Remove memcpy helper from libhtml5.js (#25785)

Instead we can move most of the implementation for these functions into
native code.

Author: sbc100

src/lib/libhtml5.js

@@ -51,10 +51,6 @@ var LibraryHTML5 = {
     currentEventHandler: null,
 #endif
 */
-    memcpy(target, src, size) {
-      HEAP8.set(HEAP8.subarray(src, src + size), target);
-    },
-
     removeAllEventListeners() {
       while (JSEvents.eventHandlers.length) {
         JSEvents._removeHandler(JSEvents.eventHandlers.length - 1);
@@ -551,16 +547,14 @@ var LibraryHTML5 = {
   emscripten_set_mouseout_callback_on_thread: (target, userData, useCapture, callbackfunc, targetThread) =>
     registerMouseEventCallback(target, userData, useCapture, callbackfunc, {{{ cDefs.EMSCRIPTEN_EVENT_MOUSEOUT }}}, "mouseout", targetThread),
 
-  emscripten_get_mouse_status__proxy: 'sync',
-  emscripten_get_mouse_status__deps: ['$JSEvents'],
-  emscripten_get_mouse_status: (mouseState) => {
-    if (!JSEvents.mouseEvent) return {{{ cDefs.EMSCRIPTEN_RESULT_NO_DATA }}};
-    // HTML5 does not really have a polling API for mouse events, so implement one manually by
-    // returning the data from the most recently received event. This requires that user has registered
-    // at least some no-op function as an event handler to any of the mouse function.
-    JSEvents.memcpy(mouseState, JSEvents.mouseEvent, {{{ C_STRUCTS.EmscriptenMouseEvent.__size__ }}});
-    return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
-  },
+  // HTML5 does not really have a polling API for mouse events, so implement one
+  // manually by returning the data from the most recently received event. This
+  // requires that user has registered at least some no-op function as an event
+  // handler to any of the mouse function.
+  _emscripten_get_last_mouse_event__proxy: 'sync',
+  _emscripten_get_last_mouse_event__internal: true,
+  _emscripten_get_last_mouse_event__deps: ['$JSEvents'],
+  _emscripten_get_last_mouse_event: () => JSEvents.mouseEvent,
 
   $registerWheelEventCallback__noleakcheck: true,
   $registerWheelEventCallback__deps: ['$JSEvents', '$fillMouseEventData', 'malloc'],
@@ -778,16 +772,14 @@ var LibraryHTML5 = {
     return registerDeviceOrientationEventCallback({{{ cDefs.EMSCRIPTEN_EVENT_TARGET_WINDOW }}}, userData, useCapture, callbackfunc, {{{ cDefs.EMSCRIPTEN_EVENT_DEVICEORIENTATION }}}, "deviceorientation", targetThread);
   },
 
-  emscripten_get_deviceorientation_status__proxy: 'sync',
-  emscripten_get_deviceorientation_status__deps: ['$JSEvents'],
-  emscripten_get_deviceorientation_status: (orientationState) => {
-    if (!JSEvents.deviceOrientationEvent) return {{{ cDefs.EMSCRIPTEN_RESULT_NO_DATA }}};
-    // HTML5 does not really have a polling API for device orientation events, so implement one manually by
-    // returning the data from the most recently received event. This requires that user has registered
-    // at least some no-op function as an event handler.
-    JSEvents.memcpy(orientationState, JSEvents.deviceOrientationEvent, {{{ C_STRUCTS.EmscriptenDeviceOrientationEvent.__size__ }}});
-    return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
-  },
+  // HTML5 does not really have a polling API for device orientation events, so
+  // implement one manually by returning the data from the most recently
+  // received event. This requires that user has registered at least some
+  // no-op function as an event handler.
+  _emscripten_get_last_deviceorientation_event__proxy: 'sync',
+  _emscripten_get_last_deviceorientation_event__internal: true,
+  _emscripten_get_last_deviceorientation_event__deps: ['$JSEvents'],
+  _emscripten_get_last_deviceorientation_event: () => JSEvents.deviceOrientationEvent,
 
