From 7fe4352786ba744c2d7212b20fa1489438215694 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Tue, 20 Oct 2026 15:33:38 -1000
Subject: [PATCH] [graph] Stop copying the trace name (#21211)

---
 esphome/components/graph/graph.cpp | 16 ++++++++--------
 esphome/components/graph/graph.h   |  8 ++++----
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/esphome/components/graph/graph.cpp b/esphome/components/graph/graph.cpp
index e09eb385e32..147890fa29a 100644
--- a/esphome/components/graph/graph.cpp
+++ b/esphome/components/graph/graph.cpp
@@ -47,7 +47,7 @@ void HistoryData::take_sample(float data) {
 }
 
 void GraphTrace::init(Graph *g) {
-  ESP_LOGI(TAG, "Init trace for sensor %s", this->get_name().c_str());
+  ESP_LOGI(TAG, "Init trace for sensor %s", this->name_);
   this->data_.init(g->get_width());
   sensor_->add_on_state_callback([this](float state) { this->data_.take_sample(state); });
   this->data_.set_update_time_ms(g->get_duration() * 1000 / g->get_width());
@@ -220,16 +220,16 @@ void GraphLegend::init(Graph *g) {
   int valw = 0, valh = 0;
   int lt = 0;
   for (auto *trace : g->traces_) {
-    std::string txtstr = trace->get_name();
+    const char *txtstr = trace->name_;
     int fw, fos, fbl, fh;
-    this->font_label_->measure(txtstr.c_str(), &fw, &fos, &fbl, &fh);
+    this->font_label_->measure(txtstr, &fw, &fos, &fbl, &fh);
     if (fw > txtw)
       txtw = fw;
     if (fh > txth)
       txth = fh;
     if (trace->get_line_thickness() > lt)
       lt = trace->get_line_thickness();
-    ESP_LOGI(TAGL, "  %s %d %d", txtstr.c_str(), fw, fh);
+    ESP_LOGI(TAGL, "  %s %d %d", txtstr, fw, fh);
 
     if (this->values_ != VALUE_POSITION_TYPE_NONE) {
       char valstr[VALUE_ACCURACY_MAX_LEN];
@@ -351,10 +351,10 @@ void Graph::draw_legend(display::Display *buff, uint16_t x_offset, uint16_t y_of
   int x = x_offset + legend_->x0_;
   int y = y_offset;
   for (auto *trace : traces_) {
-    std::string txtstr = trace->get_name();
-    ESP_LOGV(TAG, "  %s", txtstr.c_str());
+    const char *txtstr = trace->name_;
+    ESP_LOGV(TAG, "  %s", txtstr);
 
-    buff->printf(x, y, legend_->font_label_, trace->get_line_color(), TextAlign::TOP_CENTER, "%s", txtstr.c_str());
+    buff->printf(x, y, legend_->font_label_, trace->get_line_color(), TextAlign::TOP_CENTER, "%s", txtstr);
 
     if (legend_->lines_) {
       uint16_t thick = trace->get_line_thickness();
@@ -393,7 +393,7 @@ void Graph::setup() {
 
 void Graph::dump_config() {
   for (auto *trace : traces_) {
-    ESP_LOGCONFIG(TAG, "Graph for sensor %s", trace->get_name().c_str());
+    ESP_LOGCONFIG(TAG, "Graph for sensor %s", trace->name_);
   }
 }
 
diff --git a/esphome/components/graph/graph.h b/esphome/components/graph/graph.h
index dbedab6085d..0196c44e3bf 100644
--- a/esphome/components/graph/graph.h
+++ b/esphome/components/graph/graph.h
@@ -1,9 +1,9 @@
 #pragma once
 #include <cstdint>
-#include <utility>
 #include <vector>
 #include "esphome/components/sensor/sensor.h"
 #include "esphome/core/color.h"
+#include "esphome/core/string_ref.h"
 #include "esphome/core/component.h"
 
 namespace esphome {
@@ -108,7 +108,7 @@ class HistoryData {
 class GraphTrace final {
  public:
   void init(Graph *g);
-  void set_name(std::string name) { name_ = std::move(name); }
+  void set_name(const char *name) { this->name_ = name; }
   void set_sensor(sensor::Sensor *sensor) { sensor_ = sensor; }
   uint8_t get_line_thickness() { return this->line_thickness_; }
   void set_line_thickness(uint8_t val) { this->line_thickness_ = val; }
@@ -118,12 +118,12 @@ class GraphTrace final {
   void set_line_color(Color val) { this->line_color_ = val; }
   bool get_continuous() { return this->continuous_; }
   void set_continuous(bool continuous) { this->continuous_ = continuous; }
-  std::string get_name() { return name_; }
+  StringRef get_name() const { return StringRef(this->name_); }
   const HistoryData *get_tracedata() { return &data_; }
 
  protected:
   sensor::Sensor *sensor_{nullptr};
-  std::string name_;
+  const char *name_{""};
   uint8_t line_thickness_{3};
   enum LineType line_type_ { LINE_TYPE_SOLID };
   Color line_color_{COLOR_ON};