## Unreleased Released YYYY-MM-DD. ### Added * TODO (or remove section if none) ### Changed * TODO (or remove section if none) ### Deprecated * TODO (or remove section if none) ### Removed * TODO (or remove section if none) ### Fixed * TODO (or remove section if none) ### Security * TODO (or remove section if none) -------------------------------------------------------------------------------- ## 3.10.0 Released 2022-06-01. ### Added * Implement `bumpalo::collections::FromIteratorIn` for `Option` and `Result`, just like `core` does for `FromIterator`. * Implement `bumpalo::collections::FromIteratorIn` for `bumpalo::boxed::Box<'a, [T]>`. * Added running tests under MIRI in CI for additional confidence in unsafe code. * Publicly exposed `bumpalo::collections::Vec::drain_filter` since the corresponding `std::vec::Vec` method has stabilized. ### Changed * `Bump::new` will not allocate a backing chunk until the first allocation inside the bump arena now. ### Fixed * Properly account for alignment changes when growing or shrinking an existing allocation. * Removed all internal integer-to-pointer casts, to play better with UB checkers like MIRI. -------------------------------------------------------------------------------- ## 3.9.1 Released 2022-01-06. ### Fixed * Fixed link to logo in docs and README.md -------------------------------------------------------------------------------- ## 3.9.0 Released 2022-01-05. ### Changed * The minimum supported Rust version (MSRV) has been raised to Rust 1.54.0. * `bumpalo::collections::Vec` implements relevant traits for all arrays of any size `N` via const generics. Previously, it was just arrays up to length 32. Similar for `bumpalo::boxed::Box<[T; N]>`. -------------------------------------------------------------------------------- ## 3.8.0 Released 2021-10-19. ### Added * Added the `CollectIn` and `FromIteratorIn` traits to make building a collection from an iterator easier. These new traits live in the `bumpalo::collections` module and are implemented by `bumpalo::collections::{String,Vec}`. * Added the `Bump::iter_allocated_chunks_raw` method, which is an `unsafe`, raw version of `Bump::iter_allocated_chunks`. The new method does not take an exclusive borrow of the `Bump` and yields raw pointer-and-length pairs for each chunk in the bump. It is the caller's responsibility to ensure that no allocation happens in the `Bump` while iterating over chunks and that there are no active borrows of allocated data if they want to turn any pointer-and-length pairs into slices. -------------------------------------------------------------------------------- ## 3.7.1 Released 2021-09-17. ### Changed * The packaged crate uploaded to crates.io when `bumpalo` is published is now smaller, thanks to excluding unnecessary files. -------------------------------------------------------------------------------- ## 3.7.0 Released 2020-05-28. ### Added * Added `Borrow` and `BorrowMut` trait implementations for `bumpalo::collections::Vec` and `bumpalo::collections::String`. [#108](https://github.com/fitzgen/bumpalo/pull/108) ### Changed * When allocating a new chunk fails, don't immediately give up. Instead, try allocating a chunk that is half that size, and if that fails, then try half of *that* size, etc until either we successfully allocate a chunk or we fail to allocate the minimum chunk size and then finally give up. [#111](https://github.com/fitzgen/bumpalo/pull/111) -------------------------------------------------------------------------------- ## 3.6.1 Released 2020-02-18. ### Added * Improved performance of `Bump`'s `Allocator::grow_zeroed` trait method implementation. [#99](https://github.com/fitzgen/bumpalo/pull/99) -------------------------------------------------------------------------------- ## 3.6.0 Released 2020-01-29. ### Added * Added a few new flavors of allocation: * `try_alloc` for fallible, by-value allocation * `try_alloc_with` for fallible allocation with an infallible initializer function * `alloc_try_with` for infallible allocation with a fallible initializer function * `try_alloc_try_with` method for fallible allocation with a fallible initializer function We already have infallible, by-value allocation (`alloc`) and infallible allocation with an infallible initializer (`alloc_with`). With these new methods, we now have every combination covered. Thanks to [Tamme Schichler](https://github.com/Tamschi) for contributing these methods! -------------------------------------------------------------------------------- ## 