esp-idf-rs storage example

main.rs

use std::sync::Arc;

use embedded_svc::storage::{RawStorage, StorageBase};
use esp_idf_svc::{nvs::EspDefaultNvs, nvs_storage::EspNvsStorage};
use esp_idf_sys as _; // If using the `binstart` feature of `esp-idf-sys`, always keep this module imported

use log::*;

fn main() {
    // Temporary. Will disappear once ESP-IDF 4.4 is released, but for now it is necessary to call this function once,
    // or else some patches to the runtime implemented by esp-idf-sys might not link properly.
    esp_idf_sys::link_patches();

    // Bind the log crate to the ESP Logging facilities
    esp_idf_svc::log::EspLogger::initialize_default();

    #[allow(unused)]
    let default_nvs = Arc::new(EspDefaultNvs::new().expect("Unable to initialize NVS"));

    #[allow(unused)]
    let mut storage = EspNvsStorage::new_default(default_nvs, "test", true)
        .expect("Unable to initialize storage");

    if !storage
        .contains("test_key")
        .expect("Unable to query storage")
    {
        info!("No key found about to create it");
        storage
            .put_raw("test_key", "Hello world".as_bytes())
            .expect("Unable to persist value");
        info!("key created");
    }
    info!("Key found, searching length");
    let l = storage
        .len("test_key")
        .expect("Unable to get value length")
        .unwrap_or(0);
    if l == 0 {
        info!("Length == 0");
        storage
            .put_raw("test_key", "Hello world".as_bytes())
            .expect("Unable to persist value");
        info!("key created");
    }
    info!("Length > 0");
    let mut buf = vec![0; l];
    storage
        .get_raw("test_key", &mut buf)
        .expect("Unable to get raw value");
    info!("Key found, content: {buf:?}");
}