greenplumn CFileReader 代码
文件路径：/src/backend/gporca/libgpos/include/gpos/io/CFileReader.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2011 EMC Corp.
/
/ @filename:
/ CFileReader.h
/
/ @doc:
/ File Reader
/---------------------------------------------------------------------------
#ifndef GPOS_CFileReader_H
#define GPOS_CFileReader_H
#include <fcntl.h>
#include "gpos/io/CFileDescriptor.h"
namespace gpos
{
/---------------------------------------------------------------------------
/ @class:
/ CFileReader
/
/ @doc:
/ Implementation of file handler for raw input;
/ does not provide thread-safety
/
/---------------------------------------------------------------------------
class CFileReader : public CFileDescriptor
{
private:
/ file size
ULLONG m_file_size{0};
/ read size
ULLONG m_file_read_size{0};
public:
CFileReader(const CFileReader &) = delete;
/ ctor
CFileReader();
/ dtor
~CFileReader() override;
/ get file size
ULLONG FileSize() const;
/ get file read size
ULLONG FileReadSize() const;
/ open file for reading
void Open(const CHAR *file_path, const ULONG permission_bits = S_IRUSR);
/ close file
void Close();
/ read bytes to buffer
ULONG_PTR ReadBytesToBuffer(BYTE *read_buffer,
const ULONG_PTR file_read_size);
}; / class CFileReader
} / namespace gpos
#endif / !GPOS_CFileReader_H
/ EOF