This commit is contained in:
2026-01-09 13:34:11 +08:00
parent dfa6476b58
commit b2ef04d792
538 changed files with 105693 additions and 2 deletions

View File

@@ -0,0 +1,25 @@
from typing import Optional, Union
from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
CompletionRequest)
from vllm.model_executor.guided_decoding.lm_format_enforcer_decoding import (
get_lm_format_enforcer_guided_decoding_logits_processor)
from vllm.model_executor.guided_decoding.outlines_decoding import (
get_outlines_guided_decoding_logits_processor)
from vllm.sampling_params import LogitsProcessor
async def get_guided_decoding_logits_processor(
guided_decoding_backend: str, request: Union[CompletionRequest,
ChatCompletionRequest],
tokenizer) -> Optional[LogitsProcessor]:
if guided_decoding_backend == 'outlines':
return await get_outlines_guided_decoding_logits_processor(
request, tokenizer)
if guided_decoding_backend == 'lm-format-enforcer':
return await get_lm_format_enforcer_guided_decoding_logits_processor(
request, tokenizer)
raise ValueError(
f"Unknown guided decoding backend '{guided_decoding_backend}'. "
"Must be one of 'outlines, 'lm-format-enforcer'")

View File

@@ -0,0 +1,70 @@
from functools import lru_cache
from json import loads as json_loads
from typing import Optional, Union
from lmformatenforcer import (CharacterLevelParser, JsonSchemaParser,
RegexParser, StringParser,
TokenEnforcerTokenizerData, UnionParser)
from lmformatenforcer.integrations.vllm import (
build_vllm_logits_processor, build_vllm_token_enforcer_tokenizer_data)
from pydantic import BaseModel
from transformers import PreTrainedTokenizerBase
from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
CompletionRequest)
from vllm.model_executor.guided_decoding.outlines_decoding import (
get_outlines_guided_decoding_logits_processor)
from vllm.sampling_params import LogitsProcessor
async def get_lm_format_enforcer_guided_decoding_logits_processor(
request: Union[CompletionRequest, ChatCompletionRequest],
tokenizer) -> Optional[LogitsProcessor]:
"""
Given an OpenAI-compatible request, check for guided decoding parameters
and get the necessary logits processor for the given guide.
We cache logit processors by (guide, tokenizer), and on cache hit
we make a shallow copy to reuse the same underlying FSM.
"""
tokenizer_data = _cached_build_vllm_token_enforcer_tokenizer_data(
tokenizer)
character_level_parser: CharacterLevelParser
if request.guided_json:
schema = _normalize_json_schema_object(request.guided_json)
character_level_parser = JsonSchemaParser(schema)
elif request.guided_choice:
character_level_parser = UnionParser(
[StringParser(choice) for choice in request.guided_choice])
elif request.guided_regex:
character_level_parser = RegexParser(request.guided_regex)
elif request.guided_grammar:
# CFG grammar not supported by LMFE, revert to outlines
return await get_outlines_guided_decoding_logits_processor(
request, tokenizer)
elif (request.response_format is not None
and request.response_format.type == "json_object"):
character_level_parser = JsonSchemaParser(
None) # None means any json object
else:
return None
logits_processor = build_vllm_logits_processor(tokenizer_data,
character_level_parser)
return logits_processor
def _normalize_json_schema_object(schema: Union[str, dict, BaseModel]) -> dict:
if isinstance(schema, str):
return json_loads(schema)
if isinstance(schema, dict):
return schema
if isinstance(schema, BaseModel):
return schema.model_json_schema()
raise AssertionError(f"Unsupported schema type {schema}")
@lru_cache
def _cached_build_vllm_token_enforcer_tokenizer_data(
tokenizer: PreTrainedTokenizerBase) -> TokenEnforcerTokenizerData:
return build_vllm_token_enforcer_tokenizer_data(tokenizer)

