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new f0d9e89 Add `append_nulls` and `append_trusted_len_iter` to
`PrimitiveBuilder` (#728) (#759)
f0d9e89 is described below
commit f0d9e89e76e5c05f0c3fe826ca922ebd3d9fb933
Author: Andrew Lamb <[email protected]>
AuthorDate: Fri Sep 10 05:38:38 2021 -0400
Add `append_nulls` and `append_trusted_len_iter` to `PrimitiveBuilder`
(#728) (#759)
* stub out impl
* mark unsafe
* add tests
Co-authored-by: Ben Chambers <[email protected]>
---
arrow/src/array/builder.rs | 77 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)
diff --git a/arrow/src/array/builder.rs b/arrow/src/array/builder.rs
index 1d3e957..00317e6 100644
--- a/arrow/src/array/builder.rs
+++ b/arrow/src/array/builder.rs
@@ -261,6 +261,23 @@ impl<T: ArrowNativeType> BufferBuilder<T> {
self.len += slice.len();
}
+ /// # Safety
+ /// This requires the iterator be a trusted length. This could instead
require
+ /// the iterator implement `TrustedLen` once that is stabilized.
+ #[inline]
+ pub unsafe fn append_trusted_len_iter(&mut self, iter: impl
IntoIterator<Item = T>) {
+ let iter = iter.into_iter();
+ let len = iter
+ .size_hint()
+ .1
+ .expect("append_trusted_len_iter expects upper bound");
+ self.reserve(len);
+ for v in iter {
+ self.buffer.push(v)
+ }
+ self.len += len;
+ }
+
/// Resets this builder and returns an immutable
[`Buffer`](crate::buffer::Buffer).
///
/// # Example:
@@ -695,6 +712,14 @@ impl<T: ArrowPrimitiveType> PrimitiveBuilder<T> {
Ok(())
}
+ #[inline]
+ pub fn append_nulls(&mut self, n: usize) -> Result<()> {
+ self.materialize_bitmap_builder();
+ self.bitmap_builder.as_mut().unwrap().append_n(n, false);
+ self.values_builder.advance(n);
+ Ok(())
+ }
+
/// Appends an `Option<T>` into the builder
#[inline]
pub fn append_option(&mut self, v: Option<T::Native>) -> Result<()> {
@@ -737,6 +762,29 @@ impl<T: ArrowPrimitiveType> PrimitiveBuilder<T> {
Ok(())
}
+ /// Appends values from a trusted length iterator.
+ ///
+ /// # Safety
+ /// This requires the iterator be a trusted length. This could instead
require
+ /// the iterator implement `TrustedLen` once that is stabilized.
+ #[inline]
+ pub unsafe fn append_trusted_len_iter(
+ &mut self,
+ iter: impl IntoIterator<Item = T::Native>,
+ ) -> Result<()> {
+ let iter = iter.into_iter();
+ let len = iter
+ .size_hint()
+ .1
+ .expect("append_trusted_len_iter requires an upper bound");
+
+ if let Some(b) = self.bitmap_builder.as_mut() {
+ b.append_n(len, true);
+ }
+ self.values_builder.append_trusted_len_iter(iter);
+ Ok(())
+ }
+
/// Builds the `PrimitiveArray` and reset this builder.
pub fn finish(&mut self) -> PrimitiveArray<T> {
let len = self.len();
@@ -2583,6 +2631,35 @@ mod tests {
}
#[test]
+ fn test_primitive_array_builder_i32_append_iter() {
+ let mut builder = Int32Array::builder(5);
+ unsafe { builder.append_trusted_len_iter(0..5) }.unwrap();
+ let arr = builder.finish();
+ assert_eq!(5, arr.len());
+ assert_eq!(0, arr.offset());
+ assert_eq!(0, arr.null_count());
+ for i in 0..5 {
+ assert!(!arr.is_null(i));
+ assert!(arr.is_valid(i));
+ assert_eq!(i as i32, arr.value(i));
+ }
+ }
+
+ #[test]
+ fn test_primitive_array_builder_i32_append_nulls() {
+ let mut builder = Int32Array::builder(5);
+ builder.append_nulls(5).unwrap();
+ let arr = builder.finish();
+ assert_eq!(5, arr.len());
+ assert_eq!(0, arr.offset());
+ assert_eq!(5, arr.null_count());
+ for i in 0..5 {
+ assert!(arr.is_null(i));
+ assert!(!arr.is_valid(i));
+ }
+ }
+
+ #[test]
fn test_primitive_array_builder_date32() {
let mut builder = Date32Array::builder(5);
for i in 0..5 {
