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

90 lines
1.8 KiB
C++

#include <Processors/IInflatingTransform.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
IInflatingTransform::IInflatingTransform(Block input_header, Block output_header)
: IProcessor({std::move(input_header)}, {std::move(output_header)})
, input(inputs.front()), output(outputs.front())
{
}
IInflatingTransform::Status IInflatingTransform::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 (generated)
{
output.push(std::move(current_chunk));
generated = false;
}
if (can_generate)
return Status::Ready;
/// Check can input.
if (!has_input)
{
if (input.isFinished())
{
output.finish();
return Status::Finished;
}
input.setNeeded();
if (!input.hasData())
return Status::NeedData;
current_chunk = input.pull();
has_input = true;
}
/// Now transform.
return Status::Ready;
}
void IInflatingTransform::work()
{
if (can_generate)
{
if (generated)
throw Exception("IInflatingTransform cannot consume chunk because it already was generated",
ErrorCodes::LOGICAL_ERROR);
current_chunk = generate();
generated = true;
can_generate = canGenerate();
}
else
{
if (!has_input)
throw Exception("IInflatingTransform cannot consume chunk because it wasn't read",
ErrorCodes::LOGICAL_ERROR);
consume(std::move(current_chunk));
has_input = false;
can_generate = canGenerate();
}
}
}