Changeset: Improved operation iteration

CHANGELOG.md

@@ -21,6 +21,8 @@
     * `eachAttribNumber()`
     * `makeAttribsString()`
     * `opAttributeValue()`
+  * `opIterator()`: Deprecated in favor of the new `deserializeOps()` generator
+    function.
   * `appendATextToAssembler()`: Deprecated in favor of the new `opsFromAText()`
     generator function.
   * `newOp()`: Deprecated in favor of the new `Op` class.

doc/api/hooks_server-side.md

@@ -670,9 +670,8 @@ const Changeset = require('ep_etherpad-lite/static/js/Changeset');
 
 exports.getLineHTMLForExport = async (hookName, context) => {
   if (!context.attribLine) return;
-  const opIter = Changeset.opIterator(context.attribLine);
-  if (!opIter.hasNext()) return;
-  const op = opIter.next();
+  const [op] = Changeset.deserializeOps(context.attribLine);
+  if (op == null) return;
   const heading = AttributeMap.fromString(op.attribs, context.apool).get('heading');
   if (!heading) return;
   context.lineContent = `<${heading}>${context.lineContent}</${heading}>`;

src/node/db/API.js

@@ -527,12 +527,10 @@ exports.restoreRevision = async (padID, rev) => {
   atext.text += '\n';
 
   const eachAttribRun = (attribs, func) => {
-    const attribsIter = Changeset.opIterator(attribs);
     let textIndex = 0;
     const newTextStart = 0;
     const newTextEnd = atext.text.length;
-    while (attribsIter.hasNext()) {
-      const op = attribsIter.next();
+    for (const op of Changeset.deserializeOps(attribs)) {
       const nextIndex = textIndex + op.chars;
       if (!(nextIndex <= newTextStart || textIndex >= newTextEnd)) {
         func(Math.max(newTextStart, textIndex), Math.min(newTextEnd, nextIndex), op.attribs);

src/node/handler/PadMessageHandler.js

@@ -586,12 +586,7 @@ const handleUserChanges = async (socket, message) => {
     Changeset.checkRep(changeset);
 
     // Validate all added 'author' attribs to be the same value as the current user
-    const iterator = Changeset.opIterator(Changeset.unpack(changeset).ops);
-    let op;
-
-    while (iterator.hasNext()) {
-      op = iterator.next();
-
+    for (const op of Changeset.deserializeOps(Changeset.unpack(changeset).ops)) {
       // + can add text with attribs
       // = can change or add attribs
       // - can have attribs, but they are discarded and don't show up in the attribs -
@@ -741,10 +736,8 @@ const _correctMarkersInPad = (atext, apool) => {
   // collect char positions of line markers (e.g. bullets) in new atext
   // that aren't at the start of a line
   const badMarkers = [];
-  const iter = Changeset.opIterator(atext.attribs);
   let offset = 0;
-  while (iter.hasNext()) {
-    const op = iter.next();
+  for (const op of Changeset.deserializeOps(atext.attribs)) {
     const attribs = AttributeMap.fromString(op.attribs, apool);
     const hasMarker = AttributeManager.lineAttributes.some((a) => attribs.has(a));
     if (hasMarker) {

src/node/utils/ExportHelper.js

@@ -52,9 +52,8 @@ exports._analyzeLine = (text, aline, apool) => {
   let lineMarker = 0;
   line.listLevel = 0;
   if (aline) {
-    const opIter = Changeset.opIterator(aline);
-    if (opIter.hasNext()) {
-      const op = opIter.next();
+    const [op] = Changeset.deserializeOps(aline);
+    if (op != null) {
       const attribs = AttributeMap.fromString(op.attribs, apool);
       let listType = attribs.get('list');
       if (listType) {

src/node/utils/ExportHtml.js

@@ -197,13 +197,12 @@ const getHTMLFromAtext = async (pad, atext, authorColors) => {
         return;
       }
 
-      const iter = Changeset.opIterator(Changeset.subattribution(attribs, idx, idx + numChars));
+      const ops = Changeset.deserializeOps(Changeset.subattribution(attribs, idx, idx + numChars));
       idx += numChars;
 
       // this iterates over every op string and decides which tags to open or to close
       // based on the attribs used
-      while (iter.hasNext()) {
-        const o = iter.next();
+      for (const o of ops) {
         const usedAttribs = [];
 
         // mark all attribs as used

src/node/utils/ExportTxt.js

@@ -76,11 +76,10 @@ const getTXTFromAtext = (pad, atext, authorColors) => {
         return;
       }
 
