ESP32: Only save to NVS if data was changed (#3479)

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Martin 2022-05-17 00:59:36 +02:00 committed by Jesse Hills
parent 7e88938932
commit 17b8bd8316
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GPG Key ID: BEAAE804EFD8E83A

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@ -118,12 +118,17 @@ class ESP32Preferences : public ESPPreferences {
// go through vector from back to front (makes erase easier/more efficient)
for (ssize_t i = s_pending_save.size() - 1; i >= 0; i--) {
const auto &save = s_pending_save[i];
esp_err_t err = nvs_set_blob(nvs_handle, save.key.c_str(), save.data.data(), save.data.size());
if (err != 0) {
ESP_LOGV(TAG, "nvs_set_blob('%s', len=%u) failed: %s", save.key.c_str(), save.data.size(),
esp_err_to_name(err));
any_failed = true;
continue;
ESP_LOGVV(TAG, "Checking if NVS data %s has changed", save.key.c_str());
if (is_changed(nvs_handle, save)) {
esp_err_t err = nvs_set_blob(nvs_handle, save.key.c_str(), save.data.data(), save.data.size());
if (err != 0) {
ESP_LOGV(TAG, "nvs_set_blob('%s', len=%u) failed: %s", save.key.c_str(), save.data.size(),
esp_err_to_name(err));
any_failed = true;
continue;
}
} else {
ESP_LOGD(TAG, "NVS data not changed skipping %s len=%u", save.key.c_str(), save.data.size());
}
s_pending_save.erase(s_pending_save.begin() + i);
}
@ -137,6 +142,22 @@ class ESP32Preferences : public ESPPreferences {
return !any_failed;
}
bool is_changed(const uint32_t nvs_handle, const NVSData &to_save) {
NVSData stored_data{};
size_t actual_len;
esp_err_t err = nvs_get_blob(nvs_handle, to_save.key.c_str(), nullptr, &actual_len);
if (err != 0) {
ESP_LOGV(TAG, "nvs_get_blob('%s'): %s - the key might not be set yet", to_save.key.c_str(), esp_err_to_name(err));
return true;
}
stored_data.data.reserve(actual_len);
err = nvs_get_blob(nvs_handle, to_save.key.c_str(), stored_data.data.data(), &actual_len);
if (err != 0) {
ESP_LOGV(TAG, "nvs_get_blob('%s') failed: %s", to_save.key.c_str(), esp_err_to_name(err));
return true;
}
return to_save.data == stored_data.data;
}
};
void setup_preferences() {