All files / lib/internal linkedlist.js

100% Statements 55/55
100% Branches 12/12
100% Functions 5/5
100% Lines 55/55

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 55 5625x 25x 48x 48x 48x 48x 48x 25x 25x 19005x 19005x 18164x 19005x 25x 25x 30262x 30262x 29508x 29508x 30262x 30262x 29508x 29508x 30262x 30262x 30262x 30262x 25x 25x 17863x 17863x 14887x 14887x 17863x 17863x 17863x 17863x 17863x 17863x 17863x 17863x 17863x 17863x 25x 1281x 1281x 1281x 25x 25x 25x 25x 25x 25x 25x 25x  
'use strict';
 
function init(list) {
  list._idleNext = list;
  list._idlePrev = list;
  return 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
};