#125970 move user configuration writes into separate service

src/vs/platform/configuration/common/userConfigurationFileService.ts

@@ -0,0 +1,92 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Queue } from 'vs/base/common/async';
+import { VSBuffer } from 'vs/base/common/buffer';
+import { JSONPath, parse, ParseError } from 'vs/base/common/json';
+import { setProperty } from 'vs/base/common/jsonEdit';
+import { Edit, FormattingOptions } from 'vs/base/common/jsonFormatter';
+import { URI } from 'vs/base/common/uri';
+import { IEnvironmentService } from 'vs/platform/environment/common/environment';
+import { FileOperationError, FileOperationResult, IFileService } from 'vs/platform/files/common/files';
+import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
+import { ILogService } from 'vs/platform/log/common/log';
+
+export const enum UserConfigurationErrorCode {
+	ERROR_INVALID_FILE = 'ERROR_INVALID_FILE',
+	ERROR_FILE_MODIFIED_SINCE = 'ERROR_FILE_MODIFIED_SINCE'
+}
+
+export interface IJSONValue {
+	path: JSONPath;
+	value: any;
+}
+
+export const UserConfigurationFileServiceId = 'IUserConfigurationFileService';
+export const IUserConfigurationFileService = createDecorator<IUserConfigurationFileService>(UserConfigurationFileServiceId);
+
+export interface IUserConfigurationFileService {
+	readonly _serviceBrand: undefined;
+
+	updateSettings(value: IJSONValue, formattingOptions: FormattingOptions): Promise<void>;
+}
+
+export class UserConfigurationFileService implements IUserConfigurationFileService {
+
+	readonly _serviceBrand: undefined;
+
+	private readonly queue: Queue<void>;
+
+	constructor(
+		@IEnvironmentService private readonly environmentService: IEnvironmentService,
+		@IFileService private readonly fileService: IFileService,
+		@ILogService private readonly logService: ILogService,
+	) {
+		this.queue = new Queue<void>();
+	}
+
+	async updateSettings(value: IJSONValue, formattingOptions: FormattingOptions): Promise<void> {
+		return this.queue.queue(() => this.doWrite(this.environmentService.settingsResource, value, formattingOptions)); // queue up writes to prevent race conditions
+	}
+
+	private async doWrite(resource: URI, jsonValue: IJSONValue, formattingOptions: FormattingOptions): Promise<void> {
+		this.logService.trace(`${UserConfigurationFileServiceId}#write`, resource.toString(), jsonValue);
+		const { value, mtime, etag } = await this.fileService.readFile(resource, { atomic: true });
+		let content = value.toString();
+
+		const parseErrors: ParseError[] = [];
+		parse(content, parseErrors, { allowTrailingComma: true, allowEmptyContent: true });
+		if (parseErrors.length) {
+			throw new Error(UserConfigurationErrorCode.ERROR_INVALID_FILE);
+		}
+
+		const edit = this.getEdits(jsonValue, content, formattingOptions)[0];
+		if (edit) {
+			content = content.substring(0, edit.offset) + edit.content + content.substring(edit.offset + edit.length);
+			try {
+				await this.fileService.writeFile(resource, VSBuffer.fromString(content), { etag, mtime });
+			} catch (error) {
+				if ((<FileOperationError>error).fileOperationResult === FileOperationResult.FILE_MODIFIED_SINCE) {
+					throw new Error(UserConfigurationErrorCode.ERROR_FILE_MODIFIED_SINCE);
+				}
+			}
+		}
+	}
+
+	private getEdits({ value, path }: IJSONValue, modelContent: string, formattingOptions: FormattingOptions): Edit[] {
+		if (path.length) {
+			return setProperty(modelContent, path, value, formattingOptions);
+		}
+
+		// Without jsonPath, the entire configuration file is being replaced, so we just use JSON.stringify
+		const content = JSON.stringify(value, null, formattingOptions.insertSpaces && formattingOptions.tabSize ? ' '.repeat(formattingOptions.tabSize) : '\t');
+		return [{
+			content,
+			length: modelContent.length,
+			offset: 0
+		}];
+	}
+}
+