AMFPHP issue referencing ByteArray

Recently I made some test in AMFPHP sending an retrieving ByteArray to be stored in a mysql blob field.

But suddenly I encounter a problem when I was trying to return an array of ByteArrays and I could not find out the reason flash continued to show me this error:

The php file which was generating this error was:

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class Service
{
public function getArray( )
{
$GLOBALS['amfphp']['encoding'] = 'amf3';
$a = new ByteArray("\x00\x10this is a string");
$b = new ByteArray("\x00\x16this is another string");
$c = $a;
return array( $a, $b, $c );
}
}

While the Actionscript test class was:

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package
{
    import flash.display.Sprite;
    import flash.net.NetConnection;
    import flash.net.ObjectEncoding;
    import flash.net.Responder;
    import flash.utils.ByteArray;

    public class test extends Sprite
    {
        private var nc: NetConnection;
        private var rsp: Responder;

        public function test()
        {
            rsp = new Responder( onResult, null );
            nc = new NetConnection();
            nc.objectEncoding = ObjectEncoding.AMF3;
            nc.connect( "http://localhost/amfphp/trunk/gateway.php" );
            nc.call( "test.bytearray.Service.getArray", rsp );
        }

        private function onResult( e: * ): void
        {
            if ( e is Array )
            {
                for each ( var b: ByteArray in( e as Array ) )
                {
                    trace( 'reading bytearray...' );
                    b.position = 0;
                    trace( b.readUTF() );
                }
            }
        }
    }
}

After some investigation I found that the error was into the AMFSerializer.php file in the writeAmf3ByteArray method which doesn’t reference correctly the bytearray objects.

Thus I made a little modification and after that I succeeded to retrieve correctly the bytearray list ( with the 3rd element as reference of the first one ).

Here you can download the patch file, if you want to test the modification ( at your own risk 🙂 ). The patch has been created using the last svn version of amfphp and you can apply the patch with the following command:

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patch -p0 -i bytearray.patch

Expressions evaluation at (almost) native speed

Finally I found a bit of time this weekend to do some other tests with expressions evaluation.

The results are pretty interesting, even if obvious from some point of view. I took the ExpressionEvaluator I wrote as example for the first post about this topic, and then I edited a bit the code adding just in time AS Bytecode compilation.
Thanks to that, expressions evaluation is much more fast and always safe because it runs in its own ApplicationDomain.

You can download the sources here, that includes the edited code and a test file. The test file runs 1 milion of iterations and may hang your browser or at worst case your system. Reduce the value of the ITERATIONS constant if you are not sure about the power of you machine.

If you want to read a bit more details about that, click on the link below to continue reading.

Continue reading