Merge pull request #13 from hackmdio/fix/blockquote-position

Fix/blockquote position

Author: Yukaii

lib/common/utils.js

@@ -289,37 +289,13 @@ function normalizeReference(str) {
   return str.toLowerCase().toUpperCase();
 }
 
-/* eslint-env browser */
-var _g = typeof global !== 'undefined' ? global : window;
-var tokensRef = new _g.WeakMap();
-
-// TODO: performance tweaks for emphasis **_* pattern which has only 1/10 performance after adding line offset
-function getLineOffset(state, tokenIdx) {
-  var blockState = state.env.state_block;
-  var parentToken = state.env.parentToken;
-  var tokensBefore = typeof tokenIdx !== 'undefined' ? state.tokens.slice(0, tokenIdx) : state.tokens;
-
-  var resultsMap = tokensRef.get(state.tokens);
-  if (resultsMap) {
-    var cachedResult = resultsMap.get(tokenIdx);
-    if (typeof cachedResult !== 'undefined') {
-      return cachedResult;
-    }
+function getLineOffset(state) {
+  if (state.env.parentToken.parentType === 'blockquote') {
+    const blockState = state.env.state_block;
+    return blockState.lineOffsets[state.currentLine] ?? 0;
   } else {
-    resultsMap = new _g.Map();
-    tokensRef.set(state.tokens, resultsMap);
+    return 0;
   }
-
-  var linesBefore = tokensBefore.filter(function (t) { return t.type === 'softbreak' || t.type === 'hardbreak'; }).length;
-
-  var lineOffset = 0;
-  for (var i = 0; i < linesBefore; i++) {
-    var startLine = i + parentToken.map[0] + 1;
-    lineOffset += blockState.tShift[startLine];
-  }
-
-  resultsMap.set(tokenIdx, lineOffset);
-  return lineOffset;
 }
 
 function trimLeftOffset(str) {

lib/rules_block/blockquote.js

@@ -272,15 +272,38 @@ module.exports = function blockquote(state, startLine, endLine, silent) {
   state.parentType = oldParentType;
   lines[1] = state.line;
 
+  let totalLineOffset = 0;
   // Restore original tShift; this might not be necessary since the parser
   // has already been here, but just to make sure we can do that.
   for (i = 0; i < oldTShift.length; i++) {
-    state.bMarks[i + startLine] = oldBMarks[i];
-    state.tShift[i + startLine] = oldTShift[i];
-    state.sCount[i + startLine] = oldSCount[i];
-    state.bsCount[i + startLine] = oldBSCount[i];
+    const lineNumber = i + startLine;
+    if (state.lineOffsets[lineNumber] === null) {
+      state.lineOffsets[lineNumber] = totalLineOffset;
+      if (isNotEmptyLine(state, lineNumber)) {
+        totalLineOffset += calcLineOffset(state, lineNumber);
+      } else {
+        totalLineOffset = 0;
+      }
+    }
+
+    state.bMarks[lineNumber] = oldBMarks[i];
+    state.tShift[lineNumber] = oldTShift[i];
+    state.sCount[lineNumber] = oldSCount[i];
+    state.bsCount[lineNumber] = oldBSCount[i];
   }
   state.blkIndent = oldIndent;
 
   return true;
 };
+
+function calcLineOffset (state, lineNumber) {
+  const previousLineEnd = state.eMarks[lineNumber - 1] + 1 || 0;
+  return state.bMarks[lineNumber] - previousLineEnd;
+}
+
+function isNotEmptyLine (state, lineNumber) {
+  return (
+    state.bMarks[lineNumber] + state.tShift[lineNumber] <
+    state.eMarks[lineNumber]
+  )
+}

lib/rules_block/lheading.js

@@ -59,6 +59,7 @@ module.exports = function lheading(state, startLine, endLine/*, silent*/) {
 
   if (!level) {
     // Didn't find valid underline
+    state.parentType = oldParentType;
     return false;
   }
 

lib/rules_block/state_block.js

@@ -31,6 +31,7 @@ function StateBlock(src, md, env, tokens) {
   this.eMarks = [];  // line end offsets for fast jumps
   this.tShift = [];  // offsets of the first non-space characters (tabs not expanded)
   this.sCount = [];  // indents for each line (tabs expanded)
+  this.lineOffsets = [];
 
   // An amount of virtual spaces (tabs expanded) between beginning
   // of each line (bMarks) and real beginning of that line.
@@ -92,6 +93,7 @@ function StateBlock(src, md, env, tokens) {
       this.tShift.push(indent);
       this.sCount.push(offset);
       this.bsCount.push(0);
+      this.lineOffsets.push(null);
 
       indent_found = false;
       indent = 0;
@@ -106,6 +108,7 @@ function StateBlock(src, md, env, tokens) {
   this.tShift.push(0);
   this.sCount.push(0);
   this.bsCount.push(0);
+  this.lineOffsets.push(null);
 
   this.lineMax = this.bMarks.length - 1; // don't count last fake line
 }

lib/rules_inline/emphasis.js

@@ -2,9 +2,6 @@
 //
 'use strict';
 
-var getLineOffset  = require('../common/utils').getLineOffset;
-
-
 // Insert each marker as a separate text token, and add it to delimiter list
 //
 module.exports.tokenize = function emphasis(state, silent) {
@@ -107,7 +104,7 @@ function postProcess(state, delimiters) {
     token.nesting = 1;
     token.markup  = isStrong ? ch + ch : ch;
     token.content = '';
-    token.position = startDelim.position + getLineOffset(state, startDelim.token);
+    token.position = startDelim.position;
 
     token         = state.tokens[endDelim.token];
     token.type    = isStrong ? 'strong_close' : 'em_close';

lib/rules_inline/newline.js

@@ -34,6 +34,7 @@ module.exports = function newline(state, silent) {
       token.position = pos;
     }
   }
+  state.currentLine += 1;
 
   pos++;
 

lib/rules_inline/state_inline.js

@@ -32,6 +32,7 @@ function StateInline(src, md, env, outTokens) {
     }
   });
   this.pendingLevel = 0;
+  this.currentLine = env.parentToken.map[0];
 
   // Stores { start: end } pairs. Useful for backtrack
   // optimization of pairs parse (emphasis, strikes).

lib/rules_inline/strikethrough.js

@@ -2,8 +2,6 @@
 //
 'use strict';
 
-var getLineOffset  = require('../common/utils').getLineOffset;
-
 // Insert each marker as a separate text token, and add it to delimiter list
 //
 module.exports.tokenize = function strikethrough(state, silent) {
@@ -76,7 +74,7 @@ function postProcess(state, delimiters) {
     token.nesting = 1;
     token.markup  = '~~';
     token.content = '';
-    token.position = startDelim.position + getLineOffset(state, startDelim.token);
+    token.position = startDelim.position;
 
     token         = state.tokens[endDelim.token];
     token.type    = 's_close';