Am 09.04.2015 um 15:20 schrieb Martin Nowak:
On 04/09/2015 10:59 AM, Sönke Ludwig wrote:
As far as the profiler results can be trusted, a good chunk of the time
gets spent for reading individual bytes from memory, but there must be
something else low-level going on that make things this bad. However,
there is nothing fundamental in the structure/design that would cause
this, so I think spending more time with the profiler is the only
logical step now. Unfortunately my VTune license has expired and perf on
Linux makes the task quite a bit more involved.
I didn't found too many issues.
Most of the time is spent in parseJSONValue (looks like there are some
expansive struct copies)
https://github.com/s-ludwig/std_data_json/blob/1da3f828ae6c4fd7cac7f7e13ae9e51ec93e6f02/source/stdx/data/json/parser.d#L148
I'll have a look at the DOM part later. At the moment I'm looking at low
level issues of the lexer. There is a lot of potential there, but it's a
lot of detail work.
and skipWhitespace. This function could really take some optimization,
e.g. avoid UTF decoding.
All of the lexing work happens on str.representation instead of the
string directly, so no decoding should happen there.
https://github.com/s-ludwig/std_data_json/blob/1da3f828ae6c4fd7cac7f7e13ae9e51ec93e6f02/source/stdx/data/json/lexer.d#L345
Libdparse has some optimized ASM function, might be useful.
https://github.com/Hackerpilot/libdparse/blob/51b7d9d321aac0fcc4a9be99bbbed5db3158326c/src/std/d/lexer.d#L2233
