Urara-Blog/node_modules/.pnpm-store/v3/files/96/aaed85beadda3f60db6cf12dd57e1f64d956699086dcf4512ed1ba7eecf38352a266323008355be13c151aff45e367275a49b03e5f3f17c67917ddabe5affa
2022-08-14 01:14:53 +08:00

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677 B
Text

'use strict';
const {Transform} = require('stream');
class ObjectTransform extends Transform {
constructor() {
super({
objectMode: true
});
}
}
class FilterStream extends ObjectTransform {
constructor(filter) {
super();
this._filter = filter;
}
_transform(data, encoding, callback) {
if (this._filter(data)) {
this.push(data);
}
callback();
}
}
class UniqueStream extends ObjectTransform {
constructor() {
super();
this._pushed = new Set();
}
_transform(data, encoding, callback) {
if (!this._pushed.has(data)) {
this.push(data);
this._pushed.add(data);
}
callback();
}
}
module.exports = {
FilterStream,
UniqueStream
};