Duncan Coutts wrote:
Sorry, I think we've been talking at cross purposes.
I think so.
There always has to be *some* conversion from a 32-bit Char to the system's selection, right?
Yes. In text mode there is always some conversion going on. Internally there is a byte buffer and a char buffer (ie UTF32).
What exactly do we have to do to avoid the penalty?
The penalty we're talking about here is not the cost of converting bytes to characters, it's in switching which encoding the Handle is using. For example you might read some HTTP headers in ASCII and then switch the Handle encoding to UTF8 to read some XML.
Simon referenced a 30% penalty. Are you saying that if we read from a Handle using the same encoding that we used when we first opened it, that we won't see any slowdown vs. the system in 6.10?
Switching the Handle encoding has a penalty. We have to discard the characters that we pre-decoded and re-decode the byte buffer in the new encoding. It's actually slightly more complicated because we do not
Got it. That makes sense, as does the decision to optimize for the more common (not switching the encoding) case. -- John