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124 lines
2.9 KiB
C++
124 lines
2.9 KiB
C++
#include <Processors/Transforms/ExtremesTransform.h>
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#include <Core/Field.h>
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namespace DB
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{
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ExtremesTransform::ExtremesTransform(const Block & header)
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: ISimpleTransform(header, header, true)
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{
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/// Port for Extremes.
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outputs.emplace_back(outputs.front().getHeader(), this);
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}
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IProcessor::Status ExtremesTransform::prepare()
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{
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if (!finished_transform)
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{
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auto status = ISimpleTransform::prepare();
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if (status != Status::Finished)
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return status;
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finished_transform = true;
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}
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auto & totals_output = getExtremesPort();
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/// Check can output.
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if (totals_output.isFinished())
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return Status::Finished;
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if (!totals_output.canPush())
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return Status::PortFull;
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if (!extremes && !extremes_columns.empty())
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return Status::Ready;
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if (extremes)
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totals_output.push(std::move(extremes));
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totals_output.finish();
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return Status::Finished;
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}
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void ExtremesTransform::work()
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{
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if (finished_transform)
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{
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if (!extremes && !extremes_columns.empty())
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extremes.setColumns(std::move(extremes_columns), 2);
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}
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else
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ISimpleTransform::work();
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}
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void ExtremesTransform::transform(DB::Chunk & chunk)
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{
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if (chunk.getNumRows() == 0)
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return;
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size_t num_columns = chunk.getNumColumns();
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const auto & columns = chunk.getColumns();
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if (extremes_columns.empty())
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{
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extremes_columns.resize(num_columns);
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for (size_t i = 0; i < num_columns; ++i)
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{
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const ColumnPtr & src = columns[i];
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if (isColumnConst(*src))
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{
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/// Equal min and max.
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extremes_columns[i] = src->cloneResized(2);
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}
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else
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{
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Field min_value;
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Field max_value;
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src->getExtremes(min_value, max_value);
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extremes_columns[i] = src->cloneEmpty();
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extremes_columns[i]->insert(min_value);
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extremes_columns[i]->insert(max_value);
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}
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}
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}
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else
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{
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for (size_t i = 0; i < num_columns; ++i)
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{
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if (isColumnConst(*extremes_columns[i]))
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continue;
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Field min_value = (*extremes_columns[i])[0];
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Field max_value = (*extremes_columns[i])[1];
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Field cur_min_value;
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Field cur_max_value;
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columns[i]->getExtremes(cur_min_value, cur_max_value);
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if (cur_min_value < min_value)
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min_value = cur_min_value;
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if (cur_max_value > max_value)
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max_value = cur_max_value;
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MutableColumnPtr new_extremes = extremes_columns[i]->cloneEmpty();
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new_extremes->insert(min_value);
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new_extremes->insert(max_value);
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extremes_columns[i] = std::move(new_extremes);
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}
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}
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}
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}
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