Support for Binary MD5 hash - code included

[mikechambers]

Support for Binary MD5 hash - code included

[darronschall]

Updated by mikechambers on 2008-07-02T16:46:25

Added label HasAPatch
Original ticket set status to Accepted (we converted to open)

[darronschall]

Updated by mikechambers on 2008-07-02T22:30:53

Change createBlocks to use array reference instead of s.getCharCodeAt()

Can you explain this change?

Also, have you done any performance test on hashing strings between the existing
implementation, and yours?

Original ticket set status to NeedMoreInfo (we converted to open)

[darronschall]

Updated by marklynch on 2008-07-04T14:37:26

Hi Mike,

Change createBlocks to use array reference instead of s.getCharCodeAt()
As the createBlocks now takes a byteArray instead of a string, I'm using direct array
notation to get the values instead of using the original s.getCharCodeAt();

Was:
blocks[ i >> 5 ] |= ( s.charCodeAt( i / 8 ) & mask ) << ( i % 32 );
Now this:
blocks[ i >> 5 ] |= ( s[ i / 8 ] & mask ) << ( i % 32 );

Re benchmarking - I hadn't done any, but I have now.

Initially it was slower than the original version by approx 13%.

I optimised it a bit and now it runs ever so slightly faster than the original one
(about 4% faster)

This is the optimisation change, removed this code (in function hash):
for(var i:int = 0; i

[darronschall]

Updated by marklynch on 2008-07-04T14:43:59

Mike,
In case you wish to reproduced the benchmarks, here is the code I used is below.

I set up two projects with the corelibs placed in the src folder and ran this with
modified and original versions.

Timings I got were on 3 runs were:
Original: 3865,3722,3809, AVG 3799
Patched 1: 4413,4314,4140 AVG 4289
Patched 2: 3625,3561,3797 AVG 3661

Code snippet:
package {
import com.adobe.crypto.MD5;
import flash.display.Sprite;
import flash.utils.getTimer;

public class md5benchOrig extends Sprite
{
    public function md5benchOrig()
    {
        var string:String = "asda asd  da da da dasd a dasd asdasdadadad a dasda asd  da

da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dasda
asd da da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad
a dasda asd da da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd
asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dasda asd da da da
dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dasda asd
da da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a
dasda asd da da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd
asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dasda asd da da da
dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dasda asd
da da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a
dasda asd da da da dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd
asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dasda asd da da da
dasd a dasd asdasdadadad a dasda asd da da da dasd a dasd asdasdadadad a dv";
var hashed:String = "";
var startTime:uint = getTimer();
for(var i:int; i < 1000; i++){
hashed = MD5.hash(string);
}
var elapsedTime:uint = getTimer() - startTime;
trace(hashed);
trace('Time taken: ' + elapsedTime);
}
}
}

[darronschall]

Updated by mikechambers on 2008-07-06T20:30:23

I have checked in the changes (revision 49).

Could someone post a simple test case / cases for hashBinary? ill add them to the
test suite.

[darronschall]

Updated by mikechambers on 2008-07-06T20:30:38

Removed label Type-Defect
Added label Type-Enhancement

[darronschall]

Updated by mikechambers on 2008-11-07T19:28:07

Original ticket set status to Fixed (we converted to closed)