kbf/src/nvs.cpp

#include "kbf/nvs.h"

#include <esp_log.h>
#include <nvs_flash.h>

#include "kbf/macros.h"

using namespace kbf;
using std::string;

static constexpr const char *TAG = "nvs";

static std::atomic<bool> initialized = {false};

void nvs::init() {
    ESP_LOGD(TAG, "init()");

    if (initialized) {
        ESP_LOGW(TAG, "NVS already initialized");
        return;
    }

    esp_err_t err = nvs_flash_init();
    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        erase();
        err = nvs_flash_init();
    }
    CHECK(err);

    initialized = true;
}

void nvs::erase() {
    ESP_LOGW(TAG, "erasing flash");
    CHECK(nvs_flash_erase());
    initialized = false;
}

nvs::NVS::NVS(const string &name) : name(name) {
    ESP_LOGD(TAG, "NVS(\"%s\")", name.c_str());

    if (!initialized) {
        init();
    }

    CHECK(nvs_open(name.c_str(), NVS_READWRITE, &handle));
}

nvs::NVS::~NVS() {
    ESP_LOGD(TAG, "~NVS(\"%s\")", name.c_str());
    nvs_close(handle);
}

static bool checkReadError(const string &key, const string &value, esp_err_t err) {
    switch (err) {
        case ESP_OK:
            ESP_LOGD(TAG, "read %s from %s", value.c_str(), key.c_str());
            return true;
        case ESP_ERR_NVS_NOT_FOUND:
            ESP_LOGW(TAG, "key not found: %s", key.c_str());
            return false;
        default:
            CHECK(err);     // this will always fail
            return false;   // but the compiler cries anyway
    }
}

template<>
bool nvs::NVS::read<int8_t>(const string &key, int8_t &value) {
    esp_err_t err = nvs_get_i8(handle, key.c_str(), &value);
    return checkReadError(key, std::to_string(value), err);
}

template<>
bool nvs::NVS::read<uint8_t>(const string &key, uint8_t &value) {
    esp_err_t err = nvs_get_u8(handle, key.c_str(), &value);
    return checkReadError(key, std::to_string(value), err);
}

template<>
bool nvs::NVS::read<int16_t>(const string &key, int16_t &value) {
    esp_err_t err = nvs_get_i16(handle, key.c_str(), &value);
    return checkReadError(key, std::to_string(value), err);
}

template<>
bool nvs::NVS::read<uint16_t>(const string &key, uint16_t &value) {
    esp_err_t err = nvs_get_u16(handle, key.c_str(), &value);
    return checkReadError(key, std::to_string(value), err);
}

template<>
bool nvs::NVS::read<int32_t>(const string &key, int32_t &value) {
    esp_err_t err = nvs_get_i32(handle, key.c_str(), &value);
    return checkReadError(key, std::to_string(value), err);
}

template<>
bool nvs::NVS::read<uint32_t>(const string &key, uint32_t &value) {
    esp_err_t err = nvs_get_u32(handle, key.c_str(), &value);
    return checkReadError(key, std::to_string(value), err);
}

template<>
bool nvs::NVS::read<string>(const string &key, string &value) {
    size_t size = 0;
    esp_err_t err = nvs_get_blob(handle, key.c_str(), nullptr, &size);
    if (!checkReadError(key, value, err)) return false;
    if (size == 0) return false;

    char data[size];
    err = nvs_get_blob(handle, key.c_str(), data, &size);
    if (!checkReadError(key, value, err)) return false;
    value = string(data, size - 1);
    return true;
}

template<>
void nvs::NVS::write<int8_t>(const string &key, int8_t &value) {
    ESP_LOGD(TAG, "writing %d to %s", value, key.c_str());
    CHECK(nvs_set_i8(handle, key.c_str(), value));
    CHECK(nvs_commit(handle));
}

template<>
void nvs::NVS::write<uint8_t>(const string &key, uint8_t &value) {
    ESP_LOGD(TAG, "writing %d to %s", value, key.c_str());
    CHECK(nvs_set_u8(handle, key.c_str(), value));
    CHECK(nvs_commit(handle));
}

template<>
void nvs::NVS::write<int16_t>(const string &key, int16_t &value) {
    ESP_LOGD(TAG, "writing %d to %s", value, key.c_str());
    CHECK(nvs_set_i16(handle, key.c_str(), value));
    CHECK(nvs_commit(handle));
}

template<>
void nvs::NVS::write<uint16_t>(const string &key, uint16_t &value) {
    ESP_LOGD(TAG, "writing %d to %s", value, key.c_str());
    CHECK(nvs_set_u16(handle, key.c_str(), value));
    CHECK(nvs_commit(handle));
}

template<>
void nvs::NVS::write<int32_t>(const string &key, int32_t &value) {
    ESP_LOGD(TAG, "writing %d to %s", value, key.c_str());
    CHECK(nvs_set_i32(handle, key.c_str(), value));
    CHECK(nvs_commit(handle));
}

template<>
void nvs::NVS::write<uint32_t>(const string &key, uint32_t &value) {
    ESP_LOGD(TAG, "writing %u to %s", value, key.c_str());
    CHECK(nvs_set_u32(handle, key.c_str(), value));
    CHECK(nvs_commit(handle));
}

template<>
void nvs::NVS::write<string>(const string &key, string &value) {
    ESP_LOGD(TAG, "writing %s to %s", value.c_str(), key.c_str());
    CHECK(nvs_set_blob(handle, key.c_str(), value.data(), value.size() + 1));
    CHECK(nvs_commit(handle));
}