feat: cancel request

Resolves #1006

backend/apps/ollama/main.py

@@ -3,7 +3,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import StreamingResponse
 from fastapi.concurrency import run_in_threadpool
 
-from pydantic import BaseModel
+from pydantic import BaseModel, ConfigDict
 
 import random
 import requests
@@ -684,7 +684,7 @@ class GenerateChatCompletionForm(BaseModel):
 
 @app.post("/api/chat")
 @app.post("/api/chat/{url_idx}")
-async def generate_completion(
+async def generate_chat_completion(
     form_data: GenerateChatCompletionForm,
     url_idx: Optional[int] = None,
     user=Depends(get_current_user),
@@ -765,6 +765,104 @@ async def generate_completion(
         )
 
 
+# TODO: we should update this part once Ollama supports other types
+class OpenAIChatMessage(BaseModel):
+    role: str
+    content: str
+
+    model_config = ConfigDict(extra="allow")
+
+
+class OpenAIChatCompletionForm(BaseModel):
+    model: str
+    messages: List[OpenAIChatMessage]
+
+    model_config = ConfigDict(extra="allow")
+
+
+@app.post("/v1/chat/completions")
+@app.post("/v1/chat/completions/{url_idx}")
+async def generate_openai_chat_completion(
+    form_data: OpenAIChatCompletionForm,
+    url_idx: Optional[int] = None,
+    user=Depends(get_current_user),
+):
+
+    if url_idx == None:
+        if form_data.model in app.state.MODELS:
+            url_idx = random.choice(app.state.MODELS[form_data.model]["urls"])
+        else:
+            raise HTTPException(
+                status_code=400,
+                detail=ERROR_MESSAGES.MODEL_NOT_FOUND(form_data.model),
+            )
+
+    url = app.state.OLLAMA_BASE_URLS[url_idx]
+
+    r = None
+
+    def get_request():
+        nonlocal form_data
+        nonlocal r
+
+        request_id = str(uuid.uuid4())
+        try:
+            REQUEST_POOL.append(request_id)
+
+            def stream_content():
+                try:
+                    if form_data.stream:
+                        yield json.dumps(
+                            {"request_id": request_id, "done": False}
+                        ) + "\n"
+
+                    for chunk in r.iter_content(chunk_size=8192):
+                        if request_id in REQUEST_POOL:
+                            yield chunk
+                        else:
+                            print("User: canceled request")
+                            break
+                finally:
+                    if hasattr(r, "close"):
+                        r.close()
+                        if request_id in REQUEST_POOL:
+                            REQUEST_POOL.remove(request_id)
+
+            r = requests.request(
+                method="POST",
+                url=f"{url}/v1/chat/completions",
+                data=form_data.model_dump_json(exclude_none=True),
+                stream=True,
+            )
+
+            r.raise_for_status()
+
+            return StreamingResponse(
+                stream_content(),
+                status_code=r.status_code,
+                headers=dict(r.headers),
+            )
+        except Exception as e:
+            raise e
+
+    try:
+        return await run_in_threadpool(get_request)
+    except Exception as e:
+        error_detail = "Open WebUI: Server Connection Error"
+        if r is not None:
+            try:
+                res = r.json()
+                if "error" in res:
+                    error_detail = f"Ollama: {res['error']}"
+            except:
+                error_detail = f"Ollama: {e}"
+
+        raise HTTPException(
+            status_code=r.status_code if r else 500,
+            detail=error_detail,
+        )
+
+
 @app.api_route("/{path:path}", methods=["GET", "POST", "PUT", "DELETE"])
 async def deprecated_proxy(path: str, request: Request, user=Depends(get_current_user)):
     url = app.state.OLLAMA_BASE_URLS[0]