TensorRT-LLMs/tensorrt_llm/scaffolding/controller.py
WeiHaocheng cc286687c4
[None][feat] Refactor scaffolding streaming feature and fix openai wo… (#8622)
Signed-off-by: Fred Wei <20514172+WeiHaocheng@users.noreply.github.com>
2025-10-30 16:02:40 +08:00

302 lines
11 KiB
Python

import copy
from abc import ABC
from enum import Enum
from typing import Any, List, Mapping, Tuple
import torch
from torch.nn import functional as F
from tensorrt_llm.executor.result import GenerationResult
from tensorrt_llm.logger import logger
from tensorrt_llm.scaffolding.math_utils import get_digit_majority_vote_result
from tensorrt_llm.scaffolding.task import GenerationTask, Task
class Controller(ABC):
def __init__(self):
self.task_collections = {}
def clone(self):
return copy.deepcopy(self)
def generate(self, prompt: str, **kwargs) -> GenerationResult:
task = GenerationTask.create_from_prompt(prompt)
yield from self.process([task], **kwargs)
return task.create_scaffolding_output()
def process(self, tasks: List[Task], **kwargs):
raise NotImplementedError
class ParallelProcess:
def __init__(self, controllers: List[Controller],
tasks_list: List[List[Task]], kwargs_list: List[Mapping[str,
Any]]):
self.sub_gens = []
for controller, tasks, kwargs in zip(controllers, tasks_list,
kwargs_list):
gen = controller.process(tasks, **kwargs)
self.sub_gens.append(gen)
# Controller runs multiple generation tasks.
class NativeGenerationController(Controller):
class WorkerTag(Enum):
GENERATION = "generation"
def __init__(self, sampling_params: dict = None, streaming: bool = False):
super().__init__()
if sampling_params is None:
sampling_params = {}
for key, value in list(sampling_params.items()):
if key not in GenerationTask.__annotations__:
logger.warning(
f"{key} is not a supported field for GenerationTask")
sampling_params.pop(key)
self.sampling_params = sampling_params
self.streaming = streaming
def process(self, tasks: List[Task], **kwargs):
for task in tasks:
task.worker_tag = self.WorkerTag.GENERATION
for key, value in self.sampling_params.items():
if getattr(task, key) is None:
setattr(task, key, value)
task.streaming_output_flag = self.streaming
yield tasks
class NativeRewardController(Controller):
def __init__(self):
self.scores = None
class WorkerTag(Enum):
REWARD = "reward"
def process(self, tasks: List[Task], **kwargs):
task = GenerationTask()
for task in tasks:
task.worker_tag = self.WorkerTag.REWARD
yield tasks
class PRMController(NativeRewardController):
"""
Use PRM(Process Reward Model) to get the score of output. Will split
output into multi steps if `split_steps` is True. Otherwise will only
extract last token score.
Output:
The scores of each task will be stored in `self.scores`.
Example:
Suppose the model output is split using a special token like <extra_0>:
Input: "Step1,...<extra_0>Step2,...\\boxed{answer}.<extra_0>."
The function will mask out logits and remain only scores at separate_token.
Each represent the probability score for each step, eg: [0.98, 1.0].
We can assume the output is good when product of all probabilities is high.
"""
def __init__(
self,
tokenizer,
split_steps=True,
step_token="\n\n",
separate_token="<extra_0>", # nosec B107
):
super().__init__()
self.tokenizer = tokenizer
self.split_steps = split_steps
self.step_token = step_token
self.separate_token = separate_token
def _calc_steps_score(self, logits, token_mask):
probs = F.softmax(logits, dim=-1) # seq_len, num_labels=2
masked_probs = probs * token_mask.unsqueeze(-1)[0]
# only keep the logits at the separate_token
step_probs = masked_probs[masked_probs != 0].view(-1, 2)[:, 1]
score = torch.prod(step_probs).item()
return score
def _calc_last_token_score(self, logits):
# seq_len, num_labels=2
probs = F.softmax(logits, dim=-1)
score = probs[-1, 1].item()
return score
def process(self, tasks: List[Task], **kwargs):
reward_tasks = []
for task in tasks:
if self.split_steps:
steps = task.output_str.split(self.step_token)
content = "".join(
(step + self.separate_token) for step in steps)
else:
content = self.separate_token + task.output_str + self.separate_token
# Combine messages using chat template
messages = [
{
"role":
"system",
"content":
"Please reason step by step, and put your final answer within \\boxed{}."
