Send front-end log messages to log file

backend/src/api/log_it.rs

@@ -0,0 +1,35 @@
+use usdpl_back::core::serdes::Primitive;
+
+use super::ApiParameterType;
+
+/// API web method to send log messages to the back-end log, callable from the front-end
+pub fn log_it() -> impl Fn(ApiParameterType) -> ApiParameterType {
+    move |params| {
+        if let Some(Primitive::F64(level)) = params.get(0) {
+            if let Some(Primitive::String(msg)) = params.get(1) {
+                log_msg_by_level(*level as u8, msg);
+                vec![true.into()]
+            } else if let Some(Primitive::Json(msg)) = params.get(1) {
+                log_msg_by_level(*level as u8, msg);
+                vec![true.into()]
+            } else {
+                log::warn!("Got log_it call with wrong/missing 2nd parameter");
+                vec![false.into()]
+            }
+        } else {
+            log::warn!("Got log_it call with wrong/missing 1st parameter");
+            vec![false.into()]
+        }
+    }
+}
+
+fn log_msg_by_level(level: u8, msg: &str) {
+    match level {
+        1 => log::trace!("FRONT-END: {}", msg),
+        2 => log::debug!("FRONT-END: {}", msg),
+        3 => log::info!("FRONT-END: {}", msg),
+        4 => log::warn!("FRONT-END: {}", msg),
+        5 => log::error!("FRONT-END: {}", msg),
+        _ => log::trace!("FRONT-END: {}", msg),
+    }
+}

backend/src/api/mod.rs

@@ -2,6 +2,7 @@ mod about;
 pub(crate) mod async_utils;
 mod get_display;
 mod get_items;
+mod log_it;
 mod on_event;
 mod on_javascript_result;
 mod on_update;
@@ -13,6 +14,7 @@ mod types;
 pub use about::get_about;
 pub use get_display::GetDisplayEndpoint;
 pub use get_items::get_items;
+pub use log_it::log_it;
 pub use on_event::on_event;
 pub use on_javascript_result::on_javascript_result;
 pub use on_update::on_update;

backend/src/api/on_event.rs

@@ -25,7 +25,7 @@ pub fn on_event(sender: Sender<QueueItem>) -> impl Fn(ApiParameterType) -> ApiPa
                     vec![true.into()]
                 },
                 Err(e) => {
-                    log::warn!("Failed to parse event json: {}", e);
+                    log::error!("Failed to parse event json: {}", e);
                     vec![false.into()]
                 }
             }

backend/src/main.rs

@@ -31,6 +31,7 @@ fn main() -> Result<(), ()> {
         .register_async("get_display", api::GetDisplayEndpoint::new(sender.clone()))
         .register_async("get_javascript_to_run", api::GetJavascriptEndpoint::new(sender.clone()))
         .register_blocking("get_items", api::get_items(sender.clone()))
+        .register("log", api::log_it())
         .register("on_javascript_result", api::on_javascript_result(sender.clone()))
         .register("on_update", api::on_update(sender.clone()))
         .register("on_steam_event", api::on_event(sender.clone()))

main.py

@@ -11,6 +11,6 @@ class Plugin:
     # Asyncio-compatible long-running code, executed in a task when the plugin is loaded
     async def _main(self):
         # startup
-        #self.backend_proc = subprocess.Popen([PARENT_DIR + "/bin/backend", "--config", ""])
+        self.backend_proc = subprocess.Popen([PARENT_DIR + "/bin/backend", "--config", ""])
         while True:
             await asyncio.sleep(1)

src/backend.ts

@@ -98,6 +98,14 @@ export type CJavascriptResult = {
 
 export type CJavascriptResponse = CJavascriptResult | CErrorResult;
 
+export enum CLogLevel {
+    TRACE = 1,
+    DEBUG = 2,
+    INFO = 3,
+    WARN = 4,
+    ERROR = 5,
+}
+
 export async function getElements(): Promise<CElement[]> {
     return (await call_backend("get_items", []))[0];
 }
@@ -129,3 +137,7 @@ export async function onJavascriptResult(id: number, value: any): Promise<boolea
 export async function onSteamEvent(data: CSteamEvent): Promise<boolean> {
     return (await call_backend("on_steam_event", [data]))[0];
 }
+
+export async function log(level: CLogLevel, msg: string): Promise<boolean> {
+    return (await call_backend("log", [level, msg]))[0];
+}

src/index.tsx

@@ -35,36 +35,58 @@ let update = () => {};
 
 let updateTasks: (() => void)[] = [];
 
+let displayErrors: number[] = [];
+const DISPLAY_ERROR_ABORT_THRESHHOLD = 8;
+
 function displayCallback(index: number) {
   return (newVal: backend.CDisplayResponse) => {
     if (newVal != null) {
       switch (newVal.result) {
         case "value":
+          displayErrors[index] = 0;
           let val = newVal as backend.CValueResult;
           console.log("CAYLON: Got display for " + index.toString(), val);
+          backend.log(backend.CLogLevel.DEBUG, "Got display for " + index.toString());
           set_value(DISPLAY_KEY + index.toString(), val.value);
           break;
         case "error":
+          displayErrors[index]++;
           let err = newVal as backend.CErrorResult;
           console.warn("CAYLON: Got display error for " + index.toString(), err);
+          backend.log(backend.CLogLevel.WARN, "Got display error for " + index.toString());
           break;
         default:
           console.error("CAYLON: Got invalid display response for " + index.toString(), newVal);
+          backend.log(backend.CLogLevel.ERROR, "Got invalid display response for " + index.toString());
           break;
       }
     } else {
+      displayErrors[index]++;
       console.warn("CAYLON: Ignoring null display result for " + index.toString());
+      backend.log(backend.CLogLevel.WARN, "Ignoring null display result for " + index.toString());
+    }
+    if (displayErrors[index] < DISPLAY_ERROR_ABORT_THRESHHOLD) {
+      updateTasks.push(() => backend.resolve(backend.getDisplay(index), displayCallback(index)));
+      update();
+    } else {
+      console.error("CAYLON: Got too many display errors for " + index.toString() + ", stopping display updates for element");
+      backend.log(backend.CLogLevel.ERROR, "Got too many display errors for " + index.toString() + ", stopping display updates for element");
     }
-    updateTasks.push(() => backend.resolve(backend.getDisplay(index), displayCallback(index)));
-    update();
   }
 }
 
