blob: 79a7d15fe0be6768f615ad77e132a66c2dfa90df (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
#pragma once
#include <Processors/IProcessor.h>
#include <Processors/RowsBeforeLimitCounter.h>
#include <Core/SortDescription.h>
namespace DB
{
/// Implementation for OFFSET N (without limit)
/// This processor support multiple inputs and outputs (the same number).
/// Each pair of input and output port works independently.
class OffsetTransform final : public IProcessor
{
private:
UInt64 offset;
UInt64 rows_read = 0; /// including the last read block
RowsBeforeLimitCounterPtr rows_before_limit_at_least;
/// State of port's pair.
/// Chunks from different port pairs are not mixed for better cache locality.
struct PortsData
{
Chunk current_chunk;
InputPort * input_port = nullptr;
OutputPort * output_port = nullptr;
bool is_finished = false;
};
std::vector<PortsData> ports_data;
size_t num_finished_port_pairs = 0;
public:
OffsetTransform(const Block & header_, UInt64 offset_, size_t num_streams = 1);
String getName() const override { return "Offset"; }
Status prepare(const PortNumbers & /*updated_input_ports*/, const PortNumbers & /*updated_output_ports*/) override;
Status prepare() override; /// Compatibility for TreeExecutor.
Status preparePair(PortsData & data);
void splitChunk(PortsData & data) const;
InputPort & getInputPort() { return inputs.front(); }
OutputPort & getOutputPort() { return outputs.front(); }
void setRowsBeforeLimitCounter(RowsBeforeLimitCounterPtr counter) override { rows_before_limit_at_least.swap(counter); }
};
}
|
