Files
natsnet/dotnet/src/ZB.MOM.NatsNet.Server/JetStream/StoreEnumExtensions.cs

90 lines
3.1 KiB
C#

using System.Text.Json;
using IronSnappy;
namespace ZB.MOM.NatsNet.Server;
/// <summary>
/// String/JSON helpers for store enums that mirror Go enum methods.
/// </summary>
public static class StoreEnumExtensions
{
public static string String(this StoreCipher cipher)
=> cipher switch
{
StoreCipher.ChaCha => "ChaCha20-Poly1305",
StoreCipher.Aes => "AES-GCM",
StoreCipher.NoCipher => "None",
_ => "Unknown StoreCipher",
};
public static string String(this StoreCompression alg)
=> alg switch
{
StoreCompression.NoCompression => "None",
StoreCompression.S2Compression => "S2",
_ => "Unknown StoreCompression",
};
public static byte[] MarshalJSON(this StoreCompression alg)
=> alg switch
{
StoreCompression.NoCompression => JsonSerializer.SerializeToUtf8Bytes("none"),
StoreCompression.S2Compression => JsonSerializer.SerializeToUtf8Bytes("s2"),
_ => throw new InvalidOperationException("unknown compression algorithm"),
};
public static void UnmarshalJSON(this ref StoreCompression alg, ReadOnlySpan<byte> b)
{
var parsed = JsonSerializer.Deserialize<string>(b);
if (parsed == null)
throw new InvalidDataException("compression value must be a JSON string");
alg = parsed switch
{
"none" => StoreCompression.NoCompression,
"s2" => StoreCompression.S2Compression,
_ => throw new InvalidOperationException("unknown compression algorithm"),
};
}
public static void UnmarshalJSON(this ref StoreCompression alg, byte[] b)
{
ArgumentNullException.ThrowIfNull(b);
UnmarshalJSON(ref alg, b.AsSpan());
}
public static (byte[]? Buffer, Exception? Error) Compress(this StoreCompression alg, byte[] buf)
{
ArgumentNullException.ThrowIfNull(buf);
const int checksumSize = FileStoreDefaults.RecordHashSize;
if (buf.Length < checksumSize)
return (null, new InvalidDataException("uncompressed buffer is too short"));
return alg switch
{
StoreCompression.NoCompression => (buf, null),
StoreCompression.S2Compression => CompressS2(buf, checksumSize),
_ => (null, new InvalidOperationException("compression algorithm not known")),
};
}
private static (byte[]? Buffer, Exception? Error) CompressS2(byte[] buf, int checksumSize)
{
try
{
var bodyLength = buf.Length - checksumSize;
var compressedBody = Snappy.Encode(buf.AsSpan(0, bodyLength));
var output = new byte[compressedBody.Length + checksumSize];
Buffer.BlockCopy(compressedBody, 0, output, 0, compressedBody.Length);
Buffer.BlockCopy(buf, bodyLength, output, compressedBody.Length, checksumSize);
return (output, null);
}
catch (Exception ex)
{
return (null, new IOException("error writing to compression writer", ex));
}
}
}