View File

@@ -0,0 +1,130 @@
import asyncio
import concurrent.futures
from copy import copy
from enum import Enum
from functools import lru_cache
from json import dumps as json_dumps
from re import escape as regex_escape
from typing import Tuple, Union
from pydantic import BaseModel
from transformers import PreTrainedTokenizerBase
from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
CompletionRequest)
from vllm.model_executor.guided_decoding.outlines_logits_processors import (
CFGLogitsProcessor, JSONLogitsProcessor, RegexLogitsProcessor)
class GuidedDecodingMode(Enum):
JSON = "json"
REGEX = "regex"
CHOICE = "choice"
GRAMMAR = "grammar"
# https://github.com/outlines-dev/outlines/blob/main/outlines/grammars/json.lark
# the main difference is that we changed the start: value to
# start: object | array, so we are denying scalar values as the root of the
# JSON. Starting with scalars as the root seems to cause llama to generate
# without stop.
JSON_GRAMMAR = r"""
?start: object | array
?value: object
| array
| UNESCAPED_STRING
| SIGNED_NUMBER -> number
| "true" -> true
| "false" -> false
| "null" -> null
array : "[" [value ("," value)*] "]"
object : "{" [pair ("," pair)*] "}"
pair : UNESCAPED_STRING ":" value
%import common.UNESCAPED_STRING
%import common.SIGNED_NUMBER
%import common.WS
%ignore WS
"""
global_thread_pool = None # used for generating logits processor fsm
async def get_outlines_guided_decoding_logits_processor(
request: Union[CompletionRequest, ChatCompletionRequest],
tokenizer) -> Union[JSONLogitsProcessor, RegexLogitsProcessor, None]:
"""
Given an OpenAI-compatible request, check for guided decoding parameters
and get the necessary logits processor for the given guide.
We cache logit processors by (guide, tokenizer), and on cache hit
we make a shallow copy to reuse the same underlying FSM.
"""
global global_thread_pool
guide, mode = _get_guide_and_mode(request)
if not guide:
return None
if global_thread_pool is None:
global_thread_pool = concurrent.futures.ThreadPoolExecutor(
max_workers=2)
loop = asyncio.get_running_loop()
result = await loop.run_in_executor(global_thread_pool,
_get_cached_logits_processor, guide,
tokenizer, mode,
request.guided_whitespace_pattern)
logits_processor = copy(result)
# reset logits processor's internal state
logits_processor.init_state()
return logits_processor
def _get_guide_and_mode(
request: Union[CompletionRequest, ChatCompletionRequest]
) -> Union[Tuple[str, GuidedDecodingMode], Tuple[None, None]]:
if request.guided_json:
json = request.guided_json
if isinstance(json, dict):
# turn dict into hashable string
json = json_dumps(json)
elif isinstance(json, BaseModel):
# use pydantic signature so that different model classes
# with the same fields will get hashed the same
json = str(json.__signature__)
return json, GuidedDecodingMode.JSON
elif request.guided_regex:
return request.guided_regex, GuidedDecodingMode.REGEX
elif request.guided_choice:
# choice just uses regex
choices = [
regex_escape(str(choice)) for choice in request.guided_choice
]
choices_regex = "(" + "|".join(choices) + ")"
return choices_regex, GuidedDecodingMode.CHOICE
elif request.guided_grammar:
return request.guided_grammar, GuidedDecodingMode.GRAMMAR
elif (request.response_format is not None
and request.response_format.type == "json_object"):
return JSON_GRAMMAR, GuidedDecodingMode.GRAMMAR
else:
return None, None
@lru_cache(maxsize=32)
def _get_cached_logits_processor(guide: str,
tokenizer: PreTrainedTokenizerBase,
mode: GuidedDecodingMode,
whitespace_pattern: Union[str, None]):
if mode == GuidedDecodingMode.JSON:
return JSONLogitsProcessor(guide, tokenizer, whitespace_pattern)
elif mode == GuidedDecodingMode.REGEX or mode == GuidedDecodingMode.CHOICE:
return RegexLogitsProcessor(guide, tokenizer)
elif mode == GuidedDecodingMode.GRAMMAR:
return CFGLogitsProcessor(guide, tokenizer)
else:
raise ValueError(f"Unknown guided decoding mode {mode}")

