public void FileMetadata_sets_num_rows_on_file_and_row_group_multiple_row_groups()
{
var ms = new MemoryStream();
var id = new DataField <int>("id");
//write
using (var writer = new ParquetWriter(new Schema(id), ms))
{
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new[] { 1, 2, 3, 4 }));
}
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new[] { 5, 6 }));
}
}
//read back
using (var reader = new ParquetReader(ms))
{
Assert.Equal(6, reader.ThriftMetadata.Num_rows);
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(0))
{
Assert.Equal(4, rg.RowCount);
}
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(1))
{
Assert.Equal(2, rg.RowCount);
}
}
}
public void Write_in_small_row_groups()
{
//write a single file having 3 row groups
var id = new DataField <int>("id");
var ms = new MemoryStream();
using (var writer = new ParquetWriter(new Schema(id), ms))
{
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new int[] { 1 }));
}
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new int[] { 2 }));
}
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new int[] { 3 }));
}
}
//read the file back and validate
ms.Position = 0;
using (var reader = new ParquetReader(ms))
{
Assert.Equal(3, reader.RowGroupCount);
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(0))
{
Assert.Equal(1, rg.RowCount);
DataColumn dc = rg.ReadColumn(id);
Assert.Equal(new int[] { 1 }, dc.Data);
}
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(1))
{
Assert.Equal(1, rg.RowCount);
DataColumn dc = rg.ReadColumn(id);
Assert.Equal(new int[] { 2 }, dc.Data);
}
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(2))
{
Assert.Equal(1, rg.RowCount);
DataColumn dc = rg.ReadColumn(id);
Assert.Equal(new int[] { 3 }, dc.Data);
}
}
}
public static Dictionary <int, string> ReadParquetFile(string infile)
{
Dictionary <int, string> serializedRequests = new Dictionary <int, string>();
string path = Path.GetFullPath(Directory.GetCurrentDirectory() + "/" + infile);
using (Stream fileStream = File.OpenRead(path))
{
using (var parquetReader = new ParquetReader(fileStream))
{
DataField[] dataFields = parquetReader.Schema.GetDataFields();
using (ParquetRowGroupReader groupReader = parquetReader.OpenRowGroupReader(0))
{
DataColumn[] columns = dataFields.Select(groupReader.ReadColumn).ToArray();
DataColumn firstColumn = columns[0];
DataColumn secondColumn = columns[1];
Array idData = firstColumn.Data;
Array requestData = secondColumn.Data;
for (var j = 0; j < firstColumn.Data.Length; j++)
{
var convertedRequestData = (string)requestData.GetValue(j);
var convertedIdData = (int)idData.GetValue(j);
serializedRequests.Add(convertedIdData, convertedRequestData);
}
}
return(serializedRequests);
}
}
}
public void ReadIntro()
{
// open file stream
using (Stream fileStream = System.IO.File.OpenRead("c:\\test.parquet"))
{
// open parquet file reader
using (var parquetReader = new ParquetReader(fileStream))
{
// get file schema (available straight after opening parquet reader)
// however, get only data fields as only they contain data values
DataField[] dataFields = parquetReader.Schema.GetDataFields();
// enumerate through row groups in this file
for (int i = 0; i < parquetReader.RowGroupCount; i++)
{
// create row group reader
using (ParquetRowGroupReader groupReader = parquetReader.OpenRowGroupReader(i))
{
// read all columns inside each row group (you have an option to read only
// required columns if you need to.
DataColumn[] columns = dataFields.Select(groupReader.ReadColumn).ToArray();
// get first column, for instance
DataColumn firstColumn = columns[0];
// .Data member contains a typed array of column data you can cast to the type of the column
Array data = firstColumn.Data;
int[] ids = (int[])data;
}
}
}
}
}
public IEnumerable <DataColumn[]> GetData(string file)
{
using (Stream fileStream = System.IO.File.OpenRead(file))
{
// open parquet file reader
using (var parquetReader = new ParquetReader(fileStream))
{
// get file schema (available straight after opening parquet reader)
// however, get only data fields as only they contain data values
DataField[] dataFields = parquetReader.Schema.GetDataFields();
// enumerate through row groups in this file
for (int i = 0; i < parquetReader.RowGroupCount; i++)
{
// create row group reader
using (ParquetRowGroupReader groupReader = parquetReader.OpenRowGroupReader(i))
{
// read all columns inside each row group (you have an option to read only
// required columns if you need to.
