server: error handling: fixes after merge

examples/server/server.cpp

@@ -1211,6 +1211,28 @@ struct server_context {
         queue_results.send(res);
     }
 
+    static json error_to_json(const llama_error& error)
+    {
+        return {
+            { "error", {
+                { "id", error.id() },
+                { "description", error.description() }
+            } }
+        };
+    }
+
+    void send_error(const server_task & task, const llama_error& error)
+    {
+        LOG_TEE("task %i - error: %s - %s\n", task.id, error.id().c_str(), error.description().c_str());
+        server_task_result res;
+        res.id = task.id;
+        res.id_multi = task.id_multi;
+        res.stop = false;
+        res.error = true;
+        res.data = { { "content", error_to_json(error).dump() } };
+        queue_results.send(res);
+    }
+
     void send_partial_response(server_slot & slot, completion_token_output tkn) {
         server_task_result res;
         res.id       = slot.id_task;
@@ -1436,11 +1458,16 @@ struct server_context {
                     slot->infill    = task.infill;
                     slot->embedding = task.embedding;
 
-                    if (!launch_slot_with_data(*slot, task.data)) {
+                    try {
+                        if (!launch_slot_with_data(*slot, task.data))
+                        {
                             // send error result
                             send_error(task, "internal_error");
                             break;
                         }
+                    } catch (const llama_error & err) {
+                        send_error(task, err);
+                    }
                 } break;
             case SERVER_TASK_TYPE_CANCEL:
                 {
@@ -2953,7 +2980,15 @@ int main(int argc, char ** argv) {
             return;
         }
 
-        json data = json::parse(req.body);
+        json data;
+        try {
+            data = json::parse(req.body);
+        } catch (const json::exception & json_err) {
+            const auto err = llama_error("request.invalid_json", std::string("Invalid JSON: ") + json_err.what());
+            const auto err_json = server_context::error_to_json(err).dump();
+            res.set_content(err_json, "text/plain; charset=utf-8");
+            return;
+        }
 
         const int id_task = ctx_server.queue_tasks.get_new_id();