Skip to content

[57_maintenance] Mark BufferBuilder::new_from_buffer as unsafe (#9292) #9312

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
alamb merged 1 commit into from
Feb 2, 2026
Merged

[57_maintenance] Mark BufferBuilder::new_from_buffer as unsafe (#9292) #9312

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 10 additions & 14 deletions arrow-buffer/src/builder/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -70,7 +70,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
///
/// assert!(builder.capacity() >= 10);
Expand All @@ -87,7 +86,11 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
}

/// Creates a new builder from a [`MutableBuffer`]
pub fn new_from_buffer(buffer: MutableBuffer) -> Self {
///
/// # Safety
///
/// - `buffer` bytes must be aligned to type `T`
pub unsafe fn new_from_buffer(buffer: MutableBuffer) -> Self {
let buffer_len = buffer.len();
Self {
buffer,
Expand All @@ -102,7 +105,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.append(42);
///
Expand All @@ -118,7 +120,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.append(42);
///
Expand Down Expand Up @@ -149,7 +150,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.advance(2);
///
Expand All @@ -167,7 +167,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.reserve(10);
///
Expand All @@ -185,7 +184,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.append(42);
///
Expand All @@ -205,7 +203,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.append_n(10, 42);
///
Expand All @@ -223,12 +220,12 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u32>::new(10);
/// builder.append_n_zeroed(3);
///
/// assert_eq!(builder.len(), 3);
/// assert_eq!(builder.as_slice(), &[0, 0, 0])
/// ```
#[inline]
pub fn append_n_zeroed(&mut self, n: usize) {
self.buffer.extend_zeros(n * std::mem::size_of::<T>());
Expand All @@ -241,7 +238,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u8>::new(10);
/// builder.append_slice(&[42, 44, 46]);
///
Expand All @@ -257,7 +253,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<f64>::new(10);
/// builder.append(1.3);
/// builder.append_n(2, 2.3);
Expand All @@ -280,7 +275,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<f32>::new(10);
///
/// builder.append_slice(&[1., 2., 3.4]);
Expand All @@ -307,7 +301,6 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
///
/// ```
/// # use arrow_buffer::builder::BufferBuilder;
///
/// let mut builder = BufferBuilder::<u16>::new(10);
///
/// builder.append_slice(&[42, 44, 46]);
Expand Down Expand Up @@ -377,7 +370,10 @@ impl<T: ArrowNativeType> Extend<T> for BufferBuilder<T> {

impl<T: ArrowNativeType> From<Vec<T>> for BufferBuilder<T> {
fn from(value: Vec<T>) -> Self {
Self::new_from_buffer(MutableBuffer::from(value))
let buffer = MutableBuffer::from(value);
// SAFETY
// - buffer is aligned to T
unsafe { Self::new_from_buffer(buffer) }
}
}

Expand Down
Loading