3.5.0 Released 2020-01-22. ### Added * Added experimental, unstable support for the unstable, nightly Rust `allocator_api` feature. The `allocator_api` feature defines an `Allocator` trait and exposes custom allocators for `std` types. Bumpalo has a matching `allocator_api` cargo feature to enable implementing `Allocator` and using `Bump` with `std` collections. First, enable the `allocator_api` feature in your `Cargo.toml`: ```toml [dependencies] bumpalo = { version = "3.5", features = ["allocator_api"] } ``` Next, enable the `allocator_api` nightly Rust feature in your `src/lib.rs` or `src/main.rs`: ```rust # #[cfg(feature = "allocator_api")] # { #![feature(allocator_api)] # } ``` Finally, use `std` collections with `Bump`, so that their internal heap allocations are made within the given bump arena: ``` # #![cfg_attr(feature = "allocator_api", feature(allocator_api))] # #[cfg(feature = "allocator_api")] # { #![feature(allocator_api)] use bumpalo::Bump; // Create a new bump arena. let bump = Bump::new(); // Create a `Vec` whose elements are allocated within the bump arena. let mut v = Vec::new_in(&bump); v.push(0); v.push(1); v.push(2); # } ``` I'm very excited to see custom allocators in `std` coming along! Thanks to Arthur Gautier for implementing support for the `allocator_api` feature for Bumpalo. -------------------------------------------------------------------------------- ## 3.4.0 Released 2020-06-01. ### Added * Added the `bumpalo::boxed::Box` type. It is an owned pointer referencing a bump-allocated value, and it runs `T`'s `Drop` implementation on the referenced value when dropped. This type can be used by enabling the `"boxed"` cargo feature flag. -------------------------------------------------------------------------------- ## 3.3.0 Released 2020-05-13. ### Added * Added fallible allocation methods to `Bump`: `try_new`, `try_with_capacity`, and `try_alloc_layout`. * Added `Bump::chunk_capacity` * Added `bumpalo::collections::Vec::try_reserve[_exact]` -------------------------------------------------------------------------------- ## 3.2.1 Released 2020-03-24. ### Security * When `realloc`ing, if we allocate new space, we need to copy the old allocation's bytes into the new space. There are `old_size` number of bytes in the old allocation, but we were accidentally copying `new_size` number of bytes, which could lead to copying bytes into the realloc'd space from past the chunk that we're bump allocating out of, from unknown memory. If an attacker can cause `realloc`s, and can read the `realoc`ed data back, this could allow them to read things from other regions of memory that they shouldn't be able to. For example, if some crypto keys happened to live in memory right after a chunk we were bump allocating out of, this could allow the attacker to read the crypto keys. Beyond just fixing the bug and adding a regression test, I've also taken two additional steps: 1. While we were already running the testsuite under `valgrind` in CI, because `valgrind` exits with the same code that the program did, if there are invalid reads/writes that happen not to trigger a segfault, the program can still exit OK and we will be none the wiser. I've enabled the `--error-exitcode=1` flag for `valgrind` in CI so that tests eagerly fail in these scenarios. 2. I've written a quickcheck test to exercise `realloc`. Without the bug fix in this patch, this quickcheck immediately triggers invalid reads when run under `valgrind`. We didn't previously have quickchecks that exercised `realloc` because `realloc` isn't publicly exposed directly, and instead can only be indirectly called. This new quickcheck test exercises `realloc` via `bumpalo::collections::Vec::resize` and `bumpalo::collections::Vec::shrink_to_fit` calls. This bug was introduced in version 3.0.0. See [#69](https://github.com/fitzgen/bumpalo/issues/69) for details. -------------------------------------------------------------------------------- ## 3.2.0 Released 2020-02-07. ### Added * Added the `bumpalo::collections::Vec::into_bump_slice_mut` method to turn a `bumpalo::collections::Vec<'bump, T>` into a `&'bump mut [T]`. -------------------------------------------------------------------------------- ## 3.1.2 Released 2020-01-07. ### Fixed * The `bumpalo::collections::format!` macro did not used to accept a trailing comma like `format!(in bump; "{}", 1,)`, but it does now. -------------------------------------------------------------------------------- ## 3.1.1 Released 2020-01-03. ### Fixed * The `bumpalo::collections::vec!