Prefix newly added globals in Python with underscores (#2109)

* Prefix newly added globals in Python with underscores

* Python: Don't glob-import `uniffi_set_event_loop`

This name is internal to uniffi, it should be explicitly named using
`library.uniffi_set_event_loop`. Note this in the docs.

Followup of #1599.

docs/manual/src/futures.md

@@ -77,7 +77,7 @@ pub trait SayAfterTrait: Send + Sync {
 Traits with callback interface support that export async methods can be combined with async Rust code.
 See the [async-api-client example](https://github.com/mozilla/uniffi-rs/tree/main/examples/async-api-client) for an example of this.
 
-### Python: uniffi_set_event_loop()
+### Python: `uniffi_set_event_loop()`
 
 Python bindings export a function named `uniffi_set_event_loop()` which handles a corner case when
 integrating async Rust and Python code. `uniffi_set_event_loop()` is needed when Python async
@@ -93,3 +93,4 @@ In this case, we need an event loop to run the Python async function, but there'
 Use `uniffi_set_event_loop()` to handle this case.
 It should be called before the Rust code makes the async call and passed an eventloop to use.
 
+Note that `uniffi_set_event_loop` cannot be glob-imported because it's not part of the library's `__all__`.

fixtures/futures/tests/bindings/test_futures.py

@@ -176,7 +176,7 @@ async def test():
 
         asyncio.run(test())
         # check that all foreign future handles were released
-        self.assertEqual(len(futures.UNIFFI_FOREIGN_FUTURE_HANDLE_MAP), 0)
+        self.assertEqual(len(futures._UNIFFI_FOREIGN_FUTURE_HANDLE_MAP), 0)
 
     def test_async_object_param(self):
         async def test():

uniffi_bindgen/src/bindings/python/gen_python/mod.rs

@@ -366,14 +366,14 @@ impl PythonCodeOracle {
 
     /// Get the idiomatic Python rendering of an FFI callback function name
     fn ffi_callback_name(&self, nm: &str) -> String {
-        format!("UNIFFI_{}", nm.to_shouty_snake_case())
+        format!("_UNIFFI_{}", nm.to_shouty_snake_case())
     }
 
     /// Get the idiomatic Python rendering of an FFI struct name
     fn ffi_struct_name(&self, nm: &str) -> String {
         // The ctypes docs use both SHOUTY_SNAKE_CASE AND UpperCamelCase for structs. Let's use
         // UpperCamelCase and reserve shouting for global variables
-        format!("Uniffi{}", nm.to_upper_camel_case())
+        format!("_Uniffi{}", nm.to_upper_camel_case())
     }
 
     fn ffi_type_label(&self, ffi_type: &FfiType) -> String {

uniffi_bindgen/src/bindings/python/templates/Async.py

@@ -5,7 +5,7 @@
 # Stores futures for _uniffi_continuation_callback
 _UniffiContinuationHandleMap = _UniffiHandleMap()
 
-UNIFFI_GLOBAL_EVENT_LOOP = None
+_UNIFFI_GLOBAL_EVENT_LOOP = None
 
 """
 Set the event loop to use for async functions
@@ -20,18 +20,18 @@
 for the thread.  Use `uniffi_set_event_loop` to force an eventloop to be used in this case.
 """
 def uniffi_set_event_loop(eventloop: asyncio.BaseEventLoop):
-    global UNIFFI_GLOBAL_EVENT_LOOP
-    UNIFFI_GLOBAL_EVENT_LOOP = eventloop
+    global _UNIFFI_GLOBAL_EVENT_LOOP
+    _UNIFFI_GLOBAL_EVENT_LOOP = eventloop
 
 def _uniffi_get_event_loop():
-    if UNIFFI_GLOBAL_EVENT_LOOP is not None:
-        return UNIFFI_GLOBAL_EVENT_LOOP
+    if _UNIFFI_GLOBAL_EVENT_LOOP is not None:
+        return _UNIFFI_GLOBAL_EVENT_LOOP
     else:
         return asyncio.get_running_loop()
 
