github.com/klauspost/compress for snappy

[jzelinskie]

Hey there!

I noticed that this library doesn't use the snappy library from klauspost/compress, but it does import this library for zstd.
A cursory look makes it appear to be faster. Is there a reason why you aren't using it? Is it worth a PR?

[mostynb]

Hi, I'm not as familiar with snappy compared to lz4 and zstd. I'd be happy to switch if you benchmarked and found @klauspost's implementation faster though.

[klauspost]

It can either be faster or compresses more and sometimes both.

https://github.com/klauspost/compress/tree/master/s2#snappy-compatibility

Replace snappylib "github.com/golang/snappy" -> github.com/klauspost/compress/s2. If you don't want options snappylib github.com/klauspost/compress/snappy.

	c.poolCompressor.New = func() interface{} {
		w := s2.NewWriter(ioutil.Discard, s2.WriterSnappyCompat())
		return &writer{Writer: w, pool: &c.poolCompressor}
	}

Options to consider: WriterBetterCompression gives better compression. WriterConcurrency(1) if you want to disable multithreaded compression.

	if !inPool {
		newR := s2.NewReader(r, s2.ReaderMaxBlockSize(64<<10))
		return &reader{Reader: newR, pool: &c.poolDecompressor}, nil
	}

[mostynb]

If we were to add s2, I think that should be registered with the grpc framework under the name "s2" instead of "snappy" for compatibility reasons.

[klauspost]

Yeah, adding it as a separate option would be nice (and trivial)

FWIW here is a comparison of different types: https://twitter.com/sh0dan/status/1532298056082804736

[mostynb]

@klauspost: re s2, if I use WriterConcurrency(1) can I safely put s2.Writer's in a sync.Pool without leaking memory?

[klauspost]

@mostynb You can do that either way. It does not keep goroutines active.

[mostynb]

OK, it's just that the s2.NewWriter docs say that resources might not be released if Close isn't called (as would happen with sync.Pool):

Users must call Close to guarantee all data has been forwarded to the underlying io.Writer and that resources are released. They may also call Flush zero or more times before calling Close.

[mostynb]

@jzelinskie: I created a PR which you can experiment with if you like: #12.