` macro did not used to accept a trailing comma like `vec![in bump; 1, 2,]`, but it does now. -------------------------------------------------------------------------------- ## 3.1.0 Released 2019-12-27. ### Added * Added the `Bump::allocated_bytes` diagnostic method for counting the total number of bytes a `Bump` has allocated. -------------------------------------------------------------------------------- # 3.0.0 Released 2019-12-20. ## Added * Added `Bump::alloc_str` for copying string slices into a `Bump`. * Added `Bump::alloc_slice_copy` and `Bump::alloc_slice_clone` for copying or cloning slices into a `Bump`. * Added `Bump::alloc_slice_fill_iter` for allocating a slice in the `Bump` from an iterator. * Added `Bump::alloc_slice_fill_copy` and `Bump::alloc_slice_fill_clone` for creating slices of length `n` that are filled with copies or clones of an initial element. * Added `Bump::alloc_slice_fill_default` for creating slices of length `n` with the element type's default instance. * Added `Bump::alloc_slice_fill_with` for creating slices of length `n` whose elements are initialized with a function or closure. * Added `Bump::iter_allocated_chunks` as a replacement for the old `Bump::each_allocated_chunk`. The `iter_allocated_chunks` version returns an iterator, which is more idiomatic than its old, callback-taking counterpart. Additionally, `iter_allocated_chunks` exposes the chunks as `MaybeUninit`s instead of slices, which makes it usable in more situations without triggering undefined behavior. See also the note about bump direction in the "changed" section; if you're iterating chunks, you're likely affected by that change! * Added `Bump::with_capacity` so that you can pre-allocate a chunk with the requested space. ### Changed * **BREAKING:** The direction we allocate within a chunk has changed. It used to be "upwards", from low addresses within a chunk towards high addresses. It is now "downwards", from high addresses towards lower addresses. Additionally, the order in which we iterate over allocated chunks has changed! We used to iterate over chunks from oldest chunk to youngest chunk, and now we do the opposite: the youngest chunks are iterated over first, and the oldest chunks are iterated over last. If you were using `Bump::each_allocated_chunk` to iterate over data that you had previously allocated, and *you want to iterate in order of oldest-to-youngest allocation*, you need to reverse the chunks iterator and also reverse the order in which you loop through the data within a chunk! For example, if you had this code: ```rust unsafe { bump.each_allocated_chunk(|chunk| { for byte in chunk { // Touch each byte in oldest-to-youngest allocation order... } }); } ``` It should become this code: ```rust let mut chunks: Vec<_> = bump.iter_allocated_chunks().collect(); chunks.reverse(); for chunk in chunks { for byte in chunk.iter().rev() { let byte = unsafe { byte.assume_init() }; // Touch each byte in oldest-to-youngest allocation order... } } ``` The good news is that this change yielded a *speed up in allocation throughput of 3-19%!* See https://github.com/fitzgen/bumpalo/pull/37 and https://fitzgeraldnick.com/2019/11/01/always-bump-downwards.html for details. * **BREAKING:** The `collections` cargo feature is no longer on by default. You must explicitly turn it on if you intend to use the `bumpalo::collections` module. * `Bump::reset` will now retain only the last allocated chunk (the biggest), rather than only the first allocated chunk (the smallest). This should enable `Bump` to better adapt to workload sizes and quickly reach a steady state where new chunks are not requested from the global allocator. ### Removed * The `Bump::each_allocated_chunk` method is removed in favor of `Bump::iter_allocated_chunks`. Note that its safety requirements for reading from the allocated chunks are slightly different from the old `each_allocated_chunk`: only up to 16-byte alignment is supported now. If you allocate anything with greater alignment than that into the bump arena, there might be uninitilized padding inserted in the chunks, and therefore it is no longer safe to read them via `MaybeUninit::assume_init`. See also the note about bump direction in the "changed" section; if you're iterating chunks, you're likely affected by that change! * The `std` cargo feature has been removed, since this crate is now always no-std. ## Fixed * Fixed a bug involving potential