alamb commented on code in PR #9653:
URL: https://github.com/apache/arrow-rs/pull/9653#discussion_r3277136023
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parquet/src/arrow/arrow_writer/byte_array.rs:
##########
@@ -587,43 +710,111 @@ where
}
}
-/// Computes the min and max for the provided array and indices
-///
-/// This is a free function so it can be used with `downcast_op!`
-fn compute_min_max<T>(
- array: T,
- mut valid: impl Iterator<Item = usize>,
-) -> Option<(ByteArray, ByteArray)>
+/// Encodes a contiguous range from an offset-based byte array
+fn encode_dense<T>(
+ values: &GenericByteArray<T>,
+ offset: usize,
+ len: usize,
+ encoder: &mut ByteArrayEncoder,
+) where
+ T: ByteArrayType,
+{
+ if len == 0 {
+ return;
+ }
+
+ if encoder.statistics_enabled != EnabledStatistics::None {
+ update_statistics(encoder, dense_byte_values(values, offset, len));
+ }
+
+ if let Some(bloom_filter) = &mut encoder.bloom_filter {
+ update_bloom_filter(bloom_filter, dense_byte_values(values, offset,
len));
+ }
+
+ match &mut encoder.dict_encoder {
+ Some(dict_encoder) => dict_encoder.encode_dense(values, offset, len),
+ None => encoder.fallback.encode_dense(values, offset, len),
+ }
+}
+
+#[inline]
+fn byte_values<T, I>(values: T, indices: I) -> impl Iterator<Item = T::Item>
where
- T: ArrayAccessor,
- T::Item: Copy + Ord + AsRef<[u8]>,
+ T: ArrayAccessor + Copy,
+ I: Iterator<Item = usize>,
+{
+ indices.map(move |idx| values.value(idx))
+}
+
+#[inline]
+fn dense_byte_values<T>(
+ values: &GenericByteArray<T>,
+ offset: usize,
+ len: usize,
+) -> impl ExactSizeIterator<Item = &[u8]>
+where
+ T: ByteArrayType,
+{
+ let offsets = values.value_offsets();
+ let data = values.value_data();
+ (offset..offset + len).map(move |idx| dense_byte_value::<T>(offsets, data,
idx))
+}
+
+#[inline]
+fn update_statistics<T>(encoder: &mut ByteArrayEncoder, values: impl
Iterator<Item = T>)
+where
+ T: Copy + Ord + AsRef<[u8]>,
{
- let first_idx = valid.next()?;
+ if let Some(accumulator) = encoder.geo_stats_accumulator.as_mut() {
+ update_geo_stats_accumulator(accumulator.as_mut(), values);
+ } else if let Some((min, max)) = compute_min_max(values) {
+ if encoder.min_value.as_ref().is_none_or(|m| m > &min) {
+ encoder.min_value = Some(min);
+ }
- let first_val = array.value(first_idx);
+ if encoder.max_value.as_ref().is_none_or(|m| m < &max) {
+ encoder.max_value = Some(max);
+ }
+ }
+}
+
+#[inline]
+fn update_bloom_filter<T>(bloom_filter: &mut Sbbf, values: impl Iterator<Item
= T>)
+where
+ T: AsRef<[u8]>,
+{
+ for value in values {
+ bloom_filter.insert(value.as_ref());
+ }
+}
+
+/// Computes the min and max for the provided values
+#[inline]
Review Comment:
I wonder if you foudn that inlining actually helps in all these cases? We
have found that in some cases inlining actually makes the performance worse (as
there are a bunch of optimizations in LLVM that are disabled once the function
gets too big)
##########
parquet/src/arrow/arrow_writer/levels.rs:
##########
@@ -859,6 +915,163 @@ impl LevelData {
}
}
+/// Zero-allocation iterator over the indices in a [`ValueSelection`].
Review Comment:
this now has dispatch overhead for each item (the `match self`) -- we could
probably make it even faster by changing the callsite to instantiate different
loops based on the different iterators rather than checking each value 🤔
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