yield return(dataFields.Select(groupReader.ReadColumn).ToArray());
}
}
}
}
}
public void Write_read_nullable_column(Array input)
{
var id = new DataField <int?>("id");
var ms = new MemoryStream();
using (var writer = new ParquetWriter(new Schema(id), ms))
{
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, input));
}
}
ms.Position = 0;
using (var reader = new ParquetReader(ms))
{
Assert.Equal(1, reader.RowGroupCount);
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(0))
{
Assert.Equal(input.Length, rg.RowCount);
Assert.Equal(input, rg.ReadColumn(id).Data);
}
}
}
public static DataTable ParquetReaderToDataTable(ParquetReader parquetReader, out int totalRecordCount, List <string> selectedFields, int offset, int recordCount)
{
//Get list of data fields and construct the DataTable
DataTable dataTable = new DataTable();
List <Parquet.Data.DataField> fields = new List <Parquet.Data.DataField>();
var dataFields = parquetReader.Schema.GetDataFields();
foreach (string selectedField in selectedFields)
{
var dataField = dataFields.FirstOrDefault(f => f.Name.Equals(selectedField, StringComparison.InvariantCultureIgnoreCase));
if (dataField != null)
{
fields.Add(dataField);
DataColumn newColumn = new DataColumn(dataField.Name, ParquetNetTypeToCSharpType(dataField.DataType))
{
// Should not set this, or line 89 in ProcessRowGroup() will throw an exception with any required field (because assigning later than adding)
//AllowDBNull = dataField.HasNulls
};
dataTable.Columns.Add(newColumn);
}
else
{
throw new Exception(string.Format("Field '{0}' does not exist", selectedField));
}
}
//Read column by column to generate each row in the datatable
totalRecordCount = 0;
for (int i = 0; i < parquetReader.RowGroupCount; i++)
{
int rowsLeftToRead = recordCount;
using (ParquetRowGroupReader groupReader = parquetReader.OpenRowGroupReader(i))
{
if (groupReader.RowCount > int.MaxValue)
{
throw new ArgumentOutOfRangeException(string.Format("Cannot handle row group sizes greater than {0}", groupReader.RowCount));
}
int rowsPassedUntilThisRowGroup = totalRecordCount;
totalRecordCount += (int)groupReader.RowCount;
if (offset >= totalRecordCount)
{
continue;
}
if (rowsLeftToRead > 0)
{
int numberOfRecordsToReadFromThisRowGroup = Math.Min(Math.Min(totalRecordCount - offset, recordCount), (int)groupReader.RowCount);
rowsLeftToRead -= numberOfRecordsToReadFromThisRowGroup;
int recordsToSkipInThisRowGroup = Math.Max(offset - rowsPassedUntilThisRowGroup, 0);
ProcessRowGroup(dataTable, groupReader, fields, recordsToSkipInThisRowGroup, numberOfRecordsToReadFromThisRowGroup);
}
}
}
return(dataTable);
}
public void List_of_elements_with_some_items_empty_reads_file()
{
/*
* list data:
* - 1: [1, 2, 3]
* - 2: []
* - 3: [1, 2, 3]
* - 4: []
*/
using (var reader = new ParquetReader(OpenTestFile("listofitems-empty-alternates.parquet")))
{
using (ParquetRowGroupReader groupReader = reader.OpenRowGroupReader(0))
{
Assert.Equal(4, groupReader.RowCount);
DataField[] fs = reader.Schema.GetDataFields();
DataColumn id = groupReader.ReadColumn(fs[0]);
Assert.Equal(4, id.Data.Length);
Assert.False(id.HasRepetitions);
DataColumn list = groupReader.ReadColumn(fs[1]);
Assert.Equal(8, list.Data.Length);
Assert.Equal(new int[] { 0, 1, 1, 0, 0, 1, 1, 0 }, list.RepetitionLevels);
}
}
}
private bool LoadRowGroup(int rowGroup)
{
using (var reader = _parquetReader.OpenRowGroupReader(rowGroup))
{
_rowIndex = 0;
_rowCount = reader.RowCount;
var columns = new List <Parquet.Data.DataColumn>();
foreach (var f in _fields)
{
try
{
columns.Add(reader.ReadColumn(f));
}
catch (IndexOutOfRangeException)
{
// this happens if every single element in the column within the rowgroup is null,
// TODO: Figure out how to read the header to detect this without an exception
columns.Add(null);
}
}
_columns = columns;
}
return(true);
}
public static void TestAgainstThirdParty()
{
var columns = new Column[] { new Column <decimal>("Decimal", LogicalType.Decimal(precision: 29, scale: 3)) };
var values = Enumerable.Range(0, 10_000)
.Select(i => ((decimal)i * i * i) / 1000 - 10)
.Concat(new [] { decimal.MinValue / 1000, decimal.MaxValue / 1000 })
.ToArray();
using var buffer = new ResizableBuffer();
// Write using ParquetSharp
using (var outStream = new BufferOutputStream(buffer))
{
using var fileWriter = new ParquetFileWriter(outStream, columns, Compression.Snappy);
using var rowGroupWriter = fileWriter.AppendRowGroup();
using var columnWriter = rowGroupWriter.NextColumn().LogicalWriter <decimal>();
columnWriter.WriteBatch(values);
fileWriter.Close();
}
// Read using Parquet.NET
using var memoryStream = new MemoryStream(buffer.ToArray());
using var fileReader = new ParquetReader(memoryStream);
using var rowGroupReader = fileReader.OpenRowGroupReader(0);
var read = (decimal[])rowGroupReader.ReadColumn(fileReader.Schema.GetDataFields()[0]).Data;
