ClickHouse/src/Processors/IAccumulatingTransform.cpp
2020-04-03 18:14:31 +03:00

96 lines
2.0 KiB
C++

#include <Processors/IAccumulatingTransform.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
IAccumulatingTransform::IAccumulatingTransform(Block input_header, Block output_header)
: IProcessor({std::move(input_header)}, {std::move(output_header)}),
input(inputs.front()), output(outputs.front())
{
}
IAccumulatingTransform::Status IAccumulatingTransform::prepare()
{
/// Check can output.
if (output.isFinished())
{
input.close();
return Status::Finished;
}
if (!output.canPush())
{
input.setNotNeeded();
return Status::PortFull;
}
/// Output if has data.
if (current_output_chunk)
output.push(std::move(current_output_chunk));
if (finished_generate)
{
output.finish();
return Status::Finished;
}
/// Generate output block.
if (input.isFinished())
{
finished_input = true;
return Status::Ready;
}
/// Close input if flag was set manually.
if (finished_input)
{
input.close();
return Status::Ready;
}
/// Check can input.
if (!has_input)
{
input.setNeeded();
if (!input.hasData())
return Status::NeedData;
current_input_chunk = input.pull();
has_input = true;
}
return Status::Ready;
}
void IAccumulatingTransform::work()
{
if (!finished_input)
{
consume(std::move(current_input_chunk));
has_input = false;
}
else
{
current_output_chunk = generate();
if (!current_output_chunk)
finished_generate = true;
}
}
void IAccumulatingTransform::setReadyChunk(Chunk chunk)
{
if (current_output_chunk)
throw Exception("IAccumulatingTransform already has input. Cannot set another chunk. "
"Probably, setReadyChunk method was called twice per consume().", ErrorCodes::LOGICAL_ERROR);
current_output_chunk = std::move(chunk);
}
}