ClickHouse/src/IO/createReadBufferFromFileBase.h
2020-04-03 18:14:31 +03:00

29 lines
779 B
C++

#pragma once
#include <IO/ReadBufferFromFileBase.h>
#include <string>
#include <memory>
namespace DB
{
/** Create an object to read data from a file.
* estimated_size - the number of bytes to read
* aio_threshold - the minimum number of bytes for asynchronous reads
*
* If aio_threshold = 0 or estimated_size < aio_threshold, read operations are executed synchronously.
* Otherwise, the read operations are performed asynchronously.
*/
std::unique_ptr<ReadBufferFromFileBase> createReadBufferFromFileBase(
const std::string & filename_,
size_t estimated_size,
size_t aio_threshold,
size_t mmap_threshold,
size_t buffer_size_ = DBMS_DEFAULT_BUFFER_SIZE,
int flags_ = -1,
char * existing_memory_ = nullptr,
size_t alignment = 0);
}