helpers.cpp File Reference

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Namespaces
namespace	esphome

Functions
void	esphome::__attribute__ ((noinline, cold)) WarnIfComponentBlockingGuard
	esphome::if (data)
float	esphome::gamma_correct (float value, float gamma)
float	esphome::gamma_uncorrect (float value, float gamma)
Mathematics
uint8_t	esphome::crc8 (const uint8_t *data, uint8_t len, uint8_t crc=0x00, uint8_t poly=0x8C, bool msb_first=false)
	Calculate a CRC-8 checksum of data with size len.
uint16_t	esphome::crc16 (const uint8_t *data, uint16_t len, uint16_t crc=0xffff, uint16_t reverse_poly=0xa001, bool refin=false, bool refout=false)
	Calculate a CRC-16 checksum of data with size len.
uint16_t	esphome::crc16be (const uint8_t *data, uint16_t len, uint16_t crc, uint16_t poly, bool refin, bool refout)
uint32_t	esphome::fnv1_hash (const char *str)
	Calculate a FNV-1 hash of str.
uint32_t	esphome::random_uint32 ()
	Return a random 32-bit unsigned integer.
float	esphome::random_float ()
	Return a random float between 0 and 1.
int8_t	esphome::ilog10 (float value)
	Compute floor(log10(fabs(value))) using iterative comparison.
Parsing & formatting
size_t	esphome::parse_hex (const char *str, size_t len, uint8_t *data, size_t count)
	Parse bytes from a hex-encoded string into a byte array.
char *	esphome::uint32_to_str_unchecked (char *buf, uint32_t val)
	Write unsigned 32-bit integer to buffer (internal, no size check).
char *	esphome::format_hex_to (char *buffer, size_t buffer_size, const uint8_t *data, size_t length)
	Format byte array as lowercase hex to buffer (base implementation).
char *	esphome::format_hex_pretty_to (char *buffer, size_t buffer_size, const uint8_t *data, size_t length, char separator=':')
	Format byte array as uppercase hex to buffer (base implementation).
char *	esphome::format_hex_pretty_to (char *buffer, size_t buffer_size, const uint16_t *data, size_t length, char separator=':')
	Format uint16_t array as uppercase hex with separator to pre-allocated buffer.
char *	esphome::format_bin_to (char *buffer, size_t buffer_size, const uint8_t *data, size_t length)
	Format byte array as binary string to buffer.
ParseOnOffState	esphome::parse_on_off (const char *str, const char *on=nullptr, const char *off=nullptr)
	Parse a string that contains either on, off or toggle.
size_t	esphome::value_accuracy_to_buf (std::span< char, VALUE_ACCURACY_MAX_LEN > buf, float value, int8_t accuracy_decimals)
	Format value with accuracy to buffer, returns chars written (excluding null)
size_t	esphome::value_accuracy_with_uom_to_buf (std::span< char, VALUE_ACCURACY_MAX_LEN > buf, float value, int8_t accuracy_decimals, StringRef unit_of_measurement)
	Format value with accuracy and UOM to buffer, returns chars written (excluding null)
int8_t	esphome::step_to_accuracy_decimals (float step)
	Derive accuracy in decimals from an increment step.
size_t	esphome::base64_decode (const std::string &encoded_string, uint8_t *buf, size_t buf_len)
size_t	esphome::base64_decode (const uint8_t *encoded_data, size_t encoded_len, uint8_t *buf, size_t buf_len)
bool	esphome::base64_decode_int32_vector (const std::string &base64, std::vector< int32_t > &out)
	Decode base64/base64url string directly into vector of little-endian int32 values.
Colors
void	esphome::rgb_to_hsv (float red, float green, float blue, int &hue, float &saturation, float &value)
	Convert red, green and blue (all 0-1) values to hue (0-360), saturation (0-1) and value (0-1).
void	esphome::hsv_to_rgb (int hue, float saturation, float value, float &red, float &green, float &blue)
	Convert hue (0-360), saturation (0-1) and value (0-1) to red, green and blue (all 0-1).
System APIs
void	esphome::get_mac_address_into_buffer (std::span< char, MAC_ADDRESS_BUFFER_SIZE > buf)
	Get the device MAC address into the given buffer, in lowercase hex notation.
const char *	esphome::get_mac_address_pretty_into_buffer (std::span< char, MAC_ADDRESS_PRETTY_BUFFER_SIZE > buf)
	Get the device MAC address into the given buffer, in colon-separated uppercase hex notation.
bool	esphome::has_custom_mac_address ()
	Check if a custom MAC address is set (ESP32 & variants)
bool	esphome::mac_address_is_valid (const uint8_t *mac)
	Check if the MAC address is not all zeros or all ones.
void	esphome::delay_microseconds_safe (uint32_t us)
	Delay for the given amount of microseconds, possibly yielding to other processes during the wait.

Variables
uint16_t uint16_t &	esphome::capacity = new_cap
uint16_t uint16_t size_t	esphome::elem_size
uint16_t	esphome::new_cap = size + 1
auto *	esphome::new_data = ::operator new(new_cap *elem_size)

Strings
uint16_t	esphome::size
bool	esphome::str_equals_case_insensitive (const std::string &a, const std::string &b)
	Compare strings for equality in case-insensitive manner.
bool	esphome::str_equals_case_insensitive (StringRef a, StringRef b)
	Compare StringRefs for equality in case-insensitive manner.
bool	esphome::str_startswith (const std::string &str, const std::string &start)
	Check whether a string starts with a value.
bool	esphome::str_endswith (const std::string &str, const std::string &end)
	Check whether a string ends with a value.
bool	esphome::str_endswith_ignore_case (const char *str, size_t str_len, const char *suffix, size_t suffix_len)
	Case-insensitive check if string ends with suffix (no heap allocation).
char *	esphome::str_sanitize_to (char *buffer, size_t buffer_size, const char *str)
	Sanitize a string to buffer, keeping only alphanumerics, dashes, and underscores.
size_t	esphome::make_name_with_suffix_to (char *buffer, size_t buffer_size, const char *name, size_t name_len, char sep, const char *suffix_ptr, size_t suffix_len)
	Zero-allocation version: format name + separator + suffix directly into buffer.
std::string	esphome::make_name_with_suffix (const char *name, size_t name_len, char sep, const char *suffix_ptr, size_t suffix_len)
	Optimized string concatenation: name + separator + suffix (const char* overload) Uses a fixed stack buffer to avoid heap allocations.
std::string	esphome::make_name_with_suffix (const std::string &name, char sep, const char *suffix_ptr, size_t suffix_len)
	Concatenate a name with a separator and suffix using an efficient stack-based approach.