llama_toolchain -> llama_stack

llama_stack/inference/prepare_messages.py

@@ -0,0 +1,84 @@
+# 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.
+
+from llama_models.llama3.api.datatypes import *  # noqa: F403
+from llama_stack.inference.api import *  # noqa: F403
+from llama_models.llama3.prompt_templates import (
+    BuiltinToolGenerator,
+    FunctionTagCustomToolGenerator,
+    JsonCustomToolGenerator,
+    SystemDefaultGenerator,
+)
+
+
+def prepare_messages(request: ChatCompletionRequest) -> List[Message]:
+
+    assert request.tool_choice == ToolChoice.auto, "Only `ToolChoice.auto` supported"
+
+    existing_messages = request.messages
+    existing_system_message = None
+    if existing_messages[0].role == Role.system.value:
+        existing_system_message = existing_messages.pop(0)
+
+    assert (
+        existing_messages[0].role != Role.system.value
+    ), "Should only have 1 system message"
+
+    messages = []
+
+    default_gen = SystemDefaultGenerator()
+    default_template = default_gen.gen()
+
+    sys_content = ""
+
+    tool_template = None
+    if request.tools:
+        tool_gen = BuiltinToolGenerator()
+        tool_template = tool_gen.gen(request.tools)
+
+        sys_content += tool_template.render()
+        sys_content += "\n"
+
+    sys_content += default_template.render()
+
+    if existing_system_message:
+        # TODO: this fn is needed in many places
+        def _process(c):
+            if isinstance(c, str):
+                return c
+            else:
+                return "<media>"
+
+        sys_content += "\n"
+
+        if isinstance(existing_system_message.content, str):
+            sys_content += _process(existing_system_message.content)
+        elif isinstance(existing_system_message.content, list):
+            sys_content += "\n".join(
+                [_process(c) for c in existing_system_message.content]
+            )
+
+    messages.append(SystemMessage(content=sys_content))
+
+    has_custom_tools = any(isinstance(dfn.tool_name, str) for dfn in request.tools)
+    if has_custom_tools:
+        if request.tool_prompt_format == ToolPromptFormat.json:
+            tool_gen = JsonCustomToolGenerator()
+        elif request.tool_prompt_format == ToolPromptFormat.function_tag:
+            tool_gen = FunctionTagCustomToolGenerator()
+        else:
+            raise ValueError(
+                f"Non supported ToolPromptFormat {request.tool_prompt_format}"
+            )
+
+        custom_tools = [t for t in request.tools if isinstance(t.tool_name, str)]
+        custom_template = tool_gen.gen(custom_tools)
+        messages.append(UserMessage(content=custom_template.render()))
+
+    # Add back existing messages from the request
+    messages += existing_messages
+
+    return messages