Changeset: Migrate from mergingOpAssembler() to squashOps()

Author: rhansen

CHANGELOG.md

@@ -37,6 +37,8 @@
       instead.
     * The `opAssembler()` function is deprecated; use the new `serializeOps()`
       function instead.
+    * The `mergingOpAssembler()` function is deprecated; use the new
+      `squashOps()` generator function with `serializeOps()` instead.
 
 ### Notable enhancements
 

src/static/js/Changeset.js

@@ -358,7 +358,7 @@ class OpAssembler {
  * @param {boolean} finalize - If truthy, omits the final op if it is an attributeless keep op.
  * @yields {Op} The squashed operations.
  */
-const squashOps = function* (ops, finalize) {
+exports.squashOps = function* (ops, finalize) {
   let prevOp = new exports.Op();
   // If we get, for example, insertions [xxx\n,yyy], those don't merge, but if we get
   // [xxx\n,yyy,zzz\n], that merges to [xxx\nyyyzzz\n]. This variable stores the length of yyy and
@@ -417,7 +417,7 @@ class MergingOpAssembler {
   }
 
   _serialize(finalize) {
-    this._serialized = exports.serializeOps(squashOps(this._ops, finalize));
+    this._serialized = exports.serializeOps(exports.squashOps(this._ops, finalize));
   }
 
   clear() {
@@ -459,14 +459,14 @@ const canonicalizeOps = function* (ops, finalize) {
   let lengthChange = 0;
 
   const flushPlusMinus = function* () {
-    yield* squashOps(minusOps, false);
+    yield* exports.squashOps(minusOps, false);
     minusOps = [];
-    yield* squashOps(plusOps, false);
+    yield* exports.squashOps(plusOps, false);
     plusOps = [];
   };
 
   const flushKeeps = function* (finalize) {
-    yield* squashOps(keepOps, finalize);
+    yield* exports.squashOps(keepOps, finalize);
     keepOps = [];
   };
 
@@ -619,9 +619,13 @@ exports.checkRep = (cs) => {
 exports.smartOpAssembler = () => new SmartOpAssembler();
 
 /**
+ * @deprecated Use `squashOps` with `serializeOps` instead.
  * @returns {MergingOpAssembler}
  */
-exports.mergingOpAssembler = () => new MergingOpAssembler();
+exports.mergingOpAssembler = () => {
+  warnDeprecated('Changeset.mergingOpAssembler() is deprecated; use Changeset.squashOps() instead');
+  return new MergingOpAssembler();
+};
 
 /**
  * @deprecated Use `serializeOps` instead.
@@ -1332,28 +1336,26 @@ exports.mutateAttributionLines = (cs, lines, pool) => {
     if (!lineIter || !lineIter.hasNext()) return new exports.Op();
     return lineIter.next();
   };
-  let lineAssem = null;
+  let lineOps = null;
 
   const outputMutOp = (op) => {
-    if (!lineAssem) {
-      lineAssem = new MergingOpAssembler();
-    }
-    lineAssem.append(op);
+    if (lineOps == null) lineOps = [];
+    lineOps.push(op);
     if (op.lines <= 0) return;
     assert(op.lines === 1, "Can't have op.lines of ", op.lines, ' in attribution lines');
     // ship it to the mut
-    mut.insert(lineAssem.toString(), 1);
-    lineAssem = null;
+    mut.insert(exports.serializeOps(exports.squashOps(lineOps, false)), 1);
+    lineOps = null;
   };
 
   let csOp = new exports.Op();
   let attOp = new exports.Op();
   while (csOp.opcode || csIter.hasNext() || attOp.opcode || isNextMutOp()) {
     if (!csOp.opcode && csIter.hasNext()) csOp = csIter.next();
-    if ((!csOp.opcode) && (!attOp.opcode) && (!lineAssem) && (!(lineIter && lineIter.hasNext()))) {
+    if (!csOp.opcode && !attOp.opcode && lineOps == null && !(lineIter && lineIter.hasNext())) {
       break; // done
     } else if (csOp.opcode === '=' && csOp.lines > 0 && (!csOp.attribs) &&
-        (!attOp.opcode) && (!lineAssem) && (!(lineIter && lineIter.hasNext()))) {
+        !attOp.opcode && lineOps == null && !(lineIter && lineIter.hasNext())) {
       // skip multiple lines; this is what makes small changes not order of the document size
       mut.skipLines(csOp.lines);
       csOp.opcode = '';
@@ -1377,7 +1379,7 @@ exports.mutateAttributionLines = (cs, lines, pool) => {
     }
   }
 
