ddl::File_reader Struct Reference

Read rows from the temporary file. More...

#include <ddl0impl-file-reader.h>

Inheritance diagram for ddl::File_reader:

Public Types
using	Offsets = std::vector< ulint, ut::allocator< ulint > >

Public Member Functions
	File_reader (const Unique_os_file_descriptor &file, dict_index_t *index, size_t buffer_size, const Range &range) noexcept
	Constructor. More...
	~File_reader () noexcept
	Destructor. More...
dberr_t	prepare () noexcept
	Prepare the file for reading. More...
dberr_t	get_tuple (Builder *builder, mem_heap_t *heap, dtuple_t *&dtuple) noexcept
	The current row as a tuple. More...
dberr_t	read (const Range &range) noexcept
	Set the start and end offsets to read from, to avoid the possibility of overlapping reads from the other ranges in subsequent reads. More...
bool	end_of_range () const noexcept
uint64_t	get_n_rows_read () const noexcept

Public Attributes
dict_index_t *	m_index {}
	Index that the records belong to. More...
const mrec_t *	m_mrec {}
	Pointer to current row. More...
Offsets	m_field_offsets {}
	Columns offsets. More...
const Unique_os_file_descriptor &	m_file
	File handle to read from. More...

Private Types
using	Bounds = std::pair< const byte *, const byte * >

Private Member Functions
dberr_t	seek () noexcept
	Read the page in the file buffer from the start offset, and reset the cursor to the beginning of the file buffer. More...
dberr_t	read_next () noexcept
	Advance page number to the next and read in. More...
dberr_t	next () noexcept
	Advance the "cursor". More...
Private Member Functions inherited from ut::Non_copyable
	Non_copyable (const Non_copyable &)=delete
Non_copyable &	operator= (const Non_copyable &)=delete
	Non_copyable ()=default
	~Non_copyable ()=default

Private Attributes
Range	m_range {}
const byte *	m_ptr {}
	Pointer current offset within file buffer. More...
Bounds	m_bounds {}
	File buffer bounds. More...
byte *	m_aux_buf {}
	Auxiliary buffer for records that span across pages. More...
size_t	m_buffer_size {}
	IO buffer size in bytes. More...
ut::unique_ptr_aligned< byte[]>	m_aligned_buffer {}
	Aligned IO buffer. More...
IO_buffer	m_io_buffer {}
	File buffer for reading. More...
uint64_t	m_n_rows_read {}
	Number of rows read from the file. More...
friend	File_cursor

Detailed Description

Read rows from the temporary file.

Rows could be read in the from of chunks or ranges.

Member Typedef Documentation

Bounds

using ddl::File_reader::Bounds = std::pair<const byte *, const byte *>

private

Offsets

using ddl::File_reader::Offsets = std::vector<ulint, ut::allocator<ulint> >

Constructor & Destructor Documentation

File_reader()

ddl::File_reader::File_reader ( const Unique_os_file_descriptor &  file, dict_index_t *  index, size_t  buffer_size, const Range &  range  )

inlinenoexcept

Constructor.

Parameters

[in]	file	Opened file.
[in,out]	index	Index that the rows belong to.
[in]	buffer_size	Size of file buffer for reading.
[in]	range	Offsets of the chunk to read

~File_reader()

ddl::File_reader::~File_reader ( )

inlinenoexcept

Destructor.

Member Function Documentation

end_of_range()

bool ddl::File_reader::end_of_range ( ) const

inlinenoexcept

Returns

true if the range first == second.

get_n_rows_read()

uint64_t ddl::File_reader::get_n_rows_read ( ) const

inlinenoexcept

Returns

the number of rows read from the file.

get_tuple()

dberr_t ddl::File_reader::get_tuple ( Builder *  builder, mem_heap_t *  heap, dtuple_t *&  dtuple  )

noexcept

The current row as a tuple.

Note: the tuple only does a shallow copy.

Parameters

[in,out]	builder	Index builder instance.
[in,out]	heap	Heap to use for allocation.
[out]	dtuple	Row converted to a tuple.

Returns

DB_SUCCESS or error code.

next()

dberr_t ddl::File_reader::next ( void  )

privatenoexcept

Advance the "cursor".

Returns

DB_SUCCESS or error code.

prepare()

dberr_t ddl::File_reader::prepare ( )

noexcept

Prepare the file for reading.

Returns

DB_SUCCESS or error code.

read()

dberr_t ddl::File_reader::read ( const Range &  range )

noexcept

Set the start and end offsets to read from, to avoid the possibility of overlapping reads from the other ranges in subsequent reads.

Seek to the start offset, read the page and, position to the first record on the page

Parameters

[in]

range

Start and end offsets of the range to read from.

Returns

DB_SUCCESS or error code.

read_next()

dberr_t ddl::File_reader::read_next ( )

privatenoexcept

Advance page number to the next and read in.

Returns

DB_SUCCESS or error code.

seek()

dberr_t ddl::File_reader::seek ( )

privatenoexcept

Read the page in the file buffer from the start offset, and reset the cursor to the beginning of the file buffer.

Returns

DB_SUCCESS or error code.

Member Data Documentation

File_cursor

friend ddl::File_reader::File_cursor

private

m_aligned_buffer

ut::unique_ptr_aligned<byte[]> ddl::File_reader::m_aligned_buffer {}

private

Aligned IO buffer.

m_aux_buf

byte* ddl::File_reader::m_aux_buf {}

private

Auxiliary buffer for records that span across pages.

m_bounds

Bounds ddl::File_reader::m_bounds {}

private

File buffer bounds.

m_buffer_size

size_t ddl::File_reader::m_buffer_size {}

private

IO buffer size in bytes.

m_field_offsets

Offsets ddl::File_reader::m_field_offsets {}

Columns offsets.

m_file

const Unique_os_file_descriptor& ddl::File_reader::m_file

File handle to read from.

m_index

dict_index_t* ddl::File_reader::m_index {}

Index that the records belong to.

m_io_buffer

IO_buffer ddl::File_reader::m_io_buffer {}

private

File buffer for reading.

m_mrec

const mrec_t* ddl::File_reader::m_mrec {}

Pointer to current row.

m_n_rows_read

uint64_t ddl::File_reader::m_n_rows_read {}

private

Number of rows read from the file.

m_ptr

const byte* ddl::File_reader::m_ptr {}

private

Pointer current offset within file buffer.

m_range

Range ddl::File_reader::m_range {}

private

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The documentation for this struct was generated from the following files:

• storage/innobase/include/ddl0impl-file-reader.h
• storage/innobase/ddl/ddl0builder.cc
• storage/innobase/ddl/ddl0file-reader.cc