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</o:shapelayout></xml><![endif]--></head><body lang=EN-NZ link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Writing and reading integers to and from disk is fast. Writing 1.5 mil integers takes under a ms on a test here.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Sample play …<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>Var<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> Writecount : integer;<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> ArrJBird : array of integer; <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream : TFilestream;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> dtstart, dtEnd : TDateTime;</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>begin<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> randomize;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> setLength(ArrJBird, 1500000);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> for i:=0 to 1500000-1 do ArrJBird[i] := random(1000);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> dtstart := Now;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream := TFileStream.Create('c:\temp\myFileOfInts.txt',fmCreate);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream.Seek(0,soFromBeginning);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> writeCount := sizeof(integer)*1500000;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream.Write(ArrJBird[0], writeCount);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> showmessage('101st int='+inttostr(arrJBird[101])); <o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream.Destroy;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> Application.ProcessMessages;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> for i:=0 to 1500000-1 do ArrJBird[i] :=-1;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream := TFileStream.Create('c:\temp\myFileOfInts.txt',fmOpenRead);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream.Seek(0,soFromBeginning);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> fStream.read(ArrJBird[0],writeCount);<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> showmessage('101st int='+inttostr(ArrJBird[101]));<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> dtEnd := now;<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'> showmessage('write to and read from time: '+FloatToStr(dtEnd - dtStart));<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:#17375E;mso-style-textfill-fill-color:#17375E;mso-style-textfill-fill-alpha:100.0%'>// cleanup;<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> delphi-bounces@listserver.123.net.nz [mailto:delphi-bounces@listserver.123.net.nz] <b>On Behalf Of </b>John Bird<br><b>Sent:</b> Monday, 7 July 2014 8:35 p.m.<br><b>To:</b> NZ Borland Developers Group - Delphi List<br><b>Subject:</b> [DUG] Saving aray<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:black'>I have a program that builds a very large array (over 1,500,000) of integers, and the calculation to fill the array takes quite a while – around 40-50 secs. If there is a quick way to do it, I would save the array to disk if it was faster than recalculating it the next time.</span><span style='font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:black'>I am guessing that writing the elements to strings and using CSV etc would be quite slow, as it involves quite a lot of processing. I will run a test to see.</span><span style='font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif";color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:black'>Is there any really fast way to save such an array to disk? The numbers range between 0 and 256 if that helps.</span><span style='font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p></div></div></div></div></body></html>