Files
hao-ai-lab-FastVideo/v2/serving/server.py
T
SolitaryThinker 58223c0c41 [feat] Register cross-model workflows as first-class named servables
Answers "what's the right way to name/register custom pipelines like T2I→I2V":
treat a Workflow like a card — a stable namespaced id in the same servable
namespace, declared dependencies, and a two-level registry. No new concepts;
mirrors how cards are registered (and vllm-omni's pipeline_registry).

- program/workflow.py: Workflow gains `requires` (the cards it composes, derived
  from stages) and `validate(engine)` (fail-fast if a required card is absent,
  P7). New WorkflowRegistry: declarative workflow_id -> builder catalog for
  out-of-tree/ad hoc use.
- runtime/engine.py: `_workflows` registry + register_workflow (validates deps,
  rejects id collision with a model_id) + serves(); engine.run routes a request
  whose model_id is a workflow to workflow.run — addressable exactly like a model.
  Single-model hot path untouched.
- runtime/async_engine.py + serving/server.py: serves() and /models include
  workflows (discoverable as servables).
- models/__init__.py: declarative `_WORKFLOWS` catalog (the cross-model analog of
  _BUILDERS) + register_workflows() helper; build_image_video_engine now registers
  the workflow too. Adding a custom pipeline = one catalog line.
- Naming convention: dotted/namespaced workflow_id (`image_video.t2i_i2v`),
  distinct from kebab model ids, collision-checked. Renamed from `t2i_then_i2v`.
- tests (+5, 12 total in the file): addressable by id, requires/validate, id
  collision, registry catalog, register_workflows helper. Full suite 114 passed.
- designv4 §9.6: the naming & registration convention documented.
2026-07-04 17:15:34 +00:00

