ClickHouse/dbms/src/Formats/ODBCDriver2BlockOutputStream.cpp
2018-12-14 23:21:47 +03:00

105 lines
2.8 KiB
C++

#include <Core/Block.h>
#include <Formats/FormatFactory.h>
#include <Formats/ODBCDriver2BlockOutputStream.h>
#include <IO/WriteBuffer.h>
#include <IO/WriteHelpers.h>
#include <Core/iostream_debug_helpers.h>
namespace DB
{
ODBCDriver2BlockOutputStream::ODBCDriver2BlockOutputStream(
WriteBuffer & out_, const Block & header_, const FormatSettings & format_settings)
: out(out_), header(header_), format_settings(format_settings)
{
}
void ODBCDriver2BlockOutputStream::flush()
{
out.next();
}
void writeODBCString(WriteBuffer & out, const std::string & str)
{
writeIntBinary(Int32(str.size()), out);
out.write(str.data(), str.size());
}
static void writeRow(const Block & block, size_t row_idx, WriteBuffer & out, const FormatSettings & format_settings, std::string & buffer)
{
size_t columns = block.columns();
for (size_t column_idx = 0; column_idx < columns; ++column_idx)
{
buffer.clear();
const ColumnWithTypeAndName & col = block.getByPosition(column_idx);
if (col.column->isNullAt(row_idx))
{
writeIntBinary(Int32(-1), out);
}
else
{
{
WriteBufferFromString text_out(buffer);
col.type->serializeText(*col.column, row_idx, text_out, format_settings);
}
writeODBCString(out, buffer);
}
}
}
void ODBCDriver2BlockOutputStream::write(const Block & block)
{
String text_value;
const size_t rows = block.rows();
for (size_t i = 0; i < rows; ++i)
writeRow(block, i, out, format_settings, text_value);
}
void ODBCDriver2BlockOutputStream::writeSuffix()
{
if (totals)
write(totals);
}
void ODBCDriver2BlockOutputStream::writePrefix()
{
const size_t columns = header.columns();
/// Number of header rows.
writeIntBinary(Int32(2), out);
/// Names of columns.
/// Number of columns + 1 for first name column.
writeIntBinary(Int32(columns + 1), out);
writeODBCString(out, "name");
for (size_t i = 0; i < columns; ++i)
{
const ColumnWithTypeAndName & col = header.getByPosition(i);
writeODBCString(out, col.name);
}
/// Types of columns.
writeIntBinary(Int32(columns + 1), out);
writeODBCString(out, "type");
for (size_t i = 0; i < columns; ++i)
{
const ColumnWithTypeAndName & col = header.getByPosition(i);
writeODBCString(out, col.type->getName());
}
}
void registerOutputFormatODBCDriver2(FormatFactory & factory)
{
factory.registerOutputFormat(
"ODBCDriver2", [](WriteBuffer & buf, const Block & sample, const Context &, const FormatSettings & format_settings)
{
return std::make_shared<ODBCDriver2BlockOutputStream>(buf, sample, format_settings);
});
}
}