feat: reduce memory usage

src/builder/arm.h

@@ -33,7 +33,7 @@ class Arm : public Widget, public BuilderMixin<Arm, gridui::Arm> {
     }
 
 protected:
-    virtual void serialize(std::stringstream& ss) {
+    virtual void serialize(std::ostream& ss) {
         Widget::serialize(ss);
         extra().remove("info");
     }

src/builder/widget.cpp

@@ -10,8 +10,7 @@ namespace builder {
 
 Widget::Widget(const char* type, WidgetState& state)
     : m_state(state)
-    , m_type(type)
-    , m_style(nullptr) {
+    , m_type(type) {
 }
 
 Widget::~Widget() {
@@ -30,7 +29,7 @@ rbjson::Object& Widget::style() {
     return *res;
 }
 
-void Widget::serialize(std::stringstream& ss) {
+void Widget::serialize(std::ostream& ss) {
     ss << "{";
     {
         ss << "\"uuid\":" << m_state.uuid() << ",";

src/builder/widget.h

@@ -84,7 +84,7 @@ class Widget {
 protected:
     Widget(const char* type, WidgetState& state);
 
-    virtual void serialize(std::stringstream& ss);
+    virtual void serialize(std::ostream& ss);
 
     rbjson::Object& extra();
     rbjson::Object& style();
@@ -96,7 +96,6 @@ class Widget {
     Widget& operator=(const Widget&) = delete;
 
     const char* m_type;
-    rbjson::Object* m_style;
 };
 
 };

src/gridui.cpp

@@ -1,6 +1,7 @@
 #include <esp_log.h>
 #include <esp_timer.h>
 #include <stdio.h>
+#include <fstream>
 
 #include "gridui.h"
 #include "rbdns.h"
@@ -164,34 +165,54 @@ void _GridUi::commit() {
         return;
     }
 
-    std::vector<char> layout_json;
     {
-        std::stringstream ss;
-        m_layout->serialize(ss);
+
+        char buf[256];
+
+        snprintf(buf, sizeof(buf), "%s/layout.json", rb_web_get_files_root());
+
+        std::ofstream stream;
+        stream.rdbuf()->pubsetbuf(buf, sizeof(buf));
+        stream.open(buf, std::ofstream::trunc);
+
+        if(stream.fail()) {
+            ESP_LOGE("GridUI", "failed to open %s", buf);
+            return;
+        }
+
+        m_states.shrink_to_fit();
+
+        m_layout->serialize(stream);
         m_layout.reset();
 
-        ss.seekp(-1, std::stringstream::cur);
+        stream.seekp(-1, std::ofstream::cur);
 
-        ss << ",\"widgets\": [";
+        stream << ",\"widgets\": [";
         for (size_t i = 0; i < m_widgets.size(); ++i) {
             if (i != 0) {
-                ss << ",";
+                stream << ",";
             }
+
             auto& w = m_widgets[i];
-            w->serialize(ss);
+            w->serialize(stream);
             w.reset();
         }
         m_widgets.clear();
         m_widgets.shrink_to_fit();
-        m_states.shrink_to_fit();
 
-        ss << "]}";
+        stream << "]}";
 
-        layout_json.resize(((size_t)ss.tellp()) + 1);
-        ss.get(layout_json.data(), layout_json.size());
-    }
+        if(stream.fail()) {
+            ESP_LOGE("GridUI", "failed to serialize layout");
+            return;
+        }
 
-    ESP_ERROR_CHECK(rb_web_add_file("layout.json", layout_json.data(), layout_json.size() - 1));
+        stream.close();
+        if(stream.fail()) {
+            ESP_LOGE("GridUI", "failed to write layout");
+            return;
+        }
+    }
 
     esp_timer_create_args_t args = {
         .callback = stateChangeTask,

src/gridui.h

@@ -160,7 +160,7 @@ class _GridUi {
         m_states.emplace_back(std::unique_ptr<WidgetState>(state));
 
         auto* widget = new T(T::name(), *state);
-        m_widgets.push_back(std::unique_ptr<T>(widget));
+        m_widgets.emplace_back(std::unique_ptr<T>(widget));
         return widget;
     }
 

src/widgets/widget.cpp

@@ -19,7 +19,9 @@ WidgetState::WidgetState(uint16_t uuid, float x, float y, float w, float h, uint
     m_data.set("y", y);
     m_data.set("w", w);
     m_data.set("h", h);
-    m_data.set("tab", tab);
+    if(tab != 0) {
+        m_data.set("tab", tab);
+    }
 }
 
 bool WidgetState::set(const std::string& key, rbjson::Value* value) {