mapleFU commented on code in PR #46463: URL: https://github.com/apache/arrow/pull/46463#discussion_r2107194946
########## cpp/src/parquet/metadata.cc: ########## @@ -334,8 +335,19 @@ class ColumnChunkMetaData::ColumnChunkMetaDataImpl { return possible_geo_stats_ != nullptr && possible_geo_stats_->is_valid(); } + inline std::shared_ptr<EncodedStatistics> encoded_statistics() const { + return is_stats_set() ? possible_encoded_stats_ : nullptr; + } + inline std::shared_ptr<Statistics> statistics() const { - return is_stats_set() ? possible_stats_ : nullptr; + if (is_stats_set()) { + // Because we are modifying possible_stats_ in a const method + const std::lock_guard<std::mutex> guard(stats_mutex_); + if (possible_stats_ == nullptr) { + possible_stats_ = MakeColumnStats(*column_metadata_, descr_); + } + } + return possible_stats_; Review Comment: @pitrou 's idea looks good to me! -- 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