LM Format Enforcer Guided Decoding Support (#3868)

Co-authored-by: Simon Mo <simon.mo@hey.com>
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Noam Gat 2024-04-16 08:54:57 +03:00 committed by GitHub
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13 changed files with 304 additions and 87 deletions

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@ -11,6 +11,7 @@ uvicorn[standard]
pydantic >= 2.0 # Required for OpenAI server.
prometheus_client >= 0.18.0
tiktoken == 0.6.0 # Required for DBRX tokenizer
lm-format-enforcer == 0.9.3
outlines == 0.0.34 # Requires torch >= 2.1.0
typing_extensions
filelock >= 3.10.4 # filelock starts to support `mode` argument from 3.10.4

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@ -1,11 +1,14 @@
# This unit test should be moved to a new
# tests/test_guided_decoding directory.
import pytest
import torch
from transformers import AutoTokenizer
from vllm.model_executor.guided_logits_processors import (JSONLogitsProcessor,
RegexLogitsProcessor)
from vllm.entrypoints.openai.protocol import CompletionRequest
from vllm.model_executor.guided_decoding import (
get_guided_decoding_logits_processor)
from vllm.model_executor.guided_decoding.outlines_logits_processors import (
JSONLogitsProcessor, RegexLogitsProcessor)
TEST_SCHEMA = {
"type": "object",
@ -73,3 +76,36 @@ def test_guided_logits_processors():
json_LP(token_ids, tensor)
assert tensor.shape == original_tensor.shape
assert not torch.allclose(tensor, original_tensor)
@pytest.mark.asyncio
@pytest.mark.parametrize("backend", ["outlines", "lm-format-enforcer"])
async def test_guided_logits_processor_black_box(backend: str):
tokenizer = AutoTokenizer.from_pretrained('HuggingFaceH4/zephyr-7b-beta')
token_ids = tokenizer.encode(
f"Give an example IPv4 address with this regex: {TEST_REGEX}")
regex_request = CompletionRequest(model='test',
prompt=token_ids,
guided_regex=TEST_REGEX)
regex_lp = await get_guided_decoding_logits_processor(
backend, regex_request, tokenizer)
assert regex_lp is not None
tensor = torch.rand(32000)
original_tensor = torch.clone(tensor)
tensor = regex_lp(token_ids, tensor)
assert tensor.shape == original_tensor.shape
assert not torch.allclose(tensor, original_tensor)
token_ids = tokenizer.encode(
f"Give an employee profile that fits this schema: {TEST_SCHEMA}")
json_request = CompletionRequest(model='test',
prompt=token_ids,
guided_json=TEST_SCHEMA)
json_lp = await get_guided_decoding_logits_processor(
backend, json_request, tokenizer)
assert json_lp is not None
tensor = torch.rand(32000)
original_tensor = torch.clone(tensor)
tensor = json_lp(token_ids, tensor)
assert tensor.shape == original_tensor.shape
assert not torch.allclose(tensor, original_tensor)

