[Jsynthlib-devel] checksum handling

[Hiroo H. <hir...@co...>]

Hi,

I'd like to propose another core change of checksum handling.

One of my questions when I made my synth driver was when I had to call
calculateChecksum method.  Some of core methods calculate checksum.  And
a synth driver also calculate checksum.  It seems that calculateChecksum
is called many times unnecessarily.  I guess this situation occurred
because it was not clear who has to calculate checksum and some method
calculated it for safe.

Now we define the boundary between core and synthdrivers by defining
interfaces (IDriver, etc.).  Now a patch goes to outside of synthdriver
via the following methods.
        case 1. void IPatchDriver.send(IPatch, int, int)
        case 2. void ISingleDriver.send(IPatch)
        case 3. byte[] IPatch.getByteArray()
        case 4. void Driver.send(byte[])

Here is my proposal
Proposal a) call calculateChecksum(Patch) in Driver.send(IPatch, int,
int) and Driver.send(IPatch).

This cover the case 1 and 2.  This does not require any synthdriver
change.

Proposal b) Define IPatch.export(IPatch) which returns a byte array as
getByteArray() after it calculate checksum.  This does not require any
synthdriver change, either.

This cover the case 3.  case 3 is for exporting Patch.

For case 4, before Driver.send(byte[]) is called, calculateChecksum() is
always called already.

By the simple proposal a) and b),  both core and synth drivers do not
have to call calculateChecksum() method any more.  We can get rid of 
IPatchDriver.calculateCheckSum(IPatch) interface method instead of
adding IPatchDriver.export().

Driver class taking care of all of its subclass.  A Synth driver
extending Driver class does not have to call calculateChecksum method. 
And core does not have to call calculateChecksum method, either.

This sounds good, doesn't it?

I made fix locally.  If there is no objection, I'll check it in a few
days later.

Any feedback is welcome.
-- 
Hiroo Hayashi