-      const iter = Changeset.opIterator(Changeset.subattribution(attribs, idx, idx + numChars));
+      const ops = Changeset.deserializeOps(Changeset.subattribution(attribs, idx, idx + numChars));
       idx += numChars;
 
-      while (iter.hasNext()) {
-        const o = iter.next();
+      for (const o of ops) {
         let propChanged = false;
 
         for (const a of attributes.decodeAttribString(o.attribs)) {

src/node/utils/ImportHtml.js

@@ -67,12 +67,10 @@ exports.setPadHTML = async (pad, html) => {
   const builder = Changeset.builder(1);
 
   // assemble each line into the builder
-  const attribsIter = Changeset.opIterator(newAttribs);
   let textIndex = 0;
   const newTextStart = 0;
   const newTextEnd = newText.length;
-  while (attribsIter.hasNext()) {
-    const op = attribsIter.next();
+  for (const op of Changeset.deserializeOps(newAttribs)) {
     const nextIndex = textIndex + op.chars;
     if (!(nextIndex <= newTextStart || textIndex >= newTextEnd)) {
       const start = Math.max(newTextStart, textIndex);

src/node/utils/padDiff.js

@@ -35,16 +35,10 @@ PadDiff.prototype._isClearAuthorship = function (changeset) {
     return false;
   }
 
-  // lets iterator over the operators
-  const iterator = Changeset.opIterator(unpacked.ops);
-
-  // get the first operator, this should be a clear operator
-  const clearOperator = iterator.next();
+  const [clearOperator, anotherOp] = Changeset.deserializeOps(unpacked.ops);
 
   // check if there is only one operator
-  if (iterator.hasNext() === true) {
-    return false;
-  }
+  if (anotherOp != null) return false;
 
   // check if this operator doesn't change text
   if (clearOperator.opcode !== '=') {
@@ -212,18 +206,14 @@ PadDiff.prototype._extendChangesetWithAuthor = (changeset, author, apool) => {
   // unpack
   const unpacked = Changeset.unpack(changeset);
 
-  const iterator = Changeset.opIterator(unpacked.ops);
   const assem = Changeset.opAssembler();
 
   // create deleted attribs
   const authorAttrib = apool.putAttrib(['author', author || '']);
   const deletedAttrib = apool.putAttrib(['removed', true]);
   const attribs = `*${Changeset.numToString(authorAttrib)}*${Changeset.numToString(deletedAttrib)}`;
 
-  // iteratore over the operators of the changeset
-  while (iterator.hasNext()) {
-    const operator = iterator.next();
-
+  for (const operator of Changeset.deserializeOps(unpacked.ops)) {
     if (operator.opcode === '-') {
       // this is a delete operator, extend it with the author
       operator.attribs = attribs;
@@ -268,22 +258,23 @@ PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
 
   let curLine = 0;
   let curChar = 0;
-  let curLineOpIter = null;
-  let curLineOpIterLine;
+  let curLineOps = null;
+  let curLineOpsNext = null;
+  let curLineOpsLine;
   let curLineNextOp = new Changeset.Op('+');
 
   const unpacked = Changeset.unpack(cs);
-  const csIter = Changeset.opIterator(unpacked.ops);
   const builder = Changeset.builder(unpacked.newLen);
 
   const consumeAttribRuns = (numChars, func /* (len, attribs, endsLine)*/) => {
-    if ((!curLineOpIter) || (curLineOpIterLine !== curLine)) {
-      // create curLineOpIter and advance it to curChar
-      curLineOpIter = Changeset.opIterator(aLinesGet(curLine));
-      curLineOpIterLine = curLine;
+    if (!curLineOps || curLineOpsLine !== curLine) {
+      curLineOps = Changeset.deserializeOps(aLinesGet(curLine));
+      curLineOpsNext = curLineOps.next();
+      curLineOpsLine = curLine;
       let indexIntoLine = 0;
-      while (curLineOpIter.hasNext()) {
-        curLineNextOp = curLineOpIter.next();
+      while (!curLineOpsNext.done) {
+        curLineNextOp = curLineOpsNext.value;
+        curLineOpsNext = curLineOps.next();
         if (indexIntoLine + curLineNextOp.chars >= curChar) {
           curLineNextOp.chars -= (curChar - indexIntoLine);
           break;
@@ -293,16 +284,22 @@ PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
     }
 
