Alexander Klenin пишет:
Ok, I went ahead and have taken look at the code.
I assume you speak about TFPHashList vs TFPCustomHashTable.
The classes are not really comparable, because they use quite
different internal data structures.
So instead I converted TFPHashList list to use ansistrings.
Benchmarking included 3*10^6 calls to Add and Find methods
with the arguments of various lengths.
Average string length 5 characters:
ShortString: 1.15 s
AnsiString: 1.56 s
Average string length 45 characters:
ShortString: 12.0 s
AnsiString: 3.2 s
I agree that the first case is more relevant for the compiler,
but still you can see that ShortStrings are clearly not always faster.
I believe it's not ShortStrings per se to blame, but storing them in a large single memory block as
it is being done in TFPHashList. Adding a lot of keys will cause many reallocations. Large size of
the block forces memory manager to use variable-size pool, which is less efficient than using
fixed-size blocks in case of small chunks.
Regards,
Sergei
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