Christian Smith <[EMAIL PROTECTED]> wrote: > > My own personal opinion on these coding style issues is if the API > requires special handling of cleanup, then the API should do the cleanup. > Returning an allocated string that requires special cleanup results in a > potentially generic operation now being special cased by the API client. >
If all the world was Unix, this would work great. But sadly, it is not. We also have to support windows. See http://www.sqlite.org/cvstrac/tktview?tn=444 The sqlite_freemem() API is an old SQLite version 2 API that was added to work around the fact that memory allocated using malloc() in a DLL cannot be passed to free() in the main program. So I do have to provides sqlite3_free() at least, if for no other purpose than to support windows users. And notice too that if you want to your code to be portable to windows, then you have to use sqlite3_free() to release memory coming back out of sqlite3_mprintf() or sqlite3_exec(). There appears to be no way to avoid this due to the limitations of windows DLLs. The other thing is that since version 3.3.0, SQLite has allowed an implementation to define its own malloc/free implementation by overloading the sqlite3OsMalloc() and sqlite3OsFree() interfaces on the OS-layer. This is sometimes a useful thing to do. The sqlite3_malloc() and sqlite3_free() APIs provide a portable way to get the application-preferred memory allocator. The default implementation of sqlite3OsMalloc() is not compatible with malloc(), however, since it needs to be extended to support sqlite3AllocationSize() (a capability that is tragically missing from the standard unix-style malloc()). I could continue to provide an sqlite3_free() that is compatible with free() on unix systems and then provide another set of routines, sqlite3_osfree(), sqlite3_osmalloc(), sqlite3_osrealloc(), etc., that provide access to the OS-layer memory allocator. But then we would have two separate memory allocation systems which seems even more confusing than requiring the use of sqlite3_free(). And, notice also that the added complication only allows you to avoid using sqlite3_free() on Unix platforms - it is of no help on windows. -- D. Richard Hipp <[EMAIL PROTECTED]>
