using FASTER.core;

// 定义数据结构
public struct MyKey : IEquatable<MyKey>
{
    public int Id;
    public bool Equals(MyKey other) => Id == other.Id;
    public override int GetHashCode() => Id.GetHashCode();
}

public struct MyValue
{
    public byte[] Data;
    public DateTime Timestamp;
}

public struct MyInput
{
    public byte[] NewData;
}

public struct MyOutput
{
    public MyValue Value;
    public bool Updated;
}

public struct MyContext
{
    public string OperationId;
    public DateTime StartTime;
}

// 实现自定义 Functions
public class MyCustomFunctions : FunctionsBase<MyKey, MyValue, MyInput, MyOutput, MyContext>
{
    // 读取完成回调
    public override void ReadCompletionCallback(ref MyKey key, ref MyInput input, ref MyOutput output, MyContext ctx, Status status, RecordMetadata recordMetadata)
    {
        base.ReadCompletionCallback(ref key, ref input, ref output, ctx, status, recordMetadata);
    }


    //// 写入完成回调
    //public override void UpsertCompletionCallback(
    //    ref MyKey key, ref MyValue value, MyContext ctx)
    //{
    //    Console.WriteLine($"Upsert completed for key {key.Id}");
    //}

    //// 删除完成回调
    //public override void DeleteCompletionCallback(
    //    ref MyKey key, MyContext ctx)
    //{
    //    Console.WriteLine($"Delete completed for key {key.Id}");
    //}

    //// RMW (Read-Modify-Write) 操作 - 核心功能！
    //public override void RMWCompletionCallback(
    //    ref MyKey key, ref MyInput input, ref MyOutput output,
    //    MyContext ctx, Status status)
    //{
    //    if (status == Status.OK)
    //    {
    //        Console.WriteLine($"RMW completed for key {key.Id}");
    //    }
    //}

    //// 并发控制：当多个线程同时修改相同键时调用
    //public override bool ConcurrentWriter(
    //    ref MyKey key, ref MyValue value, ref MyValue newValue)
    //{
    //    // 返回 true 表示接受新值，false 表示拒绝
    //    return newValue.Timestamp > value.Timestamp;
    //}

    //// 读取时复制：允许在读取时修改返回值
    //public override bool SingleReader(
    //    ref MyKey key, ref MyInput input, ref MyValue value, ref MyOutput dst)
    //{
    //    dst.Value = value;
    //    dst.Updated = false;
    //    return true;
    //}

    //// 写入时处理：自定义写入逻辑
    //public override bool ConcurrentWriter(
    //    ref MyKey key, ref MyValue value, ref MyValue newValue)
    //{
    //    // 只有新数据的时间戳更晚时才更新
    //    if (newValue.Timestamp > value.Timestamp)
    //    {
    //        value = newValue;
    //        return true;
    //    }
    //    return false;
    //}
}