Assert.AreEqual(values, read);
}
public void Write_multiple_row_groups_to_forward_only_stream()
{
var ms = new MemoryStream();
var forwardOnly = new WriteableNonSeekableStream(ms);
var schema = new Schema(
new DataField <int>("id"),
new DataField <string>("nonsense"));
using (var writer = new ParquetWriter(schema, forwardOnly))
{
using (ParquetRowGroupWriter rgw = writer.CreateRowGroup(1))
{
rgw.WriteColumn(new DataColumn((DataField)schema[0], new[] { 1 }));
rgw.WriteColumn(new DataColumn((DataField)schema[1], new[] { "1" }));
}
using (ParquetRowGroupWriter rgw = writer.CreateRowGroup(1))
{
rgw.WriteColumn(new DataColumn((DataField)schema[0], new[] { 2 }));
rgw.WriteColumn(new DataColumn((DataField)schema[1], new[] { "2" }));
}
}
ms.Position = 0;
using (var reader = new ParquetReader(ms))
{
Assert.Equal(2, reader.RowGroupCount);
using (ParquetRowGroupReader rgr = reader.OpenRowGroupReader(0))
{
Assert.Equal(1, rgr.RowCount);
DataColumn column = rgr.ReadColumn((DataField)schema[0]);
Assert.Equal(1, column.Data.GetValue(0));
}
using (ParquetRowGroupReader rgr = reader.OpenRowGroupReader(1))
{
Assert.Equal(1, rgr.RowCount);
DataColumn column = rgr.ReadColumn((DataField)schema[0]);
Assert.Equal(2, column.Data.GetValue(0));
}
}
}
public void Append_to_file_reads_all_data()
{
//write a file with a single row group
var id = new DataField <int>("id");
var ms = new MemoryStream();
using (var writer = new ParquetWriter(new Schema(id), ms))
{
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new int[] { 1, 2 }));
}
}
//append to this file. Note that you cannot append to existing row group, therefore create a new one
ms.Position = 0;
using (var writer = new ParquetWriter(new Schema(id), ms, append: true))
{
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new int[] { 3, 4 }));
}
}
//check that this file now contains two row groups and all the data is valid
ms.Position = 0;
using (var reader = new ParquetReader(ms))
{
Assert.Equal(2, reader.RowGroupCount);
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(0))
{
Assert.Equal(2, rg.RowCount);
Assert.Equal(new int[] { 1, 2 }, rg.ReadColumn(id).Data);
}
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(1))
{
Assert.Equal(2, rg.RowCount);
Assert.Equal(new int[] { 3, 4 }, rg.ReadColumn(id).Data);
}
}
}
public static List <T> ReadParquet <T>(this Stream stream) where T : class, new()
{
Type classType = typeof(T);
List <T> results = new List <T>();
var properties = classType.GetProperties().ToDictionary(p => p.Name, p => p);
var bytes = stream.ReadAsBytes().GetAwaiter().GetResult();
using (ParquetReader reader = new ParquetReader(new MemoryStream(bytes)))
{
DataField[] fields = reader.Schema.GetDataFields();
for (int g = 0; g < reader.RowGroupCount; g++)
{
using (ParquetRowGroupReader rowGroupReader = reader.OpenRowGroupReader(g))
{
DataColumn[] columns = fields.Select(rowGroupReader.ReadColumn).ToArray();
if (columns.Length > 0)
{
for (int i = 0; i < columns[0].Data.Length; i++)
{
T item = new T();
foreach (var column in columns)
{
var prop = properties[column.Field.Name];
if (column.Field.DataType == ParquetDataType.DateTimeOffset)
{
if (prop.PropertyType == DateTimeType)
{
prop.SetValue(item, ((DateTimeOffset)column.Data.GetValue(i)).DateTime);
}
else if (prop.PropertyType == NullableDateTimeType)
{
var value = column.Data.GetValue(i);
if (value != null)
{
prop.SetValue(item, ((DateTimeOffset)value).DateTime);
}
}
}
else
{
prop.SetValue(item, column.Data.GetValue(i));
}
}
results.Add(item);
}
}
}
}
}
return(results);
}
private IEnumerable <DataColumn[]> ReadAllObjects(ParquetReader sr, Func <object, bool?> filterFunc = null)
{
DataField[] dataFields = sr.Schema.GetDataFields();
for (int i = 0; i < sr.RowGroupCount; i++)
{
using (ParquetRowGroupReader groupReader = sr.OpenRowGroupReader(i))
{
var dc = dataFields.Select(groupReader.ReadColumn).ToArray();
yield return(dc);
}
}
}
/// <summary>
/// Obtiene un dataTable a partir de un archivo parquet
/// </summary>
public DataTable ParquetReaderToDataTable(string fileName, int offset, int recordCount, out int totalRecordCount)
{
DataTable dataTable = new DataTable();
// Inicializa el número total de registros
totalRecordCount = 0;
// Lee el archivo
using (System.IO.Stream fileReader = System.IO.File.OpenRead(fileName))
{
using (ParquetReader parquetReader = new ParquetReader(fileReader))
{
DataField[] dataFields = parquetReader.Schema.GetDataFields();
// Crea las columnas en la tabla
CreateColumns(dataTable, dataFields);
//Read column by column to generate each row in the datatable
for (int rowGroup = 0; rowGroup < parquetReader.RowGroupCount; rowGroup++)
{
int rowsLeftToRead = recordCount;
using (ParquetRowGroupReader groupReader = parquetReader.OpenRowGroupReader(rowGroup))
{
if (groupReader.RowCount > int.MaxValue)
{
