All files / lib/internal linkedlist.js

100% Statements 54/54
100% Branches 13/13
100% Functions 5/5
100% Lines 54/54

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5517x 17x 13x 13x 13x 13x 17x 17x 15585x 15585x 14751x 15585x 17x 17x 27584x 27584x 26834x 26834x 27584x 27584x 26834x 26834x 27584x 27584x 27584x 27584x 17x 17x 16023x 16023x 14054x 14054x 16023x 16023x 16023x 16023x 16023x 16023x 16023x 16023x 16023x 16023x 17x 1245x 1245x 1245x 17x 17x 17x 17x 17x 17x 17x 17x  
'use strict';
 
function init(list) {
  list._idleNext = list;
  list._idlePrev = list;
}
 
// Show the most idle item.
function peek(list) {
  if (list._idlePrev === list) return null;
  return list._idlePrev;
}
 
// Remove an item from its list.
function remove(item) {
  if (item._idleNext) {
    item._idleNext._idlePrev = item._idlePrev;
  }
 
  if (item._idlePrev) {
    item._idlePrev._idleNext = item._idleNext;
  }
 
  item._idleNext = null;
  item._idlePrev = null;
}
 
// Remove an item from its list and place at the end.
function append(list, item) {
  if (item._idleNext || item._idlePrev) {
    remove(item);
  }
 
  // Items are linked  with _idleNext -> (older) and _idlePrev -> (newer).
  // Note: This linkage (next being older) may seem counter-intuitive at first.
  item._idleNext = list._idleNext;
  item._idlePrev = list;
 
  // The list _idleNext points to tail (newest) and _idlePrev to head (oldest).
  list._idleNext._idlePrev = item;
  list._idleNext = item;
}
 
function isEmpty(list) {
  return list._idleNext === list;
}
 
module.exports = {
  init,
  peek,
  remove,
  append,
  isEmpty
};