jianxind commented on a change in pull request #7531: URL: https://github.com/apache/arrow/pull/7531#discussion_r445249183
########## File path: cpp/src/arrow/util/spaced.h ########## @@ -0,0 +1,199 @@ +// 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. + +#pragma once + +#include "arrow/util/align_util.h" +#include "arrow/util/bit_block_counter.h" +#include "arrow/util/bitmap_reader.h" + +namespace arrow { +namespace util { +namespace internal { + +/// \brief Compress the buffer to spaced, excluding the null entries. +/// +/// \param[in] src the source buffer +/// \param[in] num_values the size of source buffer +/// \param[in] valid_bits bitmap data indicating position of valid slots +/// \param[in] valid_bits_offset offset into valid_bits +/// \param[out] output the output buffer spaced +/// \return The size of spaced buffer. +template <typename T> +inline int SpacedCompress(const T* src, int num_values, const uint8_t* valid_bits, + int64_t valid_bits_offset, T* output) { + int num_valid_values = 0; + int idx_src = 0; + + const auto p = + arrow::internal::BitmapWordAlign<1>(valid_bits, valid_bits_offset, num_values); + // First handle the leading bits + const int leading_bits = static_cast<int>(p.leading_bits); + while (idx_src < leading_bits) { + if (BitUtil::GetBit(valid_bits, valid_bits_offset)) { + output[num_valid_values] = src[idx_src]; + num_valid_values++; + } + idx_src++; + valid_bits_offset++; + } + + // The aligned parts scaned with BitBlockCounter Review comment: done ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
