Read_view_interface Class Reference

#include <read0read_view_interface.h>

Inheritance diagram for Read_view_interface:

Public Member Functions
virtual	~Read_view_interface ()=default
virtual bool	changes_visible (trx_id_t id) const =0
	Check whether the changes by id are visible. More...
virtual bool	sees_all_trxs_with_id_smaller_or_equal_to (trx_id_t id) const =0
	Checks if changes made by each trx with trx->id smaller or equal to id, should be visible to this read view. More...
virtual trx_id_t	get_lowest_needed_trx_no () const =0
	This read view does not need Undo Logs generated by transactions with trx->no strictly smaller than this value. More...
virtual void	print (FILE *file) const =0
	Describe the read-view. More...

Constructor & Destructor Documentation

~Read_view_interface()

virtual Read_view_interface::~Read_view_interface ( )

virtualdefault

Member Function Documentation

changes_visible()

virtual bool Read_view_interface::changes_visible ( trx_id_t  id ) const

pure virtual

Check whether the changes by id are visible.

Parameters

[in]

id

transaction id to check against the view

Returns

whether the view sees the modifications of id.

Implemented in ReadView.

get_lowest_needed_trx_no()

virtual trx_id_t Read_view_interface::get_lowest_needed_trx_no ( ) const

pure virtual

This read view does not need Undo Logs generated by transactions with trx->no strictly smaller than this value.

Returns

safe estimate of the lowest value of TRX_UNDO_TRX_NO header in Undo Logs still needed to support this read view

Implemented in ReadView.

print()

virtual void Read_view_interface::print ( FILE *  file ) const

pure virtual

Describe the read-view.

Parameters

[in]

file

file to write to

Implemented in ReadView.

sees_all_trxs_with_id_smaller_or_equal_to()

virtual bool Read_view_interface::sees_all_trxs_with_id_smaller_or_equal_to ( trx_id_t  id ) const

pure virtual

Checks if changes made by each trx with trx->id smaller or equal to id, should be visible to this read view.

Conceptually equivalent to: forall x<=id . changes_visible(x).

Parameters

[in]

id

max transaction id to check

Returns

true if view sees all transactions with smaller or equal id

Implemented in ReadView.

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The documentation for this class was generated from the following file:

• storage/innobase/include/read0read_view_interface.h