public static void TestProperties()
{
// Test the various properties exposed by ParquetFileWriter.
using var writerPropertiesBuilder = new WriterPropertiesBuilder();
using var writerProperties = writerPropertiesBuilder
.Compression(Compression.Zstd)
.DisableDictionary()
.CreatedBy("Some crazy unit test")
.Build();
var columns = new Column[]
{
new Column <int>("Index"),
new Column <float>("Value")
};
var kvm = (IReadOnlyDictionary <string, string>) new Dictionary <string, string>
{
{ "some key", "some value" },
{ "α ∧ ¬β", "2H₂ + O₂ ⇌ 2H₂O, R = 4.7 kΩ, ⌀ 200 mm" }
};
using var buffer = new ResizableBuffer();
using var outStream = new BufferOutputStream(buffer);
using var fileWriter = new ParquetFileWriter(outStream, columns, writerProperties, kvm);
Assert.AreEqual(2, fileWriter.NumColumns);
Assert.AreEqual(0, fileWriter.NumRows);
Assert.AreEqual(0, fileWriter.NumRowGroups);
Assert.IsNull(fileWriter.FileMetaData);
Assert.AreEqual(Column.CreateSchemaNode(columns), fileWriter.Schema.GroupNode);
Assert.AreEqual(Column.CreateSchemaNode(columns), fileWriter.Schema.SchemaRoot);
Assert.AreEqual(columns[0].Name, fileWriter.ColumnDescriptor(0).Name);
Assert.AreEqual(columns[1].Name, fileWriter.ColumnDescriptor(1).Name);
Assert.AreEqual(kvm, fileWriter.KeyValueMetadata);
Assert.AreEqual(Compression.Zstd, fileWriter.WriterProperties.Compression(new ColumnPath("")));
Assert.AreEqual(false, fileWriter.WriterProperties.DictionaryEnabled(new ColumnPath("")));
Assert.AreEqual("Some crazy unit test", fileWriter.WriterProperties.CreatedBy);
using (var groupWriter = fileWriter.AppendRowGroup())
{
Assert.AreEqual(0, fileWriter.NumRows);
Assert.AreEqual(1, fileWriter.NumRowGroups);
Assert.IsNull(fileWriter.FileMetaData);
using (var writer = groupWriter.NextColumn().LogicalWriter <int>())
{
writer.WriteBatch(new[] { 1, 2, 3, 4, 5, 6 });
}
Assert.AreEqual(0, fileWriter.NumRows);
Assert.AreEqual(1, fileWriter.NumRowGroups);
Assert.IsNull(fileWriter.FileMetaData);
using (var writer = groupWriter.NextColumn().LogicalWriter <float>())
{
writer.WriteBatch(new[] { 1f, 2f, 3f, 4f, 5f, 6f });
}
Assert.AreEqual(0, fileWriter.NumRows);
Assert.AreEqual(1, fileWriter.NumRowGroups);
Assert.IsNull(fileWriter.FileMetaData);
}
Assert.AreEqual(0, fileWriter.NumRows);
Assert.AreEqual(1, fileWriter.NumRowGroups);
Assert.IsNull(fileWriter.FileMetaData);
fileWriter.Close();
//Assert.AreEqual(0, fileWriter.NumRows); // 2021-04-08: calling this results in a segfault when the writer has been closed
//Assert.AreEqual(1, fileWriter.NumRowGroups); // 2021-04-08: calling this results in a segfault when the writer has been closed
Assert.IsNotNull(fileWriter.FileMetaData);
Assert.AreEqual(2, fileWriter.FileMetaData?.NumColumns);
Assert.AreEqual(6, fileWriter.FileMetaData?.NumRows);
Assert.AreEqual(1, fileWriter.FileMetaData?.NumRowGroups);
Assert.AreEqual(kvm, fileWriter.FileMetaData?.KeyValueMetadata);
}