Update

data-extraction/src/js/api/DataExtractorApiImpl.ts

@@ -1,19 +1,22 @@
-import {
-	DataExtractorApi,
-	DataResult,
-	JSONString,
-	DataExtractor,
-	DataExtraction,
-	ExtractionCollector,
-	DataExtractorContext,
-} from "./DataExtractorApi";
 import {
 	DataExtractorInfo,
 	VisualizationData,
 } from "../../DataExtractionResult";
-import { registerDefaultExtractors } from "./default-extractors";
-import { LoadDataExtractorsFn } from "./LoadDataExtractorsFn";
 import * as helpers from "../helpers";
+import {
+	CallFrameInfo,
+	CallFrameRequest,
+	CallFramesSnapshot,
+	DataExtraction,
+	DataExtractor,
+	DataExtractorApi,
+	DataExtractorContext,
+	DataResult,
+	JSONString,
+	SkippedCallFrames,
+} from "./DataExtractorApi";
+import { LoadDataExtractorsFn } from "./LoadDataExtractorsFn";
+import { registerDefaultExtractors } from "./default-extractors";
 
 /**
  * @internal
@@ -42,51 +45,18 @@ export class DataExtractorApiImpl implements DataExtractorApi {
 		valueFn: () => unknown,
 		evalFn: <T>(expression: string) => T,
 		preferredDataExtractorId: string | undefined,
-		variablesInScope: Record<string, () => unknown>
+		variablesInScope: Record<string, () => unknown>,
+		callFramesSnapshot: CallFramesSnapshot | null
 	): JSONString<DataResult> {
-		class ContextImpl implements DataExtractorContext {
-			constructor(
-				public readonly variablesInScope: Record<string, () => unknown>,
-				public readonly expression: string | undefined,
-				public readonly evalFn: <T>(expression: string) => T,
-				private readonly _api: DataExtractorApiImpl,
-				private readonly _parent: ContextImpl | undefined
-			) {}
-
-			get _level(): number {
-				return this._parent ? this._parent._level + 1 : 0;
-			}
-
-			extract(value: any): VisualizationData | undefined {
-				if (this._level > 10) {
-					throw new Error(
-						"extract() called too many times recursively"
-					);
-				}
-
-				const extractions = this._api.getExtractions(
-					value,
-					new ContextImpl(
-						this.variablesInScope,
-						undefined,
-						this.evalFn,
-						this._api,
-						this
-					)
-				);
-				if (extractions.length === 0) {
-					return undefined;
-				}
-				return extractions[0].extractData();
-			}
-		}
-
+		const callFrameRequests: CallFrameRequest[] = [];
 		const rootContext = new ContextImpl(
 			variablesInScope,
 			removeEnd(removeStart(valueFn.toString(), "() => ("), ")").trim(),
 			evalFn,
 			this,
-			undefined
+			undefined,
+			callFramesSnapshot?.frames ?? [],
+			callFrameRequests
 		);
 
 		DataExtractorApiImpl.lastContext = rootContext;
@@ -94,6 +64,20 @@ export class DataExtractorApiImpl implements DataExtractorApi {
 		const extractions = this.getExtractions(value, rootContext);
 		DataExtractorApiImpl.lastContext = undefined;
 
+		const requestId =
+			callFrameRequests.length === 0
+				? ""
+				: "" + cyrb53(JSON.stringify(callFrameRequests));
+		if ((callFramesSnapshot?.requestId ?? "") !== requestId) {
+			return this.toJson({
+				kind: "OutdatedCallFrameSnapshot",
+				callFramesRequest: {
+					requestId,
+					requestedCallFrames: callFrameRequests,
+				},
+			});
+		}
+
 		let usedExtraction = extractions[0];
 		if (!usedExtraction) {
 			return this.toJson({ kind: "NoExtractors" } as DataResult);
@@ -108,14 +92,6 @@ export class DataExtractorApiImpl implements DataExtractorApi {
 			}
 		}
 
-		function mapExtractor(e: DataExtraction): DataExtractorInfo {
-			return {
-				id: e.id! as any,
-				name: e.name!,
-				priority: e.priority,
-			};
-		}
-
 		const data = usedExtraction.extractData();
 		return this.toJson({
 			kind: "Data",
@@ -188,6 +164,60 @@ export class DataExtractorApiImpl implements DataExtractorApi {
 	}
 }
 
+function mapExtractor(e: DataExtraction): DataExtractorInfo {
+	return {
+		id: e.id! as any,
+		name: e.name!,
+		priority: e.priority,
+	};
+}
+
+class ContextImpl implements DataExtractorContext {
+	constructor(
+		public readonly variablesInScope: Record<string, () => unknown>,
+		public readonly expression: string | undefined,
+		public readonly evalFn: <T>(expression: string) => T,
+		private readonly _api: DataExtractorApiImpl,
+		private readonly _parent: ContextImpl | undefined,
+		public readonly callFrameInfos: readonly (
+			| CallFrameInfo
+			| SkippedCallFrames
+		)[],
+		private readonly _callFrameRequests: CallFrameRequest[]
+	) {}
+
+	addCallFrameRequest(request: CallFrameRequest): void {
+		this._callFrameRequests.push(request);
+	}
+
+	get _level(): number {
+		return this._parent ? this._parent._level + 1 : 0;
+	}
+
+	extract(value: any): VisualizationData | undefined {
+		if (this._level > 10) {
+			throw new Error("extract() called too many times recursively");
+		}
+
+		const extractions = this._api.getExtractions(
+			value,
+			new ContextImpl(
+				this.variablesInScope,
+				undefined,
+				this.evalFn,
+				this._api,
+				this,
+				this.callFrameInfos,
+				this._callFrameRequests
+			)
+		);
+		if (extractions.length === 0) {
+			return undefined;
+		}
+		return extractions[0].extractData();
+	}
+}
+
 function removeStart(str: string, start: string): string {
 	if (str.startsWith(start)) {
 		return str.substr(start.length);
@@ -201,3 +231,20 @@ function removeEnd(str: string, end: string): string {
 	}
 	return str;
 }
+
+// From https://stackoverflow.com/questions/7616461/generate-a-hash-from-string-in-javascript
+function cyrb53(str: string, seed = 0) {
+	let h1 = 0xdeadbeef ^ seed,
+		h2 = 0x41c6ce57 ^ seed;
+	for (let i = 0, ch; i < str.length; i++) {
+		ch = str.charCodeAt(i);
+		h1 = Math.imul(h1 ^ ch, 2654435761);
+		h2 = Math.imul(h2 ^ ch, 1597334677);
+	}
+	h1 = Math.imul(h1 ^ (h1 >>> 16), 2246822507);
+	h1 ^= Math.imul(h2 ^ (h2 >>> 13), 3266489909);
+	h2 = Math.imul(h2 ^ (h2 >>> 16), 2246822507);
+	h2 ^= Math.imul(h1 ^ (h1 >>> 13), 3266489909);
+
+	return 4294967296 * (2097151 & h2) + (h1 >>> 0);
+}