Next Iteration

extension/src/DataSource/JsDebuggerSource.ts

@@ -0,0 +1,157 @@
+import { DataSource, EvaluationWatcher } from "./DataSource";
+import { observable } from "mobx";
+import * as vscode from "vscode";
+import { Disposable } from "@hediet/std/disposable";
+import {
+	selfContainedGetInitializedDataExtractorApi,
+	DataResult,
+	DataExtractorId,
+	ApiHasNotBeenInitializedCode,
+	selfContainedInitDataExtractorApi,
+} from "@hediet/debug-visualizer-data-extraction";
+import { DataExtractionState } from "@hediet/debug-visualizer-vscode-shared";
+
+export function createJsDebuggerSource(): JsDataSource {
+	return new JsDebuggerSourceImplementation();
+}
+
+export interface JsCode extends String {
+	__brand: "JsCode";
+}
+
+export interface JsDataSource extends DataSource {
+	registerDataExtractor(classExpression: JsCode): void;
+}
+
+class JsDebuggerSourceImplementation implements JsDataSource {
+	private lastFrameId: number | null = null;
+	private readonly watchers = new Set<ObservableEvaluationWatcher>();
+
+	public readonly dispose = Disposable.fn();
+
+	constructor() {
+		this.dispose.track(
+			vscode.debug.onDidReceiveDebugSessionCustomEvent(e => {
+				if (e.event === "paused") {
+					const frameId = e.body.currentFrameId;
+					this.lastFrameId = frameId;
+
+					for (const w of this.watchers) {
+						w.refresh();
+					}
+				}
+			})
+		);
+	}
+
+	registerDataExtractor(classExpression: JsCode): void {}
+
+	public createEvaluationWatcher(expression: string): EvaluationWatcher {
+		const w = new ObservableEvaluationWatcher(expression, this);
+		this.watchers.add(w);
+		this.refresh(w);
+		return w;
+	}
+
+	public removeWatcher(w: ObservableEvaluationWatcher) {
+		this.watchers.delete(w);
+	}
+
+	public async refresh(w: ObservableEvaluationWatcher): Promise<void> {
+		const session = vscode.debug.activeDebugSession;
+		if (!session) {
+			w._state = { kind: "noDebugSession" };
+			return;
+		}
+
+		try {
+			w._state = { kind: "loading" };
+			const expression = `(${selfContainedGetInitializedDataExtractorApi.toString()})().getData(${
+				w.expression
+			})`;
+
+			const reply = await session.customRequest("evaluate", {
+				expression,
+				frameId: this.lastFrameId,
+				context: "watch",
+			});
+			const resultStr = reply.result as string;
+			const jsonData = resultStr.substr(1, resultStr.length - 2);
+			const result = JSON.parse(jsonData) as DataResult;
+			if (result.kind === "NoExtractors") {
+				throw new Error("No extractors");
+			}
+
+			w._state = {
+				kind: "data",
+				result: result.extractionResult,
+			};
+		} catch (error) {
+			const msg = error.message as string | undefined;
+			if (msg && msg.includes(ApiHasNotBeenInitializedCode)) {
+				if (await this.initializeApi(session)) {
+					await this.refresh(w);
+					return;
+				}
+			}
+
+			w._state = {
+				kind: "error",
+				message: error.message,
+			};
+		}
+	}
+
+	private async initializeApi(
+		session: vscode.DebugSession
+	): Promise<boolean> {
+		try {
+			const expression = `(${selfContainedInitDataExtractorApi.toString()})()`;
+
+			const reply = await session.customRequest("evaluate", {
+				expression,
+				frameId: this.lastFrameId,
+				context: "watch",
+			});
+			if (reply.result === "true") {
+				// register extractors
+			}
+			return true;
+		} catch (error) {
+			return false;
+		}
+	}
+}
+
+class ObservableEvaluationWatcher implements EvaluationWatcher {
+	constructor(
+		public readonly expression: string,
+		private readonly source: JsDebuggerSourceImplementation
+	) {}
+
+	@observable
+	_preferredDataExtractor: DataExtractorId | undefined = undefined;
+
+	get preferredDataExtractor(): DataExtractorId | undefined {
+		return this._preferredDataExtractor;
+	}
+
+	public setPreferredDataExtractor(id: DataExtractorId): void {
+		this._preferredDataExtractor = id;
+		this.refresh();
+	}
+
+	public refresh(): void {
+		this.source.refresh(this);
+	}
+
+	@observable
+	public _state: DataExtractionState = { kind: "loading" };
+	public get state(): DataExtractionState {
+		return this._state;
+	}
+
+	public dispose(): void {
+		this.source.removeWatcher(this);
+	}
+}