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@ -506,7 +506,10 @@ async def test_logits_bias(server, client: openai.AsyncOpenAI):
assert first_response != completion.choices[0].text
async def test_guided_json_completion(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_json_completion(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
completion = await client.completions.create(
model=MODEL_NAME,
prompt=f"Give an example JSON for an employee profile "
@ -514,7 +517,8 @@ async def test_guided_json_completion(server, client: openai.AsyncOpenAI):
n=3,
temperature=1.0,
max_tokens=500,
extra_body=dict(guided_json=TEST_SCHEMA))
extra_body=dict(guided_json=TEST_SCHEMA,
guided_decoding_backend=guided_decoding_backend))
assert completion.id is not None
assert completion.choices is not None and len(completion.choices) == 3
@ -524,7 +528,10 @@ async def test_guided_json_completion(server, client: openai.AsyncOpenAI):
jsonschema.validate(instance=output_json, schema=TEST_SCHEMA)
async def test_guided_json_chat(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_json_chat(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
messages = [{
"role": "system",
"content": "you are a helpful assistant"
@ -538,8 +545,9 @@ async def test_guided_json_chat(server, client: openai.AsyncOpenAI):
chat_completion = await client.chat.completions.create(
model=MODEL_NAME,
messages=messages,
max_tokens=500,
extra_body=dict(guided_json=TEST_SCHEMA))
max_tokens=1000,
extra_body=dict(guided_json=TEST_SCHEMA,
guided_decoding_backend=guided_decoding_backend))
message = chat_completion.choices[0].message
assert message.content is not None
json1 = json.loads(message.content)
@ -555,8 +563,9 @@ async def test_guided_json_chat(server, client: openai.AsyncOpenAI):
chat_completion = await client.chat.completions.create(
model=MODEL_NAME,
messages=messages,
max_tokens=500,
extra_body=dict(guided_json=TEST_SCHEMA))
max_tokens=1000,
extra_body=dict(guided_json=TEST_SCHEMA,
guided_decoding_backend=guided_decoding_backend))
message = chat_completion.choices[0].message
assert message.content is not None
json2 = json.loads(message.content)
@ -565,14 +574,18 @@ async def test_guided_json_chat(server, client: openai.AsyncOpenAI):
assert json1["age"] != json2["age"]
async def test_guided_regex_completion(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_regex_completion(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
completion = await client.completions.create(
model=MODEL_NAME,
prompt=f"Give an example IPv4 address with this regex: {TEST_REGEX}",
n=3,
temperature=1.0,
max_tokens=20,
extra_body=dict(guided_regex=TEST_REGEX))
extra_body=dict(guided_regex=TEST_REGEX,
guided_decoding_backend=guided_decoding_backend))
assert completion.id is not None
assert completion.choices is not None and len(completion.choices) == 3
@ -581,7 +594,10 @@ async def test_guided_regex_completion(server, client: openai.AsyncOpenAI):
assert re.fullmatch(TEST_REGEX, completion.choices[i].text) is not None
async def test_guided_regex_chat(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_regex_chat(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
messages = [{
"role": "system",
"content": "you are a helpful assistant"
@ -595,7 +611,8 @@ async def test_guided_regex_chat(server, client: openai.AsyncOpenAI):
model=MODEL_NAME,
messages=messages,
max_tokens=20,
extra_body=dict(guided_regex=TEST_REGEX))
extra_body=dict(guided_regex=TEST_REGEX,
guided_decoding_backend=guided_decoding_backend))
ip1 = chat_completion.choices[0].message.content
assert ip1 is not None
assert re.fullmatch(TEST_REGEX, ip1) is not None
@ -606,21 +623,26 @@ async def test_guided_regex_chat(server, client: openai.AsyncOpenAI):
model=MODEL_NAME,
messages=messages,
max_tokens=20,
extra_body=dict(guided_regex=TEST_REGEX))
extra_body=dict(guided_regex=TEST_REGEX,
guided_decoding_backend=guided_decoding_backend))
ip2 = chat_completion.choices[0].message.content
assert ip2 is not None
assert re.fullmatch(TEST_REGEX, ip2) is not None
assert ip1 != ip2
async def test_guided_choice_completion(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_choice_completion(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
completion = await client.completions.create(
model=MODEL_NAME,
prompt="The best language for type-safe systems programming is ",
n=2,
temperature=1.0,
max_tokens=10,
extra_body=dict(guided_choice=TEST_CHOICE))
extra_body=dict(guided_choice=TEST_CHOICE,
guided_decoding_backend=guided_decoding_backend))
assert completion.id is not None
assert completion.choices is not None and len(completion.choices) == 2
@ -628,7 +650,10 @@ async def test_guided_choice_completion(server, client: openai.AsyncOpenAI):
assert completion.choices[i].text in TEST_CHOICE
async def test_guided_choice_chat(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_choice_chat(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
messages = [{
"role": "system",
"content": "you are a helpful assistant"
@ -642,7 +667,8 @@ async def test_guided_choice_chat(server, client: openai.AsyncOpenAI):
model=MODEL_NAME,
messages=messages,
max_tokens=10,
extra_body=dict(guided_choice=TEST_CHOICE))
extra_body=dict(guided_choice=TEST_CHOICE,
guided_decoding_backend=guided_decoding_backend))
choice1 = chat_completion.choices[0].message.content
assert choice1 in TEST_CHOICE
@ -655,18 +681,23 @@ async def test_guided_choice_chat(server, client: openai.AsyncOpenAI):
model=MODEL_NAME,
messages=messages,
max_tokens=10,
extra_body=dict(guided_choice=TEST_CHOICE))
extra_body=dict(guided_choice=TEST_CHOICE,
guided_decoding_backend=guided_decoding_backend))
choice2 = chat_completion.choices[0].message.content
assert choice2 in TEST_CHOICE
assert choice1 != choice2
async def test_guided_decoding_type_error(server, client: openai.AsyncOpenAI):
@pytest.mark.parametrize("guided_decoding_backend",
["outlines", "lm-format-enforcer"])
async def test_guided_decoding_type_error(server, client: openai.AsyncOpenAI,
guided_decoding_backend: str):
with pytest.raises(openai.BadRequestError):
_ = await client.completions.create(
model=MODEL_NAME,
prompt="Give an example JSON that fits this schema: 42",
extra_body=dict(guided_json=42))
extra_body=dict(guided_json=42,
guided_decoding_backend=guided_decoding_backend))
messages = [{
"role": "system",

