ClickHouse/src/Storages/HDFS/ReadBufferFromHDFS.h

56 lines
1.2 KiB
C++

#pragma once
#include "config.h"
#if USE_HDFS
#include <IO/ReadBuffer.h>
#include <IO/BufferWithOwnMemory.h>
#include <string>
#include <memory>
#include <hdfs/hdfs.h>
#include <base/types.h>
#include <Interpreters/Context.h>
#include <IO/ReadBufferFromFileBase.h>
namespace DB
{
/** Accepts HDFS path to file and opens it.
* Closes file by himself (thus "owns" a file descriptor).
*/
class ReadBufferFromHDFS : public ReadBufferFromFileBase
{
struct ReadBufferFromHDFSImpl;
public:
ReadBufferFromHDFS(
const String & hdfs_uri_,
const String & hdfs_file_path_,
const Poco::Util::AbstractConfiguration & config_,
const ReadSettings & read_settings_,
size_t read_until_position_ = 0,
bool use_external_buffer = false,
std::optional<size_t> file_size = std::nullopt);
~ReadBufferFromHDFS() override;
bool nextImpl() override;
off_t seek(off_t offset_, int whence) override;
off_t getPosition() override;
size_t getFileSize() override;
size_t getFileOffsetOfBufferEnd() const override;
String getFileName() const override;
private:
std::unique_ptr<ReadBufferFromHDFSImpl> impl;
bool use_external_buffer;
};
}
#endif