def calculate_file_hash(file: FieldFile) -> str:
# Together the MemoryFileUploadHandler and TemporaryFileUploadHandler
# provide Django’s default file upload behavior of reading small files
# into memory and large ones onto disk.
# If a file is large file will be an instance of TemporaryUploadedFile,
# TemporaryUploadedFile.temporary_file_path() returns the full path to the temporary uploaded file.
# If a file is small file will be an instance of InMemoryUploadedFile.
file_hash = sha256()
# Returns True if the uploaded file is big enough to require reading in multiple chunks.
# By default this will be any file larger than 2.5 megabytes, but that’s configurable;
if not file.multiple_chunks():
file_hash.update(file.read())
else:
for chunk in file.chunks():
file_hash.update(chunk)
return file_hash.hexdigest()
def setup_work_dir(file: FieldFile) -> Tuple[TemporaryDirectory, Path]:
"""Create a temporary directory as working directory and make the source file locally available."""
temp_dir = TemporaryDirectory()
try:
source_file_path = Path(file.path)
except (AttributeError, NotImplementedError):
source_file_path = Path(temp_dir.name) / Path(file.name).name
with source_file_path.open('wb') as fp:
if file.multiple_chunks():
for chunk in file.chunks():
fp.write(chunk)
else:
fp.write(file.read())
return temp_dir, source_file_path
