Re: [fpc-devel] Warning for sqldb and fpc 2.1.1 users
On Sat, 01 Apr 2006 18:33:10 -0300 Luiz Americo Pereira Camara <[EMAIL PROTECTED]> wrote: > >> And what about recno? Just define it as -1, or do a quick count to get > >> the current record number? > >> > Take a look at TCustomSqliteDataset implementation. In its > implementation a count is done each time. > > Store the recno with/in the linked list entry ? > > > > > It has two drawbacks: increase memory usage and when inserting, deleting > all following records must be updated. An array of records has the same problem, no ? So these are not drawbacks IMHO. Micha ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
Re: [fpc-devel] Warning for sqldb and fpc 2.1.1 users
On Saturday 01 April 2006 18.06, Joost van der Sluis wrote: > Further I have a question: now sqldb uses a linked-list record buffer, > the RecordCount and RecNo properties are something strange. > > What should I do with recordcount? I can add a counter which keep track > of the recordcount. Ie: it does inc(recordcount) if a record is > appended. > > Or I can do a real count of the records, each time recordcount is > called. > > And what about recno? Just define it as -1, or do a quick count to get > the current record number? > RecNo and RecordCount are frequently used in MSEgui, I found them very useful. Martin ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
Re: [fpc-devel] Warning for sqldb and fpc 2.1.1 users
Micha Nelissen escreveu: On Sat, 01 Apr 2006 18:06:31 +0200 Joost van der Sluis <[EMAIL PROTECTED]> wrote: Further I have a question: now sqldb uses a linked-list record buffer, the RecordCount and RecNo properties are something strange. What should I do with recordcount? I can add a counter which keep track of the recordcount. Ie: it does inc(recordcount) if a record is appended. Keep a counter. Or I can do a real count of the records, each time recordcount is called. No, too slow. And what about recno? Just define it as -1, or do a quick count to get the current record number? Take a look at TCustomSqliteDataset implementation. In its implementation a count is done each time. Store the recno with/in the linked list entry ? It has two drawbacks: increase memory usage and when inserting, deleting all following records must be updated. Luiz ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
Re: [fpc-devel] Warning for sqldb and fpc 2.1.1 users
On Sat, 2006-04-01 at 18:32 +0200, Michael Van Canneyt wrote: > > In revision 3111 TBufDataset is almost completely rewritten. I've tested > > as much as I could, but it could be that you encounter problems with > > sqldb which weren't there before. > > > > Please test if everything still works ok, and if not, tell me or submit > > a bug-report. > > > > Further I have a question: now sqldb uses a linked-list record buffer, > > Why ? This goes against the recordset idea ? Why is that against the recordset idea? > > the RecordCount and RecNo properties are something strange. > > > > What should I do with recordcount? I can add a counter which keep track > > of the recordcount. Ie: it does inc(recordcount) if a record is > > appended. > > > > Or I can do a real count of the records, each time recordcount is > > called. > > > > And what about recno? Just define it as -1, or do a quick count to get > > the current record number? > > > > What are your thoughts on this? > > The very idea of TBufDataset was that both recno and recordcount would > always be available. So using a linked list is not so good. > Why did you change that ? Mostly because of speed-issues, and this makes the code far more easier. With the array, if you're iterating through the data, you have to read the pointer to the buffer in the array, and subsequently the data in the buffer. With this new code, the record buffers contain pointers to their precessor en successor. That makes searching and browsing a lot faster. The TDataset only asks the 'next' and 'previous' records from the TBufDataset. Or it uses bookmarks. Well, bookmarks in a linked list are easy, they are just the pointers to the list-items. And using mostly 'next' and 'previous', the linked list is the best solution. For TDataset it's a different story. Joost. JoJo, Joost. ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
Re: [fpc-devel] Warning for sqldb and fpc 2.1.1 users
On Sat, 01 Apr 2006 18:06:31 +0200 Joost van der Sluis <[EMAIL PROTECTED]> wrote: > Further I have a question: now sqldb uses a linked-list record buffer, > the RecordCount and RecNo properties are something strange. > > What should I do with recordcount? I can add a counter which keep track > of the recordcount. Ie: it does inc(recordcount) if a record is > appended. Keep a counter. > Or I can do a real count of the records, each time recordcount is > called. No, too slow. > And what about recno? Just define it as -1, or do a quick count to get > the current record number? Store the recno with/in the linked list entry ? Micha ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
[fpc-devel] Compiler compilation failure
Good afternoon, I did a clean checkout of fpc 2.1 branch and tryed to cycle the compiler to generate a arm crosscompiler. The compilation fails. I am using 2.0.2 to compile 2.1.x I noticed that the file where the error is (ogcoff.pas) changed recently, so it is probably under modification or something like that, but I thought It might be good if I comment about this. My build command is: PATH=C:\Programas\fpc202\bin\i386-win32;C:\Programas\arm make cycle CPU_TARGET=arm OS_TARGET=wince Here are the error messages: C:/Programas/fpc202/bin/i386-win32/ppc386.exe -Fuarm -Fusystems -Fu../rtl/units/ i386-win32 -Fiarm -FE. -FUarm/units/i386-win32 -darm -dGDB -dBROWSERLOG -dNOOPT pp.pas ogcoff.pas(1451,14) Error: Illegal expression ogcoff.pas(1451,14) Error: Constant Expression expected ogcoff.pas(1451,14) Fatal: Syntax error, ":" expected but "BEGIN" found ogcoff.pas(161,20) Fatal: Compilation aborted make[1]: *** [ppcrossarm.exe] Error 1 make[1]: Leaving directory `C:/Programas/fpc21/compiler' make: *** [cycle] Error 2 thanks, -- Felipe Monteiro de Carvalho ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
Re: [fpc-devel] Warning for sqldb and fpc 2.1.1 users
On Sat, 1 Apr 2006, Joost van der Sluis wrote: > Hi all, > > In revision 3111 TBufDataset is almost completely rewritten. I've tested > as much as I could, but it could be that you encounter problems with > sqldb which weren't there before. > > Please test if everything still works ok, and if not, tell me or submit > a bug-report. > > Further I have a question: now sqldb uses a linked-list record buffer, Why ? This goes against the recordset idea ? > the RecordCount and RecNo properties are something strange. > > What should I do with recordcount? I can add a counter which keep track > of the recordcount. Ie: it does inc(recordcount) if a record is > appended. > > Or I can do a real count of the records, each time recordcount is > called. > > And what about recno? Just define it as -1, or do a quick count to get > the current record number? > > What are your thoughts on this? The very idea of TBufDataset was that both recno and recordcount would always be available. So using a linked list is not so good. Why did you change that ? Michael. ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
[fpc-devel] Warning for sqldb and fpc 2.1.1 users
Hi all, In revision 3111 TBufDataset is almost completely rewritten. I've tested as much as I could, but it could be that you encounter problems with sqldb which weren't there before. Please test if everything still works ok, and if not, tell me or submit a bug-report. Further I have a question: now sqldb uses a linked-list record buffer, the RecordCount and RecNo properties are something strange. What should I do with recordcount? I can add a counter which keep track of the recordcount. Ie: it does inc(recordcount) if a record is appended. Or I can do a real count of the records, each time recordcount is called. And what about recno? Just define it as -1, or do a quick count to get the current record number? What are your thoughts on this? JoJo, Joost. ___ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
