[api] Emit every encode call through one generator helper

_encode_call() owns the cursor assignment and the _force suffix, so
the convention lives in one place instead of at every emission site;
the fixed32 fast path is an arm of the generic encode_content keyed by
a per type value template. write_fixed32_le uses convert_little_endian
instead of its own byte order switch. The integration test shares a
StateWaiter from state_utils and leaves the disconnect to the fixture.

script/api_protobuf/api_protobuf.py

@@ -131,6 +131,12 @@ def force_str(force: bool) -> str:
     return str(force).lower()
 
 
+def _encode_call(func: str, *args: str, force: bool = False) -> str:
+    """Emit one ProtoEncode call; every helper takes the cursor and returns it advanced."""
+    suffix = "_force" if force else ""
+    return f"pos = ProtoEncode::{func}{suffix}({', '.join(('pos', *args))});"
+
+
 class TypeInfo(ABC):
     """Base class for all type information."""
 
@@ -264,14 +270,16 @@ class TypeInfo(ABC):
     # write_raw_byte(tag) + raw encode instead of the full encode_* method,
     # eliminating the zero-check branch and encode_field_raw indirection.
     # {value} is replaced with the actual field expression.
-    RAW_ENCODE_MAP: dict[str, str] = {
-        "encode_uint32": "pos = ProtoEncode::encode_varint_raw(pos, {value});",
-        "encode_uint64": "pos = ProtoEncode::encode_varint_raw_64(pos, {value});",
-        "encode_sint32": "pos = ProtoEncode::encode_varint_raw_short(pos, encode_zigzag32({value}));",
-        "encode_sint64": "pos = ProtoEncode::encode_varint_raw_64(pos, encode_zigzag64({value}));",
-        "encode_int64": "pos = ProtoEncode::encode_varint_raw_64(pos, static_cast<uint64_t>({value}));",
-        "encode_bool": "pos = ProtoEncode::write_raw_byte(pos, {value} ? 0x01 : 0x00);",
+    RAW_ENCODE_MAP: dict[str, tuple[str, str]] = {
+        "encode_uint32": ("encode_varint_raw", "{value}"),
+        "encode_uint64": ("encode_varint_raw_64", "{value}"),
+        "encode_sint32": ("encode_varint_raw_short", "encode_zigzag32({value})"),
+        "encode_sint64": ("encode_varint_raw_64", "encode_zigzag64({value})"),
+        "encode_int64": ("encode_varint_raw_64", "static_cast<uint64_t>({value})"),
+        "encode_bool": ("write_raw_byte", "{value} ? 0x01 : 0x00"),
     }
+    # Fixed32 value expression for the shared tag+fixed32 writer; None for other wire types
+    fixed32_value_template: str | None = None
 
     def _encode_with_precomputed_tag(self, value_expr: str) -> str | None:
         """Try to emit a precomputed-tag encode for a field.
@@ -288,12 +296,17 @@ class TypeInfo(ABC):
             return None
         max_val = self.max_value
         # Only use RAW_ENCODE_MAP for forced fields or fields with max_value
-        raw_expr = None
+        raw = None
         if self.force or max_val is not None:
-            raw_expr = self.RAW_ENCODE_MAP.get(self.encode_func)
-        if raw_expr is None:
+            raw = self.RAW_ENCODE_MAP.get(self.encode_func)
+        if raw is None:
             return None
-        body = f"pos = ProtoEncode::write_raw_byte(pos, {tag});\n{raw_expr.format(value=value_expr)}"
+        func, arg = raw
+        body = (
+            _encode_call("write_raw_byte", str(tag))
+            + "\n"
+            + _encode_call(func, arg.format(value=value_expr))
+        )
         if self.force:
             return body
         # Non-forced with max_value: inline zero-check + raw encode
@@ -314,14 +327,16 @@ class TypeInfo(ABC):
             return None
         # When max_len < 128, length varint is always 1 byte
         len_encode = (
-            f"pos = ProtoEncode::write_raw_byte(pos, static_cast<uint8_t>({len_expr}));"
+            _encode_call("write_raw_byte", f"static_cast<uint8_t>({len_expr})")
             if max_len is not None and max_len < 128
-            else f"pos = ProtoEncode::encode_varint_raw(pos, {len_expr});"
+            else _encode_call("encode_varint_raw", len_expr)
         )
-        return (
-            f"pos = ProtoEncode::write_raw_byte(pos, {tag});\n"
-            f"{len_encode}\n"
-            f"pos = ProtoEncode::encode_raw(pos, {data_expr}, {len_expr});"
+        return "\n".join(
+            (
+                _encode_call("write_raw_byte", str(tag)),
+                len_encode,
+                _encode_call("encode_raw", data_expr, len_expr),
+            )
         )
 
