Serde_AnyMap: A serializable map that stores and retrieves elements by type

SerdeAnyMap provides map-like data structures that can store values of different types and can be serialized and deserialized with Serde. The values are stored and retrieved using their TypeId as the key, making it a powerful tool for dynamic, type-safe data storage.

There are two main types provided by this crate:

• SerdeAnyMap: A simple map from TypeId to a value of that type.
• NamedSerdeAnyMap: A map from TypeId to a further map of String names to values, allowing you to store multiple instances of the same type under different names.

How to Use

1. Add serde_anymap to your dependencies

[dependencies]
serde_anymap = "0.1.0"
# For automatic type registration (recommended)
serde_anymap = { version = "0.1.0", features = ["serdeany_autoreg"] }

2. Define Your Types and Implement SerdeAny

To be stored in a SerdeAnyMap, your types must implement the SerdeAny trait. The easiest way to do this is using the #[derive(SerdeAny)] macro from the LibAFL_Derive crate or by using the impl_serdeany! macro on the type, instead. Your types must also derive Serialize and Deserialize.

use serde::{Serialize, Deserialize};
use serde_anymap::impl_serdeany;

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct MyConfig {
    is_enabled: bool,
    port: u16,
}
impl_serdeany!(MyConfig);

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct UserData(String);
impl_serdeany!(UserData);

3. Use SerdeAnyMap

You can now insert instances of your types into the map and retrieve them by type.

# use serde::{Serialize, Deserialize};
# use serde_anymap::impl_serdeany;
# #[derive(Debug, Serialize, Deserialize, PartialEq)]
# struct MyConfig { is_enabled: bool, port: u16 }
# impl_serdeany!(MyConfig);
# #[derive(Debug, Serialize, Deserialize, PartialEq)]
# struct UserData(String);
# impl_serdeany!(UserData);
use serde_anymap::serdeany::SerdeAnyMap;

let mut map = SerdeAnyMap::new();

map.insert(MyConfig { is_enabled: true, port: 8080 });
map.insert(UserData("John Doe".to_string()));

// Retrieve values by type
assert_eq!(map.get::<MyConfig>().unwrap().port, 8080);
assert_eq!(map.get::<UserData>().unwrap().0, "John Doe");

// You can also get mutable access
let config = map.get_mut::<MyConfig>().unwrap();
config.port = 9090;
assert_eq!(map.get::<MyConfig>().unwrap().port, 9090);

4. Serialization and Deserialization

The real power of serde_anymap is its ability to serialize and deserialize these heterogeneous maps.

Important: For deserialization to work, the types you are deserializing must be registered. See the "Type Registration" section below.

# use serde::{Serialize, Deserialize};
# use serde_anymap::{impl_serdeany, serdeany::{SerdeAnyMap, RegistryBuilder}};
# #[derive(Debug, Serialize, Deserialize, PartialEq)]
# struct MyConfig { is_enabled: bool, port: u16 }
# impl_serdeany!(MyConfig);
# #[derive(Debug, Serialize, Deserialize, PartialEq)]
# struct UserData(String);
# impl_serdeany!(UserData);
# let mut map = SerdeAnyMap::new();
# map.insert(MyConfig { is_enabled: true, port: 8080 });
# map.insert(UserData("John Doe".to_string()));
// This is only needed if you don't use the `serdeany_autoreg` feature
#[cfg(not(feature = "serdeany_autoreg"))]
unsafe {
    RegistryBuilder::register::<MyConfig>();
    RegistryBuilder::register::<UserData>();
}

// Serialize the map to a JSON string
let serialized = serde_json::to_string_pretty(&map).unwrap();
println!("{}", serialized);

// Deserialize it back
let deserialized: SerdeAnyMap = serde_json::from_str(&serialized).unwrap();

assert!(deserialized.get::<MyConfig>().is_some());
assert_eq!(deserialized.get::<MyConfig>().unwrap(), map.get::<MyConfig>().unwrap());
assert_eq!(deserialized.get::<UserData>().unwrap(), map.get::<UserData>().unwrap());

Type Registration

For serde_anymap to deserialize a generic dyn SerdeAny trait object, it needs a way to map a serialized type identifier back to a concrete type. This is done via a global type registry.

Automatic Registration (Recommended)

The easiest way to handle registration is to enable the serdeany_autoreg feature. This uses the ctor crate to automatically run registration code for each type when your program starts. The impl_serdeany! macro handles this for you.

# In your Cargo.toml
serde_anymap = { version = "0.1.0", features = ["serdeany_autoreg"] }

With this feature, you don't need to do anything else. Just use impl_serdeany! and it works.

Manual Registration

If you cannot use serdeany_autoreg, you must register your types manually at the start of your program.

use serde_anymap::serdeany::RegistryBuilder;

// This must be done before any deserialization happens.
// It is safe to call multiple times.
unsafe {
    RegistryBuilder::register::<MyConfig>();
    RegistryBuilder::register::<UserData>();
}

// Your application logic...

NamedSerdeAnyMap

If you need to store multiple objects of the same type, you can use NamedSerdeAnyMap, which adds a string name as a key.

# use serde::{Serialize, Deserialize};
# use serde_anymap::{impl_serdeany, serdeany::{NamedSerdeAnyMap, RegistryBuilder}};
# #[derive(Debug, Serialize, Deserialize, PartialEq)]
# struct UserData(String);
# impl_serdeany!(UserData);
# #[cfg(not(feature = "serdeany_autoreg"))]
# unsafe { RegistryBuilder::register::<UserData>(); }
let mut named_map = NamedSerdeAnyMap::new();

named_map.insert("user1", UserData("Alice".to_string()));
named_map.insert("user2", UserData("Bob".to_string()));

assert_eq!(named_map.get::<UserData>("user1").unwrap().0, "Alice");
assert_eq!(named_map.get::<UserData>("user2").unwrap().0, "Bob");

let serialized = serde_json::to_string(&named_map).unwrap();
let deserialized: NamedSerdeAnyMap = serde_json::from_str(&serialized).unwrap();

assert_eq!(deserialized.get::<UserData>("user1").unwrap().0, "Alice");

Features

• serdeany_autoreg: Enables automatic type registration at program startup. Highly recommended.
• stable_anymap: Uses the type name (&'static str) as the key instead of TypeId. This makes the serialized output more stable across different compilations, but it can be slightly slower and may cause issues if you have types with the same name in different modules.

The LibAFL Project

The LibAFL project is part of AFLplusplus and maintained by

• Andrea Fioraldi andrea@aflplus.plus
• Dominik Maier dominik@aflplus.plus
• s1341 github@shmarya.net
• Dongjia Zhang toka@aflplus.plus
• Addison Crump me@addisoncrump.info

Contributing

For bugs, feel free to open issues or contact us directly. Thank you for your support. <3

Even though we will gladly assist you in finishing up your PR, try to

• keep all the crates compiling with stable rust (hide the eventual non-stable code under cfgs.)
• run cargo nightly fmt on your code before pushing
• check the output of cargo clippy --all or ./clippy.sh
• run cargo build --no-default-features to check for no_std compatibility (and possibly add #[cfg(feature = "std")]) to hide parts of your code.

Some parts in this list may sound hard, but don't be afraid to open a PR if you cannot fix them by yourself. We will gladly assist.

License