Initial commit

llama_toolchain/safety/shields/shield_runner.py

@@ -0,0 +1,52 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+import asyncio
+from typing import List
+
+from llama_models.llama3_1.api.datatypes import Message, Role
+
+from .base import OnViolationAction, ShieldBase, ShieldResponse
+
+
+class SafetyException(Exception):  # noqa: N818
+    def __init__(self, response: ShieldResponse):
+        self.response = response
+        super().__init__(response.violation_return_message)
+
+
+class ShieldRunnerMixin:
+
+    def __init__(
+        self,
+        input_shields: List[ShieldBase] = None,
+        output_shields: List[ShieldBase] = None,
+    ):
+        self.input_shields = input_shields
+        self.output_shields = output_shields
+
+    async def run_shields(
+        self, messages: List[Message], shields: List[ShieldBase]
+    ) -> List[ShieldResponse]:
+        # some shields like llama-guard require the first message to be a user message
+        # since this might be a tool call, first role might not be user
+        if len(messages) > 0 and messages[0].role != Role.user.value:
+            # TODO(ashwin): we need to change the type of the message, this kind of modification
+            # is no longer appropriate
+            messages[0].role = Role.user.value
+
+        results = await asyncio.gather(*[s.run(messages) for s in shields])
+        for shield, r in zip(shields, results):
+            if r.is_violation:
+                if shield.on_violation_action == OnViolationAction.RAISE:
+                    raise SafetyException(r)
+                elif shield.on_violation_action == OnViolationAction.WARN:
+                    cprint(
+                        f"[Warn]{shield.__class__.__name__} raised a warning",
+                        color="red",
+                    )
+
+        return results