 # Continuation callback for async functions
 # lift the return value or error and resolve the future, causing the async function to resume.
-@UNIFFI_RUST_FUTURE_CONTINUATION_CALLBACK
+@_UNIFFI_RUST_FUTURE_CONTINUATION_CALLBACK
 def _uniffi_continuation_callback(future_ptr, poll_code):
     (eventloop, future) = _UniffiContinuationHandleMap.remove(future_ptr)
     eventloop.call_soon_threadsafe(_uniffi_set_future_result, future, poll_code)
@@ -63,7 +63,7 @@ async def _uniffi_rust_call_async(rust_future, ffi_poll, ffi_complete, ffi_free,
         ffi_free(rust_future)
 
 {%- if ci.has_async_callback_interface_definition() %}
-def uniffi_trait_interface_call_async(make_call, handle_success, handle_error):
+def _uniffi_trait_interface_call_async(make_call, handle_success, handle_error):
     async def make_call_and_call_callback():
         try:
             handle_success(await make_call())
@@ -76,10 +76,10 @@ async def make_call_and_call_callback():
             )
     eventloop = _uniffi_get_event_loop()
     task = asyncio.run_coroutine_threadsafe(make_call_and_call_callback(), eventloop)
-    handle = UNIFFI_FOREIGN_FUTURE_HANDLE_MAP.insert((eventloop, task))
-    return UniffiForeignFuture(handle, uniffi_foreign_future_free)
+    handle = _UNIFFI_FOREIGN_FUTURE_HANDLE_MAP.insert((eventloop, task))
+    return _UniffiForeignFuture(handle, _uniffi_foreign_future_free)
 
-def uniffi_trait_interface_call_async_with_error(make_call, handle_success, handle_error, error_type, lower_error):
+def _uniffi_trait_interface_call_async_with_error(make_call, handle_success, handle_error, error_type, lower_error):
     async def make_call_and_call_callback():
         try:
             try:
@@ -98,17 +98,17 @@ async def make_call_and_call_callback():
             )
     eventloop = _uniffi_get_event_loop()
     task = asyncio.run_coroutine_threadsafe(make_call_and_call_callback(), eventloop)
-    handle = UNIFFI_FOREIGN_FUTURE_HANDLE_MAP.insert((eventloop, task))
-    return UniffiForeignFuture(handle, uniffi_foreign_future_free)
+    handle = _UNIFFI_FOREIGN_FUTURE_HANDLE_MAP.insert((eventloop, task))
+    return _UniffiForeignFuture(handle, _uniffi_foreign_future_free)
 
-UNIFFI_FOREIGN_FUTURE_HANDLE_MAP = _UniffiHandleMap()
+_UNIFFI_FOREIGN_FUTURE_HANDLE_MAP = _UniffiHandleMap()
 
-@UNIFFI_FOREIGN_FUTURE_FREE
-def uniffi_foreign_future_free(handle):
-    (eventloop, task) = UNIFFI_FOREIGN_FUTURE_HANDLE_MAP.remove(handle)
-    eventloop.call_soon(uniffi_foreign_future_do_free, task)
+@_UNIFFI_FOREIGN_FUTURE_FREE
+def _uniffi_foreign_future_free(handle):
+    (eventloop, task) = _UNIFFI_FOREIGN_FUTURE_HANDLE_MAP.remove(handle)
+    eventloop.call_soon(_uniffi_foreign_future_do_free, task)
 
-def uniffi_foreign_future_do_free(task):
+def _uniffi_foreign_future_do_free(task):
     if not task.done():
         task.cancel()
 {%- endif %}

uniffi_bindgen/src/bindings/python/templates/CallbackInterfaceImpl.py

@@ -1,5 +1,5 @@
 {% if self.include_once_check("CallbackInterfaceRuntime.py") %}{% include "CallbackInterfaceRuntime.py" %}{% endif %}
-{%- let trait_impl=format!("UniffiTraitImpl{}", name) %}
+{%- let trait_impl=format!("_UniffiTraitImpl{}", name) %}
 
 # Put all the bits inside a class to keep the top-level namespace clean
 class {{ trait_impl }}:
@@ -75,24 +75,24 @@ def handle_error(status_code, rust_buffer):
 
