add abort controller support

CHANGELOG.md

@@ -1,6 +1,9 @@
 # Libcurl.js Changelog:
 
-## v0.5.0 (3/8/24):
+## v0.5.1 (3/10/24):
+- Added support for aborting requests
+
+## v0.5.0 (3/9/24):
 - Added support for streaming HTTP responses via a readable stream
 - Improve compatibility for older browsers
 - Support for all types of fetch request bodies

README.md

@@ -94,11 +94,10 @@ console.log(await r.text());
 
 Most of the standard Fetch API's features are supported, with the exception of:
 - CORS enforcement
-- `FormData` or `URLSearchParams` as the request body
 - Sending credentials/cookies automatically
 - Caching
 
-The response may contain multiple HTTP headers with the same name, which the `Headers` object isn't able to properly represent. If this matters to you, use `response.raw_headers`, which is an array of key value pairs, instead of `response.headers`. There is support for streaming the response body using a `ReadableStream`.
+The response may contain multiple HTTP headers with the same name, which the `Headers` object isn't able to properly represent. If this matters to you, use `response.raw_headers`, which is an array of key value pairs, instead of `response.headers`. There is support for streaming the response body using a `ReadableStream`, as well as canceling requests using an `AbortSignal`.
 
 Also note that there is a hard limit of 50 active TCP connections due to emscripten limitations. 
 

client/javascript/main.js

@@ -173,6 +173,25 @@ async function create_options(params) {
 function perform_request_async(url, params, body) {
   return new Promise((resolve, reject) => {
     let stream_controller;
+    let http_handle;
+    let response_obj;
+    let aborted = false;
+
+    //handle abort signals
+    if (params.signal instanceof AbortSignal) {
+      params.signal.addEventListener("abort", () => {
+        if (aborted) return;
+        aborted = true;
+        _cleanup_handle(http_handle);
+        if (!response_obj) {
+          reject(new DOMException("The operation was aborted."));
+        }
+        else {
+          stream_controller.error("The operation was aborted.");
+        }
+      });
+    }
+
     let stream = new ReadableStream({
       start(controller) {
         stream_controller = controller;
@@ -180,10 +199,21 @@ function perform_request_async(url, params, body) {
     });
     
     function data_callback(new_data) {
+      try {
         stream_controller.enqueue(new_data);  
       }
+      catch (e) {
+        //the readable stream has been closed elsewhere, so cancel the request
+        if (e instanceof TypeError) {
+          _cleanup_handle(http_handle);
+        }
+        else {
+          throw e;
+        }
+      }
+    }
     function headers_callback(response_info) {
-      let response_obj = create_response(stream, response_info);
+      response_obj = create_response(stream, response_info);
       resolve(response_obj);
     }
     function finish_callback(error) {
@@ -196,7 +226,7 @@ function perform_request_async(url, params, body) {
       stream_controller.close();
     }
     
-    perform_request(url, params, data_callback, finish_callback, headers_callback, body);
+    http_handle = perform_request(url, params, data_callback, finish_callback, headers_callback, body);
   });
 }
 

client/package.json

@@ -1,6 +1,6 @@
 {
   "name": "libcurl.js",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "An experimental port of libcurl to WebAssembly for use in the browser.",
   "main": "libcurl.mjs",
   "scripts": {

client/publish.sh

@@ -7,6 +7,7 @@
 cp package.json out
 cp ../README.md out
 cp ../LICENSE out
+cp ../CHANGELOG.md out
 
 cd out
 npm publish