From 79071996a663925e8dbdadf79ff91181e4d39b6e Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Mon, 9 Jul 2018 16:01:05 -0700
Subject: [PATCH] WIP - put back parse queue

---
 src/tree-sitter-language-mode.js | 34 +++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/tree-sitter-language-mode.js b/src/tree-sitter-language-mode.js
index 53efc0771..7bfaaf3ec 100644
--- a/src/tree-sitter-language-mode.js
+++ b/src/tree-sitter-language-mode.js
@@ -5,6 +5,7 @@ const {Emitter, Disposable} = require('event-kit')
 const ScopeDescriptor = require('./scope-descriptor')
 const TokenizedLine = require('./tokenized-line')
 const TextMateLanguageMode = require('./text-mate-language-mode')
+const async = require('async')
 
 let nextId = 0
 const MAX_RANGE = new Range(Point.ZERO, Point.INFINITY).freeze()
@@ -55,6 +56,18 @@ class TreeSitterLanguageMode {
     this.grammarForLanguageString = this.grammarForLanguageString.bind(this)
     this.emitRangeUpdate = this.emitRangeUpdate.bind(this)
 
+    this.parsers = []
+    this.parseQueue = async.queue(async ({language, oldTree, ranges}, done) => {
+      const parser = this.parsers.pop() || new Parser()
+      parser.setLanguage(language)
+      const newTree = await parser.parseTextBuffer(this.buffer.buffer, oldTree, {
+        syncOperationLimit: 1000,
+        includedRanges: ranges
+      })
+      this.parsers.push(parser)
+      done(null, newTree)
+    }, 2)
+
     this.subscription = this.buffer.onDidChangeText(({changes}) => {
       for (let i = changes.length - 1; i >= 0; i--) {
         const {oldRange, newRange} = changes[i]
@@ -96,6 +109,12 @@ class TreeSitterLanguageMode {
     }
   }
 
+  parse (language, oldTree, ranges) {
+    return new Promise(resolve =>
+      this.parseQueue.push({language, oldTree, ranges}, (error, tree) => resolve(tree))
+    )
+  }
+
   get tree () {
     return this.rootLanguageLayer.tree
   }
@@ -275,7 +294,7 @@ class TreeSitterLanguageMode {
 
     for (const injectionMarker of injectionMarkers) {
       const {tree, grammar} = injectionMarker.languageLayer
-      callback(tree, grammar)
+      if (tree) callback(tree, grammar)
     }
   }
 
@@ -524,11 +543,10 @@ class LanguageLayer {
       if (includedRanges.length === 0) return
     }
 
-    this.languageMode.parser.setLanguage(this.grammar.languageModule)
-    const tree = await this.languageMode.parser.parseTextBuffer(
-      this.languageMode.buffer.buffer,
+    const tree = await this.languageMode.parse(
+      this.grammar.languageModule,
       this.tree,
-      {syncOperationLimit: 1000, includedRanges}
+      includedRanges
     )
     tree.buffer = this.languageMode.buffer
 
@@ -563,7 +581,7 @@ class LanguageLayer {
     await this._populateInjections(affectedRange, nodeRangeSet)
   }
 
-  async _populateInjections (range, nodeRangeSet) {
+  _populateInjections (range, nodeRangeSet) {
     const {injectionsMarkerLayer, grammarForLanguageString} = this.languageMode
 
     const existingInjectionMarkers = injectionsMarkerLayer
@@ -621,9 +639,11 @@ class LanguageLayer {
       }
     }
 
+    const promises = []
     for (const [marker, nodeRangeSet] of markersToUpdate) {
-      await marker.languageLayer.update(nodeRangeSet)
+      promises.push(marker.languageLayer.update(nodeRangeSet))
     }
+    return Promise.all(promises)
   }
 
   _treeEditForBufferChange (start, oldEnd, newEnd, oldText, newText) {