alamb commented on code in PR #6202: URL: https://github.com/apache/arrow-rs/pull/6202#discussion_r1710066463
########## parquet/src/file/metadata/writer.rs: ########## @@ -0,0 +1,608 @@ +// 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::errors::Result; +use crate::file::metadata::{KeyValue, ParquetMetaData}; +use crate::file::page_index::index::Index; +use crate::file::writer::TrackedWrite; +use crate::file::PARQUET_MAGIC; +use crate::format::{ColumnIndex, OffsetIndex, RowGroup}; +use crate::schema::types; +use crate::schema::types::{SchemaDescPtr, SchemaDescriptor, TypePtr}; +use crate::thrift::TSerializable; +use std::io::Write; +use std::sync::Arc; +use thrift::protocol::TCompactOutputProtocol; + +/// Writes `crate::file::metadata` structures to a thrift encoded byte streams +/// +/// See [`ParquetMetaDataWriter`] for background and example. +pub(crate) struct ThriftMetadataWriter<'a, W: Write> { + buf: &'a mut TrackedWrite<W>, + schema: &'a TypePtr, + schema_descr: &'a SchemaDescPtr, + row_groups: Vec<RowGroup>, + column_indexes: Option<&'a [Vec<Option<ColumnIndex>>]>, + offset_indexes: Option<&'a [Vec<Option<OffsetIndex>>]>, + key_value_metadata: Option<Vec<KeyValue>>, + created_by: Option<String>, + writer_version: i32, +} + +impl<'a, W: Write> ThriftMetadataWriter<'a, W> { + /// Serialize all the offset index to the file + fn write_offset_indexes(&mut self, offset_indexes: &[Vec<Option<OffsetIndex>>]) -> Result<()> { + // iter row group + // iter each column + // write offset index to the file + for (row_group_idx, row_group) in self.row_groups.iter_mut().enumerate() { + for (column_idx, column_metadata) in row_group.columns.iter_mut().enumerate() { + match &offset_indexes[row_group_idx][column_idx] { + Some(offset_index) => { + let start_offset = self.buf.bytes_written(); + let mut protocol = TCompactOutputProtocol::new(&mut self.buf); + offset_index.write_to_out_protocol(&mut protocol)?; + let end_offset = self.buf.bytes_written(); + // set offset and index for offset index + column_metadata.offset_index_offset = Some(start_offset as i64); + column_metadata.offset_index_length = + Some((end_offset - start_offset) as i32); + } + None => {} + } + } + } + Ok(()) + } + + /// Serialize all the column index to the file + fn write_column_indexes(&mut self, column_indexes: &[Vec<Option<ColumnIndex>>]) -> Result<()> { Review Comment: Done in cc6f9bf5d57 -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
