github.com/iqoqo/nomad@v0.11.3-0.20200911112621-d7021c74d101/ui/app/utils/classes/rolling-array.js (about)

     1  // An array with a max length.
     2  //
     3  // When max length is surpassed, items are removed from
     4  // the front of the array.
     5  
     6  // Native array methods
     7  let { push, splice } = Array.prototype;
     8  
     9  // Ember array prototype extension
    10  let { insertAt } = Array.prototype;
    11  
    12  // Using Classes to extend Array is unsupported in Babel so this less
    13  // ideal approach is taken: https://babeljs.io/docs/en/caveats#classes
    14  export default function RollingArray(maxLength, ...items) {
    15    const array = new Array(...items);
    16    array.maxLength = maxLength;
    17  
    18    // Bring the length back down to maxLength by removing from the front
    19    array._limit = function() {
    20      const surplus = this.length - this.maxLength;
    21      if (surplus > 0) {
    22        this.splice(0, surplus);
    23      }
    24    };
    25  
    26    array.push = function(...items) {
    27      push.apply(this, items);
    28      this._limit();
    29      return this.length;
    30    };
    31  
    32    array.splice = function(...args) {
    33      const returnValue = splice.apply(this, args);
    34      this._limit();
    35      return returnValue;
    36    };
    37  
    38    // All mutable array methods build on top of insertAt
    39    array.insertAt = function(...args) {
    40      const returnValue = insertAt.apply(this, args);
    41      this._limit();
    42      this.arrayContentDidChange();
    43      return returnValue;
    44    };
    45  
    46    array.unshift = function() {
    47      throw new Error('Cannot unshift onto a RollingArray');
    48    };
    49  
    50    return array;
    51  }