c/driver_manager: investigate/test overriding driver (and other params) in profile

[lidavidm]

One small unexpected behavior: If I specify connect(driver="invalid", profile="foo"), and the connection profile foo specifies a valid driver, it succeeds. I would have expected that to fail.

Originally posted by @ianmcook in #4078 (comment)

[ianmcook]

Thinking about this more:

When driver is specified in the connection profile and also passed in function arguments, and they don't match, what should the driver manager do?

Irrespective of whether they're valid, it might be best to error.

With other connection options, it makes sense for arguments in code to override the connection profiles. But for driver I think erroring is safer.

[ianmcook]

Whatever we decide here, let's make sure we implement it consistently in the Rust driver manager too.

[lidavidm]

I've also found that you can override a profile with a driver, but not when the profile is specified as a URI...

[lidavidm]

Ahhh...if we pass uri and driver, and the URI is a profile, then naturally it's ignored (or rather, passed to the driver). That's expected.

Because of that I'd vote that we don't allow overriding, because it creates confusing things like this. If a driver is explicitly passed, then profiles should not get invoked.

[lidavidm]

@amoeba @zeroshade @esadek I'd appreciate thoughts here!

[ianmcook]

Here's the behavior I think we should implement:

If the user specifies a connection profile (with the profile option or with a profile:// URI) and also specifies the driver option with AdbcDatabaseSetOption, then:

1. If driver is not set in the connection profile, then the driver manager should take it from the driver option that the user set with AdbcDatabaseSetOption.
2. If driver is set in the connection profile, and it agrees, then there's no problem; just proceed.
3. If driver is set in the connection profile, and it disagrees, then error.

[lidavidm]

Does this seem reasonable?

• If init_func is provided, use that (skip the rest of the list).
• Check all arguments for a profile first. (If the profile is in the URI or driver, remove it from the options before proceeding.)
• Multiple profiles is an error.
• If we have a profile, we load it.
• Check driver. If the driver is a URI, parse out the driver and URI. (This overrides any additional URI argument? Or does not?)
• If driver was not specified, try to parse a potential driver out of the URI. (Do not fail if we aren't able to.) Proceed as if driver is set to the URI scheme.
• Ensure specified driver (if any) matches the profile (if set in the profile). This is a string comparison (we don't try to see if they would resolve to the same binary).

driver=	uri=	profile=	Behavior
Empty	Empty	Empty	Error
Empty	Empty	Profile	Load profile
Empty	Driver URI	Empty	Load driver, set URI
Empty	Driver URI	Profile	Load profile, ensure driver in driver URI matches profile, set URI
Empty	Profile URI	Empty	Load profile
Empty	Profile URI	Profile	Error
Empty	Non-driver URI	Empty	(Probably) Error
Empty	Non-driver URI	Profile	Load profile, set URI
Driver	Empty	Empty	Load driver
Driver	Empty	Profile	Load profile, ensure driver matches profile
Driver	Driver URI	Empty	Load driver, set URI (driver in URI is ignored)
Driver	Driver URI	Profile	Load profile, ensure driver matches profile, set URI (driver in URI is ignored)
Driver	Profile URI	Empty	Load profile, ensure driver matches profile
Driver	Profile URI	Profile	Error
Driver	Non-driver URI	Empty	Load driver, set URI
Driver	Non-driver URI	Profile	Load profile, ensure driver matches profile, set URI
Driver URI	Empty	Empty	Load driver, set URI
Driver URI	Empty	Profile	Load profile, ensure driver in driver URI matches profile, set URI
Driver URI	Driver URI	Empty	Load driver, set URI (driver in URI is ignored)
Driver URI	Driver URI	Profile	Load profile, ensure driver in driver URI matches profile, set URI (driver in URI is ignored)
Driver URI	Profile URI	Empty	Load profile, ensure driver in driver URI matches profile, set URI
Driver URI	Profile URI	Profile	Error
Driver URI	Non-driver URI	Empty	Load driver, set URI
Driver URI	Non-driver URI	Profile	Load profile, ensure driver in driver URI matches profile, set URI
Profile URI	Empty	Empty	Load profile
Profile URI	Empty	Profile	Error
Profile URI	Driver URI	Empty	Load profile, ensure driver in URI matches profile, set URI
Profile URI	Driver URI	Profile	Error
Profile URI	Profile URI	Empty	Error
Profile URI	Profile URI	Profile	Error
Profile URI	Non-driver URI	Empty	Load profile, set URI
Profile URI	Non-driver URI	Profile	Error

[ianmcook]

What is the exact definition of "driver URI"?

[lidavidm]

A URI with a driver:// scheme. The intent was to present this from the user perspective (if I call connect(driver="sqlite", uri="postgres://"), what should I expect as the user? This is trying to clarify those cases, even if they're nonsensical from inside the driver manager)

[lidavidm]

Some of the entries above are mistaken, I think (e.g. if a profile URI and a driver URI are set together, then the "driver URI" is just a URI and is never parsed)