1 files changed, 48 insertions, 0 deletions
diff --git a/third_party/python/slugid/slugid/slugid.py b/third_party/python/slugid/slugid/slugid.py
new file mode 100644
index 0000000000..2a1377c84b
--- /dev/null
+++ b/third_party/python/slugid/slugid/slugid.py
@@ -0,0 +1,48 @@
+# Licensed under the Mozilla Public Licence 2.0.
+# https://www.mozilla.org/en-US/MPL/2.0
+
+import sys
+import uuid
+import base64
+
+
+def encode(uuid_):
+    """
+    Returns the given uuid.UUID object as a 22 character slug. This can be a
+    regular v4 slug or a "nice" slug.
+    """
+    return base64.urlsafe_b64encode(uuid_.bytes)[:-2]  # Drop '==' padding
+
+
+def decode(slug):
+    """
+    Returns the uuid.UUID object represented by the given v4 or "nice" slug
+    """
+    if sys.version_info.major != 2 and isinstance(slug, bytes):
+        slug = slug.decode('ascii')
+    slug = slug + '=='  # base64 padding
+    return uuid.UUID(bytes=base64.urlsafe_b64decode(slug))
+
+
+def v4():
+    """
+    Returns a randomly generated uuid v4 compliant slug
+    """
+    return base64.urlsafe_b64encode(uuid.uuid4().bytes)[:-2]  # Drop '==' padding
+
+
+def nice():
+    """
+    Returns a randomly generated uuid v4 compliant slug which conforms to a set
+    of "nice" properties, at the cost of some entropy. Currently this means one
+    extra fixed bit (the first bit of the uuid is set to 0) which guarantees the
+    slug will begin with [A-Za-f]. For example such slugs don't require special
+    handling when used as command line parameters (whereas non-nice slugs may
+    start with `-` which can confuse command line tools).
+
+    Potentially other "nice" properties may be added in future to further
+    restrict the range of potential uuids that may be generated.
+    """
+    rawBytes = bytearray(uuid.uuid4().bytes)
+    rawBytes[0] = rawBytes[0] & 0x7f  # Ensure slug starts with [A-Za-f]
+    return base64.urlsafe_b64encode(rawBytes)[:-2]  # Drop '==' padding