emkornfield commented on code in PR #48431: URL: https://github.com/apache/arrow/pull/48431#discussion_r2749835100
########## cpp/src/parquet/metadata3.h: ########## @@ -0,0 +1,71 @@ +// 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/result.h" +#include "flatbuffers/flatbuffers.h" +#include "generated/parquet3_generated.h" +#include "generated/parquet_types.h" +#include "parquet/thrift_internal.h" + +namespace parquet { + +// Convert to flatbuffer representation of the footer metadata. +// Return false if the schema is not supported by the FlatBuffer format. +bool ToFlatbuffer(format::FileMetaData* md, std::string* flatbuf); + +// The flatbuffer in `from` must be valid (such as one retured by `ToFlatbuffer`). +format::FileMetaData FromFlatbuffer(const format3::FileMetaData* md); + + +// Append/extract the flatbuffer from the footer as a thrift extension: +// https://github.com/apache/parquet-format/blob/master/BinaryProtocolExtensions.md. +// +// `flatbuf` is the flatbuffer representation of the footer metadata. +// `thrift` is the buffer containing the thrift representation of the footer metadata as its suffix. +// +// Returns the number of bytes added. +// +// The extension itself is as follows: +// +// +-------------------+------------+--------------------------------------+----------------+---------+--------------------------------+------+ +// | compress(flatbuf) | compressor | crc(compress(flatbuf) .. compressor) | compressed_len | raw_len | crc(compressed_len .. raw_len) | UUID | Review Comment: This should be documented in the parquet-format PR. -- 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]
