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<DIV><FONT face=Arial size=2>Thanks for the replies. I decided there was
not enough data to warrant the additonal complexity. I'll just do the
usual a + b.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Cheers,</FONT></DIV>
<DIV><FONT face=Arial size=2>Ross.</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=matt@ferndigital.com href="mailto:matt@ferndigital.com">Matt Comb</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=delphi@ns3.123.co.nz
href="mailto:delphi@ns3.123.co.nz">NZ Borland Developers Group - Delphi
List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, September 05, 2004 3:56
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [DUG] Fast String
concatenation</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Ill blast myself before someone else blasts me
;)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>You would expect strings to be faster than
memorystreams, I've tested with tmemorystream with using setsize to preset the
size of the stream, and it comes out at twice as quick as a normal string
concatination.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If you have some idea of how large the string you
will be dealing might be, you can choose an appropriate block size to enlarge
the memorystream by.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>If you take out the setsize, then obviously the
stream routines are slower.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>So probably you can achieve fast string
equivalents of this as well with setlength which will be even faster. Although
you will then have to do some string copying (probably useing memcpy to be as
fast as possible) to get string bits in their right places and you can no
longer just go a + b.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Matt.</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=matt@ferndigital.com href="mailto:matt@ferndigital.com">Matt
Comb</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=delphi@ns3.123.co.nz
href="mailto:delphi@ns3.123.co.nz">NZ Borland Developers Group - Delphi
List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, September 05, 2004 3:21
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [DUG] Fast String
concatenation</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Hey Ross, how big are you talking here?, the
string management routines are pretty optimized?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>You could consider instead using a
tmemorystream and writing it to that when you need to ?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What sort of sizes are you dealing with in
total ?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Matt.</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=ross@stationplaylist.com
href="mailto:ross@stationplaylist.com">Ross Levis</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=delphi@ns3.123.co.nz
href="mailto:delphi@ns3.123.co.nz">NZ Borland Developers Group - Delphi
List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, September 04, 2004
9:48 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [DUG] Fast String
concatenation</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Hi all</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I need a fast/efficient way of building
a string from data within a loop. The string is getting longer
and longer and therefore reallocating the whole string in memory every
loop. Each loop it gets a few words added, perhaps an
average of 30 bytes.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I thought of doing a SetLength on the string
every 256 bytes or so, but I'm not sure of the best method
of moving the data into the correct position in the
string.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Any suggestions?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Cheers,</FONT></DIV>
<DIV><FONT face=Arial size=2>Ross.</FONT></DIV>
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