scm: use diff algorithm for ext host communication

src/vs/workbench/api/electron-browser/mainThreadSCM.ts

@@ -13,7 +13,7 @@ import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import { ISCMService, ISCMRepository, ISCMProvider, ISCMResource, ISCMResourceGroup, ISCMResourceDecorations } from 'vs/workbench/services/scm/common/scm';
 import { IInstantiationService } from 'vs/platform/instantiation/common/instantiation';
 import { ICommandService } from 'vs/platform/commands/common/commands';
-import { ExtHostContext, MainThreadSCMShape, ExtHostSCMShape, SCMProviderFeatures, SCMRawResourceGroup, SCMGroupFeatures, MainContext, IExtHostContext } from '../node/extHost.protocol';
+import { ExtHostContext, MainThreadSCMShape, ExtHostSCMShape, SCMProviderFeatures, SCMRawResourceSplices, SCMGroupFeatures, MainContext, IExtHostContext } from '../node/extHost.protocol';
 import { Command } from 'vs/editor/common/modes';
 import { extHostNamedCustomer } from 'vs/workbench/api/electron-browser/extHostCustomers';
 
@@ -155,36 +155,43 @@ class MainThreadSCMProvider implements ISCMProvider {
 		this._onDidChange.fire();
 	}
 
-	$updateGroupResourceStates(groups: SCMRawResourceGroup[]): void {
-		for (const [groupHandle, resources] of groups) {
+	$spliceGroupResourceStates(slices: SCMRawResourceSplices[]): void {
+		for (const [groupHandle, groupSlices] of slices) {
 			const group = this._groupsByHandle[groupHandle];
 
 			if (!group) {
 				return;
 			}
 
-			group.resources = resources.map(rawResource => {
-				const [handle, sourceUri, command, icons, tooltip, strikeThrough, faded] = rawResource;
-				const icon = icons[0];
-				const iconDark = icons[1] || icon;
-				const decorations = {
-					icon: icon && URI.parse(icon),
-					iconDark: iconDark && URI.parse(iconDark),
-					tooltip,
-					strikeThrough,
-					faded
-				};
-
-				return new MainThreadSCMResource(
-					this.handle,
-					groupHandle,
-					handle,
-					URI.parse(sourceUri),
-					command,
-					group,
-					decorations
-				);
-			});
+			// reverse the splices sequence in order to apply them correctly
+			groupSlices.reverse();
+
+			for (const [start, deleteCount, rawResources] of groupSlices) {
+				const resources = rawResources.map(rawResource => {
+					const [handle, sourceUri, command, icons, tooltip, strikeThrough, faded] = rawResource;
+					const icon = icons[0];
+					const iconDark = icons[1] || icon;
+					const decorations = {
+						icon: icon && URI.parse(icon),
+						iconDark: iconDark && URI.parse(iconDark),
+						tooltip,
+						strikeThrough,
+						faded
+					};
+
+					return new MainThreadSCMResource(
+						this.handle,
+						groupHandle,
+						handle,
+						URI.parse(sourceUri),
+						command,
+						group,
+						decorations
+					);
+				});
+
+				group.resources.splice(start, deleteCount, ...resources);
+			}
 		}
 
 		this._onDidChangeResources.fire();
@@ -317,7 +324,7 @@ export class MainThreadSCM implements MainThreadSCMShape {
 		provider.$updateGroupLabel(groupHandle, label);
 	}
 
-	$updateResourceStates(sourceControlHandle: number, resources: SCMRawResourceGroup[]): void {
+	$spliceResourceStates(sourceControlHandle: number, splices: SCMRawResourceSplices[]): void {
 		const repository = this._repositories[sourceControlHandle];
 
 		if (!repository) {
@@ -325,7 +332,7 @@ export class MainThreadSCM implements MainThreadSCMShape {
 		}
 
 		const provider = repository.provider as MainThreadSCMProvider;
-		provider.$updateGroupResourceStates(resources);
+		provider.$spliceGroupResourceStates(splices);
 	}
 
