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.NET C# OnDemand cache - fetching data on demand

Arti answered on November 25, 2022 Popularity 1/10 Helpfulness 1/10

answer .NET C# OnDemand cache - fetching data on demand

.NET C# OnDemand cache - fetching data on demand

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public class OnDemandFetchCache<TKey, TValue> : IOnDemandCache<TKey, TValue>
{
    private readonly Func<Dictionary<TKey, TValue>> _fetchFunc;
    private Dictionary<TKey, TValue> _data = new Dictionary<TKey, TValue>();
    private DateTime _lastFetch;
    private TimeSpan _fetchDuration;
    public CacheStatus Status { get; private set; }

    public OnDemandFetchCache(Func<Dictionary<TKey, TValue>> fetchFunc)
    {
        Status = CacheStatus.Empty;
        _fetchFunc = fetchFunc;

        LoadData();
    }

    #region IReadOnlyDictionary

    public IEnumerable<TKey> Keys => _data.Keys;
    public IEnumerable<TValue> Values => _data.Values;
    public int Count => _data.Count;
    public TValue this[TKey key] => _data[key];

    public bool ContainsKey(TKey key)
    {
        return _data.ContainsKey(key);
    }

    public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
    {
        return _data.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return _data.GetEnumerator();
    }

    public bool TryGetValue(TKey key, out TValue value)
    {
        return _data.TryGetValue(key, out value);
    }

    public Task FetchDataAsync()
    {
        if (Status.HasFlag(CacheStatus.Loading))
            return Task.CompletedTask;

        return Task.Run(LoadData);
    }

    public void FetchData()
    {
        if (Status.HasFlag(CacheStatus.Loading))
            return;

        LoadData();
    }

    public void FlushData()
    {
        Status = CacheStatus.Empty;

        _data = new Dictionary<TKey, TValue>();
    }

    public DateTime GetLastFetchDate() => _lastFetch;

    public TimeSpan GetFetchDuration() => _fetchDuration;

    #endregion

    #region Helpers

    private void LoadData()
    {
        Status = Status | CacheStatus.Loading;

        var start = DateTime.Now;
        _data = _fetchFunc();
        _lastFetch = DateTime.Now;
        _fetchDuration = _lastFetch - start;

        Status = CacheStatus.Loaded;
    }

    #endregion
}

Popularity 1/10 Helpfulness 1/10 Language csharp

Source: Grepper

Tags: .net c# ondemand

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Contributed on Nov 25 2022

Arti

0 Answers Avg Quality 2/10

.NET C# OnDemand cache - fetching data on demand

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