mirror/esphome
1
0
Fork 0
mirror of https://github.com/esphome/esphome.git synced 2026-01-09 19:50:49 -07:00
Code Issues Packages Projects Releases Wiki Activity

[core] Add format_hex_to helper for zero-allocation hex formatting (#12670)

Browse Source
This commit is contained in:
J. Nick Koston
2025-12-27 08:34:45 -10:00
committed by GitHub
parent 34067f8b15
commit e9f2d75aab
5 changed files with 41 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
esphome/components/one_wire/one_wire_bus.cpp
View File

@@ -49,7 +49,8 @@ void OneWireBus::search() {
break;
auto *address8 = reinterpret_cast<uint8_t *>(&address);
if (crc8(address8, 7) != address8[7]) {
ESP_LOGW(TAG, "Dallas device 0x%s has invalid CRC.", format_hex(address).c_str());
char hex_buf[17];
ESP_LOGW(TAG, "Dallas device 0x%s has invalid CRC.", format_hex_to(hex_buf, address));
} else {
this->devices_.push_back(address);
}
@@ -82,8 +83,9 @@ void OneWireBus::dump_devices_(const char *tag) {
ESP_LOGW(tag, " Found no devices!");
} else {
ESP_LOGCONFIG(tag, " Found devices:");
char hex_buf[17]; // uint64_t = 16 hex chars + null
for (auto &address : this->devices_) {
ESP_LOGCONFIG(tag, " 0x%s (%s)", format_hex(address).c_str(), LOG_STR_ARG(get_model_str(address & 0xff)));
ESP_LOGCONFIG(tag, " 0x%s (%s)", format_hex_to(hex_buf, address), LOG_STR_ARG(get_model_str(address & 0xff)));
}
}
}

4
esphome/components/sx126x/sx126x.cpp
View File

@@ -527,7 +527,9 @@ void SX126x::dump_config() {
this->spreading_factor_, cr, this->preamble_size_);
}
if (!this->sync_value_.empty()) {
ESP_LOGCONFIG(TAG, " Sync Value: 0x%s", format_hex(this->sync_value_).c_str());
char hex_buf[17]; // 8 bytes max = 16 hex chars + null
ESP_LOGCONFIG(TAG, " Sync Value: 0x%s",
format_hex_to(hex_buf, this->sync_value_.data(), this->sync_value_.size()));
}
if (this->is_failed()) {
ESP_LOGE(TAG, "Configuring SX126x failed");

4
esphome/components/sx127x/sx127x.cpp
View File

@@ -476,7 +476,9 @@ void SX127x::dump_config() {
ESP_LOGCONFIG(TAG, " Payload Length: %" PRIu32, this->payload_length_);
}
if (!this->sync_value_.empty()) {
ESP_LOGCONFIG(TAG, " Sync Value: 0x%s", format_hex(this->sync_value_).c_str());
char hex_buf[17]; // 8 bytes max = 16 hex chars + null
ESP_LOGCONFIG(TAG, " Sync Value: 0x%s",
format_hex_to(hex_buf, this->sync_value_.data(), this->sync_value_.size()));
}
if (this->preamble_size_ > 0 || this->preamble_detect_ > 0) {
ESP_LOGCONFIG(TAG,

13
esphome/core/helpers.cpp
View File

@@ -297,6 +297,19 @@ std::string format_hex(const uint8_t *data, size_t length) {
}
std::string format_hex(const std::vector<uint8_t> &data) { return format_hex(data.data(), data.size()); }
char *format_hex_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length) {
size_t max_bytes = (buffer_size - 1) / 2;
if (length > max_bytes) {
length = max_bytes;
}
for (size_t i = 0; i < length; i++) {
buffer[2 * i] = format_hex_char(data[i] >> 4);
buffer[2 * i + 1] = format_hex_char(data[i] & 0x0F);
}
buffer[length * 2] = '\0';
return buffer;
}
// Shared implementation for uint8_t and string hex formatting
static std::string format_hex_pretty_uint8(const uint8_t *data, size_t length, char separator, bool show_length) {
if (data == nullptr || length == 0)

18
esphome/core/helpers.h
View File

@@ -730,6 +730,24 @@ inline void format_mac_addr_lower_no_sep(const uint8_t *mac, char *output) {
output[12] = '\0';
}
/// Format byte array as lowercase hex to buffer (base implementation).
char *format_hex_to(char *buffer, size_t buffer_size, const uint8_t *data, size_t length);
/// Format byte array as lowercase hex to buffer. Automatically deduces buffer size.
/// Truncates output if data exceeds buffer capacity. Returns pointer to buffer.
template<size_t N> inline char *format_hex_to(char (&buffer)[N], const uint8_t *data, size_t length) {
static_assert(N >= 3, "Buffer must hold at least one hex byte (3 chars)");
return format_hex_to(buffer, N, data, length);
}
/// Format an unsigned integer in lowercased hex to buffer, starting with the most significant byte.
template<size_t N, typename T, enable_if_t<std::is_unsigned<T>::value, int> = 0>
inline char *format_hex_to(char (&buffer)[N], T val) {
static_assert(N >= sizeof(T) * 2 + 1, "Buffer too small for type");
val = convert_big_endian(val);
return format_hex_to(buffer, reinterpret_cast<const uint8_t *>(&val), sizeof(T));
}
/// Format the six-byte array \p mac into a MAC address.
std::string format_mac_address_pretty(const uint8_t mac[6]);
/// Format the byte array \p data of length \p len in lowercased hex.