Thanks for clarifying that. > If the pointer refers to memory obtained from sqlite3_malloc How do I know that is the case? My callback procedure (the procedure that does the actual work, altering the string) is in a VB6 ActiveX dll, so not in sqlite3.dll
> If the pointer refers to memory obtained from your own allocator I suppose this is the case if it is a local variable in this callback procedure in my VB6 dll. In VB6 local variables will go out of scope (cleaned up) once the procedure is finished. So in that case can I use SQLITE_STATIC? > In all other cases, pass SQLITE_TRANSIENT and, if necessary, dispose of the memory appropriately. When is it necessary and what is appropriate? RBS On Tue, Dec 15, 2015 at 7:52 AM, Hick Gunter <hick at scigames.at> wrote: > The rules are quite simple: > > If the pointer refers to static memory (preallocated string constants, > global variables that you can guarantee won't change while SQLite uses > them) use SQLITE_STATIC > > If the pointer refers to memory obtained from sqlite3_malloc (directly or > indirectly e.g. via sqlite3_mprintf() ) and you won't refer to this object > again, pass sqlite3_free. > > If the pointer refers to memory obtained from your own allocator and you > won't refer to this object again, pass your own destructor. > > In all other cases, pass SQLITE_TRANSIENT and, if necessary, dispose of > the memory appropriately. > > SQLITE_TRANSIENT is safe but slow, because SQLite needs to copy the string. > Passing a destructor function is faster but implies a contract to NOT USE > THE POINTER AGAIN yourself. > SQLITE_STATIC is fastest but implies a contract that the MEMORY WILL NOT > CHANGE. > > -----Urspr?ngliche Nachricht----- > Von: sqlite-users-bounces at mailinglists.sqlite.org [mailto: > sqlite-users-bounces at mailinglists.sqlite.org] Im Auftrag von Bart > Smissaert > Gesendet: Montag, 14. Dezember 2015 20:22 > An: General Discussion of SQLite Database > Betreff: [sqlite] sqlite3_free needed when calling sqlite3_result_text ? > > Not sure if I need to call sqlite3_free after running sqlite3_result_text > or if sqlite3_free should be an argument (last one) in sqlite3_result_text. > Currently I am using SQLITE_TRANSIENT as the last argument, so that is > after the number of bytes, but have feeling I might be doing this wrong. > Thanks for any advice. > > RBS > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > ___________________________________________ > Gunter Hick > Software Engineer > Scientific Games International GmbH > FN 157284 a, HG Wien > Klitschgasse 2-4, A-1130 Vienna, Austria > Tel: +43 1 80100 0 > E-Mail: hick at scigames.at > > This communication (including any attachments) is intended for the use of > the intended recipient(s) only and may contain information that is > confidential, privileged or legally protected. Any unauthorized use or > dissemination of this communication is strictly prohibited. If you have > received this communication in error, please immediately notify the sender > by return e-mail message and delete all copies of the original > communication. Thank you for your cooperation. > > > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