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@ -66,8 +66,8 @@ class ModelConfig:
weights. If None, we assume the model weights are not quantized.
quantization_param_path: Path to JSON file containing scaling factors.
Used to load KV cache scaling factors into the model when KV cache
type is FP8_E4M3 on ROCm (AMD GPU). In the future these will also
be used to load activation and weight scaling factors when the
type is FP8_E4M3 on ROCm (AMD GPU). In the future these will also
be used to load activation and weight scaling factors when the
model dtype is FP8_E4M3 on ROCm.
enforce_eager: Whether to enforce eager execution. If True, we will
disable CUDA graph and always execute the model in eager mode.
@ -422,7 +422,7 @@ class CacheConfig:
@dataclass
class TokenizerPoolConfig:
"""Configuration for the tokenizer pool.
Args:
pool_size: Number of tokenizer workers in the pool.
pool_type: Type of the pool.
@ -446,9 +446,9 @@ class TokenizerPoolConfig:
tokenizer_pool_extra_config: Optional[Union[str, dict]]
) -> Optional["TokenizerPoolConfig"]:
"""Create a TokenizerPoolConfig from the given parameters.
If tokenizer_pool_size is 0, return None.
Args:
tokenizer_pool_size: Number of tokenizer workers in the pool.
tokenizer_pool_type: Type of the pool.
@ -1079,6 +1079,21 @@ def _get_and_verify_max_len(
return int(max_model_len)
@dataclass
class DecodingConfig:
"""Dataclass which contains the decoding strategy of the engine"""
# Which guided decoding algo to use. 'outlines' / 'lm-format-enforcer'
guided_decoding_backend: str = 'outlines'
def __post_init__(self):
valid_guided_backends = ['outlines', 'lm-format-enforcer']
backend = self.guided_decoding_backend
if backend not in valid_guided_backends:
raise ValueError(f"Invalid guided_decoding_backend '{backend},"
f"must be one of {valid_guided_backends}")
@dataclass(frozen=True)
class EngineConfig:
"""Dataclass which contains all engine-related configuration. This
@ -1093,6 +1108,7 @@ class EngineConfig:
lora_config: Optional[LoRAConfig]
vision_language_config: Optional[VisionLanguageConfig]
speculative_config: Optional[SpeculativeConfig]
decoding_config: Optional[DecodingConfig]
tensorizer_config: Optional[TensorizerConfig]
def __post_init__(self):

