Utilities

High Performance Logging

Tip

The Logger class in FileEmulationFramework.Lib provides an abstraction over Reloaded's ILogger that allows you to conditionally make log messages without the need for memory allocation.

_log = new Logger(_logger, _configuration.LogLevel);

Methods such as _log.Info will only create the string and log it if that specific log level is enabled; provided you use the various overloads that accept generics e.g. Info<T1>(string format, T1 item1).

Avoid the overloads with single message parameter unless you require custom formatting; in which case you should add manual guards via if (_log.IsEnabled(level)).

File Slices

Info

The FileSlice class can be used to provide an abstraction that allows you to read a region of a given file.

When building Stream based emulators, you will often provide a mixture of the original data and new data. This class will allow you to more easily fetch the original data when needed.

Merging File Slices

Info

Slices of the same file that touch each other (e.g. 0-4095 + 4096-65536) can be merged into singular, larger slices.

This is sometimes possible when working with archives containing file data whereby multiple files are laid out side by side.

Tip

Merging can help improve performance of resolving Read requests (i.e. IEmulator.ReadData). Specifically the performance of StreamMixer

Try using the FileSlice.TryMerge API.

If you are using streams backed by FileSlice (that use IFileSliceStream), you can merge them using FileSliceStreamExtensions.TryMerge for individual streams or FileSliceStreamExtensions.MergeStreams for collections.

File Slice Stream

Info

The FileSliceStream classes provide an abstraction that wrap FileSlice(s).
Currently two implementations exist, FileSliceStreamFs and FileSliceStreamW32.

Tip

FileSliceStreamFs is backed by FileStream. Use this class if application makes many reads with small amount of data (e.g. <= 256 byte reads.)

Tip

FileSliceStreamW32 is backed by Windows API. Use this class if reads above 4096 bytes are expected.

Should be simple enough.

OffsetRange

A utility class that stores a start and end offset [inclusive]. Can be used for testing for overlaps, testing of address is in range, etc.

Multi Stream

Info

MultiStream combines multiple streams into a single stream with read and seek support. Highly optimised.

Tip

It is possible to build entire files using this stream and just resolve read requests IEmulator.ReadData by seeking and reading from this stream. This is a recommended approach.

Padding Stream

Info

Stream that fills the read buffer with a single, user specified byte.

This can be used in conjunction with MultiStream to provide padding for emulated files.

Mathematics

Info

This class has some common mathematics related operations, such as rounding up numbers to add padding to files.

Fast Directory Searcher

Tip

The WindowsDirectorySearcher class can be used for extremely fast searching of files on the filesystem.

This implementation is around 3.5x faster than the built in .NET one at the time of writing; using the innermost NtQueryDirectoryFile API for fetching files.

It's forked from the implementation in Reloaded.Mod.Loader.IO; with Multithreading removed since it wouldn't be helpful with our too small data/file sets.