On 25 Apr 2015, at 20:41, Jeff M <jmat at mac.com> wrote: >> On Apr 24, 2015, at 2:44 AM, Simon Slavin <slavins at bigfraud.org> wrote: >> >> On 24 Apr 2015, at 6:59am, Jeff M <jmat at mac.com> wrote: >> >>> I don't need to map SQLite to iCloud -- I only need to map SQLite to Core >>> Data. Core Data then takes care of the iCloud issues. >> >> I imagine you'd do that by writing a VFS which used Core Data for storage. >> Core Data could store your data in any of the formats it has drivers for, >> including plaintext files and SQLite. And Core Data could store your data >> in any medium it has drivers for, including local storage and iCloud. >> >> The result might be slow and inefficient, since you're building a DBMS >> (SQLite) on top of a DBMS (Core Data) on top of a DBMS (SQLite). >> >> If you use Core Data the resulting file wouldn't look like a normal SQLite >> database. Core Data stores objects. It doesn't store the rows and columns >> you refer to with SQL commands. Maybe your objects would be table rows. >> >> Simon. > > Originally, I wanted to map my tables, rows, and columns to similarly-named > Core Data entities and attributes so I could continue to use the SQL > language. I was hoping to hook into the SQL parser to get the benefits of > where.c, but I realize now that's impractical. > > Your suggestion of working at the file system level is interesting, but my > objects would be disk blocks. I could use a simple Core Data model: one > entity (representing the entire database file) and create one object per > block (each having a binary attribute containing one block of data). It > would be easy to map each file system read() and write() to the corresponding > objects. Using Core Data as a memory array would earn me the Kludge of The > Year Award. But, I see data corruption in my future. > > Can you point me to some sample source code (outside of SQLite itself) that > implements sqlite3_vfs_register()?
Hmmm, searching for that function name across GitHub returns about 27k results. 16.6k+ for just C: https://github.com/search?l=c&q=sqlite3_vfs_register&type=Code&utf8=? 6k+ for C++: https://github.com/search?l=cpp&q=sqlite3_vfs_register&type=Code&utf8=? You'll probably not be short of example stuff to drawn from... :D Regards and best wishes, Justin Clift
