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const Long = require('long') | |
var tagChars = '0289PYLQGRJCUV' | |
module.exports = { | |
tag2id: (tag) => { | |
if (tag === undefined || typeof tag !== 'string') return false | |
let id = 0 | |
let tagArray = tag.split('') | |
for (let a = 0; a < tagArray.length; a++) { | |
let i = tagChars.indexOf(tagArray[a]) | |
id *= 14 | |
id += i | |
} | |
let high = id % 256 | |
// let low = (id - high) >>> 8 | |
let low = Long.fromNumber((id - high)).shiftRight(8).low | |
return { | |
high: high, | |
low: low | |
} | |
}, | |
id2tag: (high, low) => { | |
// let id = ((low << 8) >>> 0) + high | |
let id = parseInt(Long.fromNumber(low).shiftLeft(8).shiftRight(0).toString()) + high | |
let i = 0 | |
let tag = [] | |
while (id > 0) { | |
i = id % 14 | |
id = Math.floor(id / 14) | |
tag.push(tagChars.charAt(i)) | |
} | |
return tag.reverse().join('') | |
} | |
} |
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