Fix for issue zignd#85 Extension hangs / freezes VS Code in big folders

Author: egamma

src/extension.ts

@@ -33,7 +33,7 @@ function cache(): Promise<void> {
             let failedLogsCount: number = 0;
 
             console.log('Parsing documents and looking for CSS class definitions...');
-            return async.each(uris, async (uri, callback) => {
+            return async.eachLimit(uris, 100, async (uri, callback) => {
                 try {
                     Array.prototype.push.apply(definitions, await ParseEngineGateway.callParser(uri));
                     callback();

src/parse-engine-gateway.ts

@@ -1,11 +1,36 @@
 import * as vscode from 'vscode';
+import * as fs from 'fs';
+
 import CssClassDefinition from './common/css-class-definition';
 import ParseEngine from './parse-engines/common/parse-engine';
+import SimpleTextDocument from './parse-engines/common/simple-textdocument';
 import ParseEngineRegistry from './parse-engines/parse-engine-registry';
 
+async function readFile(file: string): Promise<string> {
+	return new Promise<string>((resolve, reject) => {
+		fs.readFile(file, (err, data) => {
+			if (err) {
+				reject(err);
+			}
+			resolve(data.toString());
+		});
+	});
+}
+
+async function createSimpleTextDocument(uri:vscode.Uri): Promise<SimpleTextDocument> {
+    let text = await readFile(uri.fsPath);
+    let simpleDocument:SimpleTextDocument = {
+        languageId: uri.fsPath.split('.').pop(),
+        getText():string {
+            return text;
+        }
+    }
+    return simpleDocument;
+}
+
 class ParseEngineGateway {
     public static async callParser(uri: vscode.Uri): Promise<CssClassDefinition[]> {
-        let textDocument = await vscode.workspace.openTextDocument(uri);
+        let textDocument = await createSimpleTextDocument(uri);
         let parseEngine: ParseEngine = ParseEngineRegistry.getParseEngine(textDocument.languageId);
         let cssClassDefinitions: CssClassDefinition[] = await parseEngine.parse(textDocument);
         return cssClassDefinitions;

src/parse-engines/common/parse-engine.ts

@@ -1,10 +1,10 @@
-import * as vscode from 'vscode';
 import CssClassDefinition from './../../common/css-class-definition';
+import SimpleTextDocument from './simple-textdocument';
 
 interface ParseEngine {
     languageId: string;
     extension: string;
-    parse(textDocument: vscode.TextDocument): Promise<CssClassDefinition[]>;
+    parse(textDocument: SimpleTextDocument): Promise<CssClassDefinition[]>;
 }
 
 export default ParseEngine;

src/parse-engines/common/simple-textdocument.ts

@@ -0,0 +1,9 @@
+/**
+ * A minimum standin for vscode.TextDocument that is passed to a `ParseEngine`.
+ */
+interface SimpleTextDocument {
+    languageId:string;
+    getText():string;
+}
+
+export default SimpleTextDocument;

src/parse-engines/types/css-parse-engine.ts

@@ -2,13 +2,14 @@ import * as css from 'css';
 import * as vscode from 'vscode';
 import CssClassDefinition from '../../common/css-class-definition';
 import ParseEngine from '../common/parse-engine';
+import SimpleTextDocument from '../common/simple-textdocument';
 import CssClassExtractor from '../common/css-class-extractor';
 
 class CssParseEngine implements ParseEngine {
     public languageId: string = 'css';
     public extension: string = 'css';
 
-    public async parse(textDocument: vscode.TextDocument): Promise<CssClassDefinition[]> {
+    public async parse(textDocument: SimpleTextDocument): Promise<CssClassDefinition[]> {
         let code: string = textDocument.getText();
         let codeAst: css.Stylesheet = css.parse(code);
 

src/parse-engines/types/html-parse-engine.ts

@@ -6,12 +6,13 @@ import * as vscode from 'vscode';
 import CssClassDefinition from '../../common/css-class-definition';
 import CssClassExtractor from '../common/css-class-extractor';
 import ParseEngine from '../common/parse-engine';
+import SimpleTextDocument from '../common/simple-textdocument';
 
 class HtmlParseEngine implements ParseEngine {
     public languageId: string = 'html';
     public extension: string = 'html';
 
-    public parse(textDocument: vscode.TextDocument): Promise<CssClassDefinition[]> {
+    public parse(textDocument: SimpleTextDocument): Promise<CssClassDefinition[]> {
         return new Promise((resolve, reject) => {
             const definitions: CssClassDefinition[] = [];
             const urls: string[] = [];