     while (numChars > 0) {
-      if ((!curLineNextOp.chars) && (!curLineOpIter.hasNext())) {
+      if (!curLineNextOp.chars && curLineOpsNext.done) {
         curLine++;
         curChar = 0;
-        curLineOpIterLine = curLine;
+        curLineOpsLine = curLine;
         curLineNextOp.chars = 0;
-        curLineOpIter = Changeset.opIterator(aLinesGet(curLine));
+        curLineOps = Changeset.deserializeOps(aLinesGet(curLine));
+        curLineOpsNext = curLineOps.next();
       }
 
       if (!curLineNextOp.chars) {
-        curLineNextOp = curLineOpIter.hasNext() ? curLineOpIter.next() : new Changeset.Op();
+        if (curLineOpsNext.done) {
+          curLineNextOp = new Changeset.Op();
+        } else {
+          curLineNextOp = curLineOpsNext.value;
+          curLineOpsNext = curLineOps.next();
+        }
       }
 
       const charsToUse = Math.min(numChars, curLineNextOp.chars);
@@ -314,7 +311,7 @@ PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
       curChar += charsToUse;
     }
 
-    if ((!curLineNextOp.chars) && (!curLineOpIter.hasNext())) {
+    if (!curLineNextOp.chars && curLineOpsNext.done) {
       curLine++;
       curChar = 0;
     }
@@ -324,7 +321,7 @@ PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
     if (L) {
       curLine += L;
       curChar = 0;
-    } else if (curLineOpIter && curLineOpIterLine === curLine) {
+    } else if (curLineOps && curLineOpsLine === curLine) {
       consumeAttribRuns(N, () => {});
     } else {
       curChar += N;
@@ -361,10 +358,7 @@ PadDiff.prototype._createDeletionChangeset = function (cs, startAText, apool) {
     };
   };
 
-  // iterate over all operators of this changeset
-  while (csIter.hasNext()) {
-    const csOp = csIter.next();
-
+  for (const csOp of Changeset.deserializeOps(unpacked.ops)) {
     if (csOp.opcode === '=') {
       const textBank = nextText(csOp.chars);
 

src/static/js/AttributeManager.js

@@ -150,9 +150,9 @@ AttributeManager.prototype = _(AttributeManager.prototype).extend({
     // get  `attributeName` attribute of first char of line
     const aline = this.rep.alines[lineNum];
     if (!aline) return '';
-    const opIter = Changeset.opIterator(aline);
-    if (!opIter.hasNext()) return '';
-    return AttributeMap.fromString(opIter.next().attribs, this.rep.apool).get(attributeName) || '';
+    const [op] = Changeset.deserializeOps(aline);
+    if (op == null) return '';
+    return AttributeMap.fromString(op.attribs, this.rep.apool).get(attributeName) || '';
   },
 
   /*
@@ -163,9 +163,8 @@ AttributeManager.prototype = _(AttributeManager.prototype).extend({
     // get attributes of first char of line
     const aline = this.rep.alines[lineNum];
     if (!aline) return [];
-    const opIter = Changeset.opIterator(aline);
-    if (!opIter.hasNext()) return [];
-    const op = opIter.next();
+    const [op] = Changeset.deserializeOps(aline);
+    if (op == null) return [];
     return [...attributes.attribsFromString(op.attribs, this.rep.apool)];
   },
 
@@ -221,13 +220,8 @@ AttributeManager.prototype = _(AttributeManager.prototype).extend({
       const end = selEnd[1];
       let hasAttrib = true;
 
-      // Iterate over attribs on this line
-
-      const opIter = Changeset.opIterator(rep.alines[lineNum]);
       let indexIntoLine = 0;
-
-      while (opIter.hasNext()) {
-        const op = opIter.next();
+      for (const op of Changeset.deserializeOps(rep.alines[lineNum])) {
         const opStartInLine = indexIntoLine;
         const opEndInLine = opStartInLine + op.chars;
         if (!hasIt(op.attribs)) {
@@ -260,15 +254,11 @@ AttributeManager.prototype = _(AttributeManager.prototype).extend({
     if (!aline) {
       return [];
     }
-    // iterate through all operations of a line
-    const opIter = Changeset.opIterator(aline);
 
     // we need to sum up how much characters each operations take until the wanted position
     let currentPointer = 0;
-    let currentOperation;
 
-    while (opIter.hasNext()) {
-      currentOperation = opIter.next();
+    for (const currentOperation of Changeset.deserializeOps(aline)) {
       currentPointer += currentOperation.chars;
       if (currentPointer <= column) continue;
       return [...attributes.attribsFromString(currentOperation.attribs, this.rep.apool)];