212 lines
9.8 KiB
Python

"""OmniOpenAIServer — our own OpenAI-compatible worker server (design.md §6.3.5; vllm-omni pattern).
Fronts ONE AsyncEngine (the per-pool worker surface). Routes OpenAI-shaped endpoints to typed
OmniRequests, streams chat via SSE, and serves video as an async job (POST returns a job id;
GET polls) plus a /sync variant — mirroring vllm-omni's `/v1/videos` + `/v1/videos/sync`. The fleet
(deploy/fleet.py) or Dynamo routes across multiple such servers/engines above this layer.
Unlike vllm-omni's request-scheduled opaque DIFFUSION stage, the engine underneath is step-scheduled
— the endpoint is a thin shim; the runtime-visible loop scheduler is the substance.
"""
from __future__ import annotations
import asyncio
import base64
import itertools
import time
from typing import Any
import numpy as np
from ..request.artifacts import Output
from ..request.streams import StreamChunk
from .http import HttpServer, Request, Response
def _json_default(o: Any) -> Any:
"""Make SSE event payloads JSON-safe (media.chunk carries a StreamChunk with an array)."""
if isinstance(o, StreamChunk):
shape = list(np.asarray(o.data).shape) if o.data is not None else None
return {"stream_id": o.stream_id, "modality": o.modality, "seq": o.seq,
"preview": o.preview, "final": o.final, "shape": shape}
if isinstance(o, np.ndarray):
return {"shape": list(o.shape), "dtype": str(o.dtype)}
return str(o)
from .protocol import ChatCompletionRequest, ImageGenerationRequest, VideoGenerationRequest
_job_ctr = itertools.count(1)
_chat_ctr = itertools.count(1)
def _payload(art: Any) -> Any:
for attr in ("text", "frames", "samples", "tensor", "latent", "token_ids"):
if hasattr(art, attr) and getattr(art, attr) is not None:
return getattr(art, attr)
return None
def _ser_artifacts(out: Output) -> dict:
res: dict = {}
for name, art in out.artifacts.items():
p = _payload(art)
if isinstance(p, str):
res[name] = {"type": "text", "text": p}
elif p is None:
res[name] = {"type": "empty"}
else:
a = np.asarray(p)
res[name] = {"type": "tensor", "shape": list(a.shape), "dtype": str(a.dtype),
"b64_json": base64.b64encode(np.ascontiguousarray(a).tobytes()).decode()}
return res
class OmniOpenAIServer:
def __init__(self, engine: Any, *, engine_id: str = "v2", max_jobs: int = 512):
self.engine = engine # an AsyncEngine
self.engine_id = engine_id
self.jobs: dict[str, dict] = {} # video job store
self.http = HttpServer(self.dispatch)
self.served = 0
self.max_jobs = max_jobs
self._tasks: set = set() # tracked video-job tasks (no fire-and-forget leak)
def _evict_jobs(self) -> None:
terminal = ("completed", "failed")
for jid in list(self.jobs):
if len(self.jobs) <= self.max_jobs:
break
if self.jobs[jid].get("status") in terminal:
self.jobs.pop(jid, None)
# --- routing ------------------------------------------------------------ #
async def dispatch(self, req: Request) -> Response:
m, p = req.method, req.path
if m == "GET" and p == "/health":
return Response.json(self._health())
if m == "GET" and p == "/metrics":
return Response.json(self._metrics())
if m == "GET" and p == "/v1/models":
return Response.json(self._models())
if m == "POST" and p == "/v1/images/generations":
return await self._images(req)
if m == "POST" and p == "/v1/videos":
return await self._video_create(req)
if m == "POST" and p == "/v1/videos/sync":
return await self._video_sync(req)
if m == "GET" and p.startswith("/v1/videos/"):
return self._video_get(p.rsplit("/", 1)[-1])
if m == "POST" and p == "/v1/chat/completions":
return await self._chat(req)
return Response.json({"error": f"no route for {m} {p}"}, status=404)
# --- metadata endpoints ------------------------------------------------- #
def _health(self) -> dict:
return {"status": "healthy", "engine_id": self.engine_id,
"in_flight": self.engine.in_flight, "queue_depth": self.engine.queue_depth}
def _metrics(self) -> dict:
sm = self.engine.engine.metrics
adm = self.engine.engine.admission.metrics
return {"served": self.served, "in_flight": self.engine.in_flight,
"stepped_units": sm.stepped_units, "batches": sm.batches,
"admitted": adm.admitted, "deferred": adm.deferred,
"gpu_seconds": round(adm.gpu_seconds, 6), "by_kind": dict(adm.by_kind)}
def _models(self) -> dict:
ids = (list(self.engine.engine._registry) + list(self.engine._disagg)
+ list(self.engine.engine._workflows)) # workflows are servables too
return {"object": "list", "data": [{"id": m, "object": "model"} for m in ids]}
# --- images ------------------------------------------------------------- #
async def _images(self, req: Request) -> Response:
ig = ImageGenerationRequest.from_json(req.json())
out = await self.engine.generate(ig.to_omni())
self.served += 1
arts = _ser_artifacts(out)
primary = arts.get("image") or arts.get("video") or arts.get("latents")
return Response.json({"created": int(time.time()), "model": ig.model,
"data": [primary] * max(1, ig.n), "omni": arts,
"metrics": {k: round(v, 6) for k, v in out.metrics.items()}})
# --- video: async job + poll + sync ------------------------------------- #
async def _video_create(self, req: Request) -> Response:
vg = VideoGenerationRequest.from_json(req.json())
job_id = f"video-{next(_job_ctr)}"
self.jobs[job_id] = {"id": job_id, "status": "queued", "model": vg.model}
t = asyncio.create_task(self._run_video_job(job_id, vg))
self._tasks.add(t)
t.add_done_callback(self._tasks.discard) # tracked, not fire-and-forget
self._evict_jobs()
return Response.json({"id": job_id, "status": "queued", "model": vg.model}, status=202)
async def _run_video_job(self, job_id: str, vg: VideoGenerationRequest) -> None:
self.jobs[job_id]["status"] = "running"
try:
out = await self.engine.generate(vg.to_omni())
self.served += 1
self.jobs[job_id].update(status="completed", result=_ser_artifacts(out),
metrics={k: round(v, 6) for k, v in out.metrics.items()})
except Exception as e: # noqa: BLE001
self.jobs[job_id].update(status="failed", error=str(e))
def _video_get(self, job_id: str) -> Response:
job = self.jobs.get(job_id)
if job is None:
return Response.json({"error": f"no such job {job_id}"}, status=404)
return Response.json(job)
async def _video_sync(self, req: Request) -> Response:
vg = VideoGenerationRequest.from_json(req.json())
out = await self.engine.generate(vg.to_omni())
self.served += 1
return Response.json({"model": vg.model, "data": _ser_artifacts(out),
"metrics": {k: round(v, 6) for k, v in out.metrics.items()}})
# --- chat: SSE stream or JSON ------------------------------------------- #
async def _chat(self, req: Request) -> Response:
cc = ChatCompletionRequest.from_json(req.json())
omni = cc.to_omni()
if cc.stream:
return Response.sse(self._chat_sse(omni, cc.model))
out = await self.engine.generate(omni)
self.served += 1
arts = _ser_artifacts(out)
content = arts.get("text", {}).get("text", "") if "text" in arts else ""
return Response.json({
"id": f"chatcmpl-{next(_chat_ctr)}", "object": "chat.completion",
"created": int(time.time()), "model": cc.model,
"choices": [{"index": 0, "finish_reason": "stop",
"message": {"role": "assistant", "content": content}}],
"omni": arts, "metrics": {k: round(v, 6) for k, v in out.metrics.items()}})
async def _chat_sse(self, omni: Any, model: str):
import json
cid = f"chatcmpl-{next(_chat_ctr)}"
async for ev in self.engine.submit(omni): # live OmniEvents → SSE chunks
chunk = {"id": cid, "object": "chat.completion.chunk", "model": model,
"event": ev.type, "data": ev.payload}
yield f"data: {json.dumps(chunk, default=_json_default)}\n\n"
self.served += 1
out = self.engine.result(omni.request_id)
arts = _ser_artifacts(out) if out is not None else {}
content = arts.get("text", {}).get("text", "") if "text" in arts else ""
final = {"id": cid, "object": "chat.completion.chunk", "model": model,
"choices": [{"index": 0, "delta": {"role": "assistant", "content": content},
"finish_reason": "stop"}], "omni": arts}
yield f"data: {json.dumps(final, default=_json_default)}\n\n"
yield "data: [DONE]\n\n"
# --- lifecycle ---------------------------------------------------------- #
async def serve(self, host: str = "127.0.0.1", port: int = 0) -> tuple[str, int]:
return await self.http.start(host, port)
async def close(self) -> None:
for t in list(self._tasks): # cancel + drain in-flight video jobs on shutdown
t.cancel()
for t in list(self._tasks):
try:
await t
except (asyncio.CancelledError, Exception): # noqa: BLE001
pass
await self.http.close()