feat(extension): add sapi_ipc_set_cancellation_handler method

include/socket/extension.h

@@ -1193,6 +1193,20 @@ extern "C" {
     bool finished
   );
 
+  /**
+   * When an IPC route is triggered through HTTP, you can set a cancellation
+   * handler for cleanup if the HTTP request is aborted.
+   *
+   * @param result  - An IPC request result
+   * @param handler - The cancellation handler
+   * @param data    - Optional user data
+   */
+  bool sapi_ipc_set_cancellation_handler (
+    sapi_ipc_result_t* result,
+    void (*handler)(void*),
+    void* data
+  );
+
   /**
    * Creates a "reply" for an IPC route request.
    * @param result - An IPC request result

src/extension/ipc.cc

@@ -142,6 +142,20 @@ bool sapi_ipc_reply (const sapi_ipc_result_t* result) {
   return success;
 }
 
+bool sapi_ipc_set_cancellation_handler (
+  sapi_ipc_result_t* result,
+  void (*handler)(void*),
+  void* data
+) {
+  if (result == nullptr || !result->message.isHTTP) {
+    return false;
+  }
+  auto message = result->message;
+  message.cancel = handler;
+  message.cancel_data = data;
+  return true;
+}
+
 bool sapi_ipc_send_chunk (
   sapi_ipc_result_t* result,
   const char* chunk,

src/ipc/bridge.cc

@@ -1,6 +1,5 @@
 #include <regex>
 #include <unordered_map>
-#include <set>
 
 #if defined(__APPLE__)
 #include <UniformTypeIdentifiers/UniformTypeIdentifiers.h>
@@ -2379,13 +2378,13 @@ static void registerSchemeHandler (Router *router) {
 @implementation SSCIPCSchemeHandler
 {
   SSC::Mutex mutex;
-  std::set<Task> tasks;
+  std::unordered_map<Task, IPC::Message> tasks;
 }
 
-- (void) enqueueTask: (Task) task {
+- (void) enqueueTask: (Task) task withMessage: (IPC::Message) message {
   Lock lock(mutex);
   if (task != nullptr && !tasks.contains(task)) {
-    tasks.insert(task);
+    tasks.emplace(task, message);
   }
 }
 
@@ -2402,6 +2401,14 @@ static void registerSchemeHandler (Router *router) {
 }
 
 - (void) webView: (SSCBridgedWebView*) webview stopURLSchemeTask: (Task) task {
+  Lock lock(mutex);
+  if (tasks.contains(task)) {
+    auto message = tasks[task];
+    if (message.cancel != nullptr) {
+      message.cancel(message.cancel_data);
+      message.cancel = nullptr;
+    }
+  }
   [self finalizeTask: task];
 }
 
@@ -2688,7 +2695,7 @@ static void registerSchemeHandler (Router *router) {
     body = (char *) data;
   }
 
-  [self enqueueTask: task];
+  [self enqueueTask: task withMessage: message];
 
   auto invoked = self.router->invoke(message, body, bufsize, [=](Result result) {
     // @TODO Communicate task cancellation to the route, so it can cancel its work.

src/ipc/ipc.hh

@@ -147,6 +147,8 @@ namespace SSC::IPC {
       Seq seq = "";
       Map args;
       bool isHTTP = false;
+      void (*cancel)(void*) = nullptr;
+      void *cancel_data = nullptr;
 
       Message () = default;
       Message (const Message& message);