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"""MDL Retriever."""
from typing import List, Optional
import numpy as np
import torch
import tqdm
from transformers import AutoModelForCausalLM
from opencompass.openicl.icl_prompt_template import PromptTemplate
from opencompass.openicl.icl_retriever.icl_topk_retriever import TopkRetriever
from opencompass.openicl.utils.logging import get_logger
from opencompass.registry import ICL_PROMPT_TEMPLATES, ICL_RETRIEVERS
logger = get_logger(__name__)
@ICL_RETRIEVERS.register_module()
class MDLRetriever(TopkRetriever):
"""MDL Retriever, subclass of `TopkRetriever`. MDL is a abbreviation of
Minimum Description Length, specially designed for ppl evaluation. You may
refer to the paper for more details: https://arxiv.org/pdf/2212.10375.pdf.
Args:
dataset (`BaseDataset`): Any BaseDataset instances.
Attributes of ``reader``, ``train`` and ``test`` will be used.
ice_separator (`Optional[str]`): The separator between each in-context
example template when origin `PromptTemplate` is provided. Defaults
to '\n'.
ice_eos_token (`Optional[str]`): The end of sentence token for
in-context example template when origin `PromptTemplate` is
provided. Defaults to '\n'.
ice_num (`Optional[int]`): The number of in-context example template
when origin `PromptTemplate` is provided. Defaults to 1.
sentence_transformers_model_name (`Optional[str]`): The name of the
sentence transformers model. Defaults to 'all-mpnet-base-v2'.
tokenizer_name (`Optional[str]`): The name of the tokenizer. Defaults
to 'gpt2-xl'.
batch_size (`Optional[int]`): The batch size for the dataloader.
Defaults to 1.
candidate_num (`Optional[int]`): The number of candidates to retrieve
for each example. Defaults to 1.
ce_model_name (`Optional[str]`): The name of the model for calculating
MDL. Defaults to 'gpt2-xl'.
select_time (`Optional[int]`): The number of times to select MDL.
Defaults to 5.
ice_template (`Optional[PromptTemplate]`): The template for in-context
example. Defaults to None.
prompt_template (`Optional[PromptTemplate]`): The template for prompt.
Defaults to None.
labels (`Optional[List]`): The labels for calculating MDL. Defaults to
None.
seed (`Optional[int]`): The seed for random. Defaults to 1.
"""
metric_model = None
def __init__(self,
dataset,
ice_separator: Optional[str] = '\n',
ice_eos_token: Optional[str] = '\n',
ice_num: Optional[int] = 1,
sentence_transformers_model_name: Optional[
str] = 'all-mpnet-base-v2',
tokenizer_name: Optional[str] = 'gpt2-xl',
batch_size: Optional[int] = 1,
candidate_num: Optional[int] = 1,
ce_model_name: Optional[str] = 'gpt2-xl',
select_time: Optional[int] = 5,
ice_template: Optional[PromptTemplate] = None,
prompt_template: Optional[PromptTemplate] = None,
labels: Optional[List] = None,
seed: Optional[int] = 1) -> None:
super().__init__(dataset, ice_separator, ice_eos_token, ice_num,
sentence_transformers_model_name, tokenizer_name,
batch_size)
self.ce_model_name = ce_model_name
self.candidate_num = candidate_num
self.select_time = select_time
self.ice_template = ICL_PROMPT_TEMPLATES.build(ice_template)
if prompt_template is not None:
self.prompt_template = ICL_PROMPT_TEMPLATES.build(prompt_template)
else:
self.prompt_template = None
self.labels = labels
self.seed = seed
def topk_search(self):
np.random.seed(self.seed)
res_list = self.forward(self.dataloader)
rtr_idx_list = [[] for _ in range(len(res_list))]
logger.info('Retrieving data for test set...')
for entry in tqdm.tqdm(res_list, disable=not self.is_main_process):
idx = entry['metadata']['id']
embed = np.expand_dims(entry['embed'], axis=0)
near_ids = self.index.search(
embed, min(self.candidate_num,
len(self.index_ds)))[1][0].tolist()
candidates = []
mdl_scores = []
for j in range(self.select_time):
if j == 0:
rand_idx_list = near_ids[:self.ice_num]
else:
rand_idx_list = np.random.choice(near_ids,
self.ice_num,
replace=False)
rand_idx_list = [int(i) for i in rand_idx_list]
candidates.append(rand_idx_list)
ice = self.generate_ice(rand_idx_list,
ice_template=self.ice_template)
ice = str(ice)
mask_length = len(
self.tokenizer(ice + self.ice_eos_token,
verbose=False)['input_ids'])
if self.labels is None:
labels = self.get_labels(self.ice_template,
self.prompt_template)
else:
labels = self.labels
prompt_list = []
for label in labels:
prompt = self.generate_label_prompt(
idx, ice, label, self.ice_template,
self.prompt_template)
prompt = str(prompt)
prompt_list.append(prompt)
loss_list = self.cal_ce(prompt_list, mask_length=mask_length)
probs = np.exp(-np.array(loss_list))
normalized_probs = probs / probs.sum(0, keepdims=True)
neg_entropy = -entropy(normalized_probs, label_dim=0)
mdl_scores.append(neg_entropy)
rtr_idx_list[idx] = candidates[mdl_scores.index(max(mdl_scores))]
rtr_idx_list[idx] = [int(i) for i in rtr_idx_list[idx]]
return rtr_idx_list
def retrieve(self):
"""Retrieve the in-context example index for each test example."""
return self.topk_search()
@torch.no_grad()
def cal_ce(self, input_texts: List[str], mask_length=None):
if self.metric_model is None:
logger.info(
f'Load model {self.ce_model_name} for calculating MDL...')
self.metric_model = AutoModelForCausalLM.from_pretrained(
self.ce_model_name)
self.metric_model.to(self.device)
inputs = self.tokenizer(input_texts,
padding=True,
return_tensors='pt',
truncation=True)
inputs = {k: v.to(self.device) for k, v in inputs.items()}
outputs = self.metric_model(**inputs)
shift_logits = outputs.logits[..., :-1, :].contiguous()
shift_labels = inputs['input_ids'][..., 1:].contiguous()
loss_fct = torch.nn.CrossEntropyLoss(
reduction='none', ignore_index=self.tokenizer.pad_token_id)
shift_logits = shift_logits.view(-1, shift_logits.size(-1))
loss = loss_fct(shift_logits,
shift_labels.view(-1)).view(shift_labels.size())
if mask_length is not None:
mask = torch.cat([
torch.zeros([loss.shape[0], mask_length], dtype=torch.float),
torch.ones([loss.shape[0], loss.shape[-1] - mask_length],
dtype=torch.float)
], -1)
mask = mask.to(self.device)
loss = torch.mul(mask, loss)
lens = (inputs['input_ids'] !=
self.tokenizer.pad_token_id).sum(-1).cpu().numpy()
if mask_length is not None:
lens -= mask_length
ce_loss = loss.sum(-1).cpu().detach().numpy() / lens
return ce_loss
def entropy(probs: np.array, label_dim: int = 0, mask=None):
if mask is None:
return -(probs * np.log(probs)).sum(label_dim)
return -(mask * probs * np.log(probs)).sum(label_dim)