throw new ArgumentOutOfRangeException(string.Format("Cannot handle row group sizes greater than {0}", groupReader.RowCount));
}
int rowsPassedUntilThisRowGroup = totalRecordCount;
totalRecordCount += (int)groupReader.RowCount;
if (offset >= totalRecordCount)
{
continue;
}
if (rowsLeftToRead > 0)
{
int numberOfRecordsToReadFromThisRowGroup = Math.Min(Math.Min(totalRecordCount - offset, recordCount), (int)groupReader.RowCount);
rowsLeftToRead -= numberOfRecordsToReadFromThisRowGroup;
int recordsToSkipInThisRowGroup = Math.Max(offset - rowsPassedUntilThisRowGroup, 0);
ProcessRowGroup(dataTable, groupReader, dataFields, recordsToSkipInThisRowGroup, numberOfRecordsToReadFromThisRowGroup);
}
}
}
}
}
// Devuelve los datos leidos
return(dataTable);
}
public static List <Dictionary <string, object> > ReadParquetAdDictData(this Stream stream, List <string> mappedFields = null)
{
List <Dictionary <string, object> > results = new List <Dictionary <string, object> >();
var bytes = stream.ReadAsBytes().GetAwaiter().GetResult();
using (ParquetReader reader = new ParquetReader(new MemoryStream(bytes)))
{
DataField[] fields = reader.Schema.GetDataFields();
for (int g = 0; g < reader.RowGroupCount; g++)
{
using (ParquetRowGroupReader rowGroupReader = reader.OpenRowGroupReader(g))
{
DataColumn[] columns = fields.Select(rowGroupReader.ReadColumn).ToArray();
if (columns.Length > 0)
{
Dictionary <string, DataColumn> columnDict = columns.ToDictionary(c => c.Field.Name, c => c);
if (mappedFields != null)
{
Dictionary <string, DataColumn> mappedDict = new Dictionary <string, DataColumn>();
for (int i = 0; i < mappedFields.Count; i++)
{
var mappedField = mappedFields[i];
if (!mappedDict.ContainsKey(mappedField) && columnDict.ContainsKey(mappedField))
{
mappedDict.Add(mappedField, columnDict[mappedField]);
}
}
columnDict = mappedDict;
}
for (int i = 0; i < columns[0].Data.Length; i++)
{
var item = new Dictionary <string, object>();
foreach (var column in columnDict.Values)
{
item.Add(column.Field.Name, column.Data.GetValue(i));
}
results.Add(item);
}
}
}
}
}
return(results);
}
private DataColumn[] ReadParquet(string name, bool treatByteArrayAsString)
{
using (Stream s = OpenTestFile(name))
{
using (var pr = new ParquetReader(s, new ParquetOptions {
TreatByteArrayAsString = treatByteArrayAsString
}))
{
using (ParquetRowGroupReader rgr = pr.OpenRowGroupReader(0))
{
return(pr.Schema.GetDataFields()
.Select(df => rgr.ReadColumn(df))
.ToArray());
}
}
}
}
protected object WriteReadSingle(DataField field, object value, CompressionMethod compressionMethod = CompressionMethod.None, int compressionLevel = -1)
{
//for sanity, use disconnected streams
byte[] data;
using (var ms = new MemoryStream())
{
// write single value
using (var writer = new ParquetWriter(new Schema(field), ms))
{
writer.CompressionMethod = compressionMethod;
writer.CompressionLevel = compressionLevel;
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
Array dataArray = Array.CreateInstance(field.ClrNullableIfHasNullsType, 1);
dataArray.SetValue(value, 0);
var column = new DataColumn(field, dataArray);
rg.WriteColumn(column);
}
}
data = ms.ToArray();
}
using (var ms = new MemoryStream(data))
{
// read back single value
ms.Position = 0;
using (var reader = new ParquetReader(ms))
{
using (ParquetRowGroupReader rowGroupReader = reader.OpenRowGroupReader(0))
{
DataColumn column = rowGroupReader.ReadColumn(field);
return(column.Data.GetValue(0));
}
}
}
}
protected DataColumn[] WriteReadSingleRowGroup(Schema schema, DataColumn[] columns, out Schema readSchema)
{
using (var ms = new MemoryStream())
{
ms.WriteSingleRowGroupParquetFile(schema, columns);
ms.Position = 0;
using (var reader = new ParquetReader(ms))
{
readSchema = reader.Schema;
using (ParquetRowGroupReader rgReader = reader.OpenRowGroupReader(0))
{
return(columns.Select(c =>
rgReader.ReadColumn(c.Field))
.ToArray());
}
}
}
}
protected DataColumn WriteReadSingleColumn(DataField field, DataColumn dataColumn)
{
using (var ms = new MemoryStream())
{
// write with built-in extension method
ms.WriteSingleRowGroupParquetFile(new Schema(field), dataColumn);
ms.Position = 0;
// read first gow group and first column
using (var reader = new ParquetReader(ms))
{
if (reader.RowGroupCount == 0)
{
return(null);
}
ParquetRowGroupReader rgReader = reader.OpenRowGroupReader(0);
return(rgReader.ReadColumn(field));
}
}
}
public T[] LoadColumn <T>(DataField column)
{
if (_data.TryGetValue(column, out var arr))
{
return(arr as T[]);
}
//TODO: these should not be needed
// Find the datafield we want to use
var dataField = Array.Find(_reader.Schema.GetDataFields(), field => field.Name == column.Name);
if (dataField == null)
{
throw new ArgumentException($"Couldn't find column {column.Name} in table");
}
T[] data = null;
try
{
// Read the data pages
for (var page = 0; page < _reader.RowGroupCount; page++)
{
// TODO: Do this asynchronously?