   $fillDeviceMotionEventData: (eventStruct, e, target) => {
     var supportedFields = 0;
@@ -847,16 +839,14 @@ var LibraryHTML5 = {
   emscripten_set_devicemotion_callback_on_thread: (userData, useCapture, callbackfunc, targetThread) =>
     registerDeviceMotionEventCallback({{{ cDefs.EMSCRIPTEN_EVENT_TARGET_WINDOW }}}, userData, useCapture, callbackfunc, {{{ cDefs.EMSCRIPTEN_EVENT_DEVICEMOTION }}}, "devicemotion", targetThread),
 
-  emscripten_get_devicemotion_status__proxy: 'sync',
-  emscripten_get_devicemotion_status__deps: ['$JSEvents'],
-  emscripten_get_devicemotion_status: (motionState) => {
-    if (!JSEvents.deviceMotionEvent) return {{{ cDefs.EMSCRIPTEN_RESULT_NO_DATA }}};
-    // HTML5 does not really have a polling API for device motion events, so implement one manually by
-    // returning the data from the most recently received event. This requires that user has registered
-    // at least some no-op function as an event handler.
-    JSEvents.memcpy(motionState, JSEvents.deviceMotionEvent, {{{ C_STRUCTS.EmscriptenDeviceMotionEvent.__size__ }}});
-    return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
-  },
+  // HTML5 does not really have a polling API for device motion events, so
+  // implement one manually by returning the data from the most recently
+  // received event. This requires that user has registered at least some
+  // no-op function as an event handler.
+  _emscripten_get_last_devicemotion_event__proxy: 'sync',
+  _emscripten_get_last_devicemotion_event__internal: true,
+  _emscripten_get_last_devicemotion_event__deps: ['$JSEvents'],
+  _emscripten_get_last_devicemotion_event: () => JSEvents.deviceMotionEvent,
 
   $screenOrientation: () => {
     if (!window.screen) return undefined;

src/lib/libsigs.js

@@ -320,6 +320,9 @@ sigs = {
   _emscripten_fetch_get_response_headers__sig: 'pipp',
   _emscripten_fetch_get_response_headers_length__sig: 'pi',
   _emscripten_fs_load_embedded_files__sig: 'vp',
+  _emscripten_get_last_devicemotion_event__sig: 'p',
+  _emscripten_get_last_deviceorientation_event__sig: 'p',
+  _emscripten_get_last_mouse_event__sig: 'p',
   _emscripten_get_now_is_monotonic__sig: 'i',
   _emscripten_get_progname__sig: 'vpi',
   _emscripten_init_main_thread_js__sig: 'vp',
@@ -642,15 +645,12 @@ sigs = {
   emscripten_get_canvas_size__sig: 'vppp',
   emscripten_get_compiler_setting__sig: 'pp',
   emscripten_get_device_pixel_ratio__sig: 'd',
-  emscripten_get_devicemotion_status__sig: 'ip',
-  emscripten_get_deviceorientation_status__sig: 'ip',
   emscripten_get_element_css_size__sig: 'ippp',
   emscripten_get_exported_function__sig: 'pp',
   emscripten_get_fullscreen_status__sig: 'ip',
   emscripten_get_gamepad_status__sig: 'iip',
   emscripten_get_heap_max__sig: 'p',
   emscripten_get_main_loop_timing__sig: 'vpp',
-  emscripten_get_mouse_status__sig: 'ip',
   emscripten_get_now__sig: 'd',
   emscripten_get_now_res__sig: 'd',
   emscripten_get_num_gamepads__sig: 'i',

