[core] Add integer overload for fnv1a_hash_extend (#13054)

esphome/components/bme68x_bsec2_i2c/bme68x_bsec2_i2c.cpp

@@ -31,7 +31,11 @@ void BME68xBSEC2I2CComponent::dump_config() {
   BME68xBSEC2Component::dump_config();
 }
 
-uint32_t BME68xBSEC2I2CComponent::get_hash() { return fnv1_hash("bme68x_bsec_state_" + to_string(this->address_)); }
+uint32_t BME68xBSEC2I2CComponent::get_hash() {
+  char buf[22];  // "bme68x_bsec_state_" (18) + uint8_t max (3) + null
+  snprintf(buf, sizeof(buf), "bme68x_bsec_state_%u", this->address_);
+  return fnv1_hash(buf);
+}
 
 int8_t BME68xBSEC2I2CComponent::read_bytes_wrapper(uint8_t a_register, uint8_t *data, uint32_t len, void *intfPtr) {
   ESP_LOGVV(TAG, "read_bytes_wrapper: reg = %u", a_register);

esphome/components/sen5x/sen5x.cpp

@@ -158,7 +158,7 @@ void SEN5XComponent::setup() {
         // Hash with config hash, version, and serial number
         // This ensures the baseline storage is cleared after OTA
         // Serial numbers are unique to each sensor, so multiple sensors can be used without conflict
-        uint32_t hash = fnv1a_hash_extend(App.get_config_version_hash(), std::to_string(combined_serial));
+        uint32_t hash = fnv1a_hash_extend(App.get_config_version_hash(), combined_serial);
         this->pref_ = global_preferences->make_preference<Sen5xBaselines>(hash, true);
 
         if (this->pref_.load(&this->voc_baselines_storage_)) {

esphome/components/sgp30/sgp30.cpp

@@ -75,7 +75,7 @@ void SGP30Component::setup() {
   // Hash with config hash, version, and serial number
   // This ensures the baseline storage is cleared after OTA
   // Serial numbers are unique to each sensor, so multiple sensors can be used without conflict
-  uint32_t hash = fnv1a_hash_extend(App.get_config_version_hash(), std::to_string(this->serial_number_));
+  uint32_t hash = fnv1a_hash_extend(App.get_config_version_hash(), this->serial_number_);
   this->pref_ = global_preferences->make_preference<SGP30Baselines>(hash, true);
 
   if (this->store_baseline_ && this->pref_.load(&this->baselines_storage_)) {

esphome/components/sgp4x/sgp4x.cpp

@@ -60,7 +60,7 @@ void SGP4xComponent::setup() {
     // Hash with config hash, version, and serial number
     // This ensures the baseline storage is cleared after OTA
     // Serial numbers are unique to each sensor, so multiple sensors can be used without conflict
-    uint32_t hash = fnv1a_hash_extend(App.get_config_version_hash(), std::to_string(this->serial_number_));
+    uint32_t hash = fnv1a_hash_extend(App.get_config_version_hash(), this->serial_number_);
     this->pref_ = global_preferences->make_preference<SGP4xBaselines>(hash, true);
 
     if (this->pref_.load(&this->voc_baselines_storage_)) {

esphome/core/helpers.h

@@ -404,6 +404,16 @@ constexpr uint32_t fnv1a_hash_extend(uint32_t hash, const char *str) {
 inline uint32_t fnv1a_hash_extend(uint32_t hash, const std::string &str) {
   return fnv1a_hash_extend(hash, str.c_str());
 }
+/// Extend a FNV-1a hash with an integer (hashes each byte).
+template<std::integral T> constexpr uint32_t fnv1a_hash_extend(uint32_t hash, T value) {
+  using UnsignedT = std::make_unsigned_t<T>;
+  UnsignedT uvalue = static_cast<UnsignedT>(value);
+  for (size_t i = 0; i < sizeof(T); i++) {
+    hash ^= (uvalue >> (i * 8)) & 0xFF;
+    hash *= FNV1_PRIME;
+  }
+  return hash;
+}
 /// Calculate a FNV-1a hash of \p str.
 constexpr uint32_t fnv1a_hash(const char *str) { return fnv1a_hash_extend(FNV1_OFFSET_BASIS, str); }
 inline uint32_t fnv1a_hash(const std::string &str) { return fnv1a_hash(str.c_str()); }