Merge branch 'rebornix/buffer-pt'

src/vs/editor/common/model/indentationGuesser.ts

@@ -97,14 +97,23 @@ export function guessIndentation(source: ITextBuffer, defaultTabSize: number, de
 	let spacesDiffCount = [0, 0, 0, 0, 0, 0, 0, 0, 0];		// `tabSize` scores
 
 	for (let lineNumber = 1; lineNumber <= linesCount; lineNumber++) {
+		let currentLineLength = source.getLineLength(lineNumber);
 		let currentLineText = source.getLineContent(lineNumber);
+		let charCodeAt: (offset: number) => number;
+		if (currentLineLength > 65536) {
+			// if the text buffer is chunk based, so long lines are cons-string, v8 will flattern the string when we check charCode.
+			// checking charCode on chunks directly is cheaper.
+			charCodeAt = (offset: number) => source.getLineCharCode(lineNumber, offset);
+		} else {
+			charCodeAt = (offset: number) => currentLineText.charCodeAt(offset);
+		}
 
 		let currentLineHasContent = false;			// does `currentLineText` contain non-whitespace chars
 		let currentLineIndentation = 0;				// index at which `currentLineText` contains the first non-whitespace char
 		let currentLineSpacesCount = 0;				// count of spaces found in `currentLineText` indentation
 		let currentLineTabsCount = 0;				// count of tabs found in `currentLineText` indentation
-		for (let j = 0, lenJ = currentLineText.length; j < lenJ; j++) {
-			let charCode = currentLineText.charCodeAt(j);
+		for (let j = 0, lenJ = currentLineLength; j < lenJ; j++) {
+			let charCode = charCodeAt(j);
 
 			if (charCode === CharCode.Tab) {
 				currentLineTabsCount++;