var pageReader = _reader.OpenRowGroupReader(page);
var dataColumn = pageReader.ReadColumn(dataField);
var prevLength = data?.Length ?? 0;
Array.Resize(ref data, prevLength + dataColumn.Data.Length);
Array.Copy(dataColumn.Data, 0, data, prevLength, dataColumn.Data.Length);
}
}
catch (ArrayTypeMismatchException ex)
{
throw new ArrayTypeMismatchException($"Could not load column {column.Name}. The expected data is {typeof(T)} but actual data was {dataField.DataType}.\n\n{ex.Message}");
}
_data[column] = data;
return(data);
}
/// <summary>
/// Reads data from parquet stream
/// </summary>
/// <typeparam name="TModel">Type of model</typeparam>
/// <param name="mapConfig">Mapping configuration</param>
/// <param name="fileStream">Parquet stream</param>
/// <returns>parsed data</returns>
public TModel[] Read <TModel>(MapperConfig <TModel> mapConfig, Stream fileStream)
where TModel : new()
{
using var parquetReader = new ParquetReader(fileStream);
var dataFields = parquetReader.Schema.GetDataFields();
long modelOffset = 0;
var resArr = CreateArray <TModel>(parquetReader.ThriftMetadata.Num_rows);
for (int i = 0; i < parquetReader.RowGroupCount; i++)
{
using var groupReader = parquetReader.OpenRowGroupReader(i);
var columns = dataFields.Where(w => mapConfig.Contains(w.Name)).Select(groupReader.ReadColumn).ToArray();
ReadColumns(mapConfig, resArr, columns, modelOffset);
// increment offset to read next rowGroup
modelOffset += groupReader.RowCount;
}
return(resArr);
}
public void BackwardCompat_list_with_one_array()
{
using (Stream input = OpenTestFile("legacy-list-onearray.parquet"))
{
using (var reader = new ParquetReader(input))
{
Schema schema = reader.Schema;
//validate schema
Assert.Equal("impurityStats", schema[3].Name);
Assert.Equal(SchemaType.List, schema[3].SchemaType);
Assert.Equal("gain", schema[4].Name);
Assert.Equal(SchemaType.Data, schema[4].SchemaType);
//smoke test we can read it
using (ParquetRowGroupReader rg = reader.OpenRowGroupReader(0))
{
DataColumn values4 = rg.ReadColumn((DataField)schema[4]);
}
}
}
}
public void Read_multi_page_dictionary_with_nulls()
{
using (var reader = new ParquetReader(OpenTestFile("/special/multi_page_dictionary_with_nulls.parquet")))
{
DataColumn[] columns = reader.ReadEntireRowGroup();
var rg = reader.OpenRowGroupReader(0);
// reading columns
var data = (string[])columns[0].Data;
// ground truth from spark
// check page boundary (first page contains 107432 rows)
Assert.Equal("xc3w4eudww", data[107432]);
Assert.Equal("bpywp4wtwk", data[107433]);
Assert.Equal("z6x8652rle", data[107434]);
// check near the end of the file
Assert.Null(data[310028]);
Assert.Equal("wok86kie6c", data[310029]);
Assert.Equal("le9i7kbbib", data[310030]);
}
}
public static IEnumerable <T> ReadParquet <T>(this Stream stream) where T : class, new()
{
Type classType = typeof(T);
var properties = classType.GetProperties().ToDictionary(p => p.Name, p => p);
using (ParquetReader reader = new ParquetReader(stream))
{
DataField[] fields = reader.Schema.GetDataFields();
for (int g = 0; g < reader.RowGroupCount; g++)
{
using (ParquetRowGroupReader rowGroupReader = reader.OpenRowGroupReader(g))
{
DataColumn[] columns = fields.Select(rowGroupReader.ReadColumn).ToArray();
if (columns.Length > 0)
{
for (int i = 0; i < columns[0].Data.Length; i++)
{
T item = new T();
foreach (var column in columns)
{
var prop = properties[column.Field.Name];
if (column.Field.DataType == DataType.DateTimeOffset && prop.PropertyType == DateTimeType)
{
prop.SetValue(item, ((DateTimeOffset)column.Data.GetValue(i)).DateTime);
}
else
{
prop.SetValue(item, column.Data.GetValue(i));
}
}
yield return(item);
}
}
}
}
}
}
private IEnumerable <List <DataColumn[]> > ReadObjectsByRowGroup(ParquetReader sr, Func <object, bool?> filterFunc = null)
{
DataField[] dataFields = sr.Schema.GetDataFields();
for (int i = 0; i < sr.RowGroupCount; i++)
{
if (RaiseBeforeRowGroupLoad(i, null))
{
continue;
}
List <DataColumn[]> rowGroup = new List <DataColumn[]>();
using (ParquetRowGroupReader groupReader = sr.OpenRowGroupReader(i))
{
var dc = dataFields.Select(groupReader.ReadColumn).ToArray();
rowGroup.Add(dc);
