public async ValueTask <BlockHeader> SkipTable(ServerDataMessage dataMessage, bool async, CancellationToken cancellationToken)
{
var withDecompression = dataMessage.MessageCode != ServerMessageCode.ProfileEvents;
var result = await WithCancellationToken(cancellationToken, ct => ReadTable(withDecompression, (typeInfo, rowCount) => typeInfo.CreateSkippingColumnReader(rowCount), null, async, ct));
return(new BlockHeader(dataMessage.TempTableName, result.columnInfos.AsReadOnly(), result.rowCount));
}
public async ValueTask <ClickHouseTable> ReadTable(ServerDataMessage dataMessage, IReadOnlyList <ClickHouseColumnSettings?>?columnSettings, bool async, CancellationToken cancellationToken)
{
var withDecompression = dataMessage.MessageCode != ServerMessageCode.ProfileEvents;
var result = await WithCancellationToken(
cancellationToken,
ct =>
ReadTable(
withDecompression,
(typeInfo, rowCount) => typeInfo.CreateColumnReader(rowCount),
(columnInfo, reader, index) => ReadTableColumn(columnInfo, reader, columnSettings == null || columnSettings.Count <= index ? null : columnSettings[index]),
async,
ct)
);
Debug.Assert(result.columns != null);
var blockHeader = new BlockHeader(dataMessage.TempTableName, result.columnInfos.AsReadOnly(), result.rowCount);
return(new ClickHouseTable(blockHeader, result.columns.AsReadOnly()));
}
private async ValueTask <ClickHouseTable> ReadTable(ServerDataMessage dataMessage, IReadOnlyList <ClickHouseColumnSettings?>?columnSettings, bool skip, bool async, CancellationToken cancellationToken)
{
CheckDisposed();
var compression = _client._settings.Compress ? CompressionAlgorithm.Lz4 : CompressionAlgorithm.None;
var reader = _client._reader;
reader.BeginDecompress(compression);
int blockFieldCode;
bool isOverflows = false;
// It seems that this value is used only for internal purposes and does not affect the format of the block
int bucketNum = -1;
do
{
blockFieldCode = await reader.Read7BitInt32(async, cancellationToken);
switch (blockFieldCode)
{
case BlockFieldCodes.IsOverflows:
isOverflows = await reader.ReadBool(async, cancellationToken);
break;
case BlockFieldCodes.BucketNum:
bucketNum = await reader.ReadInt32(async, cancellationToken);
break;
case BlockFieldCodes.End:
break;
default:
throw new ClickHouseException(ClickHouseErrorCodes.ProtocolUnexpectedResponse, $"Internal error. Unexpected block field code (0x{blockFieldCode:X}) received from the server.");
}
} while (blockFieldCode != BlockFieldCodes.End);
var columnCount = await reader.Read7BitInt32(async, cancellationToken);
var rowCount = await reader.Read7BitInt32(async, cancellationToken);
if (isOverflows)
{
throw new NotImplementedException("TODO: implement support for is_overflows.");
}
var columnInfos = new List <ColumnInfo>(columnCount);
var columns = new List <IClickHouseTableColumn>(columnCount);
for (int i = 0; i < columnCount; i++)
{
var columnName = await reader.ReadString(async, cancellationToken);
var columnTypeName = await reader.ReadString(async, cancellationToken);
var columnType = _client.TypeInfoProvider.GetTypeInfo(columnTypeName);
columnInfos.Add(new ColumnInfo(columnName, columnType));
var columnRowCount = rowCount;
var columnReader = columnType.CreateColumnReader(skip ? 0 : columnRowCount);
object?skipContext = null;
while (columnRowCount > 0)
{
SequenceSize sequenceSize;
if (skip)
{
sequenceSize = await reader.ReadRaw(seq => columnReader.Skip(seq, columnRowCount, ref skipContext), async, cancellationToken);
}
else
{
sequenceSize = await reader.ReadRaw(columnReader.ReadNext, async, cancellationToken);
}
if (sequenceSize.Elements < 0)
{
throw new InvalidOperationException("The number of elements must be greater than zero.");
}
if (sequenceSize.Elements > columnRowCount)
{
throw new InvalidOperationException($"The number of rows in the column \"{columnName}\" is greater than the number of rows in the table.");
}
if (sequenceSize.Elements < columnRowCount)
{
await reader.Advance(async, cancellationToken);
}
columnRowCount -= sequenceSize.Elements;
}
var settings = columnSettings == null || columnSettings.Count <= i ? null : columnSettings[i];
var column = columnReader.EndRead(settings);
columns.Add(column);
}
reader.EndDecompress();
var blockHeader = new BlockHeader(dataMessage.TempTableName, columnInfos.AsReadOnly(), rowCount);
return(new ClickHouseTable(blockHeader, columns.AsReadOnly()));
}
public async ValueTask <BlockHeader> SkipTable(ServerDataMessage dataMessage, bool async, CancellationToken cancellationToken)
{
var table = await WithCancellationToken(cancellationToken, ct => ReadTable(dataMessage, null, true, async, ct));
return(table.Header);
}
public async ValueTask <ClickHouseTable> ReadTable(ServerDataMessage dataMessage, IReadOnlyList <ClickHouseColumnSettings?>?columnSettings, bool async, CancellationToken cancellationToken)
{
return(await WithCancellationToken(cancellationToken, ct => ReadTable(dataMessage, columnSettings, false, async, ct)));
}
