ClickHouse/dbms/src/Processors/ResizeProcessor.h
2019-04-26 14:34:51 +03:00

41 lines
1.2 KiB
C++

#pragma once
#include <Processors/IProcessor.h>
namespace DB
{
/** Has arbitary non zero number of inputs and arbitary non zero number of outputs.
* All of them have the same structure.
*
* Pulls data from arbitary input (whenever it is ready) and pushes it to arbitary output (whenever is is not full).
* Doesn't do any heavy calculations.
* Doesn't preserve an order of data.
*
* Examples:
* - union data from multiple inputs to single output - to serialize data that was processed in parallel.
* - split data from single input to multiple outputs - to allow further parallel processing.
*/
class ResizeProcessor : public IProcessor
{
public:
/// TODO Check that there is non zero number of inputs and outputs.
ResizeProcessor(const Block & header, size_t num_inputs, size_t num_outputs)
: IProcessor(InputPorts(num_inputs, header), OutputPorts(num_outputs, header))
, current_input(inputs.begin())
, current_output(outputs.begin())
{
}
String getName() const override { return "Resize"; }
Status prepare() override;
private:
InputPorts::iterator current_input;
OutputPorts::iterator current_output;
};
}