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A Rust library for safe and effortless global and thread-local state management.

License: Other

Rust 100.00%

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baajur smitea icodein pinkforest tidealhub azurecloudmonk csnover rocket-org laomaiweng dmgolembiowski hashcode-iot-solutions gobraves

state's Issues

"Unstable library feature" Error while compiling

Hey!

Thanks for all the work with rocket, and all related libraries.

Since an update on Rocket, i can't seem to get state to compile. I've narrowed it down to state's 7576652 commit. (To which rocket updated on commit SergioBenitez/Rocket@63a1452).

Here's how the error looks like:

error[E0658]: use of unstable library feature 'unsafe_cell_get_mut'
  --> /home/misterio/.cargo/git/checkouts/state-461be979d187f8b7/504ef71/src/shim.rs:41:40
   |
41 |             #[cfg(not(loom))] { self.0.get_mut() }
   |                                        ^^^^^^^
   |
   = note: see issue #76943 <https://github.com/rust-lang/rust/issues/76943> for more information

error: aborting due to previous error

If i understand correctly, this seems to require users to use unstable features? Can i somehow get it to work without nightly builds?

Thanks a lot!

no `LocalStorage` in the root

error[E0432]: unresolved import `state::LocalStorage`
 --> src/lib.rs:1:5
  |
1 | use state::LocalStorage;
  |     ^^^^^^^^^^^^^^^^^^^ no `LocalStorage` in the root

error: aborting due to previous error

For more information about this error, try `rustc --explain E0432`.

If I do use state::Storage;, it imports fine... 0.4.2 in Cargo.toml... what could it be?

Thread local state in Container without Send

It would be ideal to be able to have non-Send types in thread local storage in a container. As long as they stay on the thread, that should work, right?

An alternate solution would be to create a separate thread local version of Container.

Thunk Example

In the docs you mention that we can use State to create thunks. Is there any example of this somewhere?

Container Iterator

There is no way to list all values from Container.
Getting an iterator is probably not very useful since values have distinct types. What I really need is to have a way to debug-print the Container.

calls in statics are limited to constant functions, tuple structs and tuple variants

Hi, I'm trying to follow the example code here https://docs.rs/state/0.4.1/state/

The compiler complains

error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants
 --> src/main.rs:7:49
  |
7 | static CONFIG: Storage<RwLock<Configuration>> = Storage::new();
  |                                                 ^^^^^^^^^^^^^^
error: aborting due to previous error; 1 warning emitted

Code:

use state::Storage;
use std::sync::RwLock;

struct Configuration {}

static CONFIG: Storage<RwLock<Configuration>> = Storage::new();

fn main() {
    let config = Configuration {
        /* fill in structure at run-time from user input */
    };

    // Make the config avaiable globally.
    CONFIG.set(RwLock::new(config));

    /* at any point later in the program, in any thread */
    let mut_config = CONFIG.get().write();
}

What am I missing?

What happens if two libraries use state?

If two libraries (or a library and an application) use state, does their state collide or does each library get a separate state container?

Objects are required to be Send + Sync because the container is expected to be used from multiple threads. To have mutability, it is necessary to wrap everything with Mutex. Having a single-threaded variant would simplify this process.

Compile error after update state v0.3.1 -> v0.3.2

cargo update
    Updating registry `https://github.com/rust-lang/crates.io-index`
    Updating futures v0.1.15 -> v0.1.16
    Updating futures-cpupool v0.1.5 -> v0.1.6
    Updating gcc v0.3.53 -> v0.3.54
    Updating itoa v0.3.3 -> v0.3.4
    Updating ordermap v0.2.11 -> v0.2.12
    Updating state v0.3.1 -> v0.3.2
    Updating yansi v0.3.3 -> v0.3.4

cargo build --all
 Downloading itoa v0.3.4
 Downloading gcc v0.3.54
 Downloading futures v0.1.16
 Downloading futures-cpupool v0.1.6
 Downloading yansi v0.3.4
 Downloading ordermap v0.2.12
 Downloading state v0.3.2
   Compiling ordermap v0.2.12
   Compiling itoa v0.3.4
   Compiling gcc v0.3.54
   Compiling state v0.3.2
   Compiling yansi v0.3.4
   Compiling futures v0.1.16
error[E0493]: destructors in constant functions are an unstable feature
  --> C:\Users\fluxx\.cargo\registry\src\github.com-1ecc6299db9ec823\state-0.3.2\src\container.rs:95:9
   |
95 | /         Container {
96 | |             init: Init::new(),
97 | |             map: UnsafeCell::new(0 as *mut _),
98 | |             mutex: AtomicUsize::new(0)
99 | |         }
   | |_________^
   |
   = help: in Nightly builds, add `#![feature(drop_types_in_const)]` to the crate attributes to enable

error[E0493]: destructors in constant functions are an unstable feature
  --> C:\Users\fluxx\.cargo\registry\src\github.com-1ecc6299db9ec823\state-0.3.2\src\storage.rs:70:9
   |
70 | /         Storage {
71 | |             _phantom: PhantomData,
72 | |             item: UnsafeCell::new(0 as *mut T),
73 | |             init: Init::new()
74 | |         }
   | |_________^
   |
   = help: in Nightly builds, add `#![feature(drop_types_in_const)]` to the crate attributes to enable

error: aborting due to 2 previous errors

error: Could not compile `state`.

Update loom dependency to 0.5

> cargo audit
    Fetching advisory database from `https://github.com/RustSec/advisory-db.git`
      Loaded 305 security advisories (from /Users/ryadom/.cargo/advisory-db)
    Updating crates.io index
    Scanning Cargo.lock for vulnerabilities (233 crate dependencies)
Crate:         generator
Version:       0.6.25
Title:         Generators can cause data races if non-Send types are used in their generator functions
Date:          2020-11-16
ID:            RUSTSEC-2020-0151
URL:           https://rustsec.org/advisories/RUSTSEC-2020-0151
Solution:      Upgrade to >=0.7.0
Dependency tree:
generator 0.6.25
└── loom 0.3.6
    └── state 0.4.2
        ├── rocket_http 0.5.0-dev
        │   ├── rocket_codegen 0.5.0-dev
        │   └── rocket 0.5.0-dev
        └── rocket 0.5.0-dev

Examples

Hello!

I'm very interested in this crate. However, I think getting started would be much aided by a couple of minimal examples? Do this exist somewhere? If any exist maybe they could be added to the .readme?

It's unclear it is not supposed to work with stable Rust

Please put a big notice in the README.md that today it's not supposed to work with stable Rust due to mandatory requirement of const fn not yet stabilised. It's not enough cleared in the documentation.

Thank you.

Latest rust nightly throws error with provided example

error[E0015]: calls in statics are limited to constant functions, tuple structs and tuple variants --> src/main.rs:38:38 | 38 | static GLOBAL: state::Storage<u32> = state::Storage::new();

I realize that this is likely due to a change in what are allowed to be global statics, but is there any workaround for this? I'm trying to write a server in Rust which needs to run threads at all times but they also need to referenced back to so I need some way to keep track of them. If this isn't a solution, what would you recommend? Nevermind, I found the State page of the Rocket guide which should work, but the README should still probably be updated.