implement new mark deleted / gc approach

test/DeleteStore.tests.js

@@ -0,0 +1,83 @@
+import { test } from '../node_modules/cutest/cutest.mjs'
+import simpleDiff from '../src/Util/simpleDiff.js'
+import Chance from 'chance'
+import DeleteStore from '../src/Store/DeleteStore.js'
+import ID from '../src/Util/ID/ID.js'
+
+/**
+ * Converts a DS to an array of length 10.
+ *
+ * @example
+ * const ds = new DeleteStore()
+ * ds.mark(new ID(0, 0), 1, false)
+ * ds.mark(new ID(0, 1), 1, true)
+ * ds.mark(new ID(0, 3), 1, false)
+ * dsToArray(ds) // => [0, 1, undefined, 0]
+ *
+ * @return {Array<(undefined|number)>} Array of numbers indicating if array[i] is deleted (0), garbage collected (1), or undeleted (undefined).
+ */
+function dsToArray (ds) {
+  const array = []
+  let i = 0
+  ds.iterate(null, null, function (n) {
+    // fill with null
+    while (i < n._id.clock) {
+      array[i++] = null
+    }
+    while (i < n._id.clock + n.len) {
+      array[i++] = n.gc ? 1 : 0
+    }
+  })
+  return array
+}
+
+test('DeleteStore', async function ds1 (t) {
+  const ds = new DeleteStore()
+  ds.mark(new ID(0, 1), 1, false)
+  ds.mark(new ID(0, 2), 1, false)
+  ds.mark(new ID(0, 3), 1, false)
+  t.compare(dsToArray(ds), [null, 0, 0, 0])
+  ds.mark(new ID(0, 2), 1, true)
+  t.compare(dsToArray(ds), [null, 0, 1, 0])
+  ds.mark(new ID(0, 1), 1, true)
+  t.compare(dsToArray(ds), [null, 1, 1, 0])
+  ds.mark(new ID(0, 3), 1, true)
+  t.compare(dsToArray(ds), [null, 1, 1, 1])
+  ds.mark(new ID(0, 5), 1, true)
+  ds.mark(new ID(0, 4), 1, true)
+  t.compare(dsToArray(ds), [null, 1, 1, 1, 1, 1])
+  ds.mark(new ID(0, 0), 3, false)
+  t.compare(dsToArray(ds), [0, 0, 0, 1, 1, 1])
+})
+
+test('random DeleteStore tests', async function randomDS (t) {
+  const chance = new Chance(t.getSeed() * 1000000000)
+  const ds = new DeleteStore()
+  const dsArray = []
+  for (let i = 0; i < 200; i++) {
+    const pos = chance.integer({ min: 0, max: 10 })
+    const len = chance.integer({ min: 0, max: 4 })
+    const gc = chance.bool()
+    ds.mark(new ID(0, pos), len, gc)
+    for (let j = 0; j < len; j++) {
+      dsArray[pos + j] = gc ? 1 : 0
+    }
+  }
+  // fill empty fields
+  for (let i = 0; i < dsArray.length; i++) {
+    if (dsArray[i] !== 0 && dsArray[i] !== 1) {
+      dsArray[i] = null
+    }
+  }
+  t.compare(dsToArray(ds), dsArray, 'expected DS result')
+  let size = 0
+  let lastEl = null
+  for (let i = 0; i < dsArray.length; i++) {
+    let el = dsArray[i]
+    if (lastEl !== el && el !== null) {
+      size++
+    }
+    lastEl = el
+  }
+  t.compare(size, ds.length, 'expected ds size')
+})