fbjs/lib/CircularBuffer.js

A collection of utility libraries used by other Facebook JS projects

"use strict";

/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */
var invariant = require("./invariant");

var CircularBuffer = /*#__PURE__*/function () {
  function CircularBuffer(size) {
    !(size > 0) ? process.env.NODE_ENV !== "production" ? invariant(false, 'Buffer size should be a positive integer') : invariant(false) : void 0;
    this._size = size;
    this._head = 0;
    this._buffer = [];
  }

  var _proto = CircularBuffer.prototype;

  _proto.write = function write(entry) {
    if (this._buffer.length < this._size) {
      this._buffer.push(entry);
    } else {
      this._buffer[this._head] = entry;
      this._head++;
      this._head %= this._size;
    }

    return this;
  };

  _proto.read = function read() {
    return this._buffer.slice(this._head).concat(this._buffer.slice(0, this._head));
  };

  _proto.clear = function clear() {
    this._head = 0;
    this._buffer = [];
    return this;
  };

  return CircularBuffer;
}();

module.exports = CircularBuffer;