},
{
"role": "user",
"content": task.input_str
},
{
"role": "assistant",
"content": content
},
]
processed_prompt = self.tokenizer.apply_chat_template(
messages, tokenize=False, add_generation_prompt=False)
# TODO: support input_ids as model input, avoid doing it again in worker
reward_task = GenerationTask.create_from_prompt(processed_prompt)
reward_task.worker_tag = self.WorkerTag.REWARD
# TODO: pack this logic
reward_task.max_tokens = 1
reward_task.return_context_logits = True
reward_tasks.append(reward_task)
yield reward_tasks
scores = []
for reward_task in reward_tasks:
assert reward_task.context_logits is not None
# TODO: consider running on cpu to not interrupt worker or move
# tokenizer to a worker
input_ids = self.tokenizer.encode(
reward_task.input_str,
return_tensors="pt",
).to(reward_task.context_logits.device)
if self.split_steps:
# TODO: align add_special_tokens with SamplingParams
token_mask = (input_ids == self.tokenizer.encode(
self.separate_token, add_special_tokens=True)[0])
score = self._calc_steps_score(reward_task.context_logits,
token_mask)
else:
score = self._calc_last_token_score(reward_task.context_logits)
scores.append(score)
self.scores = scores
# Controller runs a single generation task with majority vote.
class MajorityVoteController(Controller):
def __init__(self,
generation_controller: Controller,
default_sample_num: int = 1):
super().__init__()
self.generation_controller = generation_controller
self.default_sample_num = default_sample_num
def clone(self):
# As we don't know the behavior of the generation_controller's clone method,
# we explicitly call clone method instead of simply using deepcopy.
generation_controller = self.generation_controller.clone()
return MajorityVoteController(generation_controller,
self.default_sample_num)
def process(self,
tasks: List[Task],
sample_num: int = 1,
generation_kwargs: dict = {},
majority_vote_kwargs: dict = {}):
sample_num = max(sample_num, self.default_sample_num)
generation_controllers = [
self.generation_controller.clone() for _ in range(sample_num)
]
tasks_list = [copy.deepcopy(tasks) for _ in range(sample_num)]
generation_kwargs_list = [
copy.deepcopy(generation_kwargs) for _ in range(sample_num)
]
yield ParallelProcess(generation_controllers, tasks_list,
generation_kwargs_list)
majority_index, majority_answer = self.majority_vote(
tasks_list, **majority_vote_kwargs)
assert isinstance(majority_answer, str), "majority_vote failed"
# The task returned by majority vote does not have output_tokens and logits.
tasks[0].result = tasks_list[majority_index][0].result
def majority_vote(self, candidates_tasks: List[List[Task]],
**kwargs) -> Tuple[int, str]:
candidates = [tasks[0].output_str for tasks in candidates_tasks]
return get_digit_majority_vote_result(candidates)
# Controller runs a single generation task with best of N.
class BestOfNController(Controller):
def __init__(self,
generation_controller: Controller,
reward_controller: Controller,
default_sample_num: int = 4):
super().__init__()
self.generation_controller = generation_controller
self.reward_controller = reward_controller
self.default_sample_num = default_sample_num
def clone(self):
generation_controller = self.generation_controller.clone()
reward_controller = self.reward_controller.clone()
return BestOfNController(generation_controller, reward_controller,
self.default_sample_num)
def process(self,
tasks: List[Task],
sample_num: int = 4,
generation_kwargs: dict = {},
reward_kwargs: dict = {},
select_best_kwargs: dict = {}):
assert len(tasks) == 1, "BestOfNController only supports one task"
task = tasks[0]
sample_num = max(sample_num, self.default_sample_num)
generation_controllers = [
self.generation_controller for _ in range(sample_num)
]
generation_kwargs_list = [generation_kwargs for _ in range(sample_num)]
generation_tasks = [copy.deepcopy(task) for _ in range(sample_num)]
yield ParallelProcess(generation_controllers,
[[t] for t in generation_tasks],
generation_kwargs_list)
yield from self.reward_controller.process(generation_tasks,
**reward_kwargs)
assert self.reward_controller.scores is not None
reward_values = self.reward_controller.scores
for i, gen_task, reward_value in zip(range(sample_num),
generation_tasks, reward_values):
logger.info(
f"[output {i}, score {reward_value}]:\n{gen_task.output_str}")
best_task, best_idx = self.select_best(generation_tasks, reward_values,
**select_best_kwargs)
task.result = best_task.result
def select_best(self, tasks: List[Task], reward_values, **kwargs) -> Task:
max_index = torch.argmax(torch.tensor(reward_values)).item()
return tasks[max_index], max_index