public void PutFile(CacheIndex index, int fileId, CacheFile file)
{
// Throw an exception if the output directory is not yet set or does not exist.
if (string.IsNullOrWhiteSpace(this.BaseDirectory))
{
throw new InvalidOperationException("Base directory must be set before writing files.");
}
if (file.Data.Length == 0)
{
throw new ArgumentException("You cannot put an empty file into a FlatFileCache.");
}
var indexDirectory = this.GetIndexDirectory(index);
// Create index directory when it does not exist yet.
Directory.CreateDirectory(indexDirectory);
// Clean existing files (to make sure no variants with different extensions exist).
foreach (var existingFilePath in this.GetExistingFilePaths(index, fileId))
{
if (!this.OverwriteFiles)
{
Log.Debug($"{(int)index}/{fileId} already exists.");
return;
}
Log.Debug($"Deleting existing {existingFilePath}.");
System.IO.File.Delete(existingFilePath);
}
string?extension;
if (file.Info.HasEntries)
{
// TODO: Add an option to extract entries individually (which generates tons of files but is more useful).
extension = "entries";
}
else
{
extension = ExtensionGuesser.GuessExtension(file.Data);
}
extension = extension != null ? $".{extension}" : "";
var filePath = $"{indexDirectory}{fileId}{extension}";
System.IO.File.WriteAllBytes(filePath, file.Data);
}
public static string GuessExtension(byte[] fileData)
{
// ogg (OggS)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x4f, 0x67, 0x67, 0x53 }))
{
return("ogg");
}
// jaga (JAGA)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x4a, 0x41, 0x47, 0x41 }))
{
return("jaga");
}
// png (0x89504e470d0a1a0a)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a }))
{
return("png");
}
// gif (GIF87a and GIF89a)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x47, 0x49, 0x46, 0x38, 0x37, 0x61 }) || ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x47, 0x49, 0x46, 0x38, 0x39, 0x61 }))
{
return("gif");
}
// bmp (BM)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x42, 0x4d }))
{
return("bmp");
}
// midi (MThd)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x4d, 0x54, 0x68, 0x64 }))
{
return("mid");
}
// gzip (0x1f8b)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x1f, 0x8b }))
{
return("gz");
}
// bzip2 (BZh)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x42, 0x5a, 0x68 }))
{
return("bz2");
}
// tiff (0x49492a00 and 0x4d4d002a)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x49, 0x49, 0x2a, 0x00 }) || ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x4d, 0x4d, 0x00, 0x2a }))
{
return("tiff");
}
// mp3 (0xfffb and ID3).
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0xff, 0xfb }) || ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x49, 0x44, 0x33 }))
{
return("mp3");
}
// jpeg (0xffd8ff). Actually multiple numbers, but they all start with the same bytes anyway.
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0xff, 0xd8, 0xff }))
{
return("jpg");
}
// zip (0x504b). Same thing here.
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x50, 0x4b }))
{
return("zip");
}
// wav (RIFF). Same thing here.
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x52, 0x49, 0x46, 0x46 }))
{
return("wav");
}
// tar (ustar). Same thing here.
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x75, 0x73, 0x74, 0x61, 0x72 }))
{
return("tar");
}
// 7zip (0x377abcaf271c)
if (ExtensionGuesser.DataHasMagicNumber(fileData, new byte[] { 0x37, 0x7a, 0xbc, 0xaf, 0x27, 0x1c }))
{
return("7z");
}
return(null);
}
