fix fdatasync working properly

src/vs/base/node/extfs.ts

@@ -356,14 +356,13 @@ function doWriteFileStreamAndFlush(path: string, reader: NodeJS.ReadableStream,
 		}
 	};
 
-	// create writer to target
-	const writer = fs.createWriteStream(path, options);
+	// create writer to target. we set autoClose: false because we want to use the streams
+	// file descriptor to call fs.fdatasync to ensure the data is flushed to disk
+	const writer = fs.createWriteStream(path, { mode: options.mode, flags: options.flag, autoClose: false });
 
-	// handle errors properly
-	reader.once('error', error => finish(error));
-	writer.once('error', error => finish(error));
-
-	// save the fd for later use
+	// Event: 'open'
+	// Purpose: save the fd for later use
+	// Notes: will not be called when there is an error opening the file descriptor!
 	let fd: number;
 	let isOpen: boolean;
 	writer.once('open', descriptor => {
@@ -371,11 +370,16 @@ function doWriteFileStreamAndFlush(path: string, reader: NodeJS.ReadableStream,
 		isOpen = true;
 	});
 
-	// we are done (underlying fd has been closed)
-	writer.once('close', () => finish());
+	// Event: 'error'
+	// Purpose: to return the error to the outside and to close the write stream (does not happen automatically)
+	reader.once('error', error => finish(error));
+	writer.once('error', error => finish(error));
 
-	// handle end event because we are in charge
-	reader.once('end', () => {
+	// Event: 'finish'
+	// Purpose: use fs.fdatasync to flush the contents to disk
+	// Notes: event is called when the writer has finished writing to the underlying resource. we must call writer.close()
+	// because we have created the WriteStream with autoClose: false
+	writer.once('finish', () => {
 
 		// flush to disk
 		if (canFlush && isOpen) {
@@ -388,18 +392,20 @@ function doWriteFileStreamAndFlush(path: string, reader: NodeJS.ReadableStream,
 					canFlush = false;
 				}
 
-				writer.end();
+				writer.close();
 			});
-		}
-
-		// do not flush
-		else {
-			writer.end();
+		} else {
+			writer.close();
 		}
 	});
 
-	// end: false means we are in charge of ending the streams properly
-	reader.pipe(writer, { end: false });
+	// Event: 'close'
+	// Purpose: signal we are done to the outside
+	// Notes: event is called when the writer's filedescriptor is closed
+	writer.once('close', () => finish());
+
+	// start data piping
+	reader.pipe(writer);
 }
 
 // Calls fs.writeFile() followed by a fs.sync() call to flush the changes to disk

src/vs/workbench/services/files/node/fileService.ts

@@ -10,8 +10,7 @@ import fs = require('fs');
 import os = require('os');
 import crypto = require('crypto');
 import assert = require('assert');
-
-import { isParent, FileOperation, FileOperationEvent, IContent, IFileService, IResolveFileOptions, IResolveFileResult, IResolveContentOptions, IFileStat, IStreamContent, FileOperationError, FileOperationResult, IUpdateContentOptions, FileChangeType, IImportResult, FileChangesEvent, ICreateFileOptions, IContentData, ITextSnapshot, snapshotToString } from 'vs/platform/files/common/files';
+import { isParent, FileOperation, FileOperationEvent, IContent, IFileService, IResolveFileOptions, IResolveFileResult, IResolveContentOptions, IFileStat, IStreamContent, FileOperationError, FileOperationResult, IUpdateContentOptions, FileChangeType, IImportResult, FileChangesEvent, ICreateFileOptions, IContentData, ITextSnapshot } from 'vs/platform/files/common/files';
 import { MAX_FILE_SIZE } from 'vs/platform/files/node/files';
 import { isEqualOrParent } from 'vs/base/common/paths';
 import { ResourceMap } from 'vs/base/common/map';
@@ -508,8 +507,7 @@ export class FileService implements IFileService {
 
 	public updateContent(resource: uri, value: string | ITextSnapshot, options: IUpdateContentOptions = Object.create(null)): TPromise<IFileStat> {
 		if (this.options.elevationSupport && options.writeElevated) {
-			// We can currently only write strings elevated, so we need to convert snapshots properly
-			return this.doUpdateContentElevated(resource, typeof value === 'string' ? value : snapshotToString(value), options);
+			return this.doUpdateContentElevated(resource, value, options);
 		}
 
 		return this.doUpdateContent(resource, value, options);
@@ -635,7 +633,7 @@ export class FileService implements IFileService {
 		});
 	}
 
-	private doUpdateContentElevated(resource: uri, value: string, options: IUpdateContentOptions = Object.create(null)): TPromise<IFileStat> {
+	private doUpdateContentElevated(resource: uri, value: string | ITextSnapshot, options: IUpdateContentOptions = Object.create(null)): TPromise<IFileStat> {
 		const absolutePath = this.toAbsolutePath(resource);
 
 		// 1.) check file