mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-12 17:32:32 +00:00
117 lines
2.7 KiB
C++
117 lines
2.7 KiB
C++
#pragma once
|
||
|
||
#include <unistd.h>
|
||
#include <errno.h>
|
||
|
||
#include <DB/Common/Exception.h>
|
||
#include <DB/Core/ErrorCodes.h>
|
||
#include <DB/Common/ProfileEvents.h>
|
||
|
||
#include <DB/IO/WriteBufferFromFileBase.h>
|
||
#include <DB/IO/WriteBuffer.h>
|
||
#include <DB/IO/WriteHelpers.h>
|
||
#include <DB/IO/BufferWithOwnMemory.h>
|
||
|
||
|
||
namespace DB
|
||
{
|
||
|
||
/** Работает с готовым файловым дескриптором. Не открывает и не закрывает файл.
|
||
*/
|
||
class WriteBufferFromFileDescriptor : public WriteBufferFromFileBase
|
||
{
|
||
protected:
|
||
int fd;
|
||
|
||
void nextImpl()
|
||
{
|
||
if (!offset())
|
||
return;
|
||
|
||
size_t bytes_written = 0;
|
||
while (bytes_written != offset())
|
||
{
|
||
ProfileEvents::increment(ProfileEvents::WriteBufferFromFileDescriptorWrite);
|
||
|
||
ssize_t res = ::write(fd, working_buffer.begin() + bytes_written, offset() - bytes_written);
|
||
|
||
if ((-1 == res || 0 == res) && errno != EINTR)
|
||
throwFromErrno("Cannot write to file " + getFileName(), ErrorCodes::CANNOT_WRITE_TO_FILE_DESCRIPTOR);
|
||
|
||
if (res > 0)
|
||
bytes_written += res;
|
||
}
|
||
|
||
ProfileEvents::increment(ProfileEvents::WriteBufferFromFileDescriptorWriteBytes, bytes_written);
|
||
}
|
||
|
||
/// Имя или описание файла
|
||
virtual std::string getFileName() const override
|
||
{
|
||
return "(fd = " + toString(fd) + ")";
|
||
}
|
||
|
||
public:
|
||
WriteBufferFromFileDescriptor(int fd_ = -1, size_t buf_size = DBMS_DEFAULT_BUFFER_SIZE, char * existing_memory = nullptr, size_t alignment = 0)
|
||
: WriteBufferFromFileBase(buf_size, existing_memory, alignment), fd(fd_) {}
|
||
|
||
/** Можно вызывать для инициализации, если нужный fd не был передан в конструктор.
|
||
* Менять fd во время работы нельзя.
|
||
*/
|
||
void setFD(int fd_)
|
||
{
|
||
fd = fd_;
|
||
}
|
||
|
||
~WriteBufferFromFileDescriptor()
|
||
{
|
||
try
|
||
{
|
||
next();
|
||
}
|
||
catch (...)
|
||
{
|
||
tryLogCurrentException(__PRETTY_FUNCTION__);
|
||
}
|
||
}
|
||
|
||
int getFD() const override
|
||
{
|
||
return fd;
|
||
}
|
||
|
||
off_t getPositionInFile() override
|
||
{
|
||
return seek(0, SEEK_CUR);
|
||
}
|
||
|
||
void sync() override
|
||
{
|
||
/// Если в буфере ещё остались данные - запишем их.
|
||
next();
|
||
|
||
/// Попросим ОС сбросить данные на диск.
|
||
int res = fsync(fd);
|
||
if (-1 == res)
|
||
throwFromErrno("Cannot fsync " + getFileName(), ErrorCodes::CANNOT_FSYNC);
|
||
}
|
||
|
||
private:
|
||
off_t doSeek(off_t offset, int whence) override
|
||
{
|
||
off_t res = lseek(fd, offset, whence);
|
||
if (-1 == res)
|
||
throwFromErrno("Cannot seek through file " + getFileName(), ErrorCodes::CANNOT_SEEK_THROUGH_FILE);
|
||
return res;
|
||
}
|
||
|
||
void doTruncate(off_t length) override
|
||
{
|
||
int res = ftruncate(fd, length);
|
||
if (-1 == res)
|
||
throwFromErrno("Cannot truncate file " + getFileName(), ErrorCodes::CANNOT_TRUNCATE_FILE);
|
||
}
|
||
};
|
||
|
||
}
|