| # Licensed under the Mozilla Public Licence 2.0. |
| # https://www.mozilla.org/en-US/MPL/2.0 |
| |
| 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 |
| """ |
| return uuid.UUID(bytes=base64.urlsafe_b64decode(slug + '==')) # b64 padding |
| |
| |
| 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 = uuid.uuid4().bytes |
| rawBytes = chr(ord(rawBytes[0]) & 0x7f) + rawBytes[1:] # Ensure slug starts with [A-Za-f] |
| return base64.urlsafe_b64encode(rawBytes)[:-2] # Drop '==' padding |
