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#[cfg(feature = "object")]
use arrow::array::Array;
use arrow::compute::concatenate;
use super::*;
#[cfg(feature = "object")]
use crate::chunked_array::object::builder::ObjectChunkedBuilder;
use crate::utils::slice_offsets;
#[inline]
fn slice(
chunks: &[ArrayRef],
offset: i64,
slice_length: usize,
own_length: usize,
) -> (Vec<ArrayRef>, usize) {
let mut new_chunks = Vec::with_capacity(1);
let (raw_offset, slice_len) = slice_offsets(offset, slice_length, own_length);
let mut remaining_length = slice_len;
let mut remaining_offset = raw_offset;
let mut new_len = 0;
for chunk in chunks {
let chunk_len = chunk.len();
if remaining_offset > 0 && remaining_offset >= chunk_len {
remaining_offset -= chunk_len;
continue;
}
let take_len = if remaining_length + remaining_offset > chunk_len {
chunk_len - remaining_offset
} else {
remaining_length
};
new_len += take_len;
debug_assert!(remaining_offset + take_len <= chunk.len());
unsafe {
new_chunks.push(chunk.slice_unchecked(remaining_offset, take_len));
}
remaining_length -= take_len;
remaining_offset = 0;
if remaining_length == 0 {
break;
}
}
if new_chunks.is_empty() {
new_chunks.push(chunks[0].slice(0, 0));
}
(new_chunks, new_len)
}
impl<T: PolarsDataType> ChunkedArray<T> {
pub fn len(&self) -> usize {
self.length as usize
}
pub fn is_empty(&self) -> bool {
self.len() == 0
}
pub(crate) fn compute_len(&mut self) {
fn inner(chunks: &[ArrayRef]) -> usize {
match chunks.len() {
1 => chunks[0].len(),
_ => chunks.iter().fold(0, |acc, arr| acc + arr.len()),
}
}
self.length = inner(&self.chunks) as IdxSize
}
pub fn rechunk(&self) -> Self {
match self.dtype() {
#[cfg(feature = "object")]
DataType::Object(_) => {
panic!("implementation error")
}
_ => {
fn inner_rechunk(chunks: &[ArrayRef]) -> Vec<ArrayRef> {
vec![concatenate::concatenate(
chunks.iter().map(|a| &**a).collect::<Vec<_>>().as_slice(),
)
.unwrap()]
}
if self.chunks.len() == 1 {
self.clone()
} else {
let chunks = inner_rechunk(&self.chunks);
self.copy_with_chunks(chunks, true)
}
}
}
}
#[inline]
pub fn slice(&self, offset: i64, length: usize) -> Self {
let (chunks, len) = slice(&self.chunks, offset, length, self.len());
let mut out = self.copy_with_chunks(chunks, true);
out.length = len as IdxSize;
out
}
#[must_use]
pub fn limit(&self, num_elements: usize) -> Self
where
Self: Sized,
{
self.slice(0, num_elements)
}
#[must_use]
pub fn head(&self, length: Option<usize>) -> Self
where
Self: Sized,
{
match length {
Some(len) => self.slice(0, std::cmp::min(len, self.len())),
None => self.slice(0, std::cmp::min(10, self.len())),
}
}
#[must_use]
pub fn tail(&self, length: Option<usize>) -> Self
where
Self: Sized,
{
let len = match length {
Some(len) => std::cmp::min(len, self.len()),
None => std::cmp::min(10, self.len()),
};
self.slice(-(len as i64), len)
}
}
#[cfg(feature = "object")]
impl<T: PolarsObject> ObjectChunked<T> {
pub(crate) fn rechunk_object(&self) -> Self {
if self.chunks.len() == 1 {
self.clone()
} else {
let mut builder = ObjectChunkedBuilder::new(self.name(), self.len());
let chunks = self.downcast_iter();
if !self.has_validity() {
for arr in chunks {
for idx in 0..arr.len() {
builder.append_value(arr.value(idx).clone())
}
}
} else {
for arr in chunks {
for idx in 0..arr.len() {
if arr.is_valid(idx) {
builder.append_value(arr.value(idx).clone())
} else {
builder.append_null()
}
}
}
}
builder.finish()
}
}
}
#[cfg(test)]
mod test {
#[cfg(feature = "dtype-categorical")]
use crate::prelude::*;
#[test]
#[cfg(feature = "dtype-categorical")]
fn test_categorical_map_after_rechunk() {
let s = Series::new("", &["foo", "bar", "spam"]);
let mut a = s.cast(&DataType::Categorical(None)).unwrap();
a.append(&a.slice(0, 2)).unwrap();
let a = a.rechunk();
assert!(a.categorical().unwrap().get_rev_map().len() > 0);
}
}