API: Add template switching and unload endpoints

Templates can be switched and unloaded without reloading the entire
model.

Signed-off-by: kingbri <bdashore3@proton.me>

main.py

@@ -27,7 +27,11 @@ from common.config import (
 )
 from common.generators import call_with_semaphore, generate_with_semaphore
 from common.sampling import get_overrides_from_file
-from common.templating import get_all_templates, get_prompt_from_template
+from common.templating import (
+    get_all_templates,
+    get_prompt_from_template,
+    get_template_from_file,
+)
 from common.utils import get_generator_error, get_sse_packet, load_progress, unwrap
 from common.logger import init_logger
 from OAI.types.completion import CompletionRequest
@@ -39,7 +43,7 @@ from OAI.types.model import (
     ModelLoadResponse,
     ModelCardParameters,
 )
-from OAI.types.template import TemplateList
+from OAI.types.template import TemplateList, TemplateSwitchRequest
 from OAI.types.token import (
     TokenEncodeRequest,
     TokenEncodeResponse,
@@ -258,6 +262,32 @@ async def get_templates():
     return TemplateList(data=template_strings)
 
 
+@app.post(
+    "/v1/template/switch",
+    dependencies=[Depends(check_admin_key), Depends(_check_model_container)],
+)
+async def switch_template(data: TemplateSwitchRequest):
+    """Switch the currently loaded template"""
+    if not data.name:
+        raise HTTPException(400, "New template name not found.")
+
+    try:
+        template = get_template_from_file(data.name)
+        MODEL_CONTAINER.prompt_template = template
+    except FileNotFoundError as e:
+        raise HTTPException(400, "Template does not exist. Check the name?") from e
+
+
+@app.post(
+    "/v1/template/unload",
+    dependencies=[Depends(check_admin_key), Depends(_check_model_container)],
+)
+async def unload_template():
+    """Unloads the currently selected template"""
+
+    MODEL_CONTAINER.prompt_template = None
+
+
 # Lora list endpoint
 @app.get("/v1/loras", dependencies=[Depends(check_api_key)])
 @app.get("/v1/lora/list", dependencies=[Depends(check_api_key)])