vllm.v1.engine ¶

class EngineCoreEvent(msgspec.Struct):
    """A timestamped engine core event associated with a request.

    The timestamp is a monotonic timestamps and is used for by the engine
    frontend to calculate intervals between engine core events. These
    timestamps should not be compared with timestamps from other processes.
    """

    type: EngineCoreEventType
    timestamp: float

    @classmethod
    def new_event(
        cls, event_type: EngineCoreEventType, timestamp: float | None = None
    ) -> "EngineCoreEvent":
        timestamp = time.monotonic() if timestamp is None else timestamp
        return cls(event_type, timestamp)

class EngineCoreEventType(enum.IntEnum):
    """The type of engine core request event."""

    QUEUED = 1
    SCHEDULED = 2
    PREEMPTED = 3

class EngineCoreRequest(
    msgspec.Struct,
    array_like=True,  # type: ignore[call-arg]
    omit_defaults=True,  # type: ignore[call-arg]
    gc=False,
):  # type: ignore[call-arg]
    request_id: str
    prompt_token_ids: list[int] | None
    mm_features: list[MultiModalFeatureSpec] | None
    sampling_params: SamplingParams | None
    pooling_params: PoolingParams | None
    eos_token_id: int | None
    arrival_time: float
    lora_request: LoRARequest | None
    cache_salt: str | None
    data_parallel_rank: int | None
    prompt_embeds: torch.Tensor | None = None

    # Index of the client, used to ensure outputs are sent back to the same
    # client for this request when scaling out the front-end.
    client_index: int = 0

    # Used in DP case to indicate which wave of requests this is expected to
    # belong to, to cover a race condition where the request is sent before
    # a wave finished notification is received.
    current_wave: int = 0
    priority: int = 0

    trace_headers: Mapping[str, str] | None = None
    resumable: bool = False

    # The user-provided request ID. This field is set internally,
    # copied from the provided request_id that's originally assigned
    # to the request_id field, see InputProcessor.assign_request_id().
    # Used in outputs and to support abort(req_id, internal=False).
    external_req_id: str | None = None

    reasoning_ended: bool | None = None

    @property
    def params(self) -> SamplingParams | PoolingParams:
        """Return the processed params (sampling or pooling)."""
        if self.sampling_params is not None:
            return self.sampling_params
        assert self.pooling_params is not None
        return self.pooling_params

class EngineCoreRequestType(enum.Enum):
    """
    Request types defined as hex byte strings, so it can be sent over sockets
    without separate encoding step.
    """

    ADD = b"\x00"
    ABORT = b"\x01"
    START_DP_WAVE = b"\x02"
    UTILITY = b"\x03"
    # Sentinel used within EngineCoreProc.
    EXECUTOR_FAILED = b"\x04"

class FinishReason(enum.IntEnum):
    """
    Reason a request finished - stop, length, abort, or error.

    Int rather than Str for more compact serialization.

    stop - a stop string was emitted
    length - max_tokens was consumed, or max_model_len was reached
    abort - aborted by client
    error - retryable request-level internal error (e.g., KV load failure).
            Invariant: always converted to 500 Internal Server Error.

    """

    STOP = 0
    LENGTH = 1
    ABORT = 2
    ERROR = 3

    def __str__(self):
        return FINISH_REASON_STRINGS[self.value]

class ReconfigureRankType(enum.IntEnum):
    """
    Rank type for reconfiguring distributed request.
    """

    KEEP_CURRENT_RANK = -1
    SHUTDOWN_CURRENT_RANK = -2