• 12 Posts
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Joined 2 years ago
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Cake day: April 27th, 2023

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  • Definitely let go. Rust has some OOP features, but it’s mostly just the OOP idea of interfaces, which Rust models with traits. You can also do dynamic dispatch, which is another OOP feature, but you should almost never use this in Rust unless you absolutely have to. Then there’s encapsulation which is hugely important in Rust too, but yea outside of that kind of thing, I don’t think OOP patterns are too useful. Honestly, if you ask me, many of these “OOP patterns” are really just solving problems that OOP causes in the first place.

    Feel free to ask any other questions.


  • Thanks for explaining further, it’s a lot clearer now what you want to do. And no, I don’t think this DAO thing is idiomatic for Rust and you probably don’t want to do it like that. I’m not familiar with the pattern though, I’m not too much into OOP myself.

    Anyways, I’ve worked a lot with axum and sqlx before so I can tell you what I’d do.

    I am writing an axum backend which (like other backends) needs to do stuff in the database. As some endpoints update the database (and sometimes over multiple sql statements) I want to pass around the transaction as this embodies the connection I am using to update the database.

    This makes sense. You just want a database connection pool (sqlx provides this) in your axum state so your handlers can get connections to the database.

    To separate the axum stuff (parameters, urls and whatnot) from the actual database logic, I’ve first pulled out all the database interactions into separate functions. Because those functions are logically groups (e.g. stuff happening with invoices, others with contacts etc), I thought it was a good idea to create a “dao” struct (and agreed: my OO brain kicked in here which might be debatable). This would group the interactions for each logical domain into a short-lived data access struct.

    Again, not sure what this DAO struct actually entails, but what I would do and have done in the past is just do exactly what you said before: “I want to pass around the transaction”. So I would make my functions take the Transaction struct from sqlx (IIRC it has some type parameters and a life time but you can use a type alias to make it less verbose) and then I would just use that transaction in the function to call SQL. If you have a function that needs access to the database but doesn’t need a transaction, you can just use a plain connection instead of a transaction.

    To prevent passing around the transaction/connection, i wanted to pass that along during construction

    I’m not sure what you mean with “pass along during construction” but in any case, why do you want to avoid passing the transaction/connection? I feel like that is exactly what you should do. That is what you need to do anyway. Rust favours explicitness and you need to pass the transaction/connection to functions for them to use it, so just pass it.








  • Frankly, all of your points sound quite ignorant. Syntax is literally just a matter of getting used to it. Comparing HashMap ergonomics doesn’t make sense, you should rather compare to struct construction. There are many good reasons for different string types and number types. There are good reasons not to bake in async. Rust documentation is in the code for a very good reason and it’s actually really nice to read docs like that (obviously read it on docs.rs, not in the code itself).

    I could go on but there are answers to all of your specific qualms if you just bothered to look for yourself.


  • While there certainly is some blame on the programmers (to the extent that it is useful to even assign blame), I would say it is hardly fair to blame programmers for most mistakes.

    Bugs are a fact of life - the presence of bugs can hardly be blamed on a specific programmer. Rather, it is a result of the resources assigned to a project and its quality assurance. Yes, at the end of the day it comes down to the lines of code written, but everything and anyone involved in the process up to that point (like designer, project managers, people managers and of course executives at the top) are to blame as well. Especially the decision-makers who deprioritized security or quality assurance are especially to blame, much more so than the programmer who wrote the line.





  • The only time I’ve ever needed a Mutex<()> so far with Rust is when I had to interop with a C library which itself was not thread safe (unprotected use of global variables), so I needed to lock the placeholder mutex each time I called one of the C functions.

    Actually I think in this case you’re still better off using a Mutex with “data” inside. I’ve done this before. The idea is that you make a unit struct MyCFuncs or whatever and then you only call the C functions from methods of that unit struct. Then you can only access those methods once you lock the Mutex and get the instance of the unit struct. It feel elegant to me.