Initial commit: docker compose config

server/torrshash/base62.go

@@ -0,0 +1,43 @@
+package torrshash
+
+import (
+	"bytes"
+	"math/big"
+	"regexp"
+	"strings"
+)
+
+const base62Alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
+
+var base62Regex = regexp.MustCompile(`^[a-zA-Z0-9]+$`)
+
+func IsBase62(s string) bool {
+	return base62Regex.MatchString(strings.TrimSpace(s))
+}
+
+func Encode62(b []byte) string {
+	x := new(big.Int).SetBytes(b)
+	base := big.NewInt(62)
+	zero := big.NewInt(0)
+	mod := new(big.Int)
+	var res []byte
+	for x.Cmp(zero) > 0 {
+		x.QuoRem(x, base, mod)
+		res = append(res, base62Alphabet[mod.Int64()])
+	}
+	for i, j := 0, len(res)-1; i < j; i, j = i+1, j-1 {
+		res[i], res[j] = res[j], res[i]
+	}
+	return string(res)
+}
+
+func Decode62(s string) []byte {
+	res := new(big.Int)
+	base := big.NewInt(62)
+	for _, char := range s {
+		val := bytes.IndexByte([]byte(base62Alphabet), byte(char))
+		res.Mul(res, base)
+		res.Add(res, big.NewInt(int64(val)))
+	}
+	return res.Bytes()
+}