Hi Corey,
Right, the continue was so it would go back and check if the conversion was
complete. An alternative would be to repeat the check and return if
there was
no bytes left to process.
Thanks, Roger
On 9/9/20 3:13 PM, Corey Ashford wrote:
On 9/4/20 8:07 AM, Roger Riggs wrote:
Hi Corey,
The idea I had in mind is refactoring the fast path into the method
you call decodeBlock.
Base64: lines 751-768.
It leaves all the unknown/illegal character handling to the Java code.
And yes, it does not need to handle MIME, except to return on illegal
characters.
The patch is attached.
Ah, I see what you mean now, and thanks for the patch! The patch as
presented doesn't work, however, because the intrinsic processes fewer
bytes than are in the src buffer, and then executes a "continue;",
which then proceeds to loop infinitely because the intrinsic won't
process any more bytes after that.
I tried dropping the continue, but that doesn't work because the Java
(non-intrinsic) code processes all of the bytes, and the line of code
following the loop accesses one byte after the end of the src buffer
causing an array bounds error.
So this needs to be re-thought a little, but it shouldn't be too
difficult. I will work on it.
Regards,
- Corey
Regards, Roger
On 8/31/20 6:22 PM, Corey Ashford wrote:
On 8/29/20 1:19 PM, Corey Ashford wrote:
Hi Roger,
Thanks for your reply and thoughts! Comments interspersed below:
On 8/28/20 10:54 AM, Roger Riggs wrote:
...
Comparing with the way that the Base64 encoder was intrinsified, the
method that is intrinsified should have a method body that does
the same function, so it is interchangable. That likely will just
shift
the "fast path" code into the decodeBlock method.
Keeping the symmetry between encoder and decoder will
make it easier to maintain the code.
Good point. I'll investigate what this looks like in terms of the
actual code, and will report back (perhaps in a new webrev).
Having looked at this again, I don't think it makes sense. One thing
that differs significantly from the encodeBlock intrinsic is that
the decodeBlock intrinsic only needs to process a prefix of the
data, and so it can leave virtually any amount of data at the end of
the src buffer unprocessed, where as with the encodeBlock intrinsic,
if it exists, it must process the entire buffer.
In the (common) case where the decodeBlock intrinsic returns not
having processed everything, it still needs to call the Java code,
and if that Java code is "replaced" by the intrinsic, it's
inaccessible.
Is there something I'm overlooking here? Basically I want the
decode API to behave differently than the encode API, mostly to make
the arch-specific intrinsic easier to implement. If that's not
acceptable, then I need to rethink the API, and also figure out how
to deal with the illegal character case. The latter could perhaps be
done by throwing an exception from the intrinsic, or maybe by
returning a negative length that specifies the index of the illegal
src byte, and then have the Java code throw the exception).
Regards,
- Corey
