From 1244b2c25d3c37978cec4080c8a7443f2716a65f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sun, 15 Mar 2026 20:18:03 -1000
Subject: [PATCH 1/2] [logger] Inline ANSI reset sequence in
 LogBuffer::finalize_()

Replace write_() call with direct char stores for the 4-byte
ANSI reset sequence ("\033[0m"). This eliminates function call
overhead (entry/retw, bounds check, memcpy setup) on every log
message and avoids a rodata string reference that consumes RAM
on ESP8266.
---
 esphome/components/logger/log_buffer.h | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/esphome/components/logger/log_buffer.h b/esphome/components/logger/log_buffer.h
index a56276f732..30c859cf8a 100644
--- a/esphome/components/logger/log_buffer.h
+++ b/esphome/components/logger/log_buffer.h
@@ -128,12 +128,21 @@ struct LogBuffer {
     }
   }
   void finalize_() {
-    // Write color reset sequence
-    static constexpr uint16_t RESET_COLOR_LEN = sizeof(ESPHOME_LOG_RESET_COLOR) - 1;
-    this->write_(ESPHOME_LOG_RESET_COLOR, RESET_COLOR_LEN);
+    this->write_ansi_reset_();
     // Null terminate
     this->data[this->full_() ? this->size - 1 : this->pos] = '\0';
   }
+  // Write ANSI reset sequence inline (4 bytes: "\033[0m") - avoids write_() call overhead
+  void write_ansi_reset_() {
+    if (this->remaining_() >= 4) {
+      char *p = this->current_();
+      *p++ = '\033';
+      *p++ = '[';
+      *p++ = '0';
+      *p++ = 'm';
+      this->pos += 4;
+    }
+  }
   void strip_trailing_newlines_() {
     while (this->pos > 0 && this->data[this->pos - 1] == '\n')
       this->pos--;

From d201cc5d6497584c1391a2648d112357cc3e0fd8 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sun, 15 Mar 2026 20:19:34 -1000
Subject: [PATCH 2/2] [logger] Use constexpr for ANSI reset sequence length

---
 esphome/components/logger/log_buffer.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/esphome/components/logger/log_buffer.h b/esphome/components/logger/log_buffer.h
index 30c859cf8a..279ec6d371 100644
--- a/esphome/components/logger/log_buffer.h
+++ b/esphome/components/logger/log_buffer.h
@@ -132,15 +132,16 @@ struct LogBuffer {
     // Null terminate
     this->data[this->full_() ? this->size - 1 : this->pos] = '\0';
   }
-  // Write ANSI reset sequence inline (4 bytes: "\033[0m") - avoids write_() call overhead
+  // Write ANSI reset sequence inline ("\033[0m") - avoids write_() call overhead
+  static constexpr uint16_t ANSI_RESET_LEN = 4;  // "\033[0m"
   void write_ansi_reset_() {
-    if (this->remaining_() >= 4) {
+    if (this->remaining_() >= ANSI_RESET_LEN) {
       char *p = this->current_();
       *p++ = '\033';
       *p++ = '[';
       *p++ = '0';
       *p++ = 'm';
-      this->pos += 4;
+      this->pos += ANSI_RESET_LEN;
     }
   }
   void strip_trailing_newlines_() {