Noob question, how to load custom extension?

[longseespace]

Amazing library.

I have a question. I wanted to use this extension (embedding for SQLite). How can I use it with SQLite.swift?

https://github.com/asg017/sqlite-vss

Thanks,

[jberkel]

Hi,

there's no direct support for loading extensions in the library. You'll need to compile sqlite-vss in your project and then initialize the extension(s) when your app starts, for example from main.m

#include "sqlite3.h"
#include "sqlite-vector.h"
#include "sqlite-vss.h"

int main(int argc, char **argv) {
    sqlite3_auto_extension((void (*)(void)) sqlite3_vector_init);
    sqlite3_auto_extension((void (*)(void)) sqlite3_vss_init);

    // start actual iOS app
    UIApplicationMain(argc, argv, nil, NSStringFromClass(AppDelegate.class));
}

I haven't tested this, but this in general how you load SQLite extensions.

See the sample code here: https://github.com/asg017/sqlite-vss/blob/c3bacfd61ed122a581942108ee1e457767f28876/examples/c/demo.c#L28

[tantaman]

How can that solution be adapted to a Swift project? Looks like main.m doesn't exist in that context 🤷‍♂️

[jberkel]

You can create a main.m in even for a Swift project. Perhaps an easier solution could be to use the @main annotation in Swift, but I haven't tried this.

https://docs.swift.org/swift-book/documentation/the-swift-programming-language/attributes/#main

[tantaman]

Ty. Actually eventually figured it out (I'm an extension author not iOS dev 😅) --

https://github.com/tantaman/xcode-starter/blob/a755ad175caf091b3e61d4aa0fe69e996082ecf4/xcode-starter/xcode_starterApp.swift#L10-L14

The new wrinkle is this:

SQLITE_DEPRECATED_NO_REPLACEMENT("Process-global auto extensions are not supported on Apple platforms", macos(10.10, 10.10), ios(8.2, 8.2), watchos(2.0, 2.0), tvos(9.0, 9.0))
SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));

so sqlite3_auto_extension always returns an error.

We've worked around that problem by using the sqlite3 package from cocoapods