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how to speed up collections iteration_transColl is a collection of classes and it contains about 42000 objects My question is there any way I can make this code run faster? I have found out that line 2 is realy expensive (time wise) : '------------------------------------------------------------------ 1 For n As Int32 = 1 To Me._transColl.Count - 1 2 ti = CType(Me._transColl(n), TranslateImport) 3 If ti.Key.Equals(key) Then 4 ti.TranslatedValue = val 5 End If 6 Next ' ' the following code is useless by it's very fast, proving that the line 2 is the culprint ' I've moved the line 2 out out the loop ' ti = CType(Me._transColl(0), TranslateImport) For n As Int32 = 1 To Me._transColl.Count - 1 If ti.Key.Equals(key) Then ti.TranslatedValue = val End If Next Thanks for any input? You might try Directcast instead of ctype
regards Michel Show quoteHide quote "Peter" <pczurak@nospam.nospam> schreef in bericht news:%23Jt9J4TsGHA.148@TK2MSFTNGP05.phx.gbl... >I have the following code: > _transColl is a collection of classes and it contains about 42000 objects > My question is there any way I can make this code run faster? > > I have found out that line 2 is realy expensive (time wise) : > > '------------------------------------------------------------------ > > 1 For n As Int32 = 1 To Me._transColl.Count - 1 > 2 ti = CType(Me._transColl(n), TranslateImport) > 3 If ti.Key.Equals(key) Then > 4 ti.TranslatedValue = val > 5 End If > 6 Next > > ' > ' the following code is useless by it's very fast, proving that the line 2 > is the culprint > ' I've moved the line 2 out out the loop > ' > ti = CType(Me._transColl(0), TranslateImport) > > For n As Int32 = 1 To Me._transColl.Count - 1 > If ti.Key.Equals(key) Then > ti.TranslatedValue = val > End If > Next > > > Thanks for any input? > > I like to avoid indices every time it is possible (2005), code is
clearer imho: For Each TranslateImport As TranslateImport In Me._transColl with TranslateImport If .Key = key Then .TranslatedValue = Val() end with Next TranslateImport -tom Michel Posseth [MCP] ha scritto: Show quoteHide quote > You might try Directcast instead of ctype > > > regards > > > Michel > > > "Peter" <pczurak@nospam.nospam> schreef in bericht > news:%23Jt9J4TsGHA.148@TK2MSFTNGP05.phx.gbl... > >I have the following code: > > _transColl is a collection of classes and it contains about 42000 objects > > My question is there any way I can make this code run faster? > > > > I have found out that line 2 is realy expensive (time wise) : > > > > '------------------------------------------------------------------ > > > > 1 For n As Int32 = 1 To Me._transColl.Count - 1 > > 2 ti = CType(Me._transColl(n), TranslateImport) > > 3 If ti.Key.Equals(key) Then > > 4 ti.TranslatedValue = val > > 5 End If > > 6 Next > > > > ' > > ' the following code is useless by it's very fast, proving that the line 2 > > is the culprint > > ' I've moved the line 2 out out the loop > > ' > > ti = CType(Me._transColl(0), TranslateImport) > > > > For n As Int32 = 1 To Me._transColl.Count - 1 > > If ti.Key.Equals(key) Then > > ti.TranslatedValue = val > > End If > > Next > > > > > > Thanks for any input? > > > > <tommaso.gasta***@uniroma1.it> wrote in message
Show quoteHide quote news:1153985735.900504.25330@m79g2000cwm.googlegroups.com... I have tried the fillowing in .NET 2.0 and it works realy fast, but in .NET >I like to avoid indices every time it is possible (2005), code is > clearer imho: > > For Each TranslateImport As TranslateImport In Me._transColl > with TranslateImport > If .Key = key Then .TranslatedValue = Val() > end with > Next TranslateImport > > -tom > > Michel Posseth [MCP] ha scritto: > >> You might try Directcast instead of ctype >> >> >> regards >> >> >> Michel >> >> >> "Peter" <pczurak@nospam.nospam> schreef in