internal BufferedFileStreamStrategy(FileStreamStrategy strategy, int bufferSize)
{
Debug.Assert(bufferSize > 1, "Buffering must not be enabled for smaller buffer sizes");
_strategy = strategy;
_bufferSize = bufferSize;
}
internal static FileStreamStrategy ChooseStrategy(FileStream fileStream, string path, FileMode mode, FileAccess access, FileShare share, int bufferSize, FileOptions options, long preallocationSize)
{
FileStreamStrategy strategy =
EnableBufferingIfNeeded(ChooseStrategyCore(path, mode, access, share, options, preallocationSize), bufferSize);
return(WrapIfDerivedType(fileStream, strategy));
}
internal static FileStreamStrategy ChooseStrategy(FileStream fileStream, SafeFileHandle handle, FileAccess access, int bufferSize, bool isAsync)
{
FileStreamStrategy strategy =
EnableBufferingIfNeeded(ChooseStrategyCore(handle, access, isAsync), bufferSize);
return(WrapIfDerivedType(fileStream, strategy));
}
internal static FileStreamStrategy ChooseStrategy(FileStream fileStream, SafeFileHandle handle, FileAccess access, int bufferSize, bool isAsync)
{
// The .NET 5 Compat strategy does not support bufferSize == 0.
// To minimize the risk of introducing bugs to it, we just pass 1 to disable the buffering.
FileStreamStrategy strategy = UseNet5CompatStrategy ?
new Net5CompatFileStreamStrategy(handle, access, bufferSize == 0 ? 1 : bufferSize, isAsync) :
EnableBufferingIfNeeded(ChooseStrategyCore(handle, access, isAsync), bufferSize);
return(WrapIfDerivedType(fileStream, strategy));
}
internal DerivedFileStreamStrategy(FileStream fileStream, FileStreamStrategy strategy)
{
_fileStream = fileStream;
_strategy = strategy;
}
private static FileStreamStrategy WrapIfDerivedType(FileStream fileStream, FileStreamStrategy strategy)
=> fileStream.GetType() == typeof(FileStream)
? strategy
: new DerivedFileStreamStrategy(fileStream, strategy);
private static FileStreamStrategy EnableBufferingIfNeeded(FileStreamStrategy strategy, int bufferSize) => bufferSize > 1 ? new BufferedFileStreamStrategy(strategy, bufferSize) : strategy;