[wx-dev] [ wxwindows-Patches-1946506 ] wxString::Replace() very slow

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Patches item #1946506, was opened at 2008-04-19 03:35
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Category: None
Group: None
>Status: Closed
Resolution: None
Priority: 5
Private: No
Submitted By: Johannes Kulick (hildensia)
Assigned to: Nobody/Anonymous (nobody)
Summary: wxString::Replace() very slow

Initial Comment:
When you do a global replace on very large Strings with a lot of replacements (>10000 and so on) wxString::Replace() gets really slow. (> 20 s)

The problem is, that the string is copied every time a replacement is done, because of the use of wxStringImpl::replace().

I've rewritten wxString::Replace() to copy the string only once. It results in a ca. five times faster Replace().

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>Comment By: SourceForge Robot (sf-robot)
Date: 2008-05-03 19:20

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This Tracker item was closed automatically by the system. It was
previously set to a Pending status, and the original submitter
did not respond within 14 days (the time period specified by
the administrator of this Tracker).

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Comment By: Vaclav Slavik (vaclavslavik)
Date: 2008-04-19 04:18

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Couple of comments:

* Your patch doesn't apply on latest SVN sources (and it obviously isn't
for 2.8 branch). Also, please follow wx coding guidelines -- in particular,
don't use TABs.

* I think it's more likely the problem is caused by bad Replace()
implementation in UTF-8 build. I fixed that, if the problem persists
(because you don't use UTF-8 build), please update the patch to work with
latest SVN trunk (it would help to attach then benchmark you use, too).

* The patch's replacing loop unnecessarily calls operator+= for every
character in unmodified part, when it could simply do on append() to copy
the unmodified block.

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