| 1 | import { randomInt } from 'node:crypto' |
| 2 | |
| 3 | import { bench, group, run } from 'tatami-ng' |
| 4 | |
| 5 | /** |
| 6 | * @param numberOfWorkers |
| 7 | * @param maxNumberOfTasksPerWorker |
| 8 | * @returns |
| 9 | */ |
| 10 | function generateRandomTasksMap ( |
| 11 | numberOfWorkers, |
| 12 | maxNumberOfTasksPerWorker = 10 |
| 13 | ) { |
| 14 | const tasksArray = [] |
| 15 | for (let i = 0; i < numberOfWorkers; i++) { |
| 16 | const task = [i, randomInt(maxNumberOfTasksPerWorker)] |
| 17 | tasksArray.push(task) |
| 18 | } |
| 19 | return new Map(tasksArray) |
| 20 | } |
| 21 | |
| 22 | const tasksMap = generateRandomTasksMap(60, 20) |
| 23 | |
| 24 | /** |
| 25 | * @param tasksMap |
| 26 | * @returns |
| 27 | */ |
| 28 | function loopSelect (tasksMap) { |
| 29 | let minKey |
| 30 | let minValue = Number.POSITIVE_INFINITY |
| 31 | for (const [key, value] of tasksMap) { |
| 32 | if (value === 0) { |
| 33 | return key |
| 34 | } else if (value < minValue) { |
| 35 | minKey = key |
| 36 | minValue = value |
| 37 | } |
| 38 | } |
| 39 | return [minKey, minValue] |
| 40 | } |
| 41 | |
| 42 | /** |
| 43 | * @param tasksMap |
| 44 | * @returns |
| 45 | */ |
| 46 | function arraySortSelect (tasksMap) { |
| 47 | const tasksArray = Array.from(tasksMap) |
| 48 | return tasksArray.sort((a, b) => { |
| 49 | if (a[1] < b[1]) { |
| 50 | return -1 |
| 51 | } else if (a[1] > b[1]) { |
| 52 | return 1 |
| 53 | } |
| 54 | return 0 |
| 55 | })[0] |
| 56 | } |
| 57 | |
| 58 | const defaultComparator = (a, b) => { |
| 59 | return a < b |
| 60 | } |
| 61 | |
| 62 | const defaultPivotIndexSelect = (leftIndex, rightIndex) => { |
| 63 | return leftIndex + Math.floor((rightIndex - leftIndex) / 2) |
| 64 | } |
| 65 | |
| 66 | const randomPivotIndexSelect = (leftIndex, rightIndex) => { |
| 67 | return randomInt(leftIndex, rightIndex) |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * @param array |
| 72 | * @param index1 |
| 73 | * @param index2 |
| 74 | */ |
| 75 | function swap (array, index1, index2) { |
| 76 | const tmp = array[index1] |
| 77 | array[index1] = array[index2] |
| 78 | array[index2] = tmp |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * @param array |
| 83 | * @param leftIndex |
| 84 | * @param rightIndex |
| 85 | * @param pivotIndex |
| 86 | * @param compare |
| 87 | * @returns |
| 88 | */ |
| 89 | function partition ( |
| 90 | array, |
| 91 | leftIndex, |
| 92 | rightIndex, |
| 93 | pivotIndex, |
| 94 | compare = defaultComparator |
| 95 | ) { |
| 96 | const pivotValue = array[pivotIndex] |
| 97 | swap(array, pivotIndex, rightIndex) |
| 98 | let storeIndex = leftIndex |
| 99 | for (let i = leftIndex; i < rightIndex; i++) { |
| 100 | if (compare(array[i], pivotValue)) { |
| 101 | swap(array, storeIndex, i) |
| 102 | storeIndex++ |
| 103 | } |
| 104 | } |
| 105 | swap(array, rightIndex, storeIndex) |
| 106 | return storeIndex |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * @param array |
| 111 | * @param k |
| 112 | * @param leftIndex |
| 113 | * @param rightIndex |
| 114 | * @param compare |
| 115 | * @param pivotIndexSelect |
| 116 | * @returns |
| 117 | */ |
| 118 | function selectLoop ( |
| 119 | array, |
| 120 | k, |
| 121 | leftIndex, |
| 122 | rightIndex, |
| 123 | compare = defaultComparator, |
| 124 | pivotIndexSelect = defaultPivotIndexSelect |
| 125 | ) { |
| 126 | while (true) { |
| 127 | if (leftIndex === rightIndex) return array[leftIndex] |
| 128 | let pivotIndex = pivotIndexSelect(leftIndex, rightIndex) |
