Trait ConfigExtension 

pub trait ConfigExtension: ExtensionOptions {
    const PREFIX: &'static str;
}

ConfigExtension provides a mechanism to store third-party configuration within DataFusion ConfigOptions

This mechanism can be used to pass configuration to user defined functions or optimizer passes

Example

use datafusion_common::{
    config::ConfigExtension, config::ConfigOptions, extensions_options,
};
// Define a new configuration struct using the `extensions_options` macro
extensions_options! {
   /// My own config options.
   pub struct MyConfig {
       /// Should "foo" be replaced by "bar"?
       pub foo_to_bar: bool, default = true

       /// How many "baz" should be created?
       pub baz_count: usize, default = 1337
   }
}

impl ConfigExtension for MyConfig {
    const PREFIX: &'static str = "my_config";
}

// set up config struct and register extension
let mut config = ConfigOptions::default();
config.extensions.insert(MyConfig::default());

// overwrite config default
config.set("my_config.baz_count", "42").unwrap();

// check config state
let my_config = config.extensions.get::<MyConfig>().unwrap();
assert!(my_config.foo_to_bar,);
assert_eq!(my_config.baz_count, 42,);

Note:

Unfortunately associated constants are not currently object-safe, and so this extends the object-safe ExtensionOptions

Required Associated Constants

const PREFIX: &'static str

Configuration namespace prefix to use

All values under this will be prefixed with $PREFIX + "."

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors