Optimized hot-loop for logits processor

This commit is contained in:
Niels Geens
2025-04-09 11:59:26 +02:00
parent 654c32c7ac
commit 8fb30c8ed0
17 changed files with 239 additions and 272 deletions

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@@ -2,12 +2,12 @@ from pathlib import Path
from threading import Thread
from transformers import AutoTokenizer, AutoModelForCausalLM, pipeline, TextIteratorStreamer, BitsAndBytesConfig
from typing import Callable, Iterator, Optional, List
from xml_schema_validator import XmlLogitsProcessor
import json
import torch
from . import LlmEngine
from .. import util
from .xml_logits_processor import XmlLogitsProcessor
class QwQLlmEngine(LlmEngine):

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@@ -1,84 +0,0 @@
import torch
from transformers import LogitsProcessor
from xml_schema_validator import XmlSchemaValidator
class XmlLogitsProcessor(LogitsProcessor):
"""
A LogitsProcessor that enforces valid XML according to a schema.
This processor masks tokens that would lead to invalid XML
by setting their logits to negative infinity.
"""
def __init__(self, tokenizer, schema_text: str):
"""
Initialize the processor with a schema and tokenizer.
Args:
tokenizer: The tokenizer to use for decoding tokens
schema_text: The XSD schema text to validate against
"""
self.tokenizer = tokenizer
self.schema_validator = XmlSchemaValidator(schema_text)
self.prompt_length = None
self.is_first_call = True
def __call__(self, input_ids: torch.LongTensor, scores: torch.FloatTensor) -> torch.FloatTensor:
"""
Process logits to mask invalid XML tokens.
Args:
input_ids: Current input token IDs
scores: Current scores (logits) for next token prediction
Returns:
Processed scores with invalid tokens masked
"""
batch_size, _ = input_ids.shape
# If this is the first call, store the prompt length
if self.is_first_call:
self.prompt_length = input_ids.shape[1]
self.is_first_call = False
# For each sequence in the batch
for batch_idx in range(batch_size):
# Get only the generated portion of the text
current_ids = input_ids[batch_idx]
generated_ids = current_ids[self.prompt_length:]
generated_text = self.tokenizer.decode(generated_ids)
# Get all possible next tokens
vocab_size = scores.shape[-1]
# Create a mask to track which tokens are valid
valid_tokens_mask = torch.zeros(vocab_size, dtype=torch.bool, device=scores.device)
batch_validator = self.schema_validator.copy()
print("evaluate tokens continuing:", generated_text)
if generated_text:
valid, msg = batch_validator.append(generated_text)
if not valid:
print("current generated text invalid, only accept eos_token_id")
eos_token_id = self.tokenizer.eos_token_id
if eos_token_id is not None:
valid_tokens_mask[eos_token_id] = True
invalid_tokens_mask = ~valid_tokens_mask
scores[batch_idx, invalid_tokens_mask] = float('-inf')
continue
# Rest of the method remains the same
for token_idx in range(vocab_size):
token_validator = batch_validator.copy()
token_text = self.tokenizer.decode([token_idx])
valid, msg = token_validator.append(token_text)
#print("token:", token_text, "valid:", valid)
if valid:
#print("token:", generated_text + token_text)
valid_tokens_mask[token_idx] = True
invalid_tokens_mask = ~valid_tokens_mask
scores[batch_idx, invalid_tokens_mask] = float('-inf')
return scores