File size: 12,382 Bytes
f238c4c |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 |
import abc
import hashlib
import json
import logging
import os
from typing import List, Optional, Tuple, Type, TypeVar
import transformers
from sqlitedict import SqliteDict
from tqdm import tqdm
from lm_eval import utils
eval_logger = logging.getLogger("lm-eval")
T = TypeVar("T", bound="LM")
class LM(abc.ABC):
def __init__(self) -> None:
"""Defines the interface that should be implemented by all LM subclasses.
LMs are assumed to take text (strings) as input and yield strings as output
(inputs/outputs should be tokenization-agnostic.)
"""
# set rank and world size to a single process, by default.
self._rank = 0
self._world_size = 1
self.cache_hook = CacheHook(None)
@abc.abstractmethod
def loglikelihood(self, requests) -> List[Tuple[float, bool]]:
"""Compute log-likelihood of generating a continuation from a context.
Downstream tasks should attempt to use loglikelihood instead of other
LM calls whenever possible.
:param requests: list[Instance]
A list of Instance objects, with property `args` which returns a tuple (context, continuation).
`context: str`
Context string. Implementations of LM must be able to handle an
empty context string.
`continuation: str`
The continuation over which log likelihood will be calculated. If
there is a word boundary, the space should be in the continuation.
For example, context="hello" continuation=" world" is correct.
:return: list[tuple[float, bool]]
A list of pairs (logprob, isgreedy)
`logprob: float`
The log probability of `continuation`.
`isgreedy`:
Whether `continuation` would be generated by greedy sampling from `context`.
"""
pass
@abc.abstractmethod
def loglikelihood_rolling(self, requests) -> List[Tuple[float]]:
"""Compute full log-likelihood of a string, with no truncation, for perplexity computation
- We will use the full max context length of the model.
- For inputs that exceed the max context length, we divide the tokenized string into chunks of up to
the max context length.
- IMPORTANT: Each document's loglikelihood/perplexity is computed *separately*, unlike other implementations
which may simply concatenate multiple documents together.
- IMPORTANT: We maximize the amount of context for each prediction. Specifically, for inputs that we break into
multiple chunks, the last input will still a full-sized context.
Example:
Input tokens: [ 0 1 2 3 4 5 6 7 8 9 ]
Prefix: BOS/EOS
Max context length: 4
Resulting input/prediction pairs:
INPUT: BOS 0 1 2
PRED: 0 1 2 3
INPUT: 3 4 5 6
PRED: 4 5 6 7
INPUT: 5 6 7 8
PRED: 8 9
Observe that:
1. Each token is predicted exactly once
2. For the last pair, we provide the full context, but only score the last two tokens
:param requests: list[Instance]
A list of Instance objects with property `args` which returns a tuple (context,).
string: str
String for which we are computing overall loglikelihood
:return: list[tuple[float]]
A list of tuples (logprob,)
logprob: float
The log probability of `context` conditioned on the BOS/EOS token.
Can also be overridden for custom cases by `prefix_token_id`.
"""
pass
# TODO: Add an optional max length
@abc.abstractmethod
def generate_until(self, requests) -> List[str]:
"""Generate greedily until a stopping sequence
:param requests: list[Instance]
A list of Instance objects with property `args` which returns a tuple (context, until).
context: str
Context string
until: [str]
The string sequences to generate until. These string sequences
may each span across multiple tokens, or may be part of one token.
:return: list[str]
A list of strings continuation
continuation: str
The generated continuation.
"""
pass
@classmethod
def create_from_arg_string(
cls: Type[T], arg_string: str, additional_config: Optional[dict] = None
) -> T:
"""
Creates an instance of the LM class using the given argument string and additional config.
Parameters:
- arg_string: A string containing arguments in the format key1=value1,key2=value2.
- additional_config: Optional dictionary containing additional configuration parameters.
Returns:
- Instance of the LM class.
"""
additional_config = {} if additional_config is None else additional_config
args = utils.simple_parse_args_string(arg_string)
args2 = {k: v for k, v in additional_config.items() if v is not None}
return cls(**args, **args2)
@classmethod
def create_from_arg_obj(
cls: Type[T], arg_dict: dict, additional_config: Optional[dict] = None
) -> T:
"""
Creates an instance of the LM class using the given arg_obj
Parameters:
- arg_obj: A dict containing arguments in the format key1=value1,key2=value2.
- additional_config: Optional dictionary containing additional configuration parameters.
Returns:
- Instance of the LM class.
