Investigate on Netty ByteBuf/ByteBufUtil for an improved StringCodec.

[mp911de]

Netty ByteBuf and ByteBufUtil provide optimized methods to write character sequences. Investigate whether these methods can be used to provide an optimized StringCodec.

[mp911de]

Benchmark with the existing Utf8StringCodec and new StringCodec:

Benchmark                                        Mode  Cnt    Score    Error  Units
StringCodecBenchmark.decodeUtf8Unpooled          avgt    5    4,739 ±  0,405  ns/op
StringCodecBenchmark.encodeAsciiToBuf            avgt    5   17,975 ±  2,629  ns/op
StringCodecBenchmark.encodeIsoToBuf              avgt    5   34,887 ±  1,982  ns/op
StringCodecBenchmark.encodeUtf8PlainStringToBuf  avgt    5   21,818 ±  3,228  ns/op
StringCodecBenchmark.encodeUtf8ToBuf             avgt    5   69,766 ±  9,383  ns/op
StringCodecBenchmark.encodeUtf8Unpooled          avgt    5  132,238 ± 15,540  ns/op
Utf8StringCodecBenchmark.decodeUnpooled          avgt    5   25,945 ±  1,217  ns/op
Utf8StringCodecBenchmark.encodeUnpooled          avgt    5  210,475 ±  8,542  ns/op

[mp911de]

Done.