[i])
+					i++
+					charClass.WriteByte(k[i])
+					continue
+				}
+				charClass.WriteByte(k[i])
+			}
+			if charClass.Len() == 0 {
+				// '[]' is valid in Redis, but matches nothing.
+				return nil
+			}
+			re.WriteString(`\E[`)
+			re.Write(charClass.Bytes())
+			re.WriteString(`]\Q`)
+
+		case '\\':
+			if i == len(k)-1 {
+				// Ends with a '\'. U-huh.
+				return nil
+			}
+			// Forget the \, keep the next char.
+			i++
+			re.WriteByte(k[i])
+			continue
+		default:
+			re.WriteByte(p)
+		}
+	}
+	re.WriteString(`\E$`)
+	return regexp.MustCompile(re.String())
+}
+
+// matchKeys filters only matching keys.
+// The returned boolean is whether the match pattern was valid
+func matchKeys(keys []string, match string) ([]string, bool) {
+	re := patternRE(match)
+	if re == nil {
+		// Special case: the given pattern won't match anything or is invalid.
+		return nil, false
+	}
+	var res []string
+	for _, k := range keys {
+		if !re.MatchString(k) {
+			continue
+		}
+		res = append(res, k)
+	}
+	return res, true
+}