"""
additional_config = {} if additional_config is None else additional_config
additional_config = {
k: v for k, v in additional_config.items() if v is not None
}
return cls(**arg_dict, **additional_config)
@property
def rank(self):
# used in the case of parallelism. Hardcoded to
# ensure no errors arise using API models which do
# not support multi-device parallelism nor expect it.
return self._rank
@property
def world_size(self):
# used in the case of parallelism. Hardcoded to
# ensure no errors arise using API models which do
# not support multi-device parallelism nor expect it.
return self._world_size
def set_cache_hook(self, cache_hook) -> None:
self.cache_hook = cache_hook
### SQLite-based caching of LM responses
def hash_args(attr, args):
dat = json.dumps([attr] + list(args))
return hashlib.sha256(dat.encode("utf-8")).hexdigest()
class CacheHook:
def __init__(self, cachinglm) -> None:
if cachinglm is None:
self.dbdict = None
return
self.dbdict = cachinglm.dbdict
def add_partial(self, attr, req, res) -> None:
if self.dbdict is None:
return
hsh = hash_args(attr, req)
self.dbdict[hsh] = res
class CachingLM:
def __init__(self, lm, cache_db) -> None:
"""LM wrapper that returns cached results if they exist, and uses the underlying LM if not.
:param lm: LM
Underlying LM
:param cache_db: str
Path to cache db
"""
self.lm = lm
self.cache_db = cache_db
if os.path.dirname(cache_db):
os.makedirs(os.path.dirname(cache_db), exist_ok=True)
self.dbdict = SqliteDict(cache_db, autocommit=True)
# add hook to lm
lm.set_cache_hook(self.get_cache_hook())
def __getattr__(self, attr):
lm_attr = getattr(self.lm, attr)
if not callable(lm_attr):
return lm_attr
def fn(requests):
res = []
remaining_reqs = []
warned = False
# figure out which ones are cached and which ones are new
eval_logger.info(
f"Loading '{attr}' responses from cache '{self.cache_db}' where possible..."
)
for req in tqdm(requests, desc="Checking cached requests"):
hsh = hash_args(attr, req.args)
if attr == "generate_until" and req.args[1].get("do_sample", False):
# when we are doing non-greedy generation, don't use the cache
# (else every "randomly sampled" generation would be identical for repeats > 1).
if not warned:
eval_logger.warning(
f"Arguments to lm.generate_until() '{req.args[1]}' include non-deterministic sampling. Caching will not be performed for such requests."
)
warned = True
res.append(None)
remaining_reqs.append(req)
elif hsh in self.dbdict:
ob = self.dbdict[hsh]
assert ob is not None
res.append(ob)
else:
res.append(None)
remaining_reqs.append(req)
eval_logger.info(
f"Cached requests: {len(requests) - len(remaining_reqs)}, Requests remaining: {len(remaining_reqs)}"
)
# actually run the LM on the requests that do not have cached results
rem_res = getattr(self.lm, attr)(remaining_reqs)
# stick the new ones back into the list and also cache any of the new ones
resptr = 0
for req, r in zip(remaining_reqs, rem_res):
while res[resptr] is not None:
resptr += 1
res[resptr] = r
# caching
hsh = hash_args(attr, req.args)
self.dbdict[hsh] = r
self.dbdict.commit()
return res
return fn
def get_cache_hook(self):
return CacheHook(self)
class TemplateLM(LM):
"""
A class acting as intermediary between the LM base class
and boilerplate often included in other LM subclasses.
"""
@property
@abc.abstractmethod
def eot_token_id(self):
pass
@property
def prefix_token_id(self):
# it is used as prefix for loglikelihood
return self.eot_token_id
@abc.abstractmethod
def tok_encode(self, string: str, **kwargs):
pass
@abc.abstractmethod
def _loglikelihood_tokens(self, requests, **kwargs):
pass
def _encode_pair(self, context, continuation):
n_spaces = len(context) - len(context.rstrip())
if n_spaces > 0:
continuation = context[-n_spaces:] + continuation
context = context[:-n_spaces]
model_class = getattr(self, "AUTO_MODEL_CLASS", None)
if model_class == transformers.AutoModelForSeq2SeqLM:
context_enc = self.tok_encode(context)
continuation_enc = self.tok_encode(continuation, add_special_tokens=False)
else:
whole_enc = self.tok_encode(context + continuation)
context_enc = self.tok_encode(context)
context_enc_len = len(context_enc)
continuation_enc = whole_enc[context_enc_len:]
return context_enc, continuation_enc
def loglikelihood(
self, requests, disable_tqdm: bool = False
) -> List[Tuple[float, bool]]:
new_reqs = []
for context, continuation in [req.args for req in requests]:
if context == "":
# BOS or EOS as context
context_enc, continuation_enc = (
[self.prefix_token_id],
self.tok_encode(continuation),
)
else:
context_enc, continuation_enc = self._encode_pair(context, continuation)
new_reqs.append(((context, continuation), context_enc, continuation_enc))
return self._loglikelihood_tokens(new_reqs, disable_tqdm=disable_tqdm)
@abc.abstractmethod
def loglikelihood_rolling(
self, requests, disable_tqdm: bool = False
) -> List[Tuple[float, bool]]:
pass
@abc.abstractmethod
def generate_until(self, requests, disable_tqdm: bool = False) -> List[str]:
pass
|