Interoperability issue with other l4z libraries

[raffi-semerciyan]

I'm using two github versions of lz4: yours for java and github.com/bkaradzic/go-lz4 for Golang.

I used Golang version in the code below:

package main

import (
	lz4 "github.com/bkaradzic/go-lz4"
	"fmt"
	"os"
	"encoding/base64"
)

func main() {
	var data []byte
	var err error

	to_compress:="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

	if data,err=lz4.Encode(nil,[]byte(to_compress)); err!=nil {
		fmt.Fprintf(os.Stderr,"Failed to compress: '%s'",err)
		return
	}

	fmt.Fprintf(os.Stderr,"Success! Length=%d\n",len(to_compress))

	fmt.Fprintf(os.Stdout,"%s\n",base64.StdEncoding.EncodeToString(data))
}

and obtain following output:

raffi@iot-micro-raffi ~/tmp > go run ./test_lz4.go 
Success! Length=100
ZAAAAB94AQBLUHh4eHh4
raffi@iot-micro-raffi ~/tmp > 

Then I inject this output into a Java version below using your library to decode the result:

import java.util.Base64;
import net.jpountz.lz4.LZ4Factory;
import net.jpountz.lz4.LZ4FastDecompressor;

public class test_lz4_decomp {

    public static void main(String[] args) {
        String compressed_base64= "ZAAAAB94AQBLUHh4eHh4";
        int original_size = 100;
        byte [] compressed = Base64.getDecoder().decode(compressed_base64);

        LZ4Factory _factory= LZ4Factory.fastestInstance();
        LZ4FastDecompressor decompressor = _factory.fastDecompressor();
        byte []restored = new byte[original_size];
        decompressor.decompress(compressed, 0, restored, 0,original_size);

        String decompressed_str=new String(restored);

        System.out.println(decompressed_str); 
    }

}

but obtain the following output:

raffi@iot-micro-raffi ~/tmp > java -cp ".:lz4-1.3.0.jar" test_lz4_decompException in thread "main" net.jpountz.lz4.LZ4Exception: Error decoding offset 58 of input buffer
	at net.jpountz.lz4.LZ4JNIFastDecompressor.decompress(LZ4JNIFastDecompressor.java:39)
	at test_lz4_decomp.main(test_lz4_decomp.java:16)
raffi@iot-micro-raffi ~/tmp > 

The expected result would be that the Java version should be able to decompress the output of the Golang version.

[raffi-semerciyan]

I used another Golang library (https://github.com/pwaller/go-clz4) and succeeded to make it work with your library.

So I believe the issue was in the golang library.

Thanks for your nice work!