git ssb

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module.exports = class ReferanceMap {
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  /**
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   * Handle mapping arbitary JS object to ints
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   */
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  constructor () {
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    this._map = new Map()
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    this._nonce = 0
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  }
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  /**
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   * Adds an object to the referance map returning an int to be used as a
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   * referance
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   * @param {*} obj
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   * @return {integer}
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   */
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  add (obj) {
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    const nonce = this._nonce
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    this._map.set(this._nonce, obj)
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    this._nonce++
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    return nonce
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  }
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  /**
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   * gets a POJO given a refernce as an int
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   * @param {integer} ref
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   * @return {*}
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   */
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  get (ref) {
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    const obj = this._map.get(ref)
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    if (!obj) {
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      throw new Error('invalid referance')
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    }
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    return obj
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  }
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  /**
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   * deletes an object given a referance as an int
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   * @param {integer}
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   * @return {boolean} whether or not the object was deleted
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   */
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  delete (ref) {
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    return this._map.delete(ref)
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  }
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  /**
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   * clears the referance map of a objects
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   */
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  clear () {
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    this._map.clear()
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  }
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}
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