Olaf's thoughts about Delphi, IntraWeb and other dev stuff - Latest Comments in Delphi 2009: TStringBuilder (Recap and Benchmark)

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Eczema Treatments — Wed, 15 Dec 2010 12:30:26 -0000

hi Worked great for me with Delphi 2007 on Windows 7 to fix this annoying problem.

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Eric — Thu, 16 Oct 2008 11:37:54 -0000

You're actually hitting a corner case of TStringBuilder here, in practice it'll be slower, but of speed comparable to String. And you don't need to benchmarks, artificial or not to know that: you just need to look at the implementation.
TStringBuilder is implemented around a dynamic array, meaning that it's performance is going to be in the same ballpark as Strings, as the VCL internals for growth and data copy are the same. Differences are going to come from the overhead of the respective function calls.

Incidentally this means String will win (all the time) against TStringBuilder whenever you concat more than one string at once (s:=s+s1+s2+...), because the RTL has a function for that (which will realloc only once), whereas TStringBuilder doesn't.

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Olaf Monien — Wed, 15 Oct 2008 03:33:14 -0000

{$StringChecks OFF} seems to have very little Influence for me. I've added the full DPR file in the post above

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Binis — Wed, 15 Oct 2008 03:26:05 -0000

I did test this with kind of similar code but with stringchecks set to off and appending bigger strings At it turns out that StringBuilder is slower than normal operations...

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Lars D — Wed, 15 Oct 2008 02:47:37 -0000

Strictly speaking, with the stringbuilder, you also need to get the final result inside your benchmark, in order to achieve the same results as the second benchmark.

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Olaf Monien — Tue, 14 Oct 2008 10:29:53 -0000

That replace advantage is indeed interesting.

Re: Delphi 2009: TStringBuilder (Recap and Benchmark)

Bruce McGee — Tue, 14 Oct 2008 09:55:41 -0000

I'm kind of a broken record on this, but I'm happy for the addition for better code compatibility between Delphi in Win32 and .Net. Particularly for library code that is intended to be used everywhere. Even though I'm still stinging a little about losing VCL.Net.

Another example; TStringBuilder.Replace is about 3 times faster than StringReplace.