git ssb

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module.exports = class LockMap {
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  /**
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   * Creates a new instance of LockMap
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   */
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  constructor () {
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    this._map = new Map()
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    const methods = ['clear', 'delete', 'entries', 'forEach', 'get', 'has', 'keys', 'values', Symbol.iterator]
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    const self = this
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    methods.forEach(method => {
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      self[method] = function () {
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        return self._map[method].apply(self._map, arguments)
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      }
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    })
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  }
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  /**
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   * Creates a lock on a given ID and returns a resolve function to unlock the
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   * lock
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   * @param {*} id
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   * @return {Function} the resolve function to call once it to unlock
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   */
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  lock (id) {
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    let r
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    const promise = new Promise((resolve, reject) => {
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      r = resolve
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    })
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    promise.then(() => {
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      this._map.delete(id)
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    })
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    this._map.set(id, promise)
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    return r
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  }
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  get size () {
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    return this._map.size
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  }
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  get [Symbol.toStringTag] () {
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    return 'LockMap'
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  }
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}
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