Initial commit
This commit is contained in:
René Mathieu
295
dist/dicom2pacs.app/Contents/Resources/lib/python3.13/pydicom/data/download.py
vendored
Executable file
295
dist/dicom2pacs.app/Contents/Resources/lib/python3.13/pydicom/data/download.py
vendored
Executable file
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# Copyright 2020 pydicom authors. See LICENSE file for details.
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# Copyright 2018-2019 Cancer Care Associates.
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# Relicensed under pydicom LICENSE by Simon Biggs.
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import functools
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import hashlib
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import json
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import os
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import pathlib
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from typing import cast
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import urllib.request
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import urllib.error
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try:
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import requests
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HAVE_REQUESTS = True
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except ImportError:
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HAVE_REQUESTS = False
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try:
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import tqdm
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if HAVE_REQUESTS is False:
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class DownloadProgressBar(tqdm.tqdm):
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def update_to(
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self, b: int = 1, bsize: int = 1, tsize: int | None = None
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) -> None:
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if tsize is not None:
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self.total = tsize
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self.update(b * bsize - self.n)
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USE_PROGRESS_BAR = True
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except ImportError:
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USE_PROGRESS_BAR = False
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from . import retry
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from pydicom.misc import warn_and_log
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HERE = pathlib.Path(__file__).resolve().parent
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_SIMULATE_NETWORK_OUTAGE = False # For testing network outages
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def calculate_file_hash(fpath: pathlib.Path) -> str:
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"""Return the SHA256 checksum for the file at `fpath`.
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Parameters
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----------
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fpath : pathlib.Path
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The absolute path to the file that is to be checksummed.
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Returns
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-------
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str
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The SHA256 checksum of the file.
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"""
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BLOCKSIZE = 65536
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hasher = hashlib.sha256()
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with open(fpath, "rb") as f:
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buf = f.read(BLOCKSIZE)
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while len(buf) > 0:
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hasher.update(buf)
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buf = f.read(BLOCKSIZE)
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return hasher.hexdigest()
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def get_config_dir() -> pathlib.Path:
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"""Return the path to the pydicom config directory, creating it if required
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The config directory will be named ``.pydicom`` and will be created in the
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local user's home directory.
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"""
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config_dir = pathlib.Path.home() / ".pydicom"
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config_dir.mkdir(exist_ok=True)
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return config_dir
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@retry.retry(
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(urllib.error.HTTPError, urllib.error.URLError),
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exc_msg=("Installing the `requests` package may help"),
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)
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def download_with_progress(url: str, fpath: pathlib.Path) -> None:
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"""Download the file at `url` to `fpath` with a progress bar.
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Parameters
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----------
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url : str
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The URL to download the file from.
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fpath : pathlib.Path
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The absolute path where the file will be written to.
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"""
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filename = os.fspath(fpath)
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if HAVE_REQUESTS:
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if USE_PROGRESS_BAR:
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r = requests.get(url, stream=True)
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total_size_in_bytes = int(r.headers.get("content-length", 0))
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with open(fpath, "wb") as file:
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for data in tqdm.tqdm(
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r.iter_content(chunk_size=4096),
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total=total_size_in_bytes,
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unit="B",
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unit_scale=True,
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miniters=1,
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desc=url.split("/")[-1],
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):
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file.write(data)
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else:
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r = requests.get(url)
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with open(filename, "wb") as f:
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f.write(r.content)
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else:
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if USE_PROGRESS_BAR:
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with DownloadProgressBar(
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unit="B", unit_scale=True, miniters=1, desc=url.split("/")[-1]
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) as t:
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urllib.request.urlretrieve(url, filename, reporthook=t.update_to)
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else:
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urllib.request.urlretrieve(url, filename)
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def get_data_dir() -> pathlib.Path:
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"""Return the path to the cache directory, creating it if required."""
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data_dir = get_config_dir() / "data"
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data_dir.mkdir(exist_ok=True)
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return data_dir
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@functools.lru_cache
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def get_url_map() -> dict[str, str]:
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"""Return a dict containing the URL mappings from ``urls.json```."""