 	$unregisterGroup(sourceControlHandle: number, handle: number): void {

src/vs/workbench/api/node/extHost.protocol.ts

@@ -337,11 +337,17 @@ export type SCMRawResource = [
 	boolean /*faded*/
 ];
 
-export type SCMRawResourceGroup = [
-	number, /*handle*/
+export type SCMRawResourceSplice = [
+	number /* start */,
+	number /* delete count */,
 	SCMRawResource[]
 ];
 
+export type SCMRawResourceSplices = [
+	number, /*handle*/
+	SCMRawResourceSplice[]
+];
+
 export interface MainThreadSCMShape extends IDisposable {
 	$registerSourceControl(handle: number, id: string, label: string): void;
 	$updateSourceControl(handle: number, features: SCMProviderFeatures): void;
@@ -352,7 +358,7 @@ export interface MainThreadSCMShape extends IDisposable {
 	$updateGroupLabel(sourceControlHandle: number, handle: number, label: string): void;
 	$unregisterGroup(sourceControlHandle: number, handle: number): void;
 
-	$updateResourceStates(sourceControlHandle: number, resources: SCMRawResourceGroup[]): void;
+	$spliceResourceStates(sourceControlHandle: number, splices: SCMRawResourceSplices[]): void;
 
 	$setInputBoxValue(sourceControlHandle: number, value: string): void;
 }

src/vs/workbench/api/node/extHostSCM.ts

@@ -12,8 +12,9 @@ import { dispose, IDisposable } from 'vs/base/common/lifecycle';
 import { asWinJsPromise } from 'vs/base/common/async';
 import { IExtensionDescription } from 'vs/platform/extensions/common/extensions';
 import { ExtHostCommands, CommandsConverter } from 'vs/workbench/api/node/extHostCommands';
-import { MainContext, MainThreadSCMShape, SCMRawResource, SCMRawResourceGroup, IMainContext } from './extHost.protocol';
+import { MainContext, MainThreadSCMShape, SCMRawResource, SCMRawResourceSplice, SCMRawResourceSplices, IMainContext } from './extHost.protocol';
 import * as vscode from 'vscode';
+import { LcsDiff, ISequence } from 'vs/base/common/diff/diff';
 
 function getIconPath(decorations: vscode.SourceControlResourceThemableDecorations) {
 	if (!decorations) {
@@ -59,6 +60,22 @@ export class ExtHostSCMInputBox {
 	}
 }
 
+class ResourceSequence implements ISequence {
+
+	constructor(private resources: vscode.SourceControlResourceState[]) { }
+
+	getLength() {
+		return this.resources.length;
+	}
+
+	getElementHash(index) {
+		const resource = this.resources[index];
+
+		// TODO!!!
+		return resource.resourceUri.toString();
+	}
+}
+
 class ExtHostSourceControlResourceGroup implements vscode.SourceControlResourceGroup {
 
 	private static _handlePool: number = 0;
@@ -73,6 +90,9 @@ class ExtHostSourceControlResourceGroup implements vscode.SourceControlResourceG
 	private _onDidDispose = new Emitter<void>();
 	readonly onDidDispose = this._onDidDispose.event;
 
+	private _handlesSnapshot: number[] = [];
+	private _resourcesSnapshot: vscode.SourceControlResourceState[] = [];
+
 	get id(): string { return this._id; }
 
 	get label(): string { return this._label; }
@@ -94,43 +114,61 @@ class ExtHostSourceControlResourceGroup implements vscode.SourceControlResourceG
 		this._onDidUpdateResourceStates.fire();
 	}
 
