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mirror of https://github.com/QData/TextAttack.git synced 2021-10-13 00:05:06 +03:00

allow maximization goal functions

This commit is contained in:
uvafan
2020-06-23 23:33:48 -04:00
parent fe109267a1
commit 0fcfb51b7f
19 changed files with 115 additions and 78 deletions

View File

@@ -4,26 +4,29 @@ import lru
import numpy as np
import torch
from textattack.goal_function_results.goal_function_result import GoalFunctionResultStatus
from textattack.shared import utils, validators
from textattack.shared.utils import batch_model_predict, default_class_repr
class GoalFunction:
"""
Evaluates how well a perturbed attacked_text object is achieving a specified goal.
Args:
model: The PyTorch or TensorFlow model used for evaluation.
maximizable: Whether the goal function is maximizable, as opposed to a boolean result
of success or failure.
query_budget: The maximum number of model queries allowed.
"""
def __init__(
self, model, tokenizer=None, use_cache=True, query_budget=float("inf")
self, model, maximizable=False, tokenizer=None, use_cache=True, query_budget=float("inf")
):
validators.validate_model_goal_function_compatibility(
self.__class__, model.__class__
)
self.model = model
self.maximizable = maximizable
self.tokenizer = tokenizer
if not self.tokenizer:
if hasattr(self.model, "tokenizer"):
@@ -33,20 +36,16 @@ class GoalFunction:
if not hasattr(self.tokenizer, "encode"):
raise TypeError("Tokenizer must contain `encode()` method")
self.use_cache = use_cache
self.num_queries = 0
self.query_budget = query_budget
if self.use_cache:
self._call_model_cache = lru.LRU(utils.config("MODEL_CACHE_SIZE"))
else:
self._call_model_cache = None
def should_skip(self, attacked_text, ground_truth_output):
"""
Returns whether or not the goal has already been completed for ``attacked_text``\,
due to misprediction by the model.
"""
model_outputs = self._call_model([attacked_text])
return self._is_goal_complete(model_outputs[0], ground_truth_output)
def init_attack_example(self, attacked_text, ground_truth_output):
self.initial_attacked_text = attacked_text
self.ground_truth_output = ground_truth_output
self.num_queries = 0
def get_output(self, attacked_text):
"""
@@ -54,16 +53,16 @@ class GoalFunction:
"""
return self._get_displayed_output(self._call_model([attacked_text])[0])
def get_result(self, attacked_text, ground_truth_output):
def get_result(self, attacked_text):
"""
A helper method that queries `self.get_results` with a single
``AttackedText`` object.
"""
results, search_over = self.get_results([attacked_text], ground_truth_output)
results, search_over = self.get_results([attacked_text])
result = results[0] if len(results) else None
return result, search_over
def get_results(self, attacked_text_list, ground_truth_output):
def get_results(self, attacked_text_list):
"""
For each attacked_text object in attacked_text_list, returns a result
consisting of whether or not the goal has been achieved, the output for
@@ -78,23 +77,32 @@ class GoalFunction:
model_outputs = self._call_model(attacked_text_list)
for attacked_text, raw_output in zip(attacked_text_list, model_outputs):
displayed_output = self._get_displayed_output(raw_output)
succeeded = self._is_goal_complete(raw_output, ground_truth_output)
goal_function_score = self._get_score(raw_output, ground_truth_output)
goal_status = self._get_goal_status(raw_output)
goal_function_score = self._get_score(raw_output)
results.append(
self._goal_function_result_type()(
attacked_text,
raw_output,
displayed_output,
succeeded,
goal_status,
goal_function_score,
self.num_queries,
self.ground_truth_output,
)
)
return results, self.num_queries == self.query_budget
def _is_goal_complete(self, model_output, ground_truth_output):
def _get_goal_status(self, model_output):
if self.maximizable:
return GoalFunctionResultStatus.MAXIMIZING
if self._is_goal_complete(model_output):
return GoalFunctionResultStatus.SUCCEEDED
return GoalFunctionResultStatus.SEARCHING
def _is_goal_complete(self, model_output):
raise NotImplementedError()
def _get_score(self, model_output, ground_truth_output):
def _get_score(self, model_output):
raise NotImplementedError()
def _get_displayed_output(self, raw_output):