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.

Implementations on Foreign Types

impl ConfigExtension for FFI_ExtensionOptions

const PREFIX: &'static str = datafusion_common::config::DATAFUSION_FFI_CONFIG_NAMESPACE

Implementors