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@ -5,9 +5,9 @@ import os
from dataclasses import dataclass
from typing import BinaryIO, Optional, Union
from vllm.config import (CacheConfig, DeviceConfig, EngineConfig, LoRAConfig,
ModelConfig, ParallelConfig, SchedulerConfig,
SpeculativeConfig, TensorizerConfig,
from vllm.config import (CacheConfig, DecodingConfig, DeviceConfig,
EngineConfig, LoRAConfig, ModelConfig, ParallelConfig,
SchedulerConfig, SpeculativeConfig, TensorizerConfig,
TokenizerPoolConfig, VisionLanguageConfig)
from vllm.model_executor.tensorizer_loader import TensorizerArgs
from vllm.utils import str_to_int_tuple
@ -80,6 +80,7 @@ class EngineArgs:
scheduler_delay_factor: float = 0.0
enable_chunked_prefill: bool = False
guided_decoding_backend: str = 'outlines'
# Speculative decoding configuration.
speculative_model: Optional[str] = None
num_speculative_tokens: Optional[int] = None
@ -200,6 +201,13 @@ class EngineArgs:
default=EngineArgs.max_model_len,
help='model context length. If unspecified, '
'will be automatically derived from the model.')
parser.add_argument(
'--guided-decoding-backend',
type=str,
default='outlines',
choices=['outlines', 'lm-format-enforcer'],
help='Which engine will be used for guided decoding'
' (JSON schema / regex etc)')
# Parallel arguments
parser.add_argument('--worker-use-ray',
action='store_true',
@ -511,6 +519,9 @@ class EngineArgs:
else:
vision_language_config = None
decoding_config = DecodingConfig(
guided_decoding_backend=self.guided_decoding_backend)
return EngineConfig(model_config=model_config,
cache_config=cache_config,
parallel_config=parallel_config,
@ -519,6 +530,7 @@ class EngineArgs:
lora_config=lora_config,
vision_language_config=vision_language_config,
speculative_config=speculative_config,
decoding_config=decoding_config,
tensorizer_config=tensorizer_config)

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@ -4,9 +4,10 @@ from typing import Iterable, List, Optional, Tuple, Type, Union
from transformers import PreTrainedTokenizer
import vllm
from vllm.config import (CacheConfig, DeviceConfig, LoRAConfig, ModelConfig,
ParallelConfig, SchedulerConfig, SpeculativeConfig,
TensorizerConfig, VisionLanguageConfig)
from vllm.config import (CacheConfig, DecodingConfig, DeviceConfig, LoRAConfig,
ModelConfig, ParallelConfig, SchedulerConfig,
SpeculativeConfig, TensorizerConfig,
VisionLanguageConfig)
from vllm.core.scheduler import Scheduler, SchedulerOutputs
from vllm.engine.arg_utils import EngineArgs
from vllm.engine.metrics import StatLogger, Stats
@ -74,6 +75,7 @@ class LLMEngine:
lora_config: Optional[LoRAConfig],
vision_language_config: Optional[VisionLanguageConfig],
speculative_config: Optional[SpeculativeConfig],
decoding_config: Optional[DecodingConfig],
tensorizer_config: Optional[TensorizerConfig],
executor_class: Type[ExecutorBase],
log_stats: bool,
@ -100,6 +102,7 @@ class LLMEngine:
f"kv_cache_dtype={cache_config.cache_dtype}, "
f"quantization_param_path={model_config.quantization_param_path}, "
f"device_config={device_config.device}, "
f"decoding_config={decoding_config!r}, "
f"seed={model_config.seed})")
# TODO(woosuk): Print more configs in debug mode.
@ -111,6 +114,7 @@ class LLMEngine:
self.scheduler_config = scheduler_config
self.device_config = device_config
self.speculative_config = speculative_config
self.decoding_config = decoding_config or DecodingConfig()
self.tensorizer_config = tensorizer_config
self.log_stats = log_stats

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@ -133,6 +133,12 @@ class ChatCompletionRequest(BaseModel):
description=(
"If specified, the output will follow the context free grammar."),
)
guided_decoding_backend: Optional[str] = Field(
default=None,
description=(
"If specified, will override the default guided decoding backend "
"of the server for this specific request. If set, must be either "
"'outlines' / 'lm-format-enforcer'"))
# doc: end-chat-completion-extra-params
@ -265,6 +271,12 @@ class CompletionRequest(BaseModel):
description=(
"If specified, the output will follow the context free grammar."),
)
guided_decoding_backend: Optional[str] = Field(
default=None,
description=(
"If specified, will override the default guided decoding backend "
"of the server for this specific request. If set, must be one of "
"'outlines' / 'lm-format-enforcer'"))
# doc: end-completion-extra-params

