private void ReadDataBackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
{
//Parquet.NET doesn't have any async methods or readers that allow sequential records reading so we need to use the ThreadPool to support cancellation.
var task = Task <ParquetReadResult> .Run(() =>
{
//Unfortunately there's no way to quickly get the metadata from a parquet file without reading an actual data row
//BUG: Parquet.NET doesn't always respect the Count parameter, sometimes returning more than the passed value...
using (var parquetReader = ParquetReader.OpenFromFile(this.OpenFilePath, new ParquetOptions()
{
TreatByteArrayAsString = true
}))
{
int totalRowCount = 0;
DataTable result = UtilityMethods.ParquetReaderToDataTable(parquetReader, out totalRowCount, this.SelectedFields, this.CurrentOffset, this.CurrentMaxRowCount);
return(new ParquetReadResult(result, totalRowCount));
}
});
while (!task.IsCompleted && !((BackgroundWorker)sender).CancellationPending)
{
task.Wait(1000);
}
e.Cancel = ((BackgroundWorker)sender).CancellationPending;
if (task.IsCompleted)
{
e.Result = task.Result;
}
}
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 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 override IEnumerable <object> AsEnumerable(object source, Func <object, bool?> filterFunc = null)
{
if (source == null)
{
yield break;
}
ParquetReader sr = source as ParquetReader;
ChoGuard.ArgumentNotNull(sr, "ParquetReader");
InitializeRecordConfiguration(Configuration);
if (!RaiseBeginLoad(sr))
{
yield break;
}
if (InterceptRowGroup)
{
foreach (var item in AsEnumerable(ReadObjectsByRowGroup(sr).SelectMany(i => i.Select(i1 => i1)), TraceSwitch, filterFunc))
{
yield return(item);
}
}
else
{
foreach (var item in AsEnumerable(ReadAllObjects(sr), TraceSwitch, filterFunc))
{
yield return(item);
}
}
RaiseEndLoad(sr);
}
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);
}
}
}
public void Special_read_file_with_multiple_row_groups()
{
var ms = new MemoryStream();
//create multirowgroup file
//first row group
var t = new Table(new DataField <int>("id"));
t.Add(1);
t.Add(2);
using (var writer = new ParquetWriter(t.Schema, ms))
{
writer.Write(t);
}
//second row group
t.Clear();
t.Add(3);
t.Add(4);
using (var writer = new ParquetWriter(t.Schema, ms, null, true))
{
writer.Write(t);
}
//read back as table
t = ParquetReader.ReadTableFromStream(ms);
Assert.Equal(4, t.Count);
}
public void Read_simple_repeated_field()
{
/*
* root
|-- cities: array (nullable = true)
| |-- element: string (containsNull = true)
|-- id: long (nullable = true)
*/
DataSet ds = ParquetReader.ReadFile(GetDataFilePath("simplerepeated.parquet"));
Assert.Equal(2, ds.Schema.Length);
Assert.Equal(typeof(IEnumerable <string>), ds.Schema[0].ColumnType);
Assert.Equal(typeof(string), ds.Schema[0].ElementType);
Assert.Equal(typeof(long), ds.Schema[1].ElementType);
Assert.Equal("cities", ds.Schema[0].Name);
Assert.Equal("id", ds.Schema[1].Name);
Assert.True(ds.Schema[0].IsRepeated);
Assert.False(ds.Schema[1].IsRepeated);
Assert.Equal(1L, ds[0][1]);
Assert.Equal(ds[0][0], new[] { "London", "Derby", "Paris", "New York" });
}
public override IEnumerable <object> AsEnumerable(object source, Func <object, bool?> filterFunc = null)
{
if (source == null)
{
yield break;
}
ParquetReader sr = source as ParquetReader;
ChoGuard.ArgumentNotNull(sr, "ParquetReader");
