refactor(gossipsub/rpc): inline _decode_varint_at wrapper

src/lean_spec/subspecs/networking/gossipsub/rpc.py

@@ -63,16 +63,6 @@ class ProtobufDecodeError(ValueError):
     """Raised when protobuf data cannot be decoded."""
 
 
-def _decode_varint_at(data: bytes, pos: int) -> tuple[int, int]:
-    """
-    Decode varint returning (value, new_position).
-
-    Wrapper around canonical varint.decode for protobuf parsing convenience.
-    """
-    value, consumed = decode_varint(data, pos)
-    return value, pos + consumed
-
-
 def _decode_length_at(data: bytes, pos: int) -> tuple[int, int]:
     """Decode a length varint and validate bounds.
 
@@ -82,7 +72,8 @@ def _decode_length_at(data: bytes, pos: int) -> tuple[int, int]:
     Raises:
         ProtobufDecodeError: If the length exceeds available data.
     """
-    length, new_pos = _decode_varint_at(data, pos)
+    length, consumed = decode_varint(data, pos)
+    new_pos = pos + consumed
     if new_pos + length > len(data):
         raise ProtobufDecodeError(
             f"Length field {length} at position {pos} exceeds data size {len(data)}"
@@ -102,8 +93,8 @@ def decode_tag(data: bytes, pos: int) -> tuple[int, int, int]:
     Returns:
         (field_number, wire_type, new_position) tuple.
     """
-    tag, pos = _decode_varint_at(data, pos)
-    return tag >> 3, tag & 0x07, pos
+    tag, consumed = decode_varint(data, pos)
+    return tag >> 3, tag & 0x07, pos + consumed
 
 
 def encode_length_delimited(field_number: int, data: bytes) -> bytes:
@@ -159,7 +150,8 @@ def decode(cls, data: bytes) -> SubOpts:
             field_num, wire_type, pos = decode_tag(data, pos)
 
             if field_num == 1 and wire_type == WIRE_TYPE_VARINT:
-                value, pos = _decode_varint_at(data, pos)
+                value, consumed = decode_varint(data, pos)
+                pos += consumed
                 subscribe = value != 0
             elif field_num == 2 and wire_type == WIRE_TYPE_LENGTH_DELIMITED:
                 length, pos = _decode_length_at(data, pos)
@@ -440,7 +432,8 @@ def decode(cls, data: bytes) -> ControlPrune:
                 peers.append(PrunePeerInfo.decode(data[pos : pos + length]))
                 pos += length
             elif field_num == 3 and wire_type == WIRE_TYPE_VARINT:
-                backoff, pos = _decode_varint_at(data, pos)
+                backoff, consumed = decode_varint(data, pos)
+                pos += consumed
             else:
                 pos = _skip_field(data, pos, wire_type)
 
@@ -644,7 +637,8 @@ def _skip_field(data: bytes, pos: int, wire_type: int) -> int:
             group types 3/4) and cannot be skipped.
     """
     if wire_type == WIRE_TYPE_VARINT:
-        _, pos = _decode_varint_at(data, pos)
+        _, consumed = decode_varint(data, pos)
+        pos += consumed
     elif wire_type == WIRE_TYPE_LENGTH_DELIMITED:
         length, pos = _decode_length_at(data, pos)
         pos += length