greenplumn CFileWriter 代码
文件路径：/src/backend/gporca/libgpos/src/io/CFileWriter.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2010 Greenplum, Inc.
/
/ @filename:
/ CFileWriter.cpp
/
/ @doc:
/ Implementation of file handler for raw output
/---------------------------------------------------------------------------
#include "gpos/io/CFileWriter.h"
#include <fcntl.h>
#include "gpos/base.h"
#include "gpos/io/ioutils.h"
#include "gpos/task/IWorker.h"
using namespace gpos;
/---------------------------------------------------------------------------
/ @function:
/ CFileWriter::CFileWriter
/
/ @doc:
/ Ctor
/
/---------------------------------------------------------------------------
CFileWriter::CFileWriter() : CFileDescriptor()
{
}
/---------------------------------------------------------------------------
/ @function:
/ CFileWriter::Open
/
/ @doc:
/ Open file for writing
/
/---------------------------------------------------------------------------
void
CFileWriter::Open(const CHAR *file_path, ULONG permission_bits)
{
GPOS_ASSERT(nullptr != file_path);
OpenFile(file_path, O_CREAT | O_WRONLY | O_RDONLY | O_TRUNC,
permission_bits);
GPOS_ASSERT(0 == ioutils::FileSize(file_path));
m_file_size = 0;
}
/---------------------------------------------------------------------------
/ @function:
/ CFileWriter::Close
/
/ @doc:
/ Close file after writing
/
/---------------------------------------------------------------------------
void
CFileWriter::Close()
{
CloseFile();
m_file_size = 0;
}
/---------------------------------------------------------------------------
/ @function:
/ CFileWriter::Write
/
/ @doc:
/ Write bytes to file
/
/---------------------------------------------------------------------------
void
CFileWriter::Write(const BYTE *read_buffer, const ULONG_PTR write_size)
{
GPOS_ASSERT(CFileDescriptor::IsFileOpen() &&
"Attempt to write to invalid file descriptor");
GPOS_ASSERT(0 < write_size);
GPOS_ASSERT(nullptr != read_buffer);
ULONG_PTR bytes_left_to_write = write_size;
while (0 < bytes_left_to_write)
{
INT_PTR current_byte;
/ write to file
current_byte = ioutils::Write(GetFileDescriptor(), read_buffer,
bytes_left_to_write);
/ check for error
if (-1 == current_byte)
{
/ in case an interrupt was received we retry
if (EINTR == errno)
{
GPOS_CHECK_ABORT;
continue;
}
GPOS_RAISE(CException::ExmaSystem, CException::ExmiIOError, errno);
}
GPOS_ASSERT(current_byte <= (INT_PTR) bytes_left_to_write);
/ increase file size
m_file_size += current_byte;
read_buffer += current_byte;
bytes_left_to_write -= current_byte;
}
}
/ EOF