system/lib/html5/callback.c

@@ -42,3 +42,23 @@ void _emscripten_run_callback_on_thread(pthread_t t,
     assert(false && "emscripten_proxy_async failed");
   }
 }
+
+static EMSCRIPTEN_RESULT _get_last_event(void* out, void *latest, size_t len) {
+  if (!latest) {
+    return EMSCRIPTEN_RESULT_NO_DATA;
+  }
+  memcpy(out, latest, len);
+  return EMSCRIPTEN_RESULT_SUCCESS;
+}
+
+EMSCRIPTEN_RESULT emscripten_get_deviceorientation_status(EmscriptenDeviceOrientationEvent *out) {
+  return _get_last_event(out, _emscripten_get_last_deviceorientation_event(), sizeof(*out));
+}
+
+EMSCRIPTEN_RESULT emscripten_get_devicemotion_status(EmscriptenDeviceMotionEvent *out) {
+  return _get_last_event(out, _emscripten_get_last_devicemotion_event(), sizeof(*out));
+}
+
+EMSCRIPTEN_RESULT emscripten_get_mouse_status(EmscriptenMouseEvent *out) {
+  return _get_last_event(out, _emscripten_get_last_mouse_event(), sizeof(*out));
+}

system/lib/libc/emscripten_internal.h

@@ -147,6 +147,10 @@ int _emscripten_system(const char *command);
 
 void _emscripten_log_formatted(int flags, const char* str);
 
+EmscriptenDeviceOrientationEvent* _emscripten_get_last_deviceorientation_event();
+EmscriptenDeviceMotionEvent* _emscripten_get_last_devicemotion_event();
+EmscriptenMouseEvent* _emscripten_get_last_mouse_event();
+
 #ifdef __cplusplus
 }
 #endif

test/codesize/test_codesize_hello_dylink_all.json

@@ -1,7 +1,7 @@
 {
-  "a.out.js": 245475,
-  "a.out.nodebug.wasm": 573783,
-  "total": 819258,
+  "a.out.js": 245299,
+  "a.out.nodebug.wasm": 574162,
+  "total": 819461,
   "sent": [
     "IMG_Init",
     "IMG_Load",
@@ -270,6 +270,9 @@
     "_dlsym_js",
     "_emscripten_dlopen_js",
     "_emscripten_fs_load_embedded_files",
+    "_emscripten_get_last_devicemotion_event",
+    "_emscripten_get_last_deviceorientation_event",
+    "_emscripten_get_last_mouse_event",
     "_emscripten_get_now_is_monotonic",
     "_emscripten_get_progname",
     "_emscripten_log_formatted",
@@ -461,14 +464,11 @@
     "emscripten_get_canvas_size",
     "emscripten_get_compiler_setting",
     "emscripten_get_device_pixel_ratio",
-    "emscripten_get_devicemotion_status",
-    "emscripten_get_deviceorientation_status",
     "emscripten_get_element_css_size",
     "emscripten_get_fullscreen_status",
     "emscripten_get_gamepad_status",
     "emscripten_get_heap_max",
     "emscripten_get_main_loop_timing",
-    "emscripten_get_mouse_status",
     "emscripten_get_now",
     "emscripten_get_now_res",
     "emscripten_get_num_gamepads",
@@ -1457,6 +1457,9 @@
     "env._dlopen_js",
     "env._dlsym_js",
     "env._emscripten_dlopen_js",
+    "env._emscripten_get_last_devicemotion_event",
+    "env._emscripten_get_last_deviceorientation_event",
+    "env._emscripten_get_last_mouse_event",
     "env._emscripten_get_progname",
     "env._emscripten_log_formatted",
     "env._emscripten_lookup_name",
@@ -2220,7 +2223,10 @@
     "emscripten_fiber_init_from_current_context",
     "emscripten_futex_wait",
     "emscripten_futex_wake",
+    "emscripten_get_devicemotion_status",
+    "emscripten_get_deviceorientation_status",
     "emscripten_get_heap_size",
+    "emscripten_get_mouse_status",
     "emscripten_get_sbrk_ptr",
     "emscripten_has_threading_support",
     "emscripten_is_main_runtime_thread",
@@ -4082,7 +4088,10 @@
     "$emscripten_fiber_init",
     "$emscripten_fiber_init_from_current_context",
     "$emscripten_futex_wait",
+    "$emscripten_get_devicemotion_status",
+    "$emscripten_get_deviceorientation_status",
     "$emscripten_get_heap_size",
+    "$emscripten_get_mouse_status",
     "$emscripten_get_sbrk_ptr",
     "$emscripten_log",
     "$emscripten_longjmp",