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@ -68,9 +68,13 @@ class OpenAIServingChat(OpenAIServing):
request, prompt=prompt)
sampling_params = request.to_sampling_params()
lora_request = self._maybe_get_lora(request)
decoding_config = self.engine.engine.decoding_config
guided_decoding_backend = request.guided_decoding_backend \
or decoding_config.guided_decoding_backend
guided_decode_logits_processor = (
await get_guided_decoding_logits_processor(
request, await self.engine.get_tokenizer()))
guided_decoding_backend, request, await
self.engine.get_tokenizer()))
if guided_decode_logits_processor:
if sampling_params.logits_processors is None:
sampling_params.logits_processors = []

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@ -88,9 +88,13 @@ class OpenAIServingCompletion(OpenAIServing):
try:
sampling_params = request.to_sampling_params()
lora_request = self._maybe_get_lora(request)
decoding_config = self.engine.engine.decoding_config
guided_decoding_backend = request.guided_decoding_backend \
or decoding_config.guided_decoding_backend
guided_decode_logit_processor = (
await get_guided_decoding_logits_processor(
request, await self.engine.get_tokenizer()))
guided_decoding_backend, request, await
self.engine.get_tokenizer()))
if guided_decode_logit_processor is not None:
if sampling_params.logits_processors is None:
sampling_params.logits_processors = []

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@ -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'")

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@ -0,0 +1,69 @@
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()
@lru_cache
def _cached_build_vllm_token_enforcer_tokenizer_data(
tokenizer: PreTrainedTokenizerBase) -> TokenEnforcerTokenizerData:
return build_vllm_token_enforcer_tokenizer_data(tokenizer)

View File

@ -12,9 +12,8 @@ from transformers import PreTrainedTokenizerBase
from vllm.entrypoints.openai.protocol import (ChatCompletionRequest,
CompletionRequest)
from vllm.model_executor.guided_logits_processors import (CFGLogitsProcessor,
JSONLogitsProcessor,
RegexLogitsProcessor)
from vllm.model_executor.guided_decoding.outlines_logits_processors import (
CFGLogitsProcessor, JSONLogitsProcessor, RegexLogitsProcessor)
class GuidedDecodingMode(Enum):
@ -54,7 +53,7 @@ pair : UNESCAPED_STRING ":" value
global_thread_pool = None # used for generating logits processor fsm
async def get_guided_decoding_logits_processor(
async def get_outlines_guided_decoding_logits_processor(
request: Union[CompletionRequest, ChatCompletionRequest],
tokenizer) -> Union[JSONLogitsProcessor, RegexLogitsProcessor]:
"""

View File

@ -13,9 +13,11 @@
# 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, Optional, Union
import torch
@ -27,50 +29,6 @@ from transformers import PreTrainedTokenizerBase
class BaseLogitsProcessor:
def adapt_tokenizer(self, 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.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
def init_state(self):
"""Initialize the FSM states."""
self.fsm_state: DefaultDict[int, int] = defaultdict(int)
@ -78,7 +36,6 @@ class BaseLogitsProcessor:
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:
@ -96,7 +53,6 @@ class BaseLogitsProcessor:
device=scores.device)
mask[allowed_tokens] = 0
scores.add_(mask)
return scores
@ -113,7 +69,7 @@ class RegexLogitsProcessor(BaseLogitsProcessor):
The model's tokenizer
"""
tokenizer = self.adapt_tokenizer(tokenizer)
tokenizer = _adapt_tokenizer(tokenizer)
fsm = RegexFSM(regex_string, tokenizer)
self.fsm = fsm
@ -167,6 +123,54 @@ class CFGLogitsProcessor(BaseLogitsProcessor):
The model's tokenizer
"""
tokenizer = self.adapt_tokenizer(tokenizer)
tokenizer = _adapt_tokenizer(tokenizer)
fsm = CFGFSM(cfg, tokenizer)
self.fsm = fsm
@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