zeroshade commented on a change in pull request #10951: URL: https://github.com/apache/arrow/pull/10951#discussion_r700442503
########## File path: go/parquet/metadata/column_chunk.go ########## @@ -0,0 +1,385 @@ +// 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. + +package metadata + +import ( + "bytes" + "context" + "io" + "reflect" + + "github.com/apache/arrow/go/arrow/memory" + "github.com/apache/arrow/go/parquet" + "github.com/apache/arrow/go/parquet/compress" + "github.com/apache/arrow/go/parquet/internal/encryption" + format "github.com/apache/arrow/go/parquet/internal/gen-go/parquet" + "github.com/apache/arrow/go/parquet/internal/thrift" + "github.com/apache/arrow/go/parquet/schema" + "golang.org/x/xerrors" +) + +// PageEncodingStats is used for counting the number of pages of specific +// types with the given internal encoding. +type PageEncodingStats struct { + Encoding parquet.Encoding + PageType format.PageType +} + +func makeColumnStats(metadata *format.ColumnMetaData, descr *schema.Column, mem memory.Allocator) TypedStatistics { + if descr.ColumnOrder() == parquet.ColumnOrders.TypeDefinedOrder { + return NewStatisticsFromEncoded(descr, mem, metadata.Statistics.MinValue, metadata.Statistics.MaxValue, + metadata.NumValues-metadata.Statistics.GetNullCount(), + metadata.Statistics.GetNullCount(), metadata.Statistics.GetDistinctCount(), + metadata.Statistics.IsSetMaxValue() || metadata.Statistics.IsSetMinValue(), + metadata.Statistics.IsSetNullCount(), metadata.Statistics.IsSetDistinctCount()) + } + return NewStatisticsFromEncoded(descr, mem, metadata.Statistics.Min, metadata.Statistics.Max, + metadata.NumValues-metadata.Statistics.GetNullCount(), + metadata.Statistics.GetNullCount(), metadata.Statistics.GetDistinctCount(), + metadata.Statistics.IsSetMax() || metadata.Statistics.IsSetMin(), + metadata.Statistics.IsSetNullCount(), metadata.Statistics.IsSetDistinctCount()) +} + +// ColumnChunkMetaData is a proxy around format.ColumnChunkMetaData +// containing all of the information and metadata for a given column chunk +// and it's associated Column +type ColumnChunkMetaData struct { + column *format.ColumnChunk + columnMeta *format.ColumnMetaData + decryptedMeta format.ColumnMetaData + descr *schema.Column + writerVersion *AppVersion + encodings []parquet.Encoding + encodingStats []format.PageEncodingStats + possibleStats TypedStatistics + mem memory.Allocator +} + +// NewColumnChunkMetaData creates an instance of the metadata from a column chunk and descriptor +// +// this is primarily used internally or between the subpackages. ColumnChunkMetaDataBuilder should +// be used by consumers instead of using this directly. +func NewColumnChunkMetaData(column *format.ColumnChunk, descr *schema.Column, writerVersion *AppVersion, rowGroupOrdinal, columnOrdinal int16, fileDecryptor encryption.FileDecryptor) (*ColumnChunkMetaData, error) { + c := &ColumnChunkMetaData{ + column: column, + columnMeta: column.GetMetaData(), + descr: descr, + writerVersion: writerVersion, + mem: memory.DefaultAllocator, + } + if column.IsSetCryptoMetadata() { + ccmd := column.CryptoMetadata + + if ccmd.IsSetENCRYPTION_WITH_COLUMN_KEY() { + if fileDecryptor != nil && fileDecryptor.Properties() != nil { + // should decrypt metadata + path := parquet.ColumnPath(ccmd.ENCRYPTION_WITH_COLUMN_KEY.GetPathInSchema()) + keyMetadata := ccmd.ENCRYPTION_WITH_COLUMN_KEY.GetKeyMetadata() + aadColumnMetadata := encryption.CreateModuleAad(fileDecryptor.FileAad(), encryption.ColumnMetaModule, rowGroupOrdinal, columnOrdinal, -1) + decryptor := fileDecryptor.GetColumnMetaDecryptor(path.String(), string(keyMetadata), aadColumnMetadata) + thrift.DeserializeThrift(&c.decryptedMeta, decryptor.Decrypt(column.GetEncryptedColumnMetadata())) + c.columnMeta = &c.decryptedMeta + } else { + return nil, xerrors.New("cannot decrypt column metadata. file decryption not setup correctly") + } + } + } + for _, enc := range c.columnMeta.Encodings { + c.encodings = append(c.encodings, parquet.Encoding(enc)) + } + for _, enc := range c.columnMeta.EncodingStats { + c.encodingStats = append(c.encodingStats, *enc) + } + return c, nil +} + +// CryptoMetadata returns the cryptographic metadata for how this column was +// encrypted and how to decrypt it. +func (c *ColumnChunkMetaData) CryptoMetadata() *format.ColumnCryptoMetaData { + return c.column.GetCryptoMetadata() +} + +// FileOffset is the location in the file where the column data begins +func (c *ColumnChunkMetaData) FileOffset() int64 { return c.column.FileOffset } + +// FilePath gives the name of the parquet file if provided in the metadata +func (c *ColumnChunkMetaData) FilePath() string { return c.column.GetFilePath() } + +// Type is the physical storage type used in the parquet file for this column chunk. +func (c *ColumnChunkMetaData) Type() parquet.Type { return parquet.Type(c.columnMeta.Type) } + +// NumValues is the number of values stored in just this chunk Review comment: updated comment. -- This is an automated message from the Apache Git Service. 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