alamb commented on code in PR #7649: URL: https://github.com/apache/arrow-rs/pull/7649#discussion_r2153018217
########## arrow-row/src/run.rs: ########## @@ -0,0 +1,695 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use crate::{variable, RowConverter, Rows, SortField}; +use arrow_array::types::RunEndIndexType; +use arrow_array::{PrimitiveArray, RunArray}; +use arrow_buffer::{ArrowNativeType, ScalarBuffer}; +use arrow_schema::{ArrowError, SortOptions}; + +/// Computes the lengths of each row for a RunEndEncodedArray +pub fn compute_lengths<R: RunEndIndexType>( + lengths: &mut [usize], + rows: &Rows, + array: &RunArray<R>, +) { + let run_ends = array.run_ends().values(); + let mut logical_start = 0; + + // Iterate over each run and apply the same length to all logical positions in the run + for (physical_idx, &run_end) in run_ends.iter().enumerate() { + let logical_end = run_end.as_usize(); + let row = rows.row(physical_idx); + let encoded_len = variable::encoded_len(Some(row.data)); + + // Add the same length for all logical positions in this run + for length in &mut lengths[logical_start..logical_end] { + *length += encoded_len; + } + + logical_start = logical_end; + } +} + +/// Encodes the provided `RunEndEncodedArray` to `out` with the provided `SortOptions` +/// +/// `rows` should contain the encoded values +pub fn encode<R: RunEndIndexType>( + data: &mut [u8], + offsets: &mut [usize], + rows: &Rows, + opts: SortOptions, + array: &RunArray<R>, +) { + let run_ends = array.run_ends(); + + let mut logical_idx = 0; + let mut offset_idx = 1; // Skip first offset + + // Iterate over each run + for physical_idx in 0..run_ends.values().len() { + let run_end = run_ends.values()[physical_idx].as_usize(); + + // Process all elements in this run + while logical_idx < run_end && offset_idx < offsets.len() { + let offset = &mut offsets[offset_idx]; + let out = &mut data[*offset..]; + + // Use variable-length encoding to make the data self-describing + let row = rows.row(physical_idx); Review Comment: Tracking with - https://github.com/apache/arrow-rs/issues/7693 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
