1 files changed, 59 insertions, 0 deletions
diff --git a/third_party/rust/uniffi_bindgen/src/bindings/python/templates/RustBufferHelper.py b/third_party/rust/uniffi_bindgen/src/bindings/python/templates/RustBufferHelper.py
new file mode 100644
index 0000000000..daabd5b4b9
--- /dev/null
+++ b/third_party/rust/uniffi_bindgen/src/bindings/python/templates/RustBufferHelper.py
@@ -0,0 +1,59 @@
+# Types conforming to `_UniffiConverterPrimitive` pass themselves directly over the FFI.
+class _UniffiConverterPrimitive:
+    @classmethod
+    def check(cls, value):
+        return value
+
+    @classmethod
+    def lift(cls, value):
+        return value
+
+    @classmethod
+    def lower(cls, value):
+        return cls.lowerUnchecked(cls.check(value))
+
+    @classmethod
+    def lowerUnchecked(cls, value):
+        return value
+
+    @classmethod
+    def write(cls, value, buf):
+        cls.write_unchecked(cls.check(value), buf)
+
+class _UniffiConverterPrimitiveInt(_UniffiConverterPrimitive):
+    @classmethod
+    def check(cls, value):
+        try:
+            value = value.__index__()
+        except Exception:
+            raise TypeError("'{}' object cannot be interpreted as an integer".format(type(value).__name__))
+        if not isinstance(value, int):
+            raise TypeError("__index__ returned non-int (type {})".format(type(value).__name__))
+        if not cls.VALUE_MIN <= value < cls.VALUE_MAX:
+            raise ValueError("{} requires {} <= value < {}".format(cls.CLASS_NAME, cls.VALUE_MIN, cls.VALUE_MAX))
+        return super().check(value)
+
+class _UniffiConverterPrimitiveFloat(_UniffiConverterPrimitive):
+    @classmethod
+    def check(cls, value):
+        try:
+            value = value.__float__()
+        except Exception:
+            raise TypeError("must be real number, not {}".format(type(value).__name__))
+        if not isinstance(value, float):
+            raise TypeError("__float__ returned non-float (type {})".format(type(value).__name__))
+        return super().check(value)
+
+# Helper class for wrapper types that will always go through a _UniffiRustBuffer.
+# Classes should inherit from this and implement the `read` and `write` static methods.
+class _UniffiConverterRustBuffer:
+    @classmethod
+    def lift(cls, rbuf):
+        with rbuf.consume_with_stream() as stream:
+            return cls.read(stream)
+
+    @classmethod
+    def lower(cls, value):
+        with _UniffiRustBuffer.alloc_with_builder() as builder:
+            cls.write(value, builder)
+            return builder.finalize()