ClickHouse/dbms/include/DB/DataStreams/OneBlockInputStream.h
2013-05-04 04:05:15 +00:00

46 lines
712 B
C++

#pragma once
#include <Poco/SharedPtr.h>
#include <DB/DataStreams/IProfilingBlockInputStream.h>
namespace DB
{
using Poco::SharedPtr;
/** Поток блоков, из которого можно прочитать один блок.
*/
class OneBlockInputStream : public IProfilingBlockInputStream
{
public:
OneBlockInputStream(Block & block_) : block(block_), has_been_read(false) {}
String getName() const { return "OneBlockInputStream"; }
String getID() const
{
std::stringstream res;
res << this;
return res.str();
}
protected:
Block readImpl()
{
if (has_been_read)
return Block();
has_been_read = true;
return block;
}
private:
Block block;
bool has_been_read;
};
}