/// <summary>
/// 将数据写入器转换为具有键的类型的具体数据写入器。
/// </summary>
/// <param name="dataRW">数据写入器</param>
/// <typeparam name="T">键的类型</typeparam>
/// <returns>返回具体数据写入器</returns>
public static IDataRW <T> As <T>(this IDataRW dataRW)
{
if (dataRW is IDataRW <T> tRW)
{
return(tRW);
}
if (dataRW is IAsDataRW asRW)
{
return(As <T>(asRW.Original));
}
if (dataRW is IDataRW <string> strRW)
{
return(new AsDataRW <string, T>(strRW));
}
if (dataRW is IDataRW <int> intRW)
{
return(new AsDataRW <int, T>(intRW));
}
if (AsHelper.GetInstance(dataRW) is AsHelper asHelper)
{
return(asHelper.As <T>(dataRW));
}
throw new NotSupportedException("Unsupported object.");
}
/// <summary>
/// 获取数据读写器中指定键的值的类型。
/// </summary>
/// <typeparam name="TKey">键类型</typeparam>
/// <param name="dataRW">数据读写器</param>
/// <param name="key">指定键</param>
/// <returns>返回一个类型</returns>
public static Type GetItemType <TKey>(IDataRW <TKey> dataRW, TKey key)
{
var auxiliary = new AuxiliaryValueRW();
dataRW.OnReadValue(key, auxiliary);
return(auxiliary.GetValueType());
}
/// <summary>
/// 获取数据读写器中指定键的值的类型。
/// </summary>
/// <typeparam name="TKey">键类型</typeparam>
/// <param name="dataRW">数据读写器</param>
/// <param name="key">指定键</param>
/// <returns>返回一个类型</returns>
public static Type GetItemType <TKey>(IDataRW <TKey> dataRW, TKey key)
{
var auxiliary = new AuxiliaryValueRW();
if (typeof(TKey) == typeof(long) && ((dataRW as IAsDataReader)?.Content ?? dataRW) is IId64DataRW id64DataRW)
{
id64DataRW.OnReadValue(Unsafe.As <TKey, long>(ref key), auxiliary);
}
else
{
dataRW.OnReadValue(key, auxiliary);
}
return(auxiliary.GetType());
}
/// <summary>
/// 将数据写入器转换为具有键的类型的具体数据写入器。
/// </summary>
/// <param name="dataRW">数据写入器</param>
/// <typeparam name="T">键的类型</typeparam>
/// <returns>返回具体数据写入器</returns>
public static IDataRW <T> As <T>(this IDataRW dataRW)
{
if (dataRW is IDataRW <T> t)
{
return(t);
}
if (dataRW is IAsDataRW a)
{
return(As <T>(a.Content));
}
if (dataRW is IDataRW <string> s)
{
return(new AsDataRW <string, T>(s));
}
if (dataRW is IDataRW <int> i)
{
return(new AsDataRW <int, T>(i));
}
return(AsHelper.GetInstance(dataRW).As <T>(dataRW));
}
public override IDataRW <TOut> As <TOut>(IDataRW dataRW)
{
return(new AsDataRW <T, TOut>((IDataRW <T>)dataRW));
}
public abstract IDataRW <TOut> As <TOut>(IDataRW dataRW);
public static AsHelper GetInstance(IDataRW dataRW)
{
return(RWCache.GetOrCreate(dataRW));
}
/// <summary>
/// 创建数据读写器键类型转换类的实例。
/// </summary>
/// <param name="dataRW">原始数据读写器</param>
public AsDataRW(IDataRW <TIn> dataRW)
{
this.dataRW = dataRW;
}
public static AsHelper GetInstance(IDataRW dataRW) => GetOrCreateGroup(dataRW).RW;
