private static void RoundTrip(string columnName, int[] array, int batchSize = 128)
{
XDatabaseContext context = new XDatabaseContext();
string columnPath = Path.Combine("VariableIntegerReaderWriterTests", columnName);
string columnPrefix = Path.Combine(columnPath, "Vl");
context.StreamProvider.Delete(columnPath);
Directory.CreateDirectory(columnPath);
XArray values = XArray.All(array, array.Length);
using (IColumnWriter writer = new VariableIntegerWriter(context.StreamProvider, columnPrefix))
{
ArraySelector page = ArraySelector.All(0).NextPage(array.Length, batchSize);
while (page.Count > 0)
{
writer.Append(values.Reselect(page));
page = page.NextPage(array.Length, batchSize);
}
}
XArray returned = default(XArray);
using (IColumnReader reader = new VariableIntegerReader(context.StreamProvider, columnPrefix, CachingOption.AsConfigured))
{
returned = reader.Read(ArraySelector.All(array.Length));
}
TableTestHarness.AssertAreEqual(values, returned, array.Length);
context.StreamProvider.Delete(columnPath);
}
public int Next(int desiredCount, CancellationToken cancellationToken)
{
_currentEnumerateSelector = _currentEnumerateSelector.NextPage(Count, desiredCount);
_currentSelector = _currentEnumerateSelector;
CurrentRowCount = _currentEnumerateSelector.Count;
return(CurrentRowCount);
}
public int Next(int desiredCount, CancellationToken cancellationToken)
{
long countToReturn = Math.Min(_rowCount - _countEnumerated, desiredCount);
if (countToReturn == 0)
{
return(0);
}
_currentEnumerateSelector = _currentEnumerateSelector.NextPage(_arrayRowCount, (int)countToReturn);
if (_currentEnumerateSelector.Count == 0)
{
_currentEnumerateSelector = ArraySelector.All(_arrayRowCount).Slice(0, 0);
_currentEnumerateSelector = _currentEnumerateSelector.NextPage(_arrayRowCount, (int)countToReturn);
}
_currentSelector = _currentEnumerateSelector;
for (int i = 0; i < _columns.Count; ++i)
{
_columns[i].SetSelector(_currentEnumerateSelector);
}
CurrentRowCount = _currentEnumerateSelector.Count;
_countEnumerated += _currentEnumerateSelector.Count;
return(CurrentRowCount);
}
public override int Next(int desiredCount, CancellationToken cancellationToken)
{
_enumerateSelector = _enumerateSelector.NextPage(_source.Columns.Count, desiredCount);
_columns[0].SetSelector(_enumerateSelector);
_columns[1].SetSelector(_enumerateSelector);
return(_enumerateSelector.Count);
}
public int Next(int desiredCount, CancellationToken cancellationToken)
{
_currentEnumerateSelector = _currentEnumerateSelector.NextPage(_rowCount, desiredCount);
_currentSelector = _currentEnumerateSelector;
for (int i = 0; i < _columns.Count; ++i)
{
_columns[i].SetSelector(_currentEnumerateSelector);
}
CurrentRowCount = _currentEnumerateSelector.Count;
return(CurrentRowCount);
}
private void Upconvert(Type toType)
{
// Close the current writer
_writer.Dispose();
_writer = null;
// Determine previous and new file paths
string columnValuesFullPath = PathForType(_columnPathPrefix, WritingAsType);
string columnConvertedFullPath = PathForType(_columnPathPrefix, toType);
// Build a writer for the larger type
IColumnWriter writer = BuildDirectWriter(_streamProvider, toType, columnConvertedFullPath);
// Convert already written values (if any)
if (_rowCountWritten > 0)
{
// Build a converter to convert the values
Func <XArray, XArray> converter = TypeConverterFactory.GetConverter(WritingAsType, toType);
// Stream them in, convert them, and write them out
using (IColumnReader reader = TypeProviderFactory.TryGetColumnReader(_streamProvider, WritingAsType, columnValuesFullPath))
{
int rowCount = reader.Count;
ArraySelector page = ArraySelector.All(0).NextPage(rowCount, 10240);
while (page.Count > 0)
{
XArray original = reader.Read(page);
XArray converted = converter(original);
writer.Append(converted);
page = page.NextPage(rowCount, 10240);
}
}
}
// Delete the original file
_streamProvider.Delete(columnValuesFullPath);
// Re-initialize for the new writer
WritingAsType = toType;
_writer = writer;
_converter = (toType == typeof(int) ? null : TypeConverterFactory.GetConverter(typeof(int), toType));
}
public int Next(int desiredCount, CancellationToken cancellationToken)
{
// If this is the first call, walk all rows once to group them
if (!_isDictionaryBuilt)
{
_isDictionaryBuilt = true;
BuildDictionary(cancellationToken);
Reset();
}
// Once done, page through the distinct group by values found
_currentEnumerateSelector = _currentEnumerateSelector.NextPage(_distinctCount, desiredCount);
for (int i = 0; i < _columns.Length; ++i)
{
_columns[i].SetSelector(_currentEnumerateSelector);
}
CurrentRowCount = _currentEnumerateSelector.Count;
return(CurrentRowCount);
}
private void Convert()
{
// Close the row index writer
_rowIndexWriter.Dispose();
_rowIndexWriter = null;
// If we wrote any rows we need to convert...
if (_rowCountWritten > 0)
{
// Get the set of unique values and get rid of the value dictionary
XArray values = _dictionary.Values();
// Convert the indices previously written into raw values
Func <XArray, XArray> converter = TypeConverterFactory.GetConverter(typeof(byte), typeof(int));
using (IColumnReader rowIndexReader = new PrimitiveArrayReader <byte>(_streamProvider.OpenRead(Path.Combine(_columnPath, RowIndexFileName))))
{
int rowCount = rowIndexReader.Count;
ArraySelector page = ArraySelector.All(0).NextPage(rowCount, 10240);
while (page.Count > 0)
{
// Read an XArray of indices and convert to int[]
XArray rowIndices = converter(rowIndexReader.Read(page));
// Write the corresponding values
// Reselect is safe because 'values' are converted to a contiguous array
_valueWriter.Append(values.Reselect(ArraySelector.Map((int[])rowIndices.Array, rowIndices.Count)));
page = page.NextPage(rowCount, 10240);
}
}
}
// Remove the Dictionary (so future rows are streamed out as-is)
_dictionary = null;
// Delete the row index file
_streamProvider.Delete(Path.Combine(_columnPath, RowIndexFileName));
}