}
if (!RaiseAfterRowGroupLoaded(i, rowGroup))
{
yield return(rowGroup);
}
}
}
public async Task SimpleTransformation()
{
var settings = GetAzureSettings();
try
{
using (var store = GetDocumentStore())
{
var baseline = new DateTime(2020, 1, 1);
using (var session = store.OpenAsyncSession())
{
for (int i = 1; i <= 10; i++)
{
var o = new Order
{
Id = $"orders/{i}",
OrderedAt = baseline.AddDays(i),
Company = $"companies/{i}",
ShipVia = $"shippers/{i}"
};
await session.StoreAsync(o);
}
await session.SaveChangesAsync();
}
var etlDone = WaitForEtl(store, (n, statistics) => statistics.LoadSuccesses != 0);
var script = @"
var orderDate = new Date(this.OrderedAt);
var year = orderDate.getFullYear();
var month = orderDate.getMonth();
var key = new Date(year, month);
loadToOrders(partitionBy(key),
{
Company : this.Company,
ShipVia : this.ShipVia
})
";
SetupAzureEtl(store, script, settings);
etlDone.Wait(TimeSpan.FromMinutes(1));
using (var client = RavenAzureClient.Create(settings, DefaultBackupConfiguration))
{
var prefix = $"{settings.RemoteFolderName}/{CollectionName}";
var result = await client.ListBlobsAsync(prefix, delimiter : string.Empty, listFolders : false);
var list = result.List.ToList();
Assert.Equal(1, list.Count);
var blob = await client.GetBlobAsync(list[0].Name);
await using var ms = new MemoryStream();
blob.Data.CopyTo(ms);
using (var parquetReader = new ParquetReader(ms))
{
Assert.Equal(1, parquetReader.RowGroupCount);
var expectedFields = new[] { "Company", "ShipVia", ParquetTransformedItems.DefaultIdColumn, ParquetTransformedItems.LastModifiedColumn };
Assert.Equal(expectedFields.Length, parquetReader.Schema.Fields.Count);
using var rowGroupReader = parquetReader.OpenRowGroupReader(0);
foreach (var field in parquetReader.Schema.Fields)
{
Assert.True(field.Name.In(expectedFields));
var data = rowGroupReader.ReadColumn((DataField)field).Data;
Assert.True(data.Length == 10);
if (field.Name == ParquetTransformedItems.LastModifiedColumn)
{
continue;
}
var count = 1;
foreach (var val in data)
{
switch (field.Name)
{
case ParquetTransformedItems.DefaultIdColumn:
Assert.Equal($"orders/{count}", val);
break;
case "Company":
Assert.Equal($"companies/{count}", val);
break;
case "ShipVia":
Assert.Equal($"shippers/{count}", val);
break;
}
count++;
}
}
}
}
}
}
finally
{
await DeleteObjects(settings);
}
}
public async Task CanLoadToMultipleTables()
{
const string salesTableName = "Sales";
var settings = GetAzureSettings();
try
{
using (var store = GetDocumentStore())
{
var baseline = new DateTime(2020, 1, 1);
using (var session = store.OpenAsyncSession())
{
for (int i = 0; i < 31; i++)
{
var orderedAt = baseline.AddDays(i);
var lines = new List <OrderLine>();
for (int j = 1; j <= 5; j++)
{
lines.Add(new OrderLine
{
Quantity = j * 10,
PricePerUnit = i + j,
Product = $"Products/{j}"
});
}
var o = new Order
{
Id = $"orders/{i}",
OrderedAt = orderedAt,
RequireAt = orderedAt.AddDays(7),
Company = $"companies/{i}",
Lines = lines
};
await session.StoreAsync(o);
}
baseline = baseline.AddMonths(1);
for (int i = 0; i < 28; i++)
{
var orderedAt = baseline.AddDays(i);
var lines = new List <OrderLine>();
for (int j = 1; j <= 5; j++)
{
lines.Add(new OrderLine
{
Quantity = j * 10,
PricePerUnit = i + j,
Product = $"Products/{j}"
});
}
var o = new Order
{
Id = $"orders/{i + 31}",
OrderedAt = orderedAt,
RequireAt = orderedAt.AddDays(7),
Company = $"companies/{i}",
Lines = lines
};
await session.StoreAsync(o);
}
await session.SaveChangesAsync();
}
var etlDone = WaitForEtl(store, (n, statistics) => statistics.LoadSuccesses != 0);
var script = @"
var orderData = {
Company : this.Company,
RequireAt : new Date(this.RequireAt),
ItemsCount: this.Lines.length,
TotalCost: 0
};
var orderDate = new Date(this.OrderedAt);
var year = orderDate.getFullYear();
var month = orderDate.getMonth();
var key = new Date(year, month);
for (var i = 0; i < this.Lines.length; i++) {
var line = this.Lines[i];
orderData.TotalCost += (line.PricePerUnit * line.Quantity);
// load to 'sales' table
loadToSales(partitionBy(key), {
Qty: line.Quantity,
Product: line.Product,
Cost: line.PricePerUnit
});
}
