variant macro no longer parses the signature twice, Variant has gaine…

…d a function to continue unmarshalling with a given signature

rustbus/src/wire/unmarshal/traits/container.rs

@@ -4,6 +4,7 @@ use crate::signature;
 use crate::wire::errors::UnmarshalError;
 use crate::wire::marshal::traits::SignatureBuffer;
 use crate::wire::unmarshal;
+use crate::wire::unmarshal::UnmarshalResult;
 use crate::wire::unmarshal_context::UnmarshalContext;
 use crate::Signature;
 use crate::Unmarshal;
@@ -247,6 +248,22 @@ impl<'buf, 'fds> Variant<'fds, 'buf> {
         let mut ctx = self.sub_ctx;
         T::unmarshal(&mut ctx)
     }
+
+    pub fn unmarshal_with_sig(
+        sig: signature::Type,
+        ctx: &mut UnmarshalContext<'fds, 'buf>,
+    ) -> UnmarshalResult<Self> {
+        ctx.align_to(sig.get_alignment())?;
+
+        let val_bytes =
+            crate::wire::validate_raw::validate_marshalled(ctx.byteorder, 0, ctx.remainder(), &sig)
+                .map_err(|e| e.1)?;
+
+        Ok(Variant {
+            sig,
+            sub_ctx: ctx.sub_context(val_bytes)?,
+        })
+    }
 }
 
 impl Signature for Variant<'_, '_> {
@@ -277,16 +294,7 @@ impl<'buf, 'fds> Unmarshal<'buf, 'fds> for Variant<'fds, 'buf> {
         }
         let sig = sigs.remove(0);
 
-        ctx.align_to(sig.get_alignment())?;
-
-        let val_bytes =
-            crate::wire::validate_raw::validate_marshalled(ctx.byteorder, 0, ctx.remainder(), &sig)
-                .map_err(|e| e.1)?;
-
-        Ok(Variant {
-            sig,
-            sub_ctx: ctx.sub_context(val_bytes)?,
-        })
+        Self::unmarshal_with_sig(sig, ctx)
     }
 }
 

rustbus/src/wire/unmarshal_context.rs

@@ -94,10 +94,6 @@ impl<'fds, 'buf> UnmarshalContext<'fds, 'buf> {
     pub fn read_raw(&mut self, length: usize) -> UnmarshalResult<&'buf [u8]> {
         self.cursor.read_raw(length)
     }
-
-    pub fn reset(&mut self, reset_by: usize) {
-        self.cursor.reset(reset_by)
-    }
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -205,10 +201,6 @@ impl<'buf> Cursor<'buf> {
         Ok(elements)
     }
 
-    pub fn reset(&mut self, reset_by: usize) {
-        self.offset -= reset_by;
-    }
-
     pub fn advance(&mut self, advance_by: usize) {
         self.offset += advance_by;
     }

rustbus/src/wire/variant_macros.rs

@@ -341,7 +341,6 @@ macro_rules! dbus_variant_var_unmarshal {
                 ctx: &mut $crate::wire::unmarshal_context::UnmarshalContext<'fds, 'buf>
             ) -> $crate::wire::unmarshal::UnmarshalResult<Self> {
                 use $crate::Signature;
-                use $crate::Unmarshal;
                 use $crate::wire::marshal::traits::SignatureBuffer;
 
                 let sig_str = ctx.read_signature()?;
@@ -354,9 +353,14 @@ macro_rules! dbus_variant_var_unmarshal {
                     return Ok(Self::$name(v));
                 }
                 )+
-                // TODO this should just be a function on Variant that takes the signature str
-                ctx.reset(1 + sig_str.as_bytes().len() + 1);
-                let var = <$crate::wire::unmarshal::traits::Variant as Unmarshal>::unmarshal(ctx)?;
+                let Ok(mut sigs) = $crate::signature::Type::parse_description(sig_str) else {
+                    return Err($crate::wire::errors::UnmarshalError::WrongSignature);
+                };
+                if sigs.len() != 1 {
+                    return Err($crate::wire::errors::UnmarshalError::WrongSignature);
+                }
+                let sig = sigs.remove(0);
+                let var = $crate::wire::unmarshal::traits::Variant::unmarshal_with_sig(sig, ctx)?;
                 Ok(Self::Catchall(var))
             }
         }