processors(filters): add FunctionFilter

src/pipecat/processors/filters/function_filter.py

@@ -0,0 +1,30 @@
+#
+# Copyright (c) 2024, Daily
+#
+# SPDX-License-Identifier: BSD 2-Clause License
+#
+
+from typing import Awaitable, Callable
+
+from pipecat.frames.frames import Frame, SystemFrame
+from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
+
+
+class FunctionFilter(FrameProcessor):
+
+    def __init__(self, filter: Callable[[Frame], Awaitable[bool]]):
+        super().__init__()
+        self._filter = filter
+
+    #
+    # Frame processor
+    #
+
+    def _should_passthrough_frame(self, frame):
+        return isinstance(frame, SystemFrame)
+
+    async def process_frame(self, frame: Frame, direction: FrameDirection):
+        passthrough = self._should_passthrough_frame(frame)
+        allowed = await self._filter(frame)
+        if passthrough or allowed:
+            await self.push_frame(frame, direction)