bericht >> news:%23Jt9J4TsGHA.148@TK2MSFTNGP05.phx.gbl... >> >I have the following code: >> > _transColl is a collection of classes and it contains about 42000 >> > objects >> > My question is there any way I can make this code run faster? >> > >> > I have found out that line 2 is realy expensive (time wise) : >> > >> > '------------------------------------------------------------------ >> > >> > 1 For n As Int32 = 1 To Me._transColl.Count - 1 >> > 2 ti = CType(Me._transColl(n), TranslateImport) >> > 3 If ti.Key.Equals(key) Then >> > 4 ti.TranslatedValue = val >> > 5 End If >> > 6 Next >> > >> > ' >> > ' the following code is useless by it's very fast, proving that the >> > line 2 >> > is the culprint >> > ' I've moved the line 2 out out the loop >> > ' >> > ti = CType(Me._transColl(0), TranslateImport) >> > >> > For n As Int32 = 1 To Me._transColl.Count - 1 >> > If ti.Key.Equals(key) Then >> > ti.TranslatedValue = val >> > End If >> > Next >> > >> > >> > Thanks for any input? >> > >> > > 1.1 is slow the same as using for next loop. Is there anything I can do to speed this up in .NET 1.1 ? For Each TranslateImport As TranslateImport In Me._transColl with TranslateImport If .Key = key Then .TranslatedValue = Val() end with Next TranslateImport Peter,
First I would question having 42000 objects in a collection. | Is there anything I can do to speed this up in .NET 1.1 ? What type of "collection" are you using? Array, ArrayList, VB.Collection, or something else? | For Each TranslateImport As TranslateImport In Me._transColl Is the .key property unique in the collection? Have you considered a | with TranslateImport | If .Key = key Then .TranslatedValue = Val() | end with | Next TranslateImport HashTable (.NET 1.x) or Dictionary(Of T) (.NET 2.0) instead. Where .Key is the key to the HashTable/Dictionary. Alternatively: Can you sort the collection by .Key, then use a BinarySearch? ..NET 2.0 has made improvements in the performance of large DataSets, does using a DataSet instead of a class & a collection improve performance? -- Show quoteHide quoteHope this helps Jay B. Harlow [MVP - Outlook] ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "Peter" <pczurak@nospam.nospam> wrote in message news:OO8ZdvgsGHA.4872@TK2MSFTNGP02.phx.gbl... | | <tommaso.gasta***@uniroma1.it> wrote in message | news:1153985735.900504.25330@m79g2000cwm.googlegroups.com... | >I like to avoid indices every time it is possible (2005), code is | > clearer imho: | > | > For Each TranslateImport As TranslateImport In Me._transColl | > with TranslateImport | > If .Key = key Then .TranslatedValue = Val() | > end with | > Next TranslateImport | > | > -tom | > | > Michel Posseth [MCP] ha scritto: | > | >> You might try Directcast instead of ctype | >> | >> | >> regards | >> | >> | >> Michel | >> | >> | >> "Peter" <pczurak@nospam.nospam> schreef in bericht | >> news:%23Jt9J4TsGHA.148@TK2MSFTNGP05.phx.gbl... | >> >I have the following code: | >> > _transColl is a collection of classes and it contains about 42000 | >> > objects | >> > My question is there any way I can make this code run faster? | >> > | >> > I have found out that line 2 is realy expensive (time wise) : | >> > | >> > '------------------------------------------------------------------ | >> > | >> > 1 For n As Int32 = 1 To Me._transColl.Count - 1 | >> > 2 ti = CType(Me._transColl(n), TranslateImport) | >> > 3 If ti.Key.Equals(key) Then | >> > 4 ti.TranslatedValue = val | >> > 5 End If | >> > 6 Next | >> > | >> > ' | >> > ' the following code is useless by it's very fast, proving that the | >> > line 2 | >> > is the culprint | >> > ' I've moved the line 2 out out the loop | >> > ' | >> > ti = CType(Me._transColl(0), TranslateImport) | >> > | >> > For n As Int32 = 1 To Me._transColl.Count - 1 | >> > If ti.Key.Equals(key) Then | >> > ti.TranslatedValue = val | >> > End If | >> > Next | >> > | >> > | >> > Thanks for any input? | >> > | >> > | > | | I have tried the fillowing in .NET 2.0 and it works realy fast, but in ..NET | 1.1 is slow the same as using for next loop. | Is there anything I can do to speed this up in .NET 1.1 ? | | | For Each TranslateImport As TranslateImport In Me._transColl | with TranslateImport | If .Key = key Then .TranslatedValue = Val() | end with | Next TranslateImport | | try a typed collection (start from a generic (Of TranslateImport), to avoid