         {%- match meth.throws_type() %}
         {%- when None %}
-        uniffi_out_return[0] = uniffi_trait_interface_call_async(make_call, handle_success, handle_error)
+        uniffi_out_return[0] = _uniffi_trait_interface_call_async(make_call, handle_success, handle_error)
         {%- when Some(error) %}
-        uniffi_out_return[0] = uniffi_trait_interface_call_async_with_error(make_call, handle_success, handle_error, {{ error|type_name }}, {{ error|lower_fn }})
+        uniffi_out_return[0] = _uniffi_trait_interface_call_async_with_error(make_call, handle_success, handle_error, {{ error|type_name }}, {{ error|lower_fn }})
         {%- endmatch %}
         {%- endif %}
     {%- endfor %}
 
     @{{ "CallbackInterfaceFree"|ffi_callback_name }}
-    def uniffi_free(uniffi_handle):
+    def _uniffi_free(uniffi_handle):
         {{ ffi_converter_name }}._handle_map.remove(uniffi_handle)
 
     # Generate the FFI VTable.  This has a field for each callback interface method.
-    uniffi_vtable = {{ vtable|ffi_type_name }}(
+    _uniffi_vtable = {{ vtable|ffi_type_name }}(
         {%- for (_, meth) in vtable_methods.iter() %}
         {{ meth.name()|fn_name }},
         {%- endfor %}
-        uniffi_free
+        _uniffi_free
     )
     # Send Rust a pointer to the VTable.  Note: this means we need to keep the struct alive forever,
     # or else bad things will happen when Rust tries to access it.
-    _UniffiLib.{{ ffi_init_callback.name() }}(ctypes.byref(uniffi_vtable))
+    _UniffiLib.{{ ffi_init_callback.name() }}(ctypes.byref(_uniffi_vtable))

uniffi_bindgen/src/bindings/python/templates/CallbackInterfaceRuntime.py

@@ -1,12 +1,12 @@
 # Magic number for the Rust proxy to call using the same mechanism as every other method,
 # to free the callback once it's dropped by Rust.
-IDX_CALLBACK_FREE = 0
+_UNIFFI_IDX_CALLBACK_FREE = 0
 # Return codes for callback calls
 _UNIFFI_CALLBACK_SUCCESS = 0
 _UNIFFI_CALLBACK_ERROR = 1
 _UNIFFI_CALLBACK_UNEXPECTED_ERROR = 2
 
-class UniffiCallbackInterfaceFfiConverter:
+class _UniffiCallbackInterfaceFfiConverter:
     _handle_map = _UniffiHandleMap()
 
     @classmethod

uniffi_bindgen/src/bindings/python/templates/CallbackInterfaceTemplate.py

@@ -10,4 +10,4 @@
 {% include "CallbackInterfaceImpl.py" %}
 
 # The _UniffiConverter which transforms the Callbacks in to Handles to pass to Rust.
-{{ ffi_converter_name }} = UniffiCallbackInterfaceFfiConverter()
+{{ ffi_converter_name }} = _UniffiCallbackInterfaceFfiConverter()

uniffi_bindgen/src/bindings/python/templates/HandleMap.py

@@ -20,14 +20,14 @@ def get(self, handle):
             with self._lock:
                 return self._map[handle]
         except KeyError:
-            raise InternalError("UniffiHandleMap.get: Invalid handle")
+            raise InternalError("_UniffiHandleMap.get: Invalid handle")
 
     def remove(self, handle):
         try:
             with self._lock:
                 return self._map.pop(handle)
         except KeyError:
-            raise InternalError("UniffiHandleMap.remove: Invalid handle")
+            raise InternalError("_UniffiHandleMap.remove: Invalid handle")
 
     def __len__(self):
         return len(self._map)

uniffi_bindgen/src/bindings/python/templates/wrapper.py

@@ -75,9 +75,6 @@
     {%- for c in ci.callback_interface_definitions() %}
     "{{ c.name()|class_name }}",
     {%- endfor %}
-    {%- if ci.has_async_fns() %}
-    "uniffi_set_event_loop",
-    {%- endif %}
 ]
 
 {% import "macros.py" as py %}