integer overflows with large requested allocation sizes. -------------------------------------------------------------------------------- # 2.6.0 Released 2019-08-19. * Implement `Send` for `Bump`. -------------------------------------------------------------------------------- # 2.5.0 Released 2019-07-01. * Add `alloc_slice_copy` and `alloc_slice_clone` methods that allocate space for slices and either copy (with bound `T: Copy`) or clone (with bound `T: Clone`) the provided slice's data into the newly allocated space. -------------------------------------------------------------------------------- # 2.4.3 Released 2019-05-20. * Fixed a bug where chunks were always deallocated with the default chunk layout, not the layout that the chunk was actually allocated with (i.e. if we started growing largers chunks with larger layouts, we would deallocate those chunks with an incorrect layout). -------------------------------------------------------------------------------- # 2.4.2 Released 2019-05-17. * Added an implementation `Default` for `Bump`. * Made it so that if bump allocation within a chunk overflows, we still try to allocate a new chunk to bump out of for the requested allocation. This can avoid some OOMs in scenarios where the chunk we are currently allocating out of is very near the high end of the address space, and there is still available address space lower down for new chunks. -------------------------------------------------------------------------------- # 2.4.1 Released 2019-04-19. * Added readme metadata to Cargo.toml so it shows up on crates.io -------------------------------------------------------------------------------- # 2.4.0 Released 2019-04-19. * Added support for `realloc`ing in-place when the pointer being `realloc`ed is the last allocation made from the bump arena. This should speed up various `String`, `Vec`, and `format!` operations in many cases. -------------------------------------------------------------------------------- # 2.3.0 Released 2019-03-26. * Add the `alloc_with` method, that (usually) avoids stack-allocating the allocated value and then moving it into the bump arena. This avoids potential stack overflows in release mode when allocating very large objects, and also some `memcpy` calls. This is similar to the `copyless` crate. Read [the `alloc_with` doc comments][alloc-with-doc-comments] and [the original issue proposing this API][issue-proposing-alloc-with] for more. [alloc-with-doc-comments]: https://github.com/fitzgen/bumpalo/blob/9f47aee8a6839ba65c073b9ad5372aacbbd02352/src/lib.rs#L436-L475 [issue-proposing-alloc-with]: https://github.com/fitzgen/bumpalo/issues/10 -------------------------------------------------------------------------------- # 2.2.2 Released 2019-03-18. * Fix a regression from 2.2.1 where chunks were not always aligned to the chunk footer's alignment. -------------------------------------------------------------------------------- # 2.2.1 Released 2019-03-18. * Fix a regression in 2.2.0 where newly allocated bump chunks could fail to have capacity for a large requested bump allocation in some corner cases. -------------------------------------------------------------------------------- # 2.2.0 Released 2019-03-15. * Chunks in an arena now start out small, and double in size as more chunks are requested. -------------------------------------------------------------------------------- # 2.1.0 Released 2019-02-12. * Added the `into_bump_slice` method on `bumpalo::collections::Vec`. -------------------------------------------------------------------------------- # 2.0.0 Released 2019-02-11. * Removed the `BumpAllocSafe` trait. * Correctly detect overflows from large allocations and panic. -------------------------------------------------------------------------------- # 1.2.0 Released 2019-01-15. * Fixed an overly-aggressive `debug_assert!` that had false positives. * Ported to Rust 2018 edition. -------------------------------------------------------------------------------- # 1.1.0 Released 2018-11-28. * Added the `collections` module, which contains ports of `std`'s collection types that are compatible with backing their storage in `Bump` arenas. * Lifted the limits on size and alignment of allocations. -------------------------------------------------------------------------------- # 1.0.2 -------------------------------------------------------------------------------- # 1.0.1 -------------------------------------------------------------------------------- # 1.0.0