mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-24 00:22:29 +00:00
59 lines
1.5 KiB
C++
59 lines
1.5 KiB
C++
#pragma once
|
||
|
||
#include <Poco/SharedPtr.h>
|
||
|
||
#include <DB/Storages/IStorage.h>
|
||
#include <DB/DataStreams/IProfilingBlockInputStream.h>
|
||
|
||
|
||
namespace DB
|
||
{
|
||
|
||
using Poco::SharedPtr;
|
||
|
||
|
||
class NumbersBlockInputStream : public IProfilingBlockInputStream
|
||
{
|
||
public:
|
||
NumbersBlockInputStream(size_t block_size_);
|
||
String getName() const { return "NumbersBlockInputStream"; }
|
||
BlockInputStreamPtr clone() { return new NumbersBlockInputStream(block_size); }
|
||
protected:
|
||
Block readImpl();
|
||
private:
|
||
size_t block_size;
|
||
UInt64 next;
|
||
};
|
||
|
||
|
||
/** Реализует хранилище для системной таблицы Numbers.
|
||
* Таблица содержит единственный столбец number UInt64.
|
||
* Из этой таблицы можно прочитать все натуральные числа, начиная с 0 (до 2^64 - 1, а потом заново).
|
||
*/
|
||
class StorageSystemNumbers : public IStorage
|
||
{
|
||
public:
|
||
static StoragePtr create(const std::string & name_);
|
||
|
||
std::string getName() const { return "SystemNumbers"; }
|
||
std::string getTableName() const { return name; }
|
||
|
||
const NamesAndTypesList & getColumnsList() const { return columns; }
|
||
|
||
BlockInputStreams read(
|
||
const Names & column_names,
|
||
ASTPtr query,
|
||
const Settings & settings,
|
||
QueryProcessingStage::Enum & processed_stage,
|
||
size_t max_block_size = DEFAULT_BLOCK_SIZE,
|
||
unsigned threads = 1);
|
||
|
||
private:
|
||
const std::string name;
|
||
NamesAndTypesList columns;
|
||
|
||
StorageSystemNumbers(const std::string & name_);
|
||
};
|
||
|
||
}
|