InitializeRecordConfiguration(Configuration);
if (!RaiseBeginLoad(sr))
{
yield break;
}
foreach (var item in AsEnumerable(ReadObjects(sr), TraceSwitch, filterFunc))
{
yield return(item);
}
RaiseEndLoad(sr);
}
public IEnumerator <T> GetEnumerator()
{
CheckDisposed();
ChoParquetRecordReader rr = new ChoParquetRecordReader(typeof(T), Configuration);
if (_streamReader != null)
{
_parquetReader = Create(_streamReader.Value);
}
rr.Reader = this;
rr.TraceSwitch = TraceSwitch;
rr.RowsLoaded += NotifyRowsLoaded;
rr.BeforeRowGroupLoad += BeforeRowGroupLoad;
rr.AfterRowGroupLoaded += AfterRowGroupLoaded;
rr.MembersDiscovered += MembersDiscovered;
rr.RecordFieldTypeAssessment += RecordFieldTypeAssessment;
var beforeRowGroup = BeforeRowGroupLoad;
var afterRowGroup = AfterRowGroupLoaded;
if (beforeRowGroup != null || afterRowGroup != null)
{
rr.InterceptRowGroup = true;
}
var e = rr.AsEnumerable(_parquetReader).GetEnumerator();
return(ChoEnumeratorWrapper.BuildEnumerable <T>(() => {
++_recordNumber;
return e.MoveNext();
}, () => (T)ChoConvert.ChangeType <ChoRecordFieldAttribute>(e.Current, typeof(T)), () => Dispose()).GetEnumerator());
}
private void CompareWithMr(Table t)
{
string testFileName = Path.GetFullPath("temp.parquet");
if (F.Exists(testFileName))
{
F.Delete(testFileName);
}
//produce file
using (Stream s = F.OpenWrite(testFileName))
{
using (var writer = new ParquetWriter(t.Schema, s))
{
writer.Write(t);
}
}
//read back
Table t2 = ParquetReader.ReadTableFromFile(testFileName);
//check we don't have a bug internally before launching MR
Assert.Equal(t.ToString("j"), t2.ToString("j"), ignoreLineEndingDifferences: true);
string mrJson = ExecAndGetOutput(_javaExecName, $"-jar {_toolsJarPath} cat -j {testFileName}");
Assert.Equal(t.ToString("j"), mrJson);
}
public void Read_multiple_data_pages()
{
using (var reader =
new ParquetReader(OpenTestFile("/special/multi_data_page.parquet"), leaveStreamOpen: false))
{
DataColumn[] columns = reader.ReadEntireRowGroup();
string[] s = (string[])columns[0].Data;
double?[] d = (double?[])columns[1].Data;
// check for nulls (issue #370)
for (int i = 0; i < s.Length; i++)
{
Assert.True(s[i] != null, "found null in s at " + i);
Assert.True(d[i] != null, "found null in d at " + i);
}
// run aggregations checking row alignment (issue #371)
var seq = s.Zip(d.Cast <double>(), (w, v) => new { w, v })
.Where(p => p.w == "general")
.ToList();
// double matching is fuzzy, but matching strings is enough for this test
Assert.Equal("0.754359925788497", seq.Min(p => p.v).ToString(CultureInfo.InvariantCulture));
Assert.Equal("0.85776", seq.Max(p => p.v).ToString(CultureInfo.InvariantCulture));
}
}
public void Write_and_read_nullable_integers()
{
var ds = new DataSet(new DataField <int?>("id"))
{
1,
2,
3,
(object)null,
4,
(object)null,
5
};
var ms = new MemoryStream();
ParquetWriter.Write(ds, ms);
ms.Position = 0;
DataSet ds1 = ParquetReader.Read(ms);
Assert.Equal(1, ds1[0].GetInt(0));
Assert.Equal(2, ds1[1].GetInt(0));
Assert.Equal(3, ds1[2].GetInt(0));
Assert.True(ds1[3].IsNullAt(0));
Assert.Equal(4, ds1[4].GetInt(0));
Assert.True(ds1[5].IsNullAt(0));
Assert.Equal(5, ds1[6].GetInt(0));
}
public void Reads_really_mad_nested_file()
{
/* Spark schema:
* root
|-- addresses: array (nullable = true)
| |-- element: struct (containsNull = true)
| | |-- line1: string (nullable = true)
