/// <summary>
/// Gets a value that has previously been stored in this context, loading data on-demand to avoid overhead for
/// every task that may not have any data (i.e. do not pre-load as most would be empty operations).
/// </summary>
/// <param name="key">The key of the item to be loaded.</param>
/// <typeparam name="T">The type of the value that has been stored.</typeparam>
/// <returns>The stored value, or <c>default(T)</c> if it does not exist.</returns>
public async Task <T> GetAsync <T>(string key)
{
if (!this._loaded)
{
var loadedData = await this._provider.LoadDataAsync(this._contextKey)
?? new BackgroundTaskContextData(this._contextKey);
// If data has been modified before loading we need to merge those
// changes in to the existing data
if (this._modified)
{
foreach (var modifiedKvp in this._data.Data)
{
loadedData.Data[modifiedKvp.Key] = modifiedKvp.Value;
}
}
this._data = loadedData;
this._loaded = true;
}
if (this._data.Data.TryGetValue(key, out var value))
{
return((T)value);
}
return(default);
/// <inheritdoc />
/// <exception cref="NotImplementedException">Always thrown.</exception>
public Task SaveDataAsync(BackgroundTaskContextData data)
{
throw new NotImplementedException("InMemoryBackgroundTaskContextProvider is read-only");
}
