ClickHouse/dbms/src/DataStreams/ColumnGathererStream.cpp
Alexey Milovidov c8bc4d6e26 Fixed error
2019-03-28 19:48:14 +03:00

117 lines
3.7 KiB
C++

#include <DataStreams/ColumnGathererStream.h>
#include <common/logger_useful.h>
#include <Common/typeid_cast.h>
#include <IO/WriteHelpers.h>
#include <iomanip>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int INCOMPATIBLE_COLUMNS;
extern const int INCORRECT_NUMBER_OF_COLUMNS;
extern const int NOT_FOUND_COLUMN_IN_BLOCK;
extern const int EMPTY_DATA_PASSED;
extern const int RECEIVED_EMPTY_DATA;
}
ColumnGathererStream::ColumnGathererStream(
const String & column_name_, const BlockInputStreams & source_streams, ReadBuffer & row_sources_buf_,
size_t block_preferred_size_)
: column_name(column_name_), sources(source_streams.size()), row_sources_buf(row_sources_buf_)
, block_preferred_size(block_preferred_size_), log(&Logger::get("ColumnGathererStream"))
{
if (source_streams.empty())
throw Exception("There are no streams to gather", ErrorCodes::EMPTY_DATA_PASSED);
children.assign(source_streams.begin(), source_streams.end());
for (size_t i = 0; i < children.size(); ++i)
{
const Block & header = children[i]->getHeader();
/// Sometimes MergeTreeReader injects additional column with partitioning key
if (header.columns() > 2)
throw Exception(
"Block should have 1 or 2 columns, but contains " + toString(header.columns()),
ErrorCodes::INCORRECT_NUMBER_OF_COLUMNS);
if (i == 0)
{
column.name = column_name;
column.type = header.getByName(column_name).type;
column.column = column.type->createColumn();
}
else if (header.getByName(column_name).column->getName() != column.column->getName())
throw Exception("Column types don't match", ErrorCodes::INCOMPATIBLE_COLUMNS);
}
}
Block ColumnGathererStream::readImpl()
{
/// Special case: single source and there are no skipped rows
if (children.size() == 1 && row_sources_buf.eof())
return children[0]->read();
if (!source_to_fully_copy && row_sources_buf.eof())
return Block();
MutableColumnPtr output_column = column.column->cloneEmpty();
output_block = Block{column.cloneEmpty()};
output_column->gather(*this);
if (!output_column->empty())
output_block.getByPosition(0).column = std::move(output_column);
return output_block;
}
void ColumnGathererStream::fetchNewBlock(Source & source, size_t source_num)
{
try
{
source.block = children[source_num]->read();
source.update(column_name);
}
catch (Exception & e)
{
e.addMessage("Cannot fetch required block. Stream " + children[source_num]->getName() + ", part " + toString(source_num));
throw;
}
if (0 == source.size)
{
throw Exception("Fetched block is empty. Stream " + children[source_num]->getName() + ", part " + toString(source_num),
ErrorCodes::RECEIVED_EMPTY_DATA);
}
}
void ColumnGathererStream::readSuffixImpl()
{
const BlockStreamProfileInfo & profile_info = getProfileInfo();
/// Don't print info for small parts (< 10M rows)
if (profile_info.rows < 10000000)
return;
double seconds = profile_info.total_stopwatch.elapsedSeconds();
std::stringstream message;
message << std::fixed << std::setprecision(2)
<< "Gathered column " << column_name
<< " (" << static_cast<double>(profile_info.bytes) / profile_info.rows << " bytes/elem.)"
<< " in " << seconds << " sec.";
if (seconds)
message << ", " << profile_info.rows / seconds << " rows/sec., "
<< profile_info.bytes / 1048576.0 / seconds << " MiB/sec.";
LOG_TRACE(log, message.str());
}
}