ExampleParquetWriter may write illegal values for uint_8 and uint_16

Inizia dal punto di ingresso ExampleParquetWriter e confronta l'utilizzo dei file collegati CometTestBase.scala e Spark ParquetIOSuite.scala. Traccia come i valori uint_8 e uint_16 vengono convertiti prima di essere scritti, quindi verifica che i valori Parquet generati siano non negativi e conformi alle specifiche per gli altri lettori.

Describe the bug, including details regarding any error messages, version, and platform.

The DataFusion Comet project's unit test use the ExampleParquetWriter to create Parquet files - https://github.com/apache/datafusion-comet/blob/996362e78d497c02542f1e29dbb7cba3ec16f64c/spark/src/test/scala/org/apache/spark/sql/CometTestBase.scala#L432
This was inspired by similar unit test code in Spark - https://github.com/apache/spark/blob/ece14704cc083f17689d2e0b9ab8e31cf71a7a2d/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetIOSuite.scala#L871

The output files can contain uint8 and uint16 values that are illegal per the spec. For example in this file -

alltypes_extended_plain.parquet.zip

The columns _8 and _9 are uint_8 and uint_16 values and contain illegal negative values.

{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}
{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}
{"_1": true, "_2": 18, "_3": 10002, "_4": 10002, "_5": 10002, "_6": 10002.0, "_7": 10002.0, "_8": "100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002100021000210002", "_9": -18, "_10": -10002, "_11": -10002, "_12": -10002, "_13": "10002", "_14": [50, 50, 50], "_15": 10002, "_16": 10002, "_17": [50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50, 50], "_18": 10002, "_19": 10002, "_20": 10002}
{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}
{"_1": true, "_2": 20, "_3": 10004, "_4": 10004, "_5": 10004, "_6": 10004.0, "_7": 10004.0, "_8": "100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004100041000410004", "_9": -20, "_10": -10004, "_11": -10004, "_12": -10004, "_13": "10004", "_14": [52, 52, 52], "_15": 10004, "_16": 10004, "_17": [52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52, 52], "_18": 10004, "_19": 10004, "_20": 10004}
{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}
{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}
{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}
{"_1": true, "_2": 24, "_3": 10008, "_4": 10008, "_5": 10008, "_6": 10008.0, "_7": 10008.0, "_8": "100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008100081000810008", "_9": -24, "_10": -10008, "_11": -10008, "_12": -10008, "_13": "10008", "_14": [56, 56, 56], "_15": 10008, "_16": 10008, "_17": [56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56], "_18": 10008, "_19": 10008, "_20": 10008}
{"_1": null, "_2": null, "_3": null, "_4": null, "_5": null, "_6": null, "_7": null, "_8": null, "_9": null, "_10": null, "_11": null, "_12": null, "_13": null, "_14": null, "_15": null, "_16": null, "_17": null, "_18": null, "_19": null, "_20": null}

Taking as an example the first value for column _8 the bit pattern written to the file is 0xffffffee which gets read as a negative value which is illegal for a unsigned int.

The value originates in this line - https://github.com/apache/datafusion-comet/blob/996362e78d497c02542f1e29dbb7cba3ec16f64c/spark/src/test/scala/org/apache/spark/sql/CometTestBase.scala#L520
where a negative value is cast to a byte and then written to Parquet. The Parquet writer needs to cast correctly to a larger type before writing to the file.

The values written can be read by the Parquet-java reader but other implementations are free to return an error or null for such values which is not desirable.

Component(s)

Core