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dify/api/core/rag/extractor/helpers.py

51 lines
1.8 KiB
Python

"""Document loader helpers."""
import concurrent.futures
from typing import NamedTuple
import charset_normalizer
class FileEncoding(NamedTuple):
"""A file encoding as the NamedTuple."""
encoding: str | None
"""The encoding of the file."""
confidence: float
"""The confidence of the encoding."""
language: str | None
"""The language of the file."""
def detect_file_encodings(file_path: str, timeout: int = 5, sample_size: int = 1024 * 1024) -> list[FileEncoding]:
"""Try to detect the file encoding.
Returns a list of `FileEncoding` tuples with the detected encodings ordered
by confidence.
Args:
file_path: The path to the file to detect the encoding for.
timeout: The timeout in seconds for the encoding detection.
sample_size: The number of bytes to read for encoding detection. Default is 1MB.
For large files, reading only a sample is sufficient and prevents timeout.
"""
def read_and_detect(filename: str):
rst = charset_normalizer.from_path(filename)
best = rst.best()
if best is None:
return []
file_encoding = FileEncoding(encoding=best.encoding, confidence=best.coherence, language=best.language)
return [file_encoding]
with concurrent.futures.ThreadPoolExecutor() as executor:
future = executor.submit(read_and_detect, file_path)
try:
encodings = future.result(timeout=timeout)
except concurrent.futures.TimeoutError:
raise TimeoutError(f"Timeout reached while detecting encoding for {file_path}")
if all(encoding.encoding is None for encoding in encodings):
raise RuntimeError(f"Could not detect encoding for {file_path}")
return [enc for enc in encodings if enc.encoding is not None]