// load to 'orders' table
loadToOrders(partitionBy(key), orderData);
";
SetupAzureEtl(store, script, settings);
etlDone.Wait(TimeSpan.FromMinutes(1));
using (var client = RavenAzureClient.Create(settings, DefaultBackupConfiguration))
{
var prefix = $"{settings.RemoteFolderName}/{CollectionName}";
var result = await client.ListBlobsAsync(prefix, delimiter : string.Empty, listFolders : false);
var list = result.List.ToList();
Assert.Equal(2, list.Count);
Assert.Contains("2020-01-01", list[0].Name);
Assert.Contains("2020-02-01", list[1].Name);
var blob = await client.GetBlobAsync(list[0].Name);
await using var ms = new MemoryStream();
blob.Data.CopyTo(ms);
using (var parquetReader = new ParquetReader(ms))
{
Assert.Equal(1, parquetReader.RowGroupCount);
var expectedFields = new[] { "Company", "RequireAt", "ItemsCount", "TotalCost", ParquetTransformedItems.DefaultIdColumn, ParquetTransformedItems.LastModifiedColumn };
Assert.Equal(expectedFields.Length, parquetReader.Schema.Fields.Count);
using var rowGroupReader = parquetReader.OpenRowGroupReader(0);
foreach (var field in parquetReader.Schema.Fields)
{
Assert.True(field.Name.In(expectedFields));
var data = rowGroupReader.ReadColumn((DataField)field).Data;
Assert.True(data.Length == 31);
}
}
}
//sales
using (var client = RavenAzureClient.Create(settings, DefaultBackupConfiguration))
{
var prefix = $"{settings.RemoteFolderName}/{salesTableName}";
var result = await client.ListBlobsAsync(prefix, delimiter : string.Empty, listFolders : false);
var list = result.List.ToList();
Assert.Equal(2, list.Count);
Assert.Contains("2020-01-01", list[0].Name);
Assert.Contains("2020-02-01", list[1].Name);
var blob = await client.GetBlobAsync(list[1].Name);
await using var ms = new MemoryStream();
blob.Data.CopyTo(ms);
using (var parquetReader = new ParquetReader(ms))
{
Assert.Equal(1, parquetReader.RowGroupCount);
var expectedFields = new[] { "Qty", "Product", "Cost", ParquetTransformedItems.DefaultIdColumn, ParquetTransformedItems.LastModifiedColumn };
Assert.Equal(expectedFields.Length, parquetReader.Schema.Fields.Count);
using var rowGroupReader = parquetReader.OpenRowGroupReader(0);
foreach (var field in parquetReader.Schema.Fields)
{
Assert.True(field.Name.In(expectedFields));
var data = rowGroupReader.ReadColumn((DataField)field).Data;
Assert.True(data.Length == 28 * 5);
}
}
}
}
}
finally
{
await DeleteObjects(settings, salesTableName);
}
}
public async Task SimpleTransformation_NoPartition()
{
var settings = GetAzureSettings();
try
{
using (var store = GetDocumentStore())
{
var baseline = new DateTime(2020, 1, 1).ToUniversalTime();
using (var session = store.OpenAsyncSession())
{
for (int i = 0; i < 100; i++)
{
await session.StoreAsync(new Order
{
Id = $"orders/{i}",
OrderedAt = baseline.AddDays(i),
ShipVia = $"shippers/{i}",
Company = $"companies/{i}"
});
}
await session.SaveChangesAsync();
}
var etlDone = WaitForEtl(store, (n, statistics) => statistics.LoadSuccesses != 0);
var script = @"
loadToOrders(noPartition(),
{
OrderDate : this.OrderedAt
Company : this.Company,
ShipVia : this.ShipVia
});
";
SetupAzureEtl(store, script, settings);
etlDone.Wait(TimeSpan.FromMinutes(1));
using (var client = RavenAzureClient.Create(settings, DefaultBackupConfiguration))
{
var prefix = $"{settings.RemoteFolderName}/{CollectionName}";
var cloudObjects = await client.ListBlobsAsync(prefix, delimiter : string.Empty, listFolders : false);
var list = cloudObjects.List.ToList();
Assert.Equal(1, list.Count);
var blob = await client.GetBlobAsync(list[0].Name);
await using var ms = new MemoryStream();
blob.Data.CopyTo(ms);
using (var parquetReader = new ParquetReader(ms))
{
Assert.Equal(1, parquetReader.RowGroupCount);
var expectedFields = new[] { "OrderDate", "ShipVia", "Company", ParquetTransformedItems.DefaultIdColumn, ParquetTransformedItems.LastModifiedColumn };
Assert.Equal(expectedFields.Length, parquetReader.Schema.Fields.Count);
using var rowGroupReader = parquetReader.OpenRowGroupReader(0);
foreach (var field in parquetReader.Schema.Fields)
{
Assert.True(field.Name.In(expectedFields));
var data = rowGroupReader.ReadColumn((DataField)field).Data;