View File

@@ -0,0 +1,184 @@
# Copyright 2024- the Outlines developers
# This file is adapted from
# https://github.com/outlines-dev/outlines/blob/main/outlines/serve/vllm.py
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import copy
import json
import math
from collections import defaultdict
from functools import lru_cache
from typing import Callable, DefaultDict, Dict, List, Union
import torch
from outlines.fsm.fsm import CFGFSM, FSM, RegexFSM
from outlines.fsm.json_schema import build_regex_from_schema
from pydantic import BaseModel
from transformers import PreTrainedTokenizerBase
class BaseLogitsProcessor:
def __init__(self):
# Child class should use initialize in their init.
self.fsm: FSM
def init_state(self):
"""Initialize the FSM states."""
self.fsm_state: DefaultDict[int, int] = defaultdict(int)
def __call__(self, input_ids: List[int],
scores: torch.Tensor) -> torch.Tensor:
"""Use the FSM to bias the logits before sampling the next token."""
seq_id = hash(tuple(input_ids))
if len(input_ids) == 0:
self.init_state()
else:
last_token = input_ids[-1]
last_seq_id = hash(tuple(input_ids[:-1]))
self.fsm_state[seq_id] = self.fsm.next_state(
self.fsm_state[last_seq_id], last_token)
allowed_tokens = self.fsm.allowed_token_ids(self.fsm_state[seq_id])
mask = torch.full((scores.shape[-1], ),
-math.inf,
device=scores.device)
mask[allowed_tokens] = 0
scores.add_(mask)
return scores
class RegexLogitsProcessor(BaseLogitsProcessor):
def __init__(self, regex_string: str, tokenizer: PreTrainedTokenizerBase):
"""Compile the FSM that drives the regex-structured generation.
Parameters
----------
regex_string
A string that represents a regular expression
tokenizer
The model's tokenizer
"""
tokenizer = _adapt_tokenizer(tokenizer)
fsm = RegexFSM(regex_string, tokenizer)
self.fsm = fsm
class JSONLogitsProcessor(RegexLogitsProcessor):
def __init__(self, schema: Union[str, Dict, BaseModel],
tokenizer: PreTrainedTokenizerBase,
whitespace_pattern: Union[str, None]):
"""Compile the FSM that drives the JSON-guided generation.
Parameters
----------
schema
A JSON schema that encodes the structure we want the model to
generate
tokenizer
The model's tokenizer
whitespace_pattern
Pattern to use for JSON syntactic whitespace (doesn't impact
string literals)
Example: allow only a single space or newline with
`whitespace_pattern=r"[\n ]?"`
"""
if isinstance(schema, type(BaseModel)):
schema_str = json.dumps(schema.model_json_schema())
elif isinstance(schema, Dict):
schema_str = json.dumps(schema)
elif isinstance(schema, str):
schema_str = schema
else:
raise ValueError(
f"Cannot parse schema {schema}. The schema must be either "
f"a Pydantic object, a dictionary or a string that contains "
f"the JSON Schema specification")
regex_string = build_regex_from_schema(schema_str, whitespace_pattern)
super().__init__(regex_string, tokenizer)
class CFGLogitsProcessor(BaseLogitsProcessor):
def __init__(self, cfg: str, tokenizer: PreTrainedTokenizerBase):
"""Compile the FSM that drives the context free grammar generation.
Parameters
----------
cfg
A string that represents a context-free grammar
tokenizer
The model's tokenizer
"""
tokenizer = _adapt_tokenizer(tokenizer)
fsm = CFGFSM(cfg, tokenizer)
self.fsm = fsm
def init_state(self):
"""Initialize state with a CFGFSM copy."""
super().init_state()
self.fsm = self.fsm.copy()
@lru_cache
def _adapt_tokenizer(tokenizer: PreTrainedTokenizerBase):
"""Adapt vLLM's tokenizer to use to compile the FSM.
The API of Outlines tokenizers is slightly different to that of
`transformers`. The decoder of outlines, returns a list whereas
the decode of vLLM returns an str. To sync the vLLM decoder with
outlines internal api, the decoder should be adapted. In addition
we need to handle the missing spaces to Llama's tokenizer to be
able to compile FSMs for this model.
"""
if getattr(tokenizer, "_outlines_adapted", False):
return tokenizer
tokenizer = copy.deepcopy(tokenizer)
tokenizer.vocabulary = tokenizer.get_vocab()
tokenizer.special_tokens = set(tokenizer.all_special_tokens)
def convert_token_to_string(token: str) -> str:
from transformers.file_utils import SPIECE_UNDERLINE
string = tokenizer.convert_tokens_to_string([token])
# A hack to handle missing spaces to HF's Llama tokenizers
if token.startswith(SPIECE_UNDERLINE) or token == "<0x20>":
return " " + string
return string
def change_decoder(
decoder: Callable[[List[int]],
str]) -> Callable[[List[int]], List[str]]:
"""Sync vLLM's decoder with the outlines by returning list."""
def new_decoder(inp_tokens: List[int]) -> List[str]:
return [decoder(inp_tokens)]
return new_decoder
tokenizer.convert_token_to_string = convert_token_to_string
tokenizer.decode = change_decoder(tokenizer.decode)
setattr(tokenizer, "_outlines_adapted", True) # noqa: B010
return tokenizer