ClickHouse/src/Interpreters/SquashingTransform.h
Azat Khuzhin 6d4af3bac1 Move SquashingTransform to Interpreters (to fix split build)
clickhouse_common_io requires clickhouse_core:

    ld.lld: error: undefined symbol: DB::blocksHaveEqualStructure(DB::Block const&, DB::Block const&)
    >>> referenced by SquashingTransform.cpp:92 (/src/ch/clickhouse/src/Common/SquashingTransform.cpp:92)
    >>>               src/CMakeFiles/clickhouse_common_io.dir/Common/SquashingTransform.cpp.o:(void DB::SquashingTransform::append<DB::Block&&>(DB::Block&&))
    >>> referenced by SquashingTransform.cpp:92 (/src/ch/clickhouse/src/Common/SquashingTransform.cpp:92)
    >>>               src/CMakeFiles/clickhouse_common_io.dir/Common/SquashingTransform.cpp.o:(void DB::SquashingTransform::append<DB::Block const&>(DB::Block const&))

while clickhouse_core requires clickhouse_common_io:

    "clickhouse_core" of type SHARED_LIBRARY
      depends on "roaring" (weak)
      depends on "clickhouse_common_io" (weak)
      depends on "clickhouse_common_config" (weak)
      depends on "clickhouse_common_zookeeper" (weak)
      depends on "clickhouse_dictionaries_embedded" (weak)
      depends on "clickhouse_parsers" (weak)

Follow-up for: #30247 (cc @KochetovNicolai)
2021-10-18 10:28:36 +03:00

52 lines
1.4 KiB
C++

#pragma once
#include <Core/Block.h>
namespace DB
{
/** Merging consecutive passed blocks to specified minimum size.
*
* (But if one of input blocks has already at least specified size,
* then don't merge it with neighbours, even if neighbours are small.)
*
* Used to prepare blocks to adequate size for INSERT queries,
* because such storages as Memory, StripeLog, Log, TinyLog...
* store or compress data in blocks exactly as passed to it,
* and blocks of small size are not efficient.
*
* Order of data is kept.
*/
class SquashingTransform
{
public:
/// Conditions on rows and bytes are OR-ed. If one of them is zero, then corresponding condition is ignored.
SquashingTransform(size_t min_block_size_rows_, size_t min_block_size_bytes_, bool reserve_memory_ = false);
/** Add next block and possibly returns squashed block.
* At end, you need to pass empty block. As the result for last (empty) block, you will get last Result with ready = true.
*/
Block add(Block && block);
Block add(const Block & block);
private:
size_t min_block_size_rows;
size_t min_block_size_bytes;
bool reserve_memory;
Block accumulated_block;
template <typename ReferenceType>
Block addImpl(ReferenceType block);
template <typename ReferenceType>
void append(ReferenceType block);
bool isEnoughSize(const Block & block);
bool isEnoughSize(size_t rows, size_t bytes) const;
};
}