runtime cast... Show quoteHide quote "Peter" <pczurak@nospam.nospam> wrote in message news:%23Jt9J4TsGHA.148@TK2MSFTNGP05.phx.gbl... >I have the following code: > _transColl is a collection of classes and it contains about 42000 objects > My question is there any way I can make this code run faster? > > I have found out that line 2 is realy expensive (time wise) : > > '------------------------------------------------------------------ > > 1 For n As Int32 = 1 To Me._transColl.Count - 1 > 2 ti = CType(Me._transColl(n), TranslateImport) > 3 If ti.Key.Equals(key) Then > 4 ti.TranslatedValue = val > 5 End If > 6 Next > > ' > ' the following code is useless by it's very fast, proving that the line 2 > is the culprint > ' I've moved the line 2 out out the loop > ' > ti = CType(Me._transColl(0), TranslateImport) > > For n As Int32 = 1 To Me._transColl.Count - 1 > If ti.Key.Equals(key) Then > ti.TranslatedValue = val > End If > Next > > > Thanks for any input? > >
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"Trapulo" <trapulo@noemail.noemail> wrote in message Sorry I did not mention - I am running VS2003news:%2329esaWsGHA.4748@TK2MSFTNGP03.phx.gbl... > try a typed collection (start from a generic (Of TranslateImport), to > avoid runtime cast... > > > "Peter" <pczurak@nospam.nospam> wrote in message > news:%23Jt9J4TsGHA.148@TK2MSFTNGP05.phx.gbl... >>I have the following code: >> _transColl is a collection of classes and it contains about 42000 objects >> My question is there any way I can make this code run faster? >> >> I have found out that line 2 is realy expensive (time wise) : >> >> '------------------------------------------------------------------ >> >> 1 For n As Int32 = 1 To Me._transColl.Count - 1 >> 2 ti = CType(Me._transColl(n), TranslateImport) >> 3 If ti.Key.Equals(key) Then >> 4 ti.TranslatedValue = val >> 5 End If >> 6 Next >> >> ' >> ' the following code is useless by it's very fast, proving that the line >> 2 is the culprint >> ' I've moved the line 2 out out the loop >> ' >> ti = CType(Me._transColl(0), TranslateImport) >> >> For n As Int32 = 1 To Me._transColl.Count - 1 >> If ti.Key.Equals(key) Then >> ti.TranslatedValue = val >> End If >> Next >> >> >> Thanks for any input? >> >> > > >>> I have the following code: You can try DirectCast over CType, but be sure the values in your collection >>> _transColl is a collection of classes and it contains about 42000 >>> objects >>> My question is there any way I can make this code run faster? >>> I have found out that line 2 is realy expensive (time wise) : >>> >>> 1 For n As Int32 = 1 To Me._transColl.Count - 1 >>> 2 ti = CType(Me._transColl(n), TranslateImport) > Sorry I did not mention - I am running VS2003 are only the type you are trying to cast to. This is one of the key advantages of List(of T) over ArrayList(). I recommend Sahil Malik's comparison at http://codebetter.com/blogs/sahil.malik/archive/2005/01/02/40506.aspx. In general, I would question iterating over 42000 in your business layer rather than directly on the database as you are likely suffering a greater penalty with the memory footprint of that many objects, including the network bandwidth of fetching them, than you are with the casting. Jim Wooley http://devauthority.com/blogs/jwooley/default.aspx 
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