+let jsErrors: number = 0;
+const JAVASCRIPT_ERROR_ABORT_THRESHHOLD = 16;
+
 function onGetElements() {
+  displayErrors = [];
   for (let i = 0; i < items.length; i++) {
     console.log("CAYLON: req display for item #" + i.toString());
+    backend.log(backend.CLogLevel.DEBUG, "req display for item #" + i.toString());
+    displayErrors.push(0);
     backend.resolve(backend.getDisplay(i), displayCallback(i));
   }
+  jsErrors = 0;
   backend.resolve(backend.getJavascriptToRun(), jsCallback());
   register_for_steam_events();
 }
@@ -73,24 +95,43 @@ const eval2 = eval;
 
 function jsCallback() {
   return (script: backend.CJavascriptResponse) => {
+    // register next callback (before running JS, in case that crashes)
+    if (jsErrors < JAVASCRIPT_ERROR_ABORT_THRESHHOLD) {
+      backend.resolve(backend.getJavascriptToRun(), jsCallback());
+    } else {
+      console.error("CAYLON: Got too many javascript errors, stopping remote javascript execution");
+      backend.log(backend.CLogLevel.ERROR, "Got too many javascript errors, stopping remote javascript execution");
+    }
     if (script != null) {
       switch (script.result) {
         case "javascript":
-          // register next callback (before running JS, in case that crashes)
-          backend.resolve(backend.getJavascriptToRun(), jsCallback());
           let toRun = script as backend.CJavascriptResult;
           console.log("CAYLON: Got javascript " + toRun.id.toString(), toRun);
-          let result = eval2(toRun.raw);
+          backend.log(backend.CLogLevel.DEBUG, "Got javascript " + toRun.id.toString());
-          backend.onJavascriptResult(toRun.id, result);
+          try {
+            let result = eval2(toRun.raw);
+            backend.onJavascriptResult(toRun.id, result);
+            jsErrors = 0;
+          } catch (err) {
+            jsErrors++;
+            console.warn("CAYLON: Javascript " + toRun.id.toString() + "failed", err);
+            backend.log(backend.CLogLevel.WARN, "Javascript " + toRun.id.toString() + "failed");
+          }
           break;
         case "error":
+          jsErrors++;
           let err = script as backend.CErrorResult;
           console.warn("CAYLON: Got javascript retrieval error", err);
+          backend.log(backend.CLogLevel.WARN, "Got javascript retrieval error");
           break;
         default:
+          jsErrors++;
           console.error("CAYLON: Got invalid javascript response", script);
+          backend.log(backend.CLogLevel.ERROR, "Got invalid javascript response");
           break;
       }
+    } else {
+      jsErrors++;
     }
   }
 }
@@ -102,14 +143,17 @@ function jsCallback() {
   let about_promise = backend.getAbout();
   let elements_promise = backend.getElements();
   about = await about_promise;
-  console.log("CAYLON: got about", about);
+  console.log("CAYLON: Got about", about);
+  backend.log(backend.CLogLevel.DEBUG, "Got about");
   let result = await elements_promise;
-  console.log("CAYLON: got elements", result);
+  console.log("CAYLON: Got elements", result);
+  backend.log(backend.CLogLevel.DEBUG, "Got elements");
   if (result != null) {
     items = result;
     onGetElements();
   } else {
-    console.warn("CAYLON: backend connection failed");
+    console.error("CAYLON: Backend connection failed");
+    backend.log(backend.CLogLevel.ERROR, "Backend connection failed");
   }
   backend.resolve(backend.getJavascriptToRun(), jsCallback());
   register_for_steam_events();
@@ -149,19 +193,22 @@ const Content: VFC<{ serverAPI: ServerAPI }> = ({}) => {
             backend.resolve(backend.reload(),
               (reload_items: backend.CElement[]) => {
                 items = reload_items;
-                console.log("CAYLON: got elements", reload_items);
+                console.log("CAYLON: Got elements", reload_items);
+                backend.log(backend.CLogLevel.DEBUG, "Got elements for reload");
                 if (reload_items != null) {
                   items = reload_items;
                   onGetElements();
                 } else {
-                  console.warn("CAYLON: backend connection failed");
+                  console.error("CAYLON: Backend connection failed");
+                  backend.log(backend.CLogLevel.ERROR, "Backend connection failed on reload");
                 }
                 update();
               });
             backend.resolve(backend.getAbout(),
               (new_about: backend.CAbout) => {
                 about = new_about;
-                console.log("CAYLON: got about", about);
+                console.log("CAYLON: Got about", about);
+                backend.log(backend.CLogLevel.DEBUG, "Got about for reload");
                 update();
               });
           }}>
@@ -188,6 +235,7 @@ function buildHtmlElement(element: backend.CElement, index: number, updateIdc: a
       return buildEventDisplay(element as backend.CEventDisplay, index, updateIdc);
   }
   console.error("CAYLON: Unsupported element", element);
+  backend.log(backend.CLogLevel.ERROR, "Unsupported element " + element.element);
   return <div>Unsupported</div>;
 }