mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-18 12:22:12 +00:00
44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
#pragma once
|
||
|
||
#include <vector>
|
||
|
||
#include <DB/IO/WriteBuffer.h>
|
||
|
||
|
||
#define WRITE_BUFFER_FROM_VECTOR_INITIAL_SIZE_IF_EMPTY 32
|
||
|
||
|
||
namespace DB
|
||
{
|
||
|
||
/** Инициализируется вектором. Пишет данные в него. Когда вектор закончится - увеличивает его размер в два раза.
|
||
* CharType - char или unsigned char.
|
||
*/
|
||
template <typename VectorType = std::vector<char> >
|
||
class WriteBufferFromVector : public WriteBuffer
|
||
{
|
||
private:
|
||
VectorType & vector;
|
||
|
||
void nextImpl()
|
||
{
|
||
size_t old_size = vector.size();
|
||
vector.resize(old_size * 2);
|
||
internal_buffer = Buffer(reinterpret_cast<Position>(&vector[old_size]), reinterpret_cast<Position>(&*vector.end()));
|
||
working_buffer = internal_buffer;
|
||
}
|
||
|
||
public:
|
||
WriteBufferFromVector(VectorType & vector_)
|
||
: WriteBuffer(reinterpret_cast<Position>(&vector_[0]), vector_.size()), vector(vector_)
|
||
{
|
||
if (vector.empty())
|
||
{
|
||
vector.resize(WRITE_BUFFER_FROM_VECTOR_INITIAL_SIZE_IF_EMPTY);
|
||
set(reinterpret_cast<Position>(&vector[0]), vector.size());
|
||
}
|
||
}
|
||
};
|
||
|
||
}
|