esp32-alarm-clock/main/storage.c

/*
 * SPDX-FileCopyrightText: 2022 Helmut Pozimski <helmut@pozimski.eu>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 */
#include <time.h>
#include <stdio.h>
#include <esp_err.h>
#include <nvs_flash.h>
#include <esp_log.h>

#define TAG "storage"

static nvs_handle_t handle;

static void format_date(struct tm* datetime, char* output) {
    char year[12], month[12], day[12];
    snprintf(year, 12, "%4d", datetime->tm_year + 1900);
    snprintf(month, 12, "%02d", datetime->tm_mon +1);
    snprintf(day, 12, "%02d", datetime->tm_mday);
    snprintf(output, 9, "%.4s%.2s%.2s", year, month, day);
}

esp_err_t storage_init(char* name) {
   return nvs_open(name, NVS_READWRITE, &handle);
}

esp_err_t write_wakeup_time_str(char* key, int16_t value) {
	esp_err_t ret = nvs_set_i16(handle, key, value);
	return ret | nvs_commit(handle);
}

esp_err_t write_wakeup_time_tm(struct tm* datetime, int16_t value) {
	char key[9];
	format_date(datetime, key);
	return write_wakeup_time_str(key, value);
}

esp_err_t read_wakeup_time_str(char* key, int16_t* value) {
	return nvs_get_i16(handle, key, value);
}

esp_err_t read_wakeup_time_tm(struct tm* datetime, int16_t* value) {
	char key[9];
	format_date(datetime, key);
	return read_wakeup_time_str(key, value);
}

esp_err_t delete_wakeup_time_str(char* key) {
	esp_err_t ret = nvs_erase_key(handle, key);
	return ret | nvs_commit(handle);
}

void delete_outdated_entries(struct tm* datetime, char* namespace) {
	char reference_date_str[9];
	format_date(datetime, reference_date_str);
	int reference_date = atoi(reference_date_str);
	if (reference_date == 0) {
		ESP_LOGE(TAG, "Error while determining reference date");
		return;
	}
	nvs_iterator_t it = NULL;
 	esp_err_t res = nvs_entry_find("nvs", namespace, NVS_TYPE_ANY, &it);
 	while(res == ESP_OK) {
  		nvs_entry_info_t info;
     	nvs_entry_info(it, &info);
     	int entry_date = atoi(info.key);
     	if (entry_date == 0) {
			ESP_LOGI(TAG, "Could not convert key %s to int, skipping entry during cleanup", info.key);     	
     	} else if (entry_date < reference_date) {
     		ESP_LOGI(TAG, "Erasing outdated entry %s", info.key);
     		nvs_erase_key(handle, info.key);
     	}
     	res = nvs_entry_next(&it);
 }
 nvs_commit(handle);
 nvs_release_iterator(it);
}