Merge from vscode 2b0b9136329c181a9e381463a1f7dc3a2d105a34 (#4880)

src/vs/editor/contrib/codelens/codeLensCache.ts

@@ -0,0 +1,120 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { ITextModel } from 'vs/editor/common/model';
+import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
+import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
+import { ICodeLensData } from 'vs/editor/contrib/codelens/codelens';
+import { LRUCache, values } from 'vs/base/common/map';
+import { ICodeLensSymbol, CodeLensProvider } from 'vs/editor/common/modes';
+import { IStorageService, StorageScope } from 'vs/platform/storage/common/storage';
+import { Range } from 'vs/editor/common/core/range';
+
+export const ICodeLensCache = createDecorator<ICodeLensCache>('ICodeLensCache');
+
+export interface ICodeLensCache {
+	_serviceBrand: any;
+	put(model: ITextModel, data: ICodeLensData[]): void;
+	get(model: ITextModel): ICodeLensData[] | undefined;
+	delete(model: ITextModel): void;
+}
+
+interface ISerializedCacheData {
+	lineCount: number;
+	lines: number[];
+}
+
+class CacheItem {
+
+	constructor(
+		readonly lineCount: number,
+		readonly data: ICodeLensData[]
+	) { }
+}
+
+class CodeLensCache implements ICodeLensCache {
+
+	_serviceBrand: any;
+
+	private readonly _fakeProvider = new class implements CodeLensProvider {
+		provideCodeLenses(): ICodeLensSymbol[] {
+			throw new Error('not supported');
+		}
+	};
+
+	private readonly _cache = new LRUCache<string, CacheItem>(20, 0.75);
+
+	constructor(@IStorageService storageService: IStorageService) {
+
+		const key = 'codelens/cache';
+
+		// restore lens data on start
+		const raw = storageService.get(key, StorageScope.WORKSPACE, '{}');
+		this._deserialize(raw);
+
+		// store lens data on shutdown
+		const listener = storageService.onWillSaveState(() => {
+			storageService.store(key, this._serialize(), StorageScope.WORKSPACE);
+			listener.dispose();
+		});
+	}
+
+	put(model: ITextModel, data: ICodeLensData[]): void {
+		const item = new CacheItem(model.getLineCount(), data.map(item => {
+			return {
+				symbol: item.symbol,
+				provider: this._fakeProvider
+			};
+		}));
+		this._cache.set(model.uri.toString(), item);
+	}
+
+	get(model: ITextModel) {
+		const item = this._cache.get(model.uri.toString());
+		return item && item.lineCount === model.getLineCount() ? item.data : undefined;
+	}
+
+	delete(model: ITextModel): void {
+		this._cache.delete(model.uri.toString());
+	}
+
+	// --- persistence
+
+	private _serialize(): string {
+		const data: Record<string, ISerializedCacheData> = Object.create(null);
+		this._cache.forEach((value, key) => {
+			const lines = new Set<number>();
+			for (const d of value.data) {
+				lines.add(d.symbol.range.startLineNumber);
+			}
+			data[key] = {
+				lineCount: value.lineCount,
+				lines: values(lines)
+			};
+		});
+		return JSON.stringify(data);
+	}
+
+	private _deserialize(raw: string): void {
+		try {
+			const data: Record<string, ISerializedCacheData> = JSON.parse(raw);
+			for (const key in data) {
+				const element = data[key];
+				const symbols: ICodeLensData[] = [];
+				for (const line of element.lines) {
+					symbols.push({
+						provider: this._fakeProvider,
+						symbol: { range: new Range(line, 1, line, 11) }
+					});
+				}
+				this._cache.set(key, new CacheItem(element.lineCount, symbols));
+			}
+		} catch {
+			// ignore...
+		}
+	}
+}
+
+registerSingleton(ICodeLensCache, CodeLensCache);