diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index 9aa5077d4a4c876bfed39d3efd90860e7372b323..2c99635f9fd351b5e6c8c442f564e78a502c327f 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -5,3 +5,4 @@ #[cfg(not(test))] #[cfg(not(testlib))] mod allocator; +pub mod vec_ext; diff --git a/rust/kernel/alloc/vec_ext.rs b/rust/kernel/alloc/vec_ext.rs new file mode 100644 index 0000000000000000000000000000000000000000..311e62cc578455443160b7ea611fb9555660db58 --- /dev/null +++ b/rust/kernel/alloc/vec_ext.rs @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Extensions to [`Vec`] for fallible allocations. + +use alloc::{collections::TryReserveError, vec::Vec}; +use core::result::Result; + +/// Extensions to [`Vec`]. +pub trait VecExt<T>: Sized { + /// Creates a new [`Vec`] instance with at least the given capacity. + fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError>; + + /// Appends an element to the back of the [`Vec`] instance. + fn try_push(&mut self, v: T) -> Result<(), TryReserveError>; + + /// Pushes clones of the elements of slice into the [`Vec`] instance. + fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError> + where + T: Clone; +} + +impl<T> VecExt<T> for Vec<T> { + fn try_with_capacity(capacity: usize) -> Result<Self, TryReserveError> { + let mut v = Vec::new(); + v.try_reserve(capacity)?; + Ok(v) + } + + fn try_push(&mut self, v: T) -> Result<(), TryReserveError> { + if let Err(retry) = self.push_within_capacity(v) { + self.try_reserve(1)?; + let _ = self.push_within_capacity(retry); + } + Ok(()) + } + + fn try_extend_from_slice(&mut self, other: &[T]) -> Result<(), TryReserveError> + where + T: Clone, + { + self.try_reserve(other.len())?; + for item in other { + self.try_push(item.clone())?; + } + + Ok(()) + } +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 1e910fe7c2c774af96171bf174ffc9ee6f945c52..d3d345aed218a993d34ca02c165740f2ab8b8a6e 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -18,6 +18,7 @@ #![feature(new_uninit)] #![feature(receiver_trait)] #![feature(unsize)] +#![feature(vec_push_within_capacity)] // Ensure conditional compilation based on the kernel configuration works; // otherwise we may silently break things like initcall handling. diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index ae21600970b395436f8dcd3337060765759ac4a6..c85b5972c0d3747b36b4e7efb5958dab8b91476a 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -14,6 +14,8 @@ #[doc(no_inline)] pub use core::pin::Pin; +pub use crate::alloc::vec_ext::VecExt; + #[doc(no_inline)] pub use alloc::{boxed::Box, vec::Vec};