     def _encode_fixed32_with_precomputed_tag(self, value_expr: str) -> str | None:
@@ -330,22 +345,25 @@ class TypeInfo(ABC):
         if tag >= 128:
             return None
         if self.force:
-            return (
-                f"pos = ProtoEncode::write_tag_and_fixed32(pos, {tag}, {value_expr});"
-            )
+            return _encode_call("write_tag_and_fixed32", str(tag), value_expr)
         return (
             f"if (uint32_t raw = {value_expr}; raw != 0) [[likely]] {{\n"
-            f"  pos = ProtoEncode::write_tag_and_fixed32(pos, {tag}, raw);\n"
+            f"  {_encode_call('write_tag_and_fixed32', str(tag), 'raw')}\n"
             "}"
         )
 
     @property
     def encode_content(self) -> str:
-        if result := self._encode_with_precomputed_tag(f"this->{self.field_name}"):
+        value = f"this->{self.field_name}"
+        if result := self._encode_with_precomputed_tag(value):
             return result
-        if self.force:
-            return f"pos = ProtoEncode::{self.encode_func}_force(pos, {self.number}, this->{self.field_name});"
-        return f"pos = ProtoEncode::{self.encode_func}(pos, {self.number}, this->{self.field_name});"
+        if self.fixed32_value_template is not None and (
+            result := self._encode_fixed32_with_precomputed_tag(
+                self.fixed32_value_template.format(value=value)
+            )
+        ):
+            return result
+        return _encode_call(self.encode_func, str(self.number), value, force=self.force)
 
     encode_func = None
 
@@ -650,13 +668,7 @@ class FloatType(FixedSizeTypeMixin, TypeInfo):
     encode_func = "encode_float"
     wire_type = WireType.FIXED32  # Uses wire type 5
 
-    @property
-    def encode_content(self) -> str:
-        if result := self._encode_fixed32_with_precomputed_tag(
-            f"float_to_raw(this->{self.field_name})"
-        ):
-            return result
-        return super().encode_content
+    fixed32_value_template = "float_to_raw({value})"
 
     def dump(self, name: str) -> str:
         o = f'snprintf(buffer, sizeof(buffer), "%g", {name});\n'
@@ -724,7 +736,7 @@ class UInt64Type(VarintTypeMixin, TypeInfo):
         if self.mac_address:
             return {
                 **TypeInfo.RAW_ENCODE_MAP,
-                "encode_uint64": "pos = ProtoEncode::encode_varint_raw_48bit(pos, {value});",
+                "encode_uint64": ("encode_varint_raw_48bit", "{value}"),
             }
         return TypeInfo.RAW_ENCODE_MAP
 
@@ -792,13 +804,7 @@ class Fixed32Type(FixedSizeTypeMixin, TypeInfo):
         o += "out.append(buffer);"
         return o
 
-    @property
-    def encode_content(self) -> str:
-        if result := self._encode_fixed32_with_precomputed_tag(
-            f"this->{self.field_name}"
-        ):
-            return result
-        return super().encode_content
+    fixed32_value_template = "{value}"
 
     def get_size_calculation(self, name: str, force: bool = False) -> str:
         field_id_size = self.calculate_field_id_size()
@@ -872,9 +878,12 @@ class StringType(TypeInfo):
             f"this->{self.field_name}_ref_.size()",
         ):
             return result
-        if self.force:
-            return f"pos = ProtoEncode::encode_string_force(pos, {self.number}, this->{self.field_name}_ref_);"
-        return f"pos = ProtoEncode::encode_string(pos, {self.number}, this->{self.field_name}_ref_);"
+        return _encode_call(
+            "encode_string",
+            str(self.number),
+            f"this->{self.field_name}_ref_",
+            force=self.force,
+        )
 
     def dump(self, name):
         # If name is 'it', this is a repeated field element - always use string
@@ -972,7 +981,9 @@ class MessageType(TypeInfo):
     @property
     def encode_content(self) -> str:
         # Sub-message encoding needs buffer for backpatch/sync
-        return f"pos = ProtoEncode::{self.encode_func}(pos, buffer, {self.number}, this->{self.field_name});"
+        return _encode_call(
+            self.encode_func, "buffer", str(self.number), f"this->{self.field_name}"
+        )
 
