Function fetch_item

pub async fn fetch_item<'d, K: Key, V: Value<'d>, S: NorFlash>(
    flash: &mut S,
    flash_range: Range<u32>,
    cache: &mut impl KeyCacheImpl<K>,
    data_buffer: &'d mut [u8],
    search_key: &K,
) -> Result<Option<V>, Error<S::Error>>

Get the last stored value from the flash that is associated with the given key. If no value with the key is found, None is returned.

The data buffer must be long enough to hold the longest serialized data of your Key + Value types combined, rounded up to flash word alignment.

You are required to, on a given flash range, use the same Key type every time. You are allowed to use multiple Value types. See the module-level docs for more information about this.

Also watch out for using integers. This function will take any integer and it’s easy to pass the wrong type.