Assert.True(data.Length == 100);
if (field.Name == ParquetTransformedItems.LastModifiedColumn)
{
continue;
}
var count = 0;
foreach (var val in data)
{
if (field.Name == "OrderDate")
{
var expectedDto = new DateTimeOffset(DateTime.SpecifyKind(baseline.AddDays(count), DateTimeKind.Utc));
Assert.Equal(expectedDto, val);
}
else
{
var expected = field.Name switch
{
ParquetTransformedItems.DefaultIdColumn => $"orders/{count}",
"Company" => $"companies/{count}",
"ShipVia" => $"shippers/{count}",
_ => null
};
Assert.Equal(expected, val);
}
count++;
}
}
}
}
}
}
finally
{
await DeleteObjects(settings);
}
}
public async Task SimpleTransformation_MultiplePartitions()
{
var settings = GetAzureSettings();
var prefix = $"{settings.RemoteFolderName}/{CollectionName}/";
try
{
using (var store = GetDocumentStore())
{
var baseline = DateTime.SpecifyKind(new DateTime(2020, 1, 1), DateTimeKind.Utc);
using (var session = store.OpenAsyncSession())
{
const int total = 31 + 28; // days in January + days in February
for (int i = 0; i < total; i++)
{
var orderedAt = baseline.AddDays(i);
await session.StoreAsync(new Order
{
Id = $"orders/{i}",
OrderedAt = orderedAt,
RequireAt = orderedAt.AddDays(7),
ShipVia = $"shippers/{i}",
Company = $"companies/{i}"
});
}
for (int i = 1; i <= 37; i++)
{
var index = i + total;
var orderedAt = baseline.AddYears(1).AddMonths(1).AddDays(i);
await session.StoreAsync(new Order
{
Id = $"orders/{index}",
OrderedAt = orderedAt,
RequireAt = orderedAt.AddDays(7),
ShipVia = $"shippers/{index}",
Company = $"companies/{index}"
});
}
await session.SaveChangesAsync();
}
var etlDone = WaitForEtl(store, (n, statistics) => statistics.LoadSuccesses != 0 && statistics.LoadErrors == 0);
var script = @"
var orderDate = new Date(this.OrderedAt);
loadToOrders(partitionBy(
['year', orderDate.getFullYear()],
['month', orderDate.getMonth() + 1]
),
{
Company : this.Company,
ShipVia : this.ShipVia,
RequireAt : this.RequireAt
});
";
SetupAzureEtl(store, script, settings);
etlDone.Wait(TimeSpan.FromMinutes(1));
var expectedFields = new[] { "RequireAt", "ShipVia", "Company", ParquetTransformedItems.DefaultIdColumn, ParquetTransformedItems.LastModifiedColumn };
using (var client = RavenAzureClient.Create(settings, DefaultBackupConfiguration))
{
var cloudObjects = await client.ListBlobsAsync(prefix, delimiter : "/", listFolders : true);
var list = cloudObjects.List.ToList();
Assert.Equal(2, list.Count);
Assert.Contains("Orders/year=2020/", list[0].Name);
Assert.Contains("Orders/year=2021/", list[1].Name);
for (var index = 1; index <= list.Count; index++)
{
var folder = list[index - 1];
var objectsInFolder = await client.ListBlobsAsync(prefix : folder.Name, delimiter : "/", listFolders : true);
var objects = objectsInFolder.List.ToList();
Assert.Equal(2, objects.Count);
Assert.Contains($"month={index}/", objects[0].Name);
Assert.Contains($"month={index + 1}/", objects[1].Name);
}
var files = await ListAllFilesInFolders(client, list);
Assert.Equal(4, files.Count);
foreach (var filePath in files)
{
var blob = await client.GetBlobAsync(filePath);
await using var ms = new MemoryStream();
blob.Data.CopyTo(ms);
using (var parquetReader = new ParquetReader(ms))
{
Assert.Equal(1, parquetReader.RowGroupCount);
Assert.Equal(expectedFields.Length, parquetReader.Schema.Fields.Count);
using var rowGroupReader = parquetReader.OpenRowGroupReader(0);
foreach (var field in parquetReader.Schema.Fields)
{
Assert.True(field.Name.In(expectedFields));
var data = rowGroupReader.ReadColumn((DataField)field).Data;
Assert.True(data.Length == 31 || data.Length == 28 || data.Length == 27 || data.Length == 10);
if (field.Name != "RequireAt")
{
continue;
}
var count = data.Length switch
{
31 => 0,
28 => 31,
27 => 365 + 33,
10 => 365 + 33 + 27,
_ => throw new ArgumentOutOfRangeException()
};
foreach (var val in data)
{
var expectedOrderDate = new DateTimeOffset(DateTime.SpecifyKind(baseline.AddDays(count++), DateTimeKind.Utc));
var expected = expectedOrderDate.AddDays(7);
Assert.Equal(expected, val);
}
}
}
}
}
}
}
finally
{
await DeleteObjects(settings, prefix, delimiter : "/", listFolder : true);
}
}