public Lmdb.ChunkDto Compress(byte[] symmetricKey)
{
var fileName = _stream.Name + ".lz4";
_stream.Seek(0, SeekOrigin.Begin);
using (var chunkFile = File.Create(fileName)) {
var flags = LZ4StreamFlags.HighCompression | LZ4StreamFlags.IsolateInnerStream;
using (var aes = new AesCryptoServiceProvider()) {
aes.Key = symmetricKey;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
aes.GenerateIV();
var iv = aes.IV;
chunkFile.Write(iv, 0, iv.Length);
using (var enc = aes.CreateEncryptor())
using (var crypto = new CryptoStream(chunkFile, enc, CryptoStreamMode.Write))
using (var lz4 = new LZ4Stream(crypto, LZ4StreamMode.Compress, flags, 1048576 * 4)) {
Streams.Copy(_stream, lz4, (int)_pos);
}
}
}
var size = new FileInfo(fileName).Length;
return(Lmdb.NewChunkDto()
.SetChunkFileName(fileName)
.SetUncompressedByteSize(_pos)
.SetChunkRecords(_records)
.SetCompressedDiskSize((int)size)
.SetChunkStartPos(_startPos));
}
public long GetCheckpoint(string name, long dv = default(long))
{
using (var tx = _env.Read()) {
return(Lmdb.GetStreamPosition(tx, name, dv));
}
}