| | |-- name: string (nullable = true)
| | |-- openingHours: array (nullable = true)
| | | |-- element: long (containsNull = true)
| | |-- postcode: string (nullable = true)
|-- cities: array (nullable = true)
| |-- element: string (containsNull = true)
|-- comment: string (nullable = true)
|-- id: long (nullable = true)
|-- location: struct (nullable = true)
| |-- latitude: double (nullable = true)
| |-- longitude: double (nullable = true)
|-- price: struct (nullable = true)
| |-- lunch: struct (nullable = true)
| | |-- max: long (nullable = true)
| | |-- min: long (nullable = true)
*/
DataSet ds = ParquetReader.Read(OpenTestFile("nested.parquet"));
//much easier to compare mad nestness with .ToString(), but will break when it changes
Assert.Equal("{[{Dante Road;Head Office;[9;10;11;12;13;14;15;16;17;18];SE11};{Somewhere Else;Small Office;[6;7;19;20;21;22;23];TN19}];[London;Derby];this file contains all the permunations for nested structures and arrays to test Parquet parser;1;{51.2;66.3};{{2;1}}}", ds[0].ToString());
Assert.Equal("{[{Dante Road;Head Office;[9;10;11;12;13;14;15;16;17;18];SE11};{Somewhere Else;Small Office;[6;7;19;20;21;22;23];TN19}];[London;Derby];this file contains all the permunations for nested structures and arrays to test Parquet parser;1;{51.2;66.3};{{2;1}}}", ds[1].ToString());
}
public void Type_writes_and_reads_end_to_end(SchemaElement schema, object value, string name = null)
{
var ds = new DataSet(schema)
{
new Row(value)
};
var ms = new MemoryStream();
ParquetWriter.Write(ds, ms);
ms.Position = 0;
DataSet ds1 = ParquetReader.Read(ms);
object expectedValue = ds[0][0];
object actualValue = ds1[0][0];
if (schema.ElementType == typeof(DateTime))
{
actualValue = ((DateTimeOffset)actualValue).DateTime;
}
Assert.True(expectedValue.Equals(actualValue),
$"{name}| expected: {expectedValue}, actual: {actualValue}, schema element: {schema}");
//if (schema.ElementType == typeof(decimal)) ParquetWriter.WriteFile(ds1, "c:\\tmp\\decimals.parquet");
}
public void List_simple_element_write_read()
{
var table = new Table(
new Schema(
new DataField <int>("id"),
new ListField("cities",
new DataField <string>("name"))));
var ms = new MemoryStream();
table.Add(1, new[] { "London", "Derby" });
table.Add(2, new[] { "Paris", "New York" });
//write as table
using (var writer = new ParquetWriter(table.Schema, ms))
{
writer.Write(table);
}
//read back into table
ms.Position = 0;
Table table2;
using (var reader = new ParquetReader(ms))
{
table2 = reader.ReadAsTable();
}
//validate data
Assert.Equal(table.ToString(), table2.ToString(), ignoreLineEndingDifferences: true);
}
public static async Task <DataSet> LoadAsync(StorageFile file, int offset = 0, int count = 100)
{
using (IRandomAccessStreamWithContentType uwpStream = await file.OpenReadAsync())
{
using (Stream stream = uwpStream.AsStreamForRead())
{
var readerOptions = new ReaderOptions()
{
Offset = offset,
Count = count
};
var formatOptions = new ParquetOptions
{
TreatByteArrayAsString = true
};
try
{
return(ParquetReader.Read(stream, formatOptions, readerOptions));
}
catch (Exception ex)
{
var dialog = new MessageDialog(ex.Message, "Cannot open file");
await dialog.ShowAsync();
return(null);
}
}
}
}
public void Flat_write_read()
{
var table = new Table(new Schema(new DataField <int>("id"), new DataField <string>("city")));
var ms = new MemoryStream();
