speed up extension query

fixes #439

src/vs/workbench/parts/extensions/common/extensions.ts

@@ -20,6 +20,7 @@ export interface IExtensionManifest {
 export interface IGalleryInformation {
 	galleryApiUrl: string;
 	id: string;
+	downloadUrl: string;
 	publisherId: string;
 	publisherDisplayName: string;
 	date: string;

src/vs/workbench/parts/extensions/node/extensionsService.ts

@@ -117,7 +117,7 @@ export class ExtensionsService implements IExtensionsService {
 			return TPromise.wrapError(new Error(nls.localize('missingGalleryInformation', "Gallery information is missing")));
 		}
 
-		const url = `${ galleryInformation.galleryApiUrl }/publisher/${ extension.publisher }/extension/${ extension.name }/latest/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage?install=true`;
+		const url = galleryInformation.downloadUrl;
 		const zipPath = path.join(tmpdir(), galleryInformation.id);
 		const extensionPath = path.join(this.extensionsPath, `${ extension.publisher }.${ extension.name }`);
 		const manifestPath = path.join(extensionPath, 'package.json');

src/vs/workbench/parts/extensions/node/vsoGalleryService.ts

@@ -21,6 +21,7 @@ export interface IGalleryExtensionFile {
 export interface IGalleryExtensionVersion {
 	version: string;
 	lastUpdated: string;
+	assetUri: string;
 	files: IGalleryExtensionFile[];
 }
 
@@ -68,7 +69,7 @@ export class GalleryService implements IGalleryService {
 					value: 'vscode'
 				}]
 			}],
-			flags: 0x1 | 0x2 | 0x4 | 0x8 | 0x10
+			flags: 0x1 | 0x4 | 0x80
 		});
 
 		const request = {
@@ -94,6 +95,7 @@ export class GalleryService implements IGalleryService {
 					galleryInformation: {
 						galleryApiUrl: this.extensionsGalleryUrl,
 						id: extension.extensionId,
+						downloadUrl: `${ extension.versions[0].assetUri }/Microsoft.VisualStudio.Services.VSIXPackage?install=true`,
 						publisherId: extension.publisher.publisherId,
 						publisherDisplayName: extension.publisher.displayName,
 						date: extension.versions[0].lastUpdated