1 files changed, 157 insertions, 0 deletions
diff --git a/src/python/gudhi/datasets/remote.py b/src/python/gudhi/datasets/remote.py
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+++ b/src/python/gudhi/datasets/remote.py
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+# This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
+# See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
+# Author(s):       Hind Montassif
+#
+# Copyright (C) 2021 Inria
+#
+# Modification(s):
+#   - YYYY/MM Author: Description of the modification
+
+from os.path import join, exists
+from os import makedirs
+
+from urllib.request import urlretrieve
+import hashlib
+
+import numpy as np
+
+def _checksum_sha256(file_path):
+    """
+    Compute the file checksum using sha256.
+
+    Parameters
+    ----------
+    file_path: string
+        Full path of the created file.
+
+    Returns
+    -------
+        The hex digest of file_path.
+    """
+    sha256_hash = hashlib.sha256()
+    chunk_size = 4096
+    with open(file_path,"rb") as f:
+        # Read and update hash string value in blocks of 4K
+        while True:
+            buffer = f.read(chunk_size)
+            if not buffer:
+                break
+            sha256_hash.update(buffer)
+    return sha256_hash.hexdigest()
+
+def _fetch_remote(url, filename, dirname = "remote_datasets", file_checksum = None, accept_license = False):
+    """
+    Fetch the wanted dataset from the given url and save it in file_path.
+
+    Parameters
+    ----------
+    url : string
+        The url to fetch the dataset from.
+    filename : string
+        The name to give to downloaded file.
+    dirname : string
+        The directory to save the file to. Default is "remote_datasets".
+    file_checksum : string
+        The file checksum using sha256 to check against the one computed on the downloaded file.
+        Default is 'None'.
+    accept_license : boolean
+        Flag to specify if user accepts the file LICENSE and prevents from printing the corresponding license terms.
+        Default is False.
+
+    Returns
+    -------
+    file_path: string
+        Full path of the created file.
+    """
+
+    file_path = join(dirname, filename)
+
+    # Get the file
+    urlretrieve(url, file_path)
+
+    if file_checksum is not None:
+        checksum = _checksum_sha256(file_path)
+        if file_checksum != checksum:
+            raise IOError("{} has a SHA256 checksum : {}, "
+                        "different from expected : {}."
+                        "The file may be corrupted or the given url may be wrong !".format(file_path, checksum, file_checksum))
+
+    # Print license terms unless accept_license is set to True
+    if not accept_license:
+        license_file = join(dirname, "LICENSE")
+        if exists(license_file) and (file_path != license_file):
+            with open(license_file, 'r') as f:
+                print(f.read())
+
+    return file_path
+
+def fetch_spiral_2d(filename = "spiral_2d.csv", dirname = "remote_datasets"):
+    """
+    Fetch "spiral_2d.csv" remotely.
+
+    Parameters
+    ----------
+    filename : string
+        The name to give to downloaded file. Default is "spiral_2d.csv".
+    dirname : string
+        The directory to save the file to. Default is "remote_datasets".
+
+    Returns
+    -------
+    points: array
+        Array of points stored in "spiral_2d.csv".
+    """
+    file_url = "https://raw.githubusercontent.com/GUDHI/gudhi-data/main/points/spiral_2d.csv"
+    file_checksum = '37530355d980d957c4ec06b18c775f90a91e446107d06c6201c9b4000b077f38'
+
+    archive_path = join(dirname, filename)
+
+    if not exists(archive_path):
+        # Create directory if not existing
+        if not exists(dirname):
+            makedirs(dirname)
+
+        file_path_pkl = _fetch_remote(file_url, filename, dirname, file_checksum)
+
+        return np.loadtxt(file_path_pkl)
+    else:
+        return np.loadtxt(archive_path)
+
+def fetch_bunny(filename = "bunny.npy", dirname = "remote_datasets/bunny", accept_license = False):
+    """
+    Fetch "bunny.npy" remotely and its LICENSE file.
+
+    Parameters
+    ----------
+    filename : string
+        The name to give to downloaded file. Default is "bunny.npy".
+    dirname : string
+        The directory to save the file to. Default is "remote_datasets/bunny".
+    accept_license : boolean
+        Flag to specify if user accepts the file LICENSE and prevents from printing the corresponding license terms.
+        Default is False.
+
+    Returns
+    -------
+    points: array
+        Array of points stored in "bunny.npy".
+    """
+
+    file_url = "https://raw.githubusercontent.com/GUDHI/gudhi-data/main/points/bunny/bunny.npy"
+    file_checksum = '13f7842ebb4b45370e50641ff28c88685703efa5faab14edf0bb7d113a965e1b'
+    license_url = "https://raw.githubusercontent.com/GUDHI/gudhi-data/main/points/bunny/LICENSE"
+    license_checksum = 'aeb1bad319b7d74fa0b8076358182f9c6b1284c67cc07dc67cbc9bc73025d956'
+
+    archive_path = join(dirname, filename)
+
+    if not exists(archive_path):
+        # Create directory if not existing
+        if not exists(dirname):
+            makedirs(dirname)
+
+        license_path = _fetch_remote(license_url, "LICENSE", dirname, license_checksum)
+        file_path_pkl = _fetch_remote(file_url, filename, dirname, file_checksum, accept_license)
+
+        return np.load(file_path_pkl, mmap_mode='r')
+    else:
+        return np.load(archive_path, mmap_mode='r')