Reviewbase64url

2 files changed, 12 insertions, 16 deletions

diff --git a/libbutl/base64.cxx b/libbutl/base64.cxx
index 03191c8..f764aaf 100644
--- a/libbutl/base64.cxx
+++ b/libbutl/base64.cxx
@@ -16,6 +16,9 @@ namespace butl
   static const char codes[] =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
+  static const char codes_url[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+
   // base64-encode the data in the iterator range [i, e). Write the encoded
   // data starting at the iterator position o. If url is true, encode using
   // base64url.
@@ -49,9 +52,6 @@ namespace butl
         i4 = c & 0x3F;
       }
 
-      // @@ TMP Lots of redundant branches. Would making it a template
-      //    parameter help?
-      //
       if (!url)
       {
         if (n && n % 19 == 0)
@@ -67,15 +67,11 @@ namespace butl
       //
       else
       {
-        auto code = [] (size_t i)
-        {
-          return i == 62 ? '-' : i == 63 ? '_' : codes[i];
-        };
 
-        *o++ = code (i1);
-        *o++ = code (i2);
-        if (i3 != un) *o++ = code (i3);
-        if (i4 != un) *o++ = code (i4);
+        *o++ = codes_url[i1];
+        *o++ = codes_url[i2];
+        if (i3 != un) *o++ = codes_url[i3];
+        if (i4 != un) *o++ = codes_url[i4];
       }
     }
   }
diff --git a/libbutl/base64.hxx b/libbutl/base64.hxx
index 6f8ef02..a0d1450 100644
--- a/libbutl/base64.hxx
+++ b/libbutl/base64.hxx
@@ -27,13 +27,13 @@ namespace butl
   LIBBUTL_SYMEXPORT std::string
   base64_encode (const std::vector<char>&);
 
-  // Encode a stream or a buffer using base64url (RFC 4648), a base64 variant
+  // Encode a stream or a buffer using base64url (RFC4648), a base64 variant
   // with different 62nd and 63rd alphabet characters (- and _ instead of ~
-  // and .) to make it filesystem safe, and optional padding because the
+  // and .; to make it filesystem safe) and optional padding because the
   // padding character `=` would have to be percent-encoded to be safe in
-  // URLs.  This implementation does not output any padding, newlines or any
-  // other whitespace in order to conform to RFC7519: JSON Web Token (JWT) and
-  // RFC7515: JSON Web Signature (JWS).
+  // URLs. This implementation does not output any padding, newlines or any
+  // other whitespace (which is required, for example, by RFC7519: JSON Web
+  // Token (JWT) and RFC7515: JSON Web Signature (JWS)).
   //
   // Note that base64url decoding has not yet been implemented.
   //