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, extensions_options,
    config::ConfigOptions,
};
 // 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