public static CompressedPortion Compress(StreamPortion portion)
{
using (var uncompressedStream = new MemoryStream(portion.Data))
{
using (var compressedStream = new MemoryStream())
{
using (var zipStream = new GZipStream(compressedStream, CompressionMode.Compress))
{
uncompressedStream.CopyTo(zipStream);
}
return new CompressedPortion(portion.StartPostion, compressedStream.ToArray());
}
}
}
private static void PopulateFolderFileHierarchy(BinaryReaderEx br, FolderEntry parentFolder, BlockHierarchy hierarchy, LIFFFolderEntry folderEntry)
{
if (hierarchy.ChildCount != folderEntry.EntryCount)
{
throw new IOException("The file is not a valid LIF. Entry count mismatch.");
}
for (int i = 0; i < folderEntry.EntryCount; i++)
{
var expectedBlock = hierarchy.Childs[i];
short entryType = br.ReadInt16();
br.BaseStream.Skip(-2);
LifEntry entry;
if (entryType == 1)
{
var folderInfo = br.ReadStruct <LIFFFolderEntry>();
entry = new FolderEntry(folderInfo.Filename);
PopulateFolderFileHierarchy(br, (FolderEntry)entry, expectedBlock, folderInfo);
}
else if (entryType == 2)
{
var fileInfo = br.ReadStruct <LIFFFileEntry>();
var dataStream = new StreamPortion(br.BaseStream, expectedBlock.PositionInStream + LIFFBLOCK_SIZE, fileInfo.FileSize - LIFFBLOCK_SIZE);
entry = new FileEntry(dataStream, fileInfo.Filename);
((FileEntry)entry).SetFileAttributes(
DateTime.FromFileTime(fileInfo.Created),
DateTime.FromFileTime(fileInfo.Modified),
DateTime.FromFileTime(fileInfo.Accessed));
}
else
{
throw new IOException("The file is not a valid LIF.");
}
parentFolder.Entries.Add(entry);
}
}
private static bool TryRead(Stream stream, int length, out StreamPortion chunk)
{
chunk = null;
var streamPosition = stream.Position;
using (var memStream = new MemoryStream())
{
if (stream.CopyAmountTo(memStream, length) == 0)
return false;
chunk = new StreamPortion(streamPosition, memStream.ToArray());
return true;
}
}
