Decompressing with zlib

[aalekizoglou]

I am writing a PHP tunnel to connect to MySQL, as well as a B4A class to create a dataset that will connect to the tunnel and manage (Query, Insert, Delete, Update) the DB. Will post the script and the class once I am near a working copy.

In the PHP script there is a PrintResult function to echo back the data. I am trying to implement a compress function to keep data transmitted to device at a minimum rate. Here it is:

    public function PrintResult($compress = 0) {
        $res = array();        
        $res["tunnelversion"]   = tunnelversion;
        $res["query"]           = $this->Query;
        $res["errornumber"]     = $this->ErrorNumber;
        $res["errordescr"]      = $this->ErrorDescr;
        $res["serverversion"]   = $this->ServerInfo;
        $res["affectedrows"]    = $this->AffecteRows;
        $res["lastinsert_id"]   = $this->InsertID;
        $res["fieldcount"]      = $this->FieldCount;
        $res["fieldsdescr"]     = $this->FieldsDescription;
        $res["rows"]            = $this->Rows;
        utf8_encode_array($res);
        $res = json_encode($res, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE);
        if ($compress)
        {
            $res = gzencode($res, -1, FORCE_DEFLATE);  
            $res = base64_encode($res);
        }
        echo $res;
    }

I am using gzencode to encode data, and then base64_encode to ensure characters are transmitable over the net. Lines:
$res = gzencode($res, -1, FORCE_DEFLATE);
$res = base64_encode($res);

In B4A I am using HTTPUtils2 where in JobDone I have the following:

                strResult = Job.GetString   
      If MySQLConnection.Compress = 1 Then
         Dim cs As CompressedStreams   
         Dim compressed(), decompressed() As Byte
         Dim B64 As Base64
                  
         Log(strResult.Length)
         compressed = B64.DecodeStoB(strResult)   
         Log(compressed.Length)
                  
         decompressed = cs.DecompressBytes(compressed, "zlib")
         strResult = BytesToString(decompressed, 0, decompressed.Length, "UTF8")
      End If

I keep getting an java.IO.IOException in
decompressed = cs.DecompressBytes(compressed, "zlib")

clsdbmysqlutils_jobdone (B4A line: 121)
decompressed = cs.DecompressBytes(compressed, "gzip")
java.io.IOException
   at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:176)
   at java.util.zip.GZIPInputStream.read(GZIPInputStream.java:167)
   at java.io.InputStream.read(InputStream.java:163)
   at anywheresoftware.b4a.objects.streams.File.Copy2(File.java:336)
   at anywheresoftware.b4a.randomaccessfile.CompressedStreams.DecompressBytes(CompressedStreams.java:135)
   at anywheresoftware.b4a.samples.mysql.clsdbmysqlutils._jobdone(clsdbmysqlutils.java:674)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:511)
   at anywheresoftware.b4a.BA.raiseEvent2(BA.java:167)
   at anywheresoftware.b4a.keywords.Common$4.run(Common.java:885)
   at android.os.Handler.handleCallback(Handler.java:605)
   at android.os.Handler.dispatchMessage(Handler.java:92)
   at android.os.Looper.loop(Looper.java:137)
   at android.app.ActivityThread.main(ActivityThread.java:4424)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:511)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
   at dalvik.system.NativeStart.main(Native Method)
Caused by: java.util.zip.DataFormatException: data error
   at java.util.zip.Inflater.inflateImpl(Native Method)
   at java.util.zip.Inflater.inflate(Inflater.java:228)
   at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:157)
   ... 18 more
java.io.IOException

I don't know what to check to find my error.

 

[Erel]

Please do not post duplicate questions. See my answer in the other thread.

 

[aalekizoglou]

Please do not post duplicate questions. See my answer in the other thread.

Erel,

sorry for that. I keep up on thread

http://www.b4x.com/forum/basic4android-updates-questions/21676-gzip-issues.html