vllm/cacheflow/sampling_params.py
2023-05-10 12:51:36 -07:00

90 lines
3.2 KiB
Python

from typing import Dict, Set
class SamplingParams:
def __init__(
self,
n: int,
temperature: float,
top_p: float,
top_k: int,
use_beam_search: bool,
stop_token_ids: Set[int],
max_num_steps: int,
num_logprobs: int,
) -> None:
if n < 1:
raise ValueError(f"n must be at least 1, got {n}.")
if temperature < 0.0:
raise ValueError(
f"temperature must be non-negative, got {temperature}.")
if not 0.0 < top_p <= 1.0:
raise ValueError(f"top_p must be in (0, 1], got {top_p}.")
if top_k < -1 or top_k == 0:
raise ValueError(f"top_k must be -1 (disable), or at least 1, "
f"got {top_k}.")
if max_num_steps < 1:
raise ValueError(
f"max_num_steps must be at least 1, got {max_num_steps}.")
if num_logprobs < 0:
raise ValueError(
f"num_logprobs must be non-negative, got {num_logprobs}.")
if use_beam_search:
if n == 1:
raise ValueError(
"n must be greater than 1 when using beam search.")
if temperature > 0.0:
raise ValueError(
"temperature must be 0 when using beam search.")
if top_p < 1.0:
raise ValueError(
"top_p must be 1 when using beam search.")
if top_k != -1:
raise ValueError(
"top_k must be -1 when using beam search.")
elif temperature == 0.0:
# Zero temperature means greedy sampling.
if n > 1:
raise ValueError(
"n must be 1 when using greedy sampling.")
if top_p < 1.0:
raise ValueError(
"top_p must be 1 when using greedy sampling.")
if top_k != -1:
raise ValueError(
"top_k must be -1 when using greedy sampling.")
self.n = n
self.temperature = temperature
self.top_p = top_p
self.top_k = top_k
self.use_beam_search = use_beam_search
self.stop_token_ids = stop_token_ids
self.max_num_steps = max_num_steps
self.num_logprobs = num_logprobs
def __repr__(self) -> str:
return (f"SamplingParams(n={self.n}, "
f"temperature={self.temperature}, "
f"top_p={self.top_p}, "
f"top_k={self.top_k},"
f"use_beam_search={self.use_beam_search}, "
f"stop_token_ids={self.stop_token_ids}, "
f"max_num_steps={self.max_num_steps}, "
f"num_logprobs={self.num_logprobs}")
@classmethod
def from_dict(cls, d: Dict) -> "SamplingParams":
return cls(
n=d.get("n", 1),
temperature=d.get("temperature", 1.0),
top_p=d.get("top_p", 1.0),
top_k=d.get("top_k", -1),
use_beam_search=d.get("use_beam_search", False),
stop_token_ids=set(d.get("stop_token_ids", set())),
max_num_steps=d.get("max_num_steps", 16),
num_logprobs=d.get("num_logprobs", 0),
)