Files
nano-vllm/nanovllm/engine/sequence.py
2025-06-14 13:36:57 +08:00

82 lines
2.2 KiB
Python

from copy import copy
from enum import Enum, auto
from itertools import count
from nanovllm.sampling_params import SamplingParams
class SequenceStatus(Enum):
WAITING = auto()
RUNNING = auto()
FINISHED = auto()
class Sequence:
block_size = 256
counter = count()
def __init__(self, token_ids: list[int], sampling_params: SamplingParams):
self.seq_id = next(Sequence.counter)
self.status = SequenceStatus.WAITING
self.token_ids = copy(token_ids)
self.last_token = token_ids[-1]
self.num_tokens = len(self.token_ids)
self.num_prompt_tokens = len(token_ids)
self.num_cached_tokens = 0
self.block_table = []
self.temperature = sampling_params.temperature
self.max_tokens = sampling_params.max_tokens
self.ignore_eos = sampling_params.ignore_eos
def __len__(self):
return self.num_tokens
def __lt__(self, other):
return self.seq_id < other.seq_id
def __getitem__(self, key):
return self.token_ids[key]
@property
def is_finished(self):
return self.status == SequenceStatus.FINISHED
@property
def num_completion_tokens(self):
return self.num_tokens - self.num_prompt_tokens
@property
def prompt_token_ids(self):
return self.token_ids[:self.num_prompt_tokens]
@property
def completion_token_ids(self):
return self.token_ids[self.num_prompt_tokens:]
@property
def num_cached_blocks(self):
return self.num_cached_tokens // self.block_size
@property
def num_blocks(self):
return (self.num_tokens + self.block_size - 1) // self.block_size
@property
def last_block_num_tokens(self):
return self.num_tokens - (self.num_blocks - 1) * self.block_size
def block(self, i):
assert 0 <= i < self.num_blocks
return self.token_ids[i*self.block_size: (i+1)*self.block_size]
def append_token(self, token_id: int):
self.token_ids.append(token_id)
self.last_token = token_id
self.num_tokens += 1
def __getstate__(self):
state = super().__getstate__()
if self.num_completion_tokens:
state.pop("token_ids")
return state