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with open(HERE / "urls.json") as url_file:
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return cast(dict[str, str], json.load(url_file))
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def get_url(filename: str) -> str:
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"""Return the download URL corresponding to `filename`.
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The filename:URL mappings are located in the ``urls.json`` file.
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Parameters
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----------
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filename : str
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The filename of the file to get the corresponding URL for.
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Returns
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-------
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str
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The download URL corresponding to `filename`.
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Raises
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------
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ValueError
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If `filename` is not in the ``urls.json`` record.
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"""
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# Convert filename to lowercase because windows filenames are
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# case-insensitive
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urls = {k.lower(): v for k, v in get_url_map().items()}
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try:
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return urls[filename.lower()]
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except KeyError:
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raise ValueError("The file provided isn't within pydicom's urls.json record.")
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def data_path_with_download(
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filename: str,
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check_hash: bool = True,
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redownload_on_hash_mismatch: bool = True,
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url: str | None = None,
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quiet: bool = True,
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) -> pathlib.Path:
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"""Return the absolute path to the cached file with `filename`.
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If the file isn't available in the cache then it will be downloaded.
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Parameters
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----------
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filename : str
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The filename of the file to return the path to.
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check_hash : bool, optional
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``True`` to perform a SHA256 checksum on the file, ``False`` otherwise.
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redownload_on_hash_mismatch : bool, optional
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``True`` to redownload the file on checksum failure, ``False``
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otherwise.
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url : str, optional
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The file's corresponding download URL
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Returns
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-------
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pathlib.Path
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The absolute path to the file.
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"""
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if _SIMULATE_NETWORK_OUTAGE:
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raise RuntimeError("No network!")
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filepath = get_data_dir().joinpath(filename)
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if check_hash and filepath.exists():
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try:
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get_cached_filehash(filename)
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except NoHashFound:
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filepath.unlink() # Force a redownload
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if not filepath.exists():
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if url is None:
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url = get_url(filename)
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download_with_progress(url, filepath)
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if check_hash:
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try:
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hash_agrees = data_file_hash_check(filename)
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except NoHashFound:
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return filepath.resolve()
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if not hash_agrees:
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if redownload_on_hash_mismatch:
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filepath.unlink()
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return data_path_with_download(
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filename, redownload_on_hash_mismatch=False
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)
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raise ValueError("The file on disk does not match the recorded hash.")
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return filepath.resolve()
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class NoHashFound(KeyError):
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pass
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def get_cached_filehash(filename: str) -> str:
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"""Return the SHA256 checksum of a cached file.
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Parameters
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----------
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filename : str
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The filename of the cached file to calculate the checksum for.
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Returns
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-------
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str
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The SHA256 checksum of the cached file.
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"""
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with open(HERE / "hashes.json") as hash_file:
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hashes = cast(dict[str, str], json.load(hash_file))
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# Convert filenames to lowercase because windows filenames are
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# case-insensitive
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hashes = {k.lower(): v for k, v in hashes.items()}
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try:
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return hashes[filename.lower()]
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except KeyError:
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raise NoHashFound
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def data_file_hash_check(filename: str) -> bool:
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"""Return ``True`` if the SHA256 checksum of the cached file is correct.
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Parameters
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----------
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filename : str
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The filename of the cached file to check.
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Returns
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-------
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bool
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``True`` if the cached file has the correct checksum, ``False``
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otherwise.
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"""
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filename = os.fspath(filename)
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filepath = get_data_dir().joinpath(filename)
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calculated_filehash = calculate_file_hash(filepath)
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try:
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cached_filehash = get_cached_filehash(filename)
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except NoHashFound:
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warn_and_log("Hash not found in hashes.json. File will be updated.")
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with open(HERE / "hashes.json") as hash_file:
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hashes = json.load(hash_file)
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hashes[filename] = calculated_filehash
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with open(HERE / "hashes.json", "w") as hash_file:
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json.dump(hashes, hash_file, indent=2, sort_keys=True)
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raise
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return cached_filehash == calculated_filehash
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