| 129 | pivotIndex = partition(array, leftIndex, rightIndex, pivotIndex, compare) |
| 130 | if (k === pivotIndex) { |
| 131 | return array[k] |
| 132 | } else if (k < pivotIndex) { |
| 133 | rightIndex = pivotIndex - 1 |
| 134 | } else { |
| 135 | leftIndex = pivotIndex + 1 |
| 136 | } |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * @param array |
| 142 | * @param k |
| 143 | * @param leftIndex |
| 144 | * @param rightIndex |
| 145 | * @param compare |
| 146 | * @param pivotIndexSelect |
| 147 | * @returns |
| 148 | */ |
| 149 | function selectRecursion ( |
| 150 | array, |
| 151 | k, |
| 152 | leftIndex, |
| 153 | rightIndex, |
| 154 | compare = defaultComparator, |
| 155 | pivotIndexSelect = defaultPivotIndexSelect |
| 156 | ) { |
| 157 | if (leftIndex === rightIndex) return array[leftIndex] |
| 158 | let pivotIndex = pivotIndexSelect(leftIndex, rightIndex) |
| 159 | pivotIndex = partition(array, leftIndex, rightIndex, pivotIndex, compare) |
| 160 | if (k === pivotIndex) { |
| 161 | return array[k] |
| 162 | } else if (k < pivotIndex) { |
| 163 | return selectRecursion(array, k, leftIndex, pivotIndex - 1, compare) |
| 164 | } else { |
| 165 | return selectRecursion(array, k, pivotIndex + 1, rightIndex, k, compare) |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * @param tasksMap |
| 171 | * @returns |
| 172 | */ |
| 173 | function quickSelectLoop (tasksMap) { |
| 174 | const tasksArray = Array.from(tasksMap) |
| 175 | |
| 176 | return selectLoop(tasksArray, 0, 0, tasksArray.length - 1, (a, b) => { |
| 177 | return a[1] < b[1] |
| 178 | }) |
| 179 | } |
| 180 | |
| 181 | /** |
| 182 | * @param tasksMap |
| 183 | * @returns |
| 184 | */ |
| 185 | function quickSelectLoopRandomPivot (tasksMap) { |
| 186 | const tasksArray = Array.from(tasksMap) |
| 187 | |
| 188 | return selectLoop( |
| 189 | tasksArray, |
| 190 | 0, |
| 191 | 0, |
| 192 | tasksArray.length - 1, |
| 193 | (a, b) => { |
| 194 | return a[1] < b[1] |
| 195 | }, |
| 196 | randomPivotIndexSelect |
| 197 | ) |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * @param tasksMap |
| 202 | * @returns |
| 203 | */ |
| 204 | function quickSelectRecursion (tasksMap) { |
| 205 | const tasksArray = Array.from(tasksMap) |
| 206 | |
| 207 | return selectRecursion(tasksArray, 0, 0, tasksArray.length - 1, (a, b) => { |
| 208 | return a[1] < b[1] |
| 209 | }) |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * @param tasksMap |
| 214 | * @returns |
| 215 | */ |
| 216 | function quickSelectRecursionRandomPivot (tasksMap) { |
| 217 | const tasksArray = Array.from(tasksMap) |
| 218 | |
| 219 | return selectRecursion( |
| 220 | tasksArray, |
| 221 | 0, |
| 222 | 0, |
| 223 | tasksArray.length - 1, |
| 224 | (a, b) => { |
| 225 | return a[1] < b[1] |
| 226 | }, |
| 227 | randomPivotIndexSelect |
| 228 | ) |
| 229 | } |
| 230 | |
| 231 | group('Quick select', () => { |
| 232 | bench('Loop select', () => { |
| 233 | loopSelect(tasksMap) |
| 234 | }) |
| 235 | bench('Array sort select', () => { |
| 236 | arraySortSelect(tasksMap) |
| 237 | }) |
| 238 | bench('Quick select loop', () => { |
| 239 | quickSelectLoop(tasksMap) |
| 240 | }) |
| 241 | bench('Quick select loop with random pivot', () => { |
| 242 | quickSelectLoopRandomPivot(tasksMap) |
| 243 | }) |
| 244 | bench('Quick select recursion', () => { |
| 245 | quickSelectRecursion(tasksMap) |
| 246 | }) |
| 247 | bench('Quick select recursion with random pivot', () => { |
| 248 | quickSelectRecursionRandomPivot(tasksMap) |
| 249 | }) |
| 250 | }) |
| 251 | |
| 252 | await run({ |
| 253 | units: true, |
| 254 | }) |