30 lines
902 B
Python
30 lines
902 B
Python
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"""Utilities to efficiently compute the SHA 256 hash of a bunch of bytes."""
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from typing import BinaryIO, Optional
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from .insecure_hashlib import sha256
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def sha_fileobj(fileobj: BinaryIO, chunk_size: Optional[int] = None) -> bytes:
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"""
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Computes the sha256 hash of the given file object, by chunks of size `chunk_size`.
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Args:
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fileobj (file-like object):
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The File object to compute sha256 for, typically obtained with `open(path, "rb")`
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chunk_size (`int`, *optional*):
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The number of bytes to read from `fileobj` at once, defaults to 1MB.
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Returns:
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`bytes`: `fileobj`'s sha256 hash as bytes
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"""
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chunk_size = chunk_size if chunk_size is not None else 1024 * 1024
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sha = sha256()
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while True:
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chunk = fileobj.read(chunk_size)
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sha.update(chunk)
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if not chunk:
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break
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return sha.digest()
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