> be fist commit

internal/generate/generate.go

@@ -0,0 +1,48 @@
+package generate
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	mathRand "math/rand"
+	"strconv"
+)
+
+const alphabet = "0123456789abcdefghijklmnopqrstuvwxyz"
+
+func generateWeak(length int, prefix string) string {
+	result := prefix
+	for len(result) < length {
+		result += string(alphabet[mathRand.Intn(len(alphabet))])
+	}
+
+	return result
+}
+
+// Generate generates an ID either strongly or weakly depending on the system.
+func Generate(length int, prefix string) string {
+	var buffer [32]byte
+
+	result := prefix
+	offset := 0
+
+	_, err := rand.Read(buffer[:32])
+	if err != nil {
+		return generateWeak(length, prefix)
+	}
+
+	for len(result) < length {
+		result += strconv.FormatUint(binary.LittleEndian.Uint64(buffer[offset:]), 36)
+		offset += 8
+
+		if offset >= 32 {
+			_, err = rand.Read(buffer[:32])
+			if err != nil {
+				return generateWeak(length, prefix)
+			}
+
+			offset = 0
+		}
+	}
+
+	return result[:length]
+}

internal/generate/ids.go

@@ -0,0 +1,9 @@
+package generate
+
+func ItemID() string {
+	return Generate(32, "I")
+}
+
+func SessionID() string {
+	return Generate(32, "S")
+}

internal/xlerrors/notfound.go

@@ -0,0 +1,18 @@
+package xlerrors
+
+type notFoundError struct {
+	Subject string
+}
+
+func (err *notFoundError) Error() string {
+	return err.Subject + " not found"
+}
+
+func NotFound(subject string) error {
+	return &notFoundError{Subject: subject}
+}
+
+func IsNotFound(err error) bool {
+	_, ok := err.(*notFoundError)
+	return ok
+}