utils: Add "hashutil.py" with function "md5()"

md5(): Calculate the MD5 checksum of the file.

Credit: https://stackoverflow.com/a/3431838/4856091

1 files changed, 40 insertions, 0 deletions

diff --git a/fg21sim/utils/hashutil.py b/fg21sim/utils/hashutil.py
new file mode 100644
index 0000000..394ef04
--- /dev/null
+++ b/fg21sim/utils/hashutil.py
@@ -0,0 +1,40 @@
+# Copyright (c) 2016 Weitian LI <liweitianux@live.com>
+# MIT license
+
+"""
+Hash utilities.
+
+md5 :
+    Calculate the MD5 checksum of the file.
+"""
+
+import hashlib
+
+
+def md5(filepath, blocksize=65536):
+    """
+    Calculate the MD5 checksum/digest of the file data.
+
+    Parameters
+    ----------
+    filepath : str
+        The path to the file
+    blocksize : int, optional
+        The block size (bytes) of chunks when read the file.
+
+    Returns
+    -------
+    digest : str
+        The checksum/digest of the file data, containing only hexadecimal
+        digits.
+
+    Credits
+    -------
+    - Stackoverflow: Generating an MD5 checksum of a file
+      https://stackoverflow.com/a/3431838/4856091
+    """
+    hasher = hashlib.md5()
+    with open(filepath, "rb") as f:
+        for chunk in iter(lambda: f.read(blocksize), b""):
+            hasher.update(chunk)
+    return hasher.hexdigest()