neo-go/pkg/network/compress.go

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package network
import (
"encoding/binary"
"errors"
"github.com/nspcc-dev/neo-go/pkg/network/payload"
"github.com/pierrec/lz4"
)
// compress compresses bytes using lz4.
func compress(source []byte) ([]byte, error) {
dest := make([]byte, 4+lz4.CompressBlockBound(len(source)))
size, err := lz4.CompressBlock(source, dest[4:], nil)
if err != nil {
return nil, err
}
binary.LittleEndian.PutUint32(dest[:4], uint32(len(source)))
return dest[:size+4], nil
}
// decompress decompresses bytes using lz4.
func decompress(source []byte) ([]byte, error) {
length := binary.LittleEndian.Uint32(source[:4])
if length > payload.MaxSize {
return nil, errors.New("invalid uncompressed payload length")
}
dest := make([]byte, length)
size, err := lz4.UncompressBlock(source[4:], dest)
if err != nil {
return nil, err
}
if uint32(size) != length {
return nil, errors.New("decompressed payload size doesn't match header")
}
return dest, nil
}