//generate fake data
for (int i = 0; i < 1000; i++)
{
table.Add(new Row(i, "record#" + i));
}
//write to stream
using (var writer = new ParquetWriter(table.Schema, ms))
{
writer.Write(table);
}
//read back into table
ms.Position = 0;
Table table2;
using (var reader = new ParquetReader(ms))
{
table2 = reader.ReadAsTable();
}
//validate data
Assert.True(table.Equals(table2, true));
}
public void Write_and_read_nullable_integers()
{
var ds = new DataSet(new SchemaElement <int>("id"))
{
1,
2,
3,
(object)null,
4,
(object)null,
5
};
var ms = new MemoryStream();
ParquetWriter.Write(ds, ms);
ms.Position = 0;
DataSet ds1 = ParquetReader.Read(ms);
Assert.Equal(ds1[0].GetInt(0), 1);
Assert.Equal(ds1[1].GetInt(0), 2);
Assert.Equal(ds1[2].GetInt(0), 3);
Assert.True(ds1[3].IsNullAt(0));
Assert.Equal(ds1[4].GetInt(0), 4);
Assert.True(ds1[5].IsNullAt(0));
Assert.Equal(ds1[6].GetInt(0), 5);
}
public void Array_write_read()
{
var table = new Table(
new Schema(
new DataField <int>("id"),
new DataField <string[]>("categories") //array field
)
);
var ms = new MemoryStream();
table.Add(1, new[] { "1", "2", "3" });
table.Add(3, new[] { "3", "3", "3" });
//write to stream
using (var writer = new ParquetWriter(table.Schema, ms))
{
writer.Write(table);
}
//System.IO.File.WriteAllBytes("c:\\tmp\\1.parquet", ms.ToArray());
//read back into table
ms.Position = 0;
Table table2;
using (var reader = new ParquetReader(ms))
{
table2 = reader.ReadAsTable();
}
//validate data
Assert.Equal(table.ToString(), table2.ToString(), ignoreLineEndingDifferences: true);
}
public ParquetDataReader(ParquetReader parquetReader, IEnumerable <DataField> fields, IEnumerable <ColumnConverter> columnConverters)
{
_parquetReader = parquetReader ?? throw new ArgumentNullException(nameof(parquetReader));
_fields = fields?.ToList() ?? throw new ArgumentNullException(nameof(fields));
_rowGroupCount = parquetReader.RowGroupCount;
_columnConverters = new Lazy <List <Func <object, object> > >(() => InitializeColumnConverters(columnConverters), true);
}
public void Read_simple_nested_field()
{
/*
* root
|-- city: struct (nullable = true)
| |-- country: string (nullable = true)
| |-- isCapital: boolean (nullable = true)
| |-- name: string (nullable = true)
|-- id: long (nullable = true)
*/
//Assert.Throws<NotSupportedException>(() => ParquetReader.ReadFile(GetDataFilePath("simplenested.parquet")));
//return;
DataSet ds = ParquetReader.ReadFile(GetDataFilePath("simplenested.parquet"));
Assert.Equal(1, ds.RowCount);
Assert.Equal(2, ds.ColumnCount);
Assert.Equal(typeof(Row), ds.Schema[0].ElementType);
Assert.Equal(typeof(long), ds.Schema[1].ElementType);
Assert.Equal("city", ds.Schema.ColumnNames[0]);
Assert.Equal("id", ds.Schema.ColumnNames[1]);
Row mr = ds[0];
Row city = mr.Get <Row>(0);
Assert.Equal("United Kingdom", city[0]);
Assert.True((bool)city[1]);
Assert.Equal("London", city[2]);
Assert.Equal(1L, mr[1]);
}
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 Read_multiple_data_pages()
{
using (var reader =
new ParquetReader(OpenTestFile("/special/multi_data_page.parquet"), leaveStreamOpen: false))
{
DataColumn[] columns = reader.ReadEntireRowGroup();
string[] s = (string[])columns[0].Data;
double?[] d = (double?[])columns[1].Data;
// check for nulls (issue #370)
for (int i = 0; i < s.Length; i++)
{
Assert.True(s[i] != null, "found null in s at " + i);
