84 lines
3.4 KiB
JavaScript
84 lines
3.4 KiB
JavaScript
// The MIT License (MIT)
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//
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// Copyright (c) 2014 Jonas Finnemann Jensen
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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var uuid = require('uuid');
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/**
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* Returns the given uuid as a 22 character slug. This can be a regular v4
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* slug or a "nice" slug.
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*/
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exports.encode = function(uuid_) {
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var bytes = uuid.parse(uuid_);
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var base64 = (new Buffer(bytes)).toString('base64');
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var slug = base64
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.replace(/\+/g, '-') // Replace + with - (see RFC 4648, sec. 5)
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.replace(/\//g, '_') // Replace / with _ (see RFC 4648, sec. 5)
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.substring(0, 22); // Drop '==' padding
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return slug;
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};
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/**
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* Returns the uuid represented by the given v4 or "nice" slug
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*/
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exports.decode = function(slug) {
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var base64 = slug
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.replace(/-/g, '+')
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.replace(/_/g, '/')
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+ '==';
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return uuid.unparse(new Buffer(base64, 'base64'));
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};
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/**
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* Returns a randomly generated uuid v4 compliant slug
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*/
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exports.v4 = function() {
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var bytes = uuid.v4(null, new Buffer(16));
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var base64 = bytes.toString('base64');
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var slug = base64
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.replace(/\+/g, '-') // Replace + with - (see RFC 4648, sec. 5)
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.replace(/\//g, '_') // Replace / with _ (see RFC 4648, sec. 5)
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.substring(0, 22); // Drop '==' padding
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return slug;
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};
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/**
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* Returns a randomly generated uuid v4 compliant slug which conforms to a set
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* of "nice" properties, at the cost of some entropy. Currently this means one
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* extra fixed bit (the first bit of the uuid is set to 0) which guarantees the
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* slug will begin with [A-Za-f]. For example such slugs don't require special
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* handling when used as command line parameters (whereas non-nice slugs may
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* start with `-` which can confuse command line tools).
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*
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* Potentially other "nice" properties may be added in future to further
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* restrict the range of potential uuids that may be generated.
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*/
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exports.nice = function() {
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var bytes = uuid.v4(null, new Buffer(16));
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bytes[0] = bytes[0] & 0x7f; // unset first bit to ensure [A-Za-f] first char
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var base64 = bytes.toString('base64');
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var slug = base64
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.replace(/\+/g, '-') // Replace + with - (see RFC 4648, sec. 5)
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.replace(/\//g, '_') // Replace / with _ (see RFC 4648, sec. 5)
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.substring(0, 22); // Drop '==' padding
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return slug;
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};
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