nordisk/skade

vendor/iceberg-arrow59/src/test_utils/runtime.rs

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//! A shared tokio runtime for tests that build a [`Table`](crate::table::Table).
//!
//! Twin of `iceberg_test_utils::test_runtime`, which serves other crates in the
//! workspace. The two cannot be merged: a dev-dependency links a separate
//! instance of this crate, so a `Runtime` built there is a distinct type from
//! `crate::Runtime` here.

use std::sync::OnceLock;

use crate::runtime::Runtime;

/// Returns a process-wide [`Runtime`] suitable for tests that need to construct
/// a [`Table`](crate::table::Table) outside a tokio context.
///
/// The returned [`Runtime`] wraps a single shared multi-thread tokio runtime
/// that is lazily built on first call and lives until process exit. Cloning is
/// cheap, so test code can call this every time it needs a runtime to feed
/// into [`TableBuilder::runtime`](crate::table::TableBuilder::runtime).
pub(crate) fn test_runtime() -> Runtime {
    static TOKIO_RT: OnceLock<tokio::runtime::Runtime> = OnceLock::new();
    let tokio_rt = TOKIO_RT.get_or_init(|| {
        tokio::runtime::Builder::new_multi_thread()
            .enable_all()
            .build()
            .expect("failed to build test tokio runtime")
    });
    Runtime::new(tokio_rt)
}