-	get _rawResources(): SCMRawResource[] {
-		const handles: number[] = [];
-		const rawResources = this._resourceStates.map(r => {
-			const handle = this._resourceHandlePool++;
-			this._resourceStatesMap.set(handle, r);
-			handles.push(handle);
+	_snapshot(): SCMRawResourceSplice[] {
+		const original = new ResourceSequence(this._resourcesSnapshot);
+		const modified = new ResourceSequence(this._resourceStates);
+		const lcs = new LcsDiff(original, modified);
+		const diffs = lcs.ComputeDiff(false);
+		const handlesToDelete: number[] = [];
+
+		const splices = diffs.map(diff => {
+			const start = diff.originalStart;
+			const deleteCount = diff.originalLength;
+			const handles: number[] = [];
+
+			const rawResources = this._resourceStates
+				.slice(diff.modifiedStart, diff.modifiedStart + diff.modifiedLength)
+				.map(r => {
+					const handle = this._resourceHandlePool++;
+					this._resourceStatesMap.set(handle, r);
+					handles.push(handle);
+
+					const sourceUri = r.resourceUri.toString();
+					const command = this._commands.toInternal(r.command);
+					const iconPath = getIconPath(r.decorations);
+					const lightIconPath = r.decorations && getIconPath(r.decorations.light) || iconPath;
+					const darkIconPath = r.decorations && getIconPath(r.decorations.dark) || iconPath;
+					const icons: string[] = [];
+
+					if (lightIconPath || darkIconPath) {
+						icons.push(lightIconPath);
+					}
 
-			const sourceUri = r.resourceUri.toString();
-			const command = this._commands.toInternal(r.command);
-			const iconPath = getIconPath(r.decorations);
-			const lightIconPath = r.decorations && getIconPath(r.decorations.light) || iconPath;
-			const darkIconPath = r.decorations && getIconPath(r.decorations.dark) || iconPath;
-			const icons: string[] = [];
+					if (darkIconPath !== lightIconPath) {
+						icons.push(darkIconPath);
+					}
 
-			if (lightIconPath || darkIconPath) {
-				icons.push(lightIconPath);
-			}
+					const tooltip = (r.decorations && r.decorations.tooltip) || '';
+					const strikeThrough = r.decorations && !!r.decorations.strikeThrough;
+					const faded = r.decorations && !!r.decorations.faded;
 
-			if (darkIconPath !== lightIconPath) {
-				icons.push(darkIconPath);
-			}
+					return [handle, sourceUri, command, icons, tooltip, strikeThrough, faded] as SCMRawResource;
+				});
 
-			const tooltip = (r.decorations && r.decorations.tooltip) || '';
-			const strikeThrough = r.decorations && !!r.decorations.strikeThrough;
-			const faded = r.decorations && !!r.decorations.faded;
+			handlesToDelete.push(...this._handlesSnapshot.splice(start, deleteCount, ...handles));
 
-			return [handle, sourceUri, command, icons, tooltip, strikeThrough, faded] as SCMRawResource;
+			return [start, deleteCount, rawResources] as SCMRawResourceSplice;
 		});
 
-		const disposable = () => handles.forEach(handle => this._resourceStatesMap.delete(handle));
+		const disposable = () => handlesToDelete.forEach(handle => this._resourceStatesMap.delete(handle));
 		this._resourceStatesRollingDisposables.push(disposable);
 
 		while (this._resourceStatesRollingDisposables.length >= 10) {
 			this._resourceStatesRollingDisposables.shift()();
 		}
 
-		return rawResources;
+		this._resourcesSnapshot = this._resourceStates;
+		return splices;
 	}
 
 	readonly handle = ExtHostSourceControlResourceGroup._handlePool++;
@@ -266,12 +304,12 @@ class ExtHostSourceControl implements vscode.SourceControl {
 
 	@debounce(100)
 	eventuallyUpdateResourceStates(): void {
-		const resources: SCMRawResourceGroup[] = [];
+		const resources: SCMRawResourceSplices[] = [];
 
 		this.updatedResourceGroups
-			.forEach(group => resources.push([group.handle, group._rawResources]));
+			.forEach(group => resources.push([group.handle, group._snapshot()]));
 
-		this._proxy.$updateResourceStates(this.handle, resources);
+		this._proxy.$spliceResourceStates(this.handle, resources);
 		this.updatedResourceGroups.clear();
 	}