taler-util: cancellation and timeouts on qjs

2 files changed, 77 insertions, 4 deletions

diff --git a/packages/taler-util/src/http-impl.qtart.ts b/packages/taler-util/src/http-impl.qtart.ts
index a37029d6e..0be9f2c23 100644
--- a/packages/taler-util/src/http-impl.qtart.ts
+++ b/packages/taler-util/src/http-impl.qtart.ts
@@ -19,9 +19,9 @@
 /**
  * Imports.
  */
-import { Logger } from "@gnu-taler/taler-util";
+import { Logger, openPromise } from "@gnu-taler/taler-util";
 import { TalerError } from "./errors.js";
-import { encodeBody, getDefaultHeaders, HttpLibArgs } from "./http-common.js";
+import { HttpLibArgs, encodeBody, getDefaultHeaders } from "./http-common.js";
 import {
   Headers,
   HttpRequestLibrary,
@@ -29,12 +29,26 @@ import {
   HttpResponse,
 } from "./http.js";
 import { RequestThrottler, TalerErrorCode, URL } from "./index.js";
-import { qjsOs } from "./qtart.js";
+import { QjsHttpResp, qjsOs } from "./qtart.js";
 
 const logger = new Logger("http-impl.qtart.ts");
 
 const textDecoder = new TextDecoder();
 
+export class RequestTimeoutError extends Error {
+  public constructor() {
+    super("Request timed out");
+    Object.setPrototypeOf(this, RequestTimeoutError.prototype);
+  }
+}
+
+export class RequestCancelledError extends Error {
+  public constructor() {
+    super("Request cancelled");
+    Object.setPrototypeOf(this, RequestCancelledError.prototype);
+  }
+}
+
 /**
  * Implementation of the HTTP request library interface for node.
  */
@@ -92,12 +106,70 @@ export class HttpLibImpl implements HttpRequestLibrary {
     if (method === "POST") {
       data = encodeBody(opt?.body);
     }
-    const res = await qjsOs.fetchHttp(url, {
+
+    const cancelPromCap = openPromise<QjsHttpResp>();
+
+    // Just like WHATWG fetch(), the qjs http client doesn't
+    // really support cancellation, so cancellation here just
+    // means that the result is ignored!
+    const fetchProm = qjsOs.fetchHttp(url, {
       method,
       data,
       headers: headersList,
     });
 
+    let timeoutHandle: any = undefined;
+    let cancelCancelledHandler: (() => void) | undefined = undefined;
+
+    if (opt?.timeout && opt.timeout.d_ms !== "forever") {
+      timeoutHandle = setTimeout(() => {
+        cancelPromCap.reject(new RequestTimeoutError());
+      }, opt.timeout.d_ms);
+    }
+
+    if (opt?.cancellationToken) {
+      cancelCancelledHandler = opt.cancellationToken.onCancelled(() => {
+        cancelPromCap.reject(new RequestCancelledError());
+      });
+    }
+
+    let res: QjsHttpResp;
+    try {
+      res = await Promise.race([fetchProm, cancelPromCap.promise]);
+    } catch (e) {
+      if (e instanceof RequestCancelledError) {
+        throw TalerError.fromDetail(
+          TalerErrorCode.WALLET_UNEXPECTED_REQUEST_ERROR,
+          {
+            requestUrl: url,
+            requestMethod: method,
+            httpStatusCode: 0,
+          },
+          `Request cancelled`,
+        );
+      }
+      if (e instanceof RequestTimeoutError) {
+        throw TalerError.fromDetail(
+          TalerErrorCode.WALLET_UNEXPECTED_REQUEST_ERROR,
+          {
+            requestUrl: url,
+            requestMethod: method,
+            httpStatusCode: 0,
+          },
+          `Request timed out`,
+        );
+      }
+      throw e;
+    }
+
+    if (timeoutHandle != null) {
+      clearTimeout(timeoutHandle);
+    }
+
+    if (cancelCancelledHandler != null) {
+      cancelCancelledHandler();
+    }
+
     const headers: Headers = new Headers();
 
     if (res.headers) {
diff --git a/packages/taler-util/src/index.ts b/packages/taler-util/src/index.ts
index 2045a4717..edc9c4ff2 100644
--- a/packages/taler-util/src/index.ts
+++ b/packages/taler-util/src/index.ts
@@ -44,6 +44,7 @@ export {
 export * from "./notifications.js";
 export * from "./operation.js";
 export * from "./payto.js";
+export * from "./promises.js";
 export * from "./rfc3548.js";
 export * from "./taler-crypto.js";
 export * from "./taler-types.js";