Assert.True(d[i] != null, "found null in d at " + i);
}
// run aggregations checking row alignment (issue #371)
var seq = s.Zip(d.Cast <double>(), (w, v) => new { w, v })
.Where(p => p.w == "favorable")
.ToList();
// double matching is fuzzy, but matching strings is enough for this test
// ground truth was computed using Spark
Assert.Equal(26706.6185312147, seq.Sum(p => p.v), 5);
Assert.Equal(0.808287234987281, seq.Average(p => p.v), 5);
Assert.Equal(0.71523915461624, seq.Min(p => p.v), 5);
Assert.Equal(0.867111980015206, seq.Max(p => p.v), 5);
}
}
public void All_compression_methods_supported(CompressionMethod compressionMethod)
{
//v2
var ms = new MemoryStream();
DataSet ds1 = new DataSet(new DataField <int>("id"));
DataSet ds2;
ds1.Add(5);
//write
using (var writer = new ParquetWriter(ms))
{
writer.Write(ds1, CompressionMethod.Gzip);
}
//read back
using (var reader = new ParquetReader(ms))
{
ms.Position = 0;
ds2 = reader.Read();
}
Assert.Equal(5, ds2[0].GetInt(0));
//v3
const int value = 5;
object actual = WriteReadSingle(new DataField <int>("id"), value, compressionMethod);
Assert.Equal(5, (int)actual);
}
protected override bool MoveNextCore()
{
if (_dataSetEnumerator.MoveNext())
{
_curDataSetRow = _dataSetEnumerator.Current;
return(true);
}
else if (_blockEnumerator.MoveNext())
{
_readerOptions.Offset = (long)_blockEnumerator.Current * _readerOptions.Count;
// When current dataset runs out, read the next portion of the parquet file.
DataSet ds;
lock (_loader._parquetStream)
{
ds = ParquetReader.Read(_loader._parquetStream, _loader._parquetOptions, _readerOptions);
}
var dataSetOrder = CreateOrderSequence(ds.RowCount);
_dataSetEnumerator = dataSetOrder.GetEnumerator();
_curDataSetRow = dataSetOrder.ElementAt(0);
// Cache list for each active column
for (int i = 0; i < _actives.Length; i++)
{
Column col = _loader._columnsLoaded[_actives[i]];
_columnValues[i] = ds.GetColumn(col.DataField);
}
return(_dataSetEnumerator.MoveNext());
}
return(false);
}
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 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 void I_can_write_snappy_and_read_back()
{
var ms = new MemoryStream();
var ds1 = new DataSet(
new DataField<int>("id"),
new DataField<int>("no"));
ds1.Add(1, 3);
ds1.Add(2, 4);
DataSet ds2;
//write
using (var writer = new ParquetWriter(ms))
{
writer.Write(ds1, CompressionMethod.Snappy);
}
//read back
using (var reader = new ParquetReader(ms))
{
ms.Position = 0;
ds2 = reader.Read();
}
Assert.Equal(1, ds2[0].GetInt(0));
Assert.Equal(2, ds2[1].GetInt(0));
Assert.Equal(3, ds2[0].GetInt(1));
Assert.Equal(4, ds2[1].GetInt(1));
}
public void CustomMetadata_can_write_and_read()
{
var ms = new MemoryStream();
var id = new DataField <int>("id");
//write
using (var writer = new ParquetWriter(new Schema(id), ms))
{
writer.CustomMetadata = new Dictionary <string, string>
{
["key1"] = "value1",
["key2"] = "value2"
};
using (ParquetRowGroupWriter rg = writer.CreateRowGroup())
{
rg.WriteColumn(new DataColumn(id, new[] { 1, 2, 3, 4 }));
}
}
//read back
using (var reader = new ParquetReader(ms))
{
Assert.Equal("value1", reader.CustomMetadata["key1"]);
Assert.Equal("value2", reader.CustomMetadata["key2"]);
}
}
protected Thrift.FileMetaData ReadInternalMetadata()
{
using (var reader = ParquetReader.OpenFromFile(_path))
{
return(reader.ThriftMetadata);
}
}