/// <summary>
/// Performs a Step based Seek on the loaded Btrieve File
/// </summary>
/// <param name="operationCode"></param>
/// <returns></returns>
public ushort Seek(EnumBtrieveOperationCodes operationCode)
{
return(operationCode switch
{
EnumBtrieveOperationCodes.GetFirst => StepFirst(),
EnumBtrieveOperationCodes.GetNext => StepNext(),
EnumBtrieveOperationCodes.GetPrevious => StepPrevious(),
_ => throw new Exception($"Unsupported Btrieve Operation: {operationCode}")
});
public static bool AcquiresData(this EnumBtrieveOperationCodes code)
{
var memberInstance = code.GetType().GetMember(code.ToString());
if (memberInstance.Length <= 0)
{
return(false);
}
return(System.Attribute.GetCustomAttribute(memberInstance[0], typeof(AcquiresData)) != null);
}
/// <summary>
/// Performs a Key Based Query on the loaded Btrieve File
/// </summary>
/// <param name="keyNumber">Which key to query against</param>
/// <param name="key">The key data to query against</param>
/// <param name="btrieveOperationCode">Which query to perform</param>
/// <param name="newQuery">true to start a new query, false to continue a prior one</param>
public bool PerformOperation(int keyNumber, ReadOnlySpan <byte> key, EnumBtrieveOperationCodes btrieveOperationCode)
{
switch (btrieveOperationCode)
{
case EnumBtrieveOperationCodes.StepFirst:
return(StepFirst());
case EnumBtrieveOperationCodes.StepLast:
return(StepLast());
case EnumBtrieveOperationCodes.StepNext:
case EnumBtrieveOperationCodes.StepNextExtended:
return(StepNext());
case EnumBtrieveOperationCodes.StepPrevious:
case EnumBtrieveOperationCodes.StepPreviousExtended:
return(StepPrevious());
}
var newQuery = !btrieveOperationCode.UsesPreviousQuery();
BtrieveQuery currentQuery;
if (newQuery || PreviousQuery == null)
{
currentQuery = new BtrieveQuery
{
Key = Keys[(ushort)keyNumber],
KeyData = key == null ? null : new byte[key.Length],
};
if (key != null)
{
Array.Copy(key.ToArray(), 0, currentQuery.KeyData, 0, key.Length);
}
// Wipe any previous query we have and store this new query
PreviousQuery?.Dispose();
PreviousQuery = currentQuery;
}
else if (PreviousQuery == null)
{
return(false);
}
else
{
currentQuery = PreviousQuery;
}
return(btrieveOperationCode switch
{
EnumBtrieveOperationCodes.AcquireEqual => GetByKeyEqual(currentQuery),
EnumBtrieveOperationCodes.QueryEqual => GetByKeyEqual(currentQuery),
EnumBtrieveOperationCodes.AcquireFirst => GetByKeyFirst(currentQuery),
EnumBtrieveOperationCodes.QueryFirst => GetByKeyFirst(currentQuery),
EnumBtrieveOperationCodes.AcquireLast => GetByKeyLast(currentQuery),
EnumBtrieveOperationCodes.QueryLast => GetByKeyLast(currentQuery),
EnumBtrieveOperationCodes.AcquireGreater => GetByKeyGreater(currentQuery, ">"),
EnumBtrieveOperationCodes.QueryGreater => GetByKeyGreater(currentQuery, ">"),
EnumBtrieveOperationCodes.AcquireGreaterOrEqual => GetByKeyGreater(currentQuery, ">="),
EnumBtrieveOperationCodes.QueryGreaterOrEqual => GetByKeyGreater(currentQuery, ">="),
EnumBtrieveOperationCodes.AcquireLess => GetByKeyLess(currentQuery, "<"),
EnumBtrieveOperationCodes.QueryLess => GetByKeyLess(currentQuery, "<"),
EnumBtrieveOperationCodes.AcquireLessOrEqual => GetByKeyLess(currentQuery, "<="),
EnumBtrieveOperationCodes.QueryLessOrEqual => GetByKeyLess(currentQuery, "<="),
EnumBtrieveOperationCodes.AcquireNext => GetByKeyNext(currentQuery),
EnumBtrieveOperationCodes.QueryNext => GetByKeyNext(currentQuery),
EnumBtrieveOperationCodes.AcquirePrevious => GetByKeyPrevious(currentQuery),
EnumBtrieveOperationCodes.QueryPrevious => GetByKeyPrevious(currentQuery),
_ => throw new Exception($"Unsupported Operation Code: {btrieveOperationCode}")
});