     @property
     def decode_length(self) -> str:
@@ -1079,9 +1090,13 @@ class BytesType(TypeInfo):
             f"this->{self.field_name}_ptr_", f"this->{self.field_name}_len_"
         ):
             return result
-        if self.force:
-            return f"pos = ProtoEncode::encode_bytes_force(pos, {self.number}, this->{self.field_name}_ptr_, this->{self.field_name}_len_);"
-        return f"pos = ProtoEncode::encode_bytes(pos, {self.number}, this->{self.field_name}_ptr_, this->{self.field_name}_len_);"
+        return _encode_call(
+            "encode_bytes",
+            str(self.number),
+            f"this->{self.field_name}_ptr_",
+            f"this->{self.field_name}_len_",
+            force=self.force,
+        )
 
     def dump(self, name: str) -> str:
         ptr_dump = f"format_hex_pretty(this->{self.field_name}_ptr_, this->{self.field_name}_len_)"
@@ -1191,9 +1206,13 @@ class PointerToBytesBufferType(PointerToBufferTypeBase):
             f"this->{self.field_name}", f"this->{self.field_name}_len"
         ):
             return result
-        if self.force:
-            return f"pos = ProtoEncode::encode_bytes_force(pos, {self.number}, this->{self.field_name}, this->{self.field_name}_len);"
-        return f"pos = ProtoEncode::encode_bytes(pos, {self.number}, this->{self.field_name}, this->{self.field_name}_len);"
+        return _encode_call(
+            "encode_bytes",
+            str(self.number),
+            f"this->{self.field_name}",
+            f"this->{self.field_name}_len",
+            force=self.force,
+        )
 
     @property
     def decode_length_content(self) -> str | None:
@@ -1245,15 +1264,20 @@ class PointerToStringBufferType(PointerToBufferTypeBase):
         if max_len is not None and max_len < 128 and self.force:
             tag = self.calculate_tag()
             if tag < 128:
-                return f"pos = ProtoEncode::encode_short_string_force(pos, {tag}, this->{self.field_name});"
+                return _encode_call(
+                    "encode_short_string_force", str(tag), f"this->{self.field_name}"
+                )
         if result := self._encode_bytes_with_precomputed_tag(
             f"this->{self.field_name}.c_str()",
             f"this->{self.field_name}.size()",
         ):
             return result
-        if self.force:
-            return f"pos = ProtoEncode::encode_string_force(pos, {self.number}, this->{self.field_name});"
-        return f"pos = ProtoEncode::encode_string(pos, {self.number}, this->{self.field_name});"
+        return _encode_call(
+            "encode_string",
+            str(self.number),
+            f"this->{self.field_name}",
+            force=self.force,
+        )
 
     @property
     def decode_length_content(self) -> str | None:
@@ -1440,9 +1464,13 @@ class FixedArrayBytesType(TypeInfo):
             f"this->{self.field_name}", f"this->{self.field_name}_len", max_len=max_len
         ):
             return result
-        if self.force:
-            return f"pos = ProtoEncode::encode_bytes_force(pos, {self.number}, this->{self.field_name}, this->{self.field_name}_len);"
-        return f"pos = ProtoEncode::encode_bytes(pos, {self.number}, this->{self.field_name}, this->{self.field_name}_len);"
+        return _encode_call(
+            "encode_bytes",
+            str(self.number),
+            f"this->{self.field_name}",
+            f"this->{self.field_name}_len",
+            force=self.force,
+        )
 
