PR: Feature - SQLite uuid Extension

[LucaCappelletti94]

This PR introduces implementations of SQLite UUID extensions, specifically UUIDv4 (Random) and UUIDv7 (Time-ordered). These extensions are implemented as separate crates within the workspace (extensions/uuid4, extensions/uuid7) using sqlite-wasm-rs bindings and the native uuid crate.

This allows users to generate and manipulate RFC-9562 UUIDs directly within SQL queries in a WASM environment.

UUIDv4 (Random)

Based on the standard SQLite uuid.c API but implemented in Rust.

• uuid(): Generates a random 36-char string.
• uuid_str(X): Standardizes input (Blob/Text) to 36-char string.
• uuid_blob(X): Converts input to 16-byte BLOB.
• uuid_blob(): (Added) Generates a new random 16-byte BLOB directly.

UUIDv7 (Time-Ordered)

A new extension for timestamp-based UUIDs, providing better index locality for direct SQLite use.

• uuid7(): Generates a time-ordered 36-char string.
• uuid7_blob(X): Converts input to 16-byte BLOB.
• uuid7_blob(): Generates a new time-ordered 16-byte BLOB directly.

Testing

• Verified correct UUID version bits (v4 vs v7).
• Generation formats (Text vs Blob).
• Usage as DEFAULT column values in schemas.
• Sorting/Monotonicity for UUIDv7, uniqueness for UUIDv4.
• Round-trip conversions between String and BLOB formats.

[Spxg]

Thank you for your work. I haven't reviewed it yet, but would it be possible to put these changes in a new repository, such as extensions/sqlite-uuid?

[LucaCappelletti94]

I suppose so, but how is that crate then folded into the first one at compile time? Maybe it is straightforward, I just haven't understood.

[Spxg]

just like https://github.com/Spxg/sqlite-wasm-rs/tree/master/extensions/sqlite-vec?

[LucaCappelletti94]

No ok sure, just I wasn't clear how it was compiled against sqlite. I will read more in details later.

[LucaCappelletti94]

Would you prefer these extension to be in one or two crates?

[LucaCappelletti94]

Just fyi, I also tried to use directly the uuid instead of using the c code, making bindings to it, but it turned into a very hard to read/debug mess of function pointers.

I will continue with the original approach of just slightly reworking the uuid extension from SQLite and using the customized version of the postgres one.

[LucaCappelletti94]

Ok I managed to rewrite the whole thing solely using the uuid crate in the end, instead of adapting the original C extension code or the postgres code. This makes me much more comfortable of the correctness of the implementation.

[LucaCappelletti94]

I have updated the original post to reflect the changes made.

[Spxg]

I haven't looked at the implementation in detail yet, but it seems that those C shims from sqlite-wasm-rs are no longer needed, right? Then I think this can be considered your own project, rather than contributing code to sqlite-wasm-rs.

[LucaCappelletti94]

I haven't looked at the implementation in detail yet, but it seems that those C shims from sqlite-wasm-rs are no longer needed, right? Then I think this can be considered your own project, rather than contributing code to sqlite-wasm-rs.

Yes I think that as it is now, it should be rather modular.

Still, with uuid being a very standard type it is somewhat reasonable to have it here and avoid future API changes potentially breaking something. That being said, if you prefer I can fold it into a crate of my own.

[Spxg]

avoid future API changes potentially breaking something

Given that sqlite-wasm-rs is currently used by diesel and rusqlite, it now and in the future only provides SQLite C API, so it is stable.

I can fold it into a crate of my own.

Yeah, thanks for your work!

[LucaCappelletti94]

Trivial question - are these extensions usable in diesel? Right now your example only shows how to load this extension in rustqlite.

[Spxg]

Adding extension is unrelated to diesel, just use sqlite_wasm_rs::sqlite3_auto_extension(xxxx).

[LucaCappelletti94]

Ok! My confusion was only caused by:

sqlite-wasm-rs/extensions/sqlite-vec/README.md

Line 18 in a1fc2cb

use rusqlite::{ffi::sqlite3_auto_extension, Connection};

[Spxg]

yeah.. rusqlite re-exported the ffi from sqlite-wasm-rs

[LucaCappelletti94]

For future reference, it is here: https://docs.rs/sqlite-wasm-uuid-rs/latest/sqlite_wasm_uuid_rs/