refactor the whole damn thing

src/MessageHandler/deleteSet.js

@@ -0,0 +1,117 @@
+import deleteItemRange from 'deleteItemRange'
+
+export function stringifyDeleteSet (y, decoder, strBuilder) {
+  let dsLength = decoder.readUint32()
+  for (let i = 0; i < dsLength; i++) {
+    let user = decoder.readVarUint()
+    strBuilder.push(' -' + user + ':')
+    let dvLength = decoder.readVarUint()
+    for (let j = 0; j < dvLength; j++) {
+      let from = decoder.readVarUint()
+      let len = decoder.readVarUint()
+      let gc = decoder.readUint8() === 1
+      strBuilder.push(`clock: ${from}, length: ${len}, gc: ${gc}`)
+    }
+  }
+  return strBuilder
+}
+
+export function writeDeleteSet (y, encoder) {
+  let currentUser = null
+  let currentLength = 0
+  let lastLenPos
+
+  let numberOfUsers = 0
+  let laterDSLenPus = encoder.pos
+  encoder.writeUint32(0)
+
+  y.ds.iterate(null, null, function (n) {
+    var user = n._id.user
+    var clock = n._id.clock
+    var len = n.len
+    var gc = n.gc
+    if (currentUser !== user) {
+      numberOfUsers++
+      // a new user was found
+      if (currentUser !== null) { // happens on first iteration
+        encoder.setUint32(lastLenPos, currentLength)
+      }
+      encoder.writeVarUint(user)
+      // pseudo-fill pos
+      lastLenPos = encoder.pos
+      encoder.writeUint32(0)
+    }
+    encoder.writeVarUint(clock)
+    encoder.writeVarUint(len)
+    encoder.writeUint8(gc ? 1 : 0)
+  })
+  if (currentUser !== null) { // happens on first iteration
+    encoder.setUint32(lastLenPos, currentLength)
+  }
+  encoder.writeUint32(laterDSLenPus, numberOfUsers)
+}
+
+export function readDeleteSet (y, decoder) {
+  let dsLength = decoder.readUint32()
+  for (let i = 0; i < dsLength; i++) {
+    let user = decoder.readVarUint()
+    let dv = []
+    let dvLength = decoder.readVarUint()
+    for (let j = 0; j < dvLength; j++) {
+      let from = decoder.readVarUint()
+      let len = decoder.readVarUint()
+      let gc = decoder.readUint8() === 1
+      dv.push([from, len, gc])
+    }
+    var pos = 0
+    var d = dv[pos]
+    y.ds.iterate(this, [user, 0], [user, Number.MAX_VALUE], function (n) {
+      // cases:
+      // 1. d deletes something to the right of n
+      //  => go to next n (break)
+      // 2. d deletes something to the left of n
+      //  => create deletions
+      //  => reset d accordingly
+      //  *)=> if d doesn't delete anything anymore, go to next d (continue)
+      // 3. not 2) and d deletes something that also n deletes
+      //  => reset d so that it doesn't contain n's deletion
+      //  *)=> if d does not delete anything anymore, go to next d (continue)
+      while (d != null) {
+        var diff = 0 // describe the diff of length in 1) and 2)
+        if (n.id[1] + n.len <= d[0]) {
+          // 1)
+          break
+        } else if (d[0] < n.id[1]) {
+          // 2)
+          // delete maximum the len of d
+          // else delete as much as possible
+          diff = Math.min(n.id[1] - d[0], d[1])
+          deleteItemRange(y, user, d[0], diff)
+          // deletions.push([user, d[0], diff, d[2]])
+        } else {
+          // 3)
+          diff = n.id[1] + n.len - d[0] // never null (see 1)
+          if (d[2] && !n.gc) {
+            // d marks as gc'd but n does not
+            // then delete either way
+            deleteItemRange(y, user, d[0], Math.min(diff, d[1]))
+            // deletions.push([user, d[0], Math.min(diff, d[1]), d[2]])
+          }
+        }
+        if (d[1] <= diff) {
+          // d doesn't delete anything anymore
+          d = dv[++pos]
+        } else {
+          d[0] = d[0] + diff // reset pos
+          d[1] = d[1] - diff // reset length
+        }
+      }
+    })
+    // for the rest.. just apply it
+    for (; pos < dv.length; pos++) {
+      d = dv[pos]
+      deleteItemRange(y, user, d[0], d[1])
+      // deletions.push([user, d[0], d[1], d[2]])
+    }
+  }
+}