     def dump(self, name: str) -> str:
         return f"out.append(format_hex_pretty({name}, {name}_len));"
@@ -1539,10 +1567,8 @@ class EnumType(VarintTypeMixin, TypeInfo):
     @property
     def encode_content(self) -> str:
         value_expr = f"static_cast<uint32_t>(this->{self.field_name})"
-        if self.force:
-            return f"pos = ProtoEncode::{self.encode_func}_force(pos, {self.number}, {value_expr});"
-        return (
-            f"pos = ProtoEncode::{self.encode_func}(pos, {self.number}, {value_expr});"
+        return _encode_call(
+            self.encode_func, str(self.number), value_expr, force=self.force
         )
 
     def dump(self, name: str) -> str:
@@ -1722,9 +1748,9 @@ def _generate_inline_encode_block(
 
     lines = []
     lines.append(f"auto &sub_msg = {element};")
-    lines.append(f"pos = ProtoEncode::write_raw_byte(pos, {tag});")
+    lines.append(_encode_call("write_raw_byte", str(tag)))
     lines.append("uint8_t *len_pos = pos;")
-    lines.append("pos = ProtoEncode::reserve_byte(pos);")
+    lines.append(_encode_call("reserve_byte"))
 
     # Generate inline field encoding for each sub-message field
     for field in sub_desc.field:
@@ -1796,15 +1822,22 @@ class FixedArrayRepeatedType(TypeInfo):
     def _encode_element(self, element: str) -> str:
         """Helper to generate encode statement for a single element."""
         if isinstance(self._ti, EnumType):
-            return f"pos = ProtoEncode::{self._ti.encode_func}_force(pos, {self.number}, static_cast<uint32_t>({element}));"
+            return _encode_call(
+                self._ti.encode_func,
+                str(self.number),
+                f"static_cast<uint32_t>({element})",
+                force=True,
+            )
         # Repeated message elements use encode_sub_message (force=true is default)
         if isinstance(self._ti, MessageType):
             if _is_inline_encode(self._ti.cpp_type):
                 return _generate_inline_encode_block(
                     self.number, self._ti.cpp_type, element
                 )
-            return f"pos = ProtoEncode::encode_sub_message(pos, buffer, {self.number}, {element});"
-        return f"pos = ProtoEncode::{self._ti.encode_func}_force(pos, {self.number}, {element});"
+            return _encode_call(
+                "encode_sub_message", "buffer", str(self.number), element
+            )
+        return _encode_call(self._ti.encode_func, str(self.number), element, force=True)
 
     @property
     def cpp_type(self) -> str:
@@ -2156,11 +2189,18 @@ class RepeatedTypeInfo(TypeInfo):
     def _encode_element_call(self, element: str) -> str:
         """Helper to generate encode call for a single element."""
         if isinstance(self._ti, EnumType):
-            return f"pos = ProtoEncode::{self._ti.encode_func}_force(pos, {self.number}, static_cast<uint32_t>({element}));"
+            return _encode_call(
+                self._ti.encode_func,
+                str(self.number),
+                f"static_cast<uint32_t>({element})",
+                force=True,
+            )
         # Repeated message elements use encode_sub_message (force=true is default)
         if isinstance(self._ti, MessageType):
-            return f"pos = ProtoEncode::encode_sub_message(pos, buffer, {self.number}, {element});"
-        return f"pos = ProtoEncode::{self._ti.encode_func}_force(pos, {self.number}, {element});"
+            return _encode_call(
+                "encode_sub_message", "buffer", str(self.number), element
+            )
+        return _encode_call(self._ti.encode_func, str(self.number), element, force=True)
 
     @property
     def encode_content(self) -> str:
@@ -2169,7 +2209,7 @@ class RepeatedTypeInfo(TypeInfo):
             # Special handling for const char* elements (when container_no_template contains "const char")
             if "const char" in self._container_no_template:
                 o = f"for (const char *it : *this->{self.field_name}) {{\n"
-                o += f"  pos = ProtoEncode::{self._ti.encode_func}_force(pos, {self.number}, it, strlen(it));\n"
+                o += f"  {_encode_call(self._ti.encode_func, str(self.number), 'it', 'strlen(it)', force=True)}\n"
             else:
                 o = f"for (const auto &it : *this->{self.field_name}) {{\n"
                 o += f"  {self._encode_element_call('it')}\n"