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 5518x 18x 13x 13x 13x 13x 18x 18x 14788x 14788x 13969x 14788x 18x 18x 26754x 26754x 26003x 26003x 26754x 26754x 26003x 26003x 26754x 26754x 26754x 26754x 18x 18x 15427x 15427x 13840x 13840x 15427x 15427x 15427x 15427x 15427x 15427x 15427x 15427x 15427x 15427x 18x 1026x 1026x 1026x 18x 18x 18x 18x 18x 18x 18x 18x  
'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
};