-  assert(!lineAssem, `line assembler not finished:${cs}`);
+  assert(lineOps == null, `line assembler not finished:${cs}`);
   mut.close();
 };
 
@@ -1387,24 +1389,20 @@ exports.mutateAttributionLines = (cs, lines, pool) => {
  * @param {string[]} theAlines - collection of Attribution lines
  * @returns {string} joined Attribution lines
  */
-exports.joinAttributionLines = (theAlines) => {
-  const assem = new MergingOpAssembler();
-  for (const aline of theAlines) {
-    for (const op of new exports.OpIter(aline)) assem.append(op);
-  }
-  return assem.toString();
-};
+exports.joinAttributionLines = (theAlines) => exports.serializeOps(exports.squashOps((function* () {
+  for (const aline of theAlines) yield* new exports.OpIter(aline);
+})(), false));
 
 exports.splitAttributionLines = (attrOps, text) => {
-  const assem = new MergingOpAssembler();
+  let ops = [];
   const lines = [];
   let pos = 0;
 
   const appendOp = (op) => {
-    assem.append(op);
+    ops.push(op);
     if (op.lines > 0) {
-      lines.push(assem.toString());
-      assem.clear();
+      lines.push(exports.serializeOps(exports.squashOps(ops, false)));
+      ops = [];
     }
     pos += op.chars;
   };

src/static/js/changesettracker.js

@@ -162,7 +162,7 @@ const makeChangesetTracker = (scheduler, apool, aceCallbacksProvider) => {
 
           // Replace all added 'author' attribs with the value of the current user
           const cs = Changeset.unpack(userChangeset);
-          const assem = Changeset.mergingOpAssembler();
+          const ops = [];
 
           for (const op of new Changeset.OpIter(cs.ops)) {
             if (op.opcode === '+') {
@@ -179,10 +179,10 @@ const makeChangesetTracker = (scheduler, apool, aceCallbacksProvider) => {
               });
               op.attribs = newAttrs;
             }
-            assem.append(op);
+            ops.push(op);
           }
-          assem.endDocument();
-          userChangeset = Changeset.pack(cs.oldLen, cs.newLen, assem.toString(), cs.charBank);
+          const serializedOps = Changeset.serializeOps(Changeset.squashOps(ops, true));
+          userChangeset = Changeset.pack(cs.oldLen, cs.newLen, serializedOps, cs.charBank);
           Changeset.checkRep(userChangeset);
         }
         if (Changeset.isIdentity(userChangeset)) toSubmit = null;

src/tests/frontend/specs/easysync.js

@@ -646,16 +646,16 @@ describe('easysync', function () {
 
   const testSplitJoinAttributionLines = (randomSeed) => {
     const stringToOps = (str) => {
-      const assem = Changeset.mergingOpAssembler();
-      const o = new Changeset.Op('+');
-      o.chars = 1;
+      const ops = [];
       for (let i = 0; i < str.length; i++) {
         const c = str.charAt(i);
+        const o = new Changeset.Op('+');
+        o.chars = 1;
         o.lines = (c === '\n' ? 1 : 0);
         o.attribs = (c === 'a' || c === 'b' ? `*${c}` : '');
-        assem.append(o);
+        ops.push(o);
       }
-      return assem.toString();
+      return Changeset.serializeOps(Changeset.squashOps(ops, false));
     };
 
     it(`testSplitJoinAttributionLines#${randomSeed}`, async function () {