zstd.go

package bstates

import (
	"bytes"
	"io"

	"github.com/klauspost/compress/zstd"

	"github.com/nayarsystems/buffer/buffer"
)

// ZstdEnc compresses the provided buffer using Zstandard (Zstd) compression
// and returns a new buffer containing the compressed data.
func ZstdEnc(b *buffer.Buffer) (*buffer.Buffer, error) {
	buf := new(bytes.Buffer)
	wr, err := zstd.NewWriter(buf, zstd.WithEncoderConcurrency(1))
	if err != nil {
		return nil, err
	}
	_, err = wr.Write(b.GetRawBuffer()[:b.GetByteSize()])
	wr.Close()
	if err != nil {
		return nil, err
	}
	var out []byte
	out, err = io.ReadAll(buf)
	if err != nil {
		return nil, err
	}
	outb := &buffer.Buffer{}
	outb.InitFromRawBuffer(out)
	return outb, nil
}

// ZstdDec decompresses the provided buffer which is expected to be in
// Zstandard (Zstd) format and returns a new buffer containing the
// decompressed data.
func ZstdDec(b *buffer.Buffer) (*buffer.Buffer, error) {
	r := bytes.NewReader(b.GetRawBuffer()[:b.GetByteSize()])
	var gzr *zstd.Decoder
	gzr, err := zstd.NewReader(r, zstd.WithDecoderConcurrency(1))
	if err != nil {
		return nil, err
	}
	var out []byte
	out, err = io.ReadAll(gzr)
	gzr.Close()
	if err != nil {
		return nil, err
	}
	outb := &buffer.Buffer{}
	outb.InitFromRawBuffer(out)
	return outb, nil
}