ClickHouse/src/Interpreters/IJoin.h
2021-04-28 20:32:12 +03:00

54 lines
1.6 KiB
C++

#pragma once
#include <memory>
#include <vector>
#include <Core/Names.h>
#include <Columns/IColumn.h>
#include <DataStreams/IBlockStream_fwd.h>
namespace DB
{
class Block;
struct ExtraBlock;
using ExtraBlockPtr = std::shared_ptr<ExtraBlock>;
class TableJoin;
class IJoin
{
public:
virtual ~IJoin() = default;
virtual const TableJoin & getTableJoin() const = 0;
/// Add block of data from right hand of JOIN.
/// @returns false, if some limit was exceeded and you should not insert more data.
virtual bool addJoinedBlock(const Block & block, bool check_limits = true) = 0;
/// Join the block with data from left hand of JOIN to the right hand data (that was previously built by calls to addJoinedBlock).
/// Could be called from different threads in parallel.
virtual void joinBlock(Block & block, std::shared_ptr<ExtraBlock> & not_processed) = 0;
virtual bool hasTotals() const = 0;
/// Set totals for right table
virtual void setTotals(const Block & block) = 0;
/// Add totals to block from left table
virtual void joinTotals(Block & block) const = 0;
virtual size_t getTotalRowCount() const = 0;
virtual size_t getTotalByteCount() const = 0;
virtual bool alwaysReturnsEmptySet() const { return false; }
/// StorageJoin is already filled. No need to call addJoinedBlock.
/// Different query plan is used for storage join.
virtual bool isStorageJoin() const { return false; }
virtual BlockInputStreamPtr createStreamWithNonJoinedRows(const Block &, UInt64) const { return {}; }
};
using JoinPtr = std::shared_ptr<IJoin>;
}