Class: Innodb::Page::SysRsegHeader

Inherits:
Innodb::Page show all
Defined in:
lib/innodb/page/sys_rseg_header.rb

Defined Under Namespace

Classes: Header

Constant Summary collapse

UNDO_SEGMENT_SLOTS =

The number of undo log slots in the page.

1024

Constants inherited from Innodb::Page

PAGE_TYPE, PAGE_TYPE_BY_VALUE, UNDEFINED_PAGE_NUMBER

Instance Attribute Summary

Attributes inherited from Innodb::Page

#space

Instance Method Summary collapse

Methods inherited from Innodb::Page

#checksum_crc32, #checksum_crc32?, #checksum_innodb, #checksum_innodb?, #checksum_invalid?, #checksum_type, #checksum_valid?, #corrupt?, #cursor, #default_page_size?, #each_page_body_byte_as_uint8, #each_page_header_byte_as_uint8, #extent_descriptor?, #fil_header, #fil_trailer, handle, #in_doublewrite_buffer?, #initialize, #inspect, #inspect_header_fields, maybe_undefined, #misplaced?, #misplaced_offset?, #misplaced_space?, #name, page_type_by_value, parse, #pos_fil_header, #pos_fil_trailer, #pos_page_body, #pos_partial_page_header, register_specialization, #size, #size_fil_header, #size_fil_trailer, #size_page_body, #size_partial_page_header, specialization_for, specialization_for?, #torn?, undefined?

Constructor Details

This class inherits a constructor from Innodb::Page

Instance Method Details

#dump ⇒ Object 



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# File 'lib/innodb/page/sys_rseg_header.rb', line 90

def dump
  super

  puts
  puts "rollback segment header:"
  pp rseg_header

  puts
  puts "undo segment array:"
  each_undo_segment do |slot, page_number|
    puts "  #{slot}: #{page_number}"
  end
end

#each_region {|Region.new( offset: pos_rseg_header, length: size_rseg_header, name: :rseg_header, info: "Rollback Segment Header" )| ... } ⇒ Object

Yields:



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# File 'lib/innodb/page/sys_rseg_header.rb', line 66

def each_region(&block)
  return enum_for(:each_region) unless block_given?

  super

  yield Region.new(
    offset: pos_rseg_header,
    length: size_rseg_header,
    name: :rseg_header,
    info: "Rollback Segment Header"
  )

  (0...UNDO_SEGMENT_SLOTS).each do |slot|
    yield Region.new(
      offset: pos_undo_segment_array + (slot * size_undo_segment_slot),
      length: size_undo_segment_slot,
      name: :undo_segment_slot,
      info: "Undo Segment Slot"
    )
  end

  nil
end

#each_undo_segment ⇒ Object 



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# File 'lib/innodb/page/sys_rseg_header.rb', line 53

def each_undo_segment
  return enum_for(:each_undo_segment) unless block_given?

  cursor(pos_undo_segment_array).name("undo_segment_array") do |c|
    (0...UNDO_SEGMENT_SLOTS).each do |slot|
      page_number = c.name("slot[#{slot}]") do
        Innodb::Page.maybe_undefined(c.read_uint32)
      end
      yield slot, page_number
    end
  end
end

#history_list ⇒ Object 



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# File 'lib/innodb/page/sys_rseg_header.rb', line 49

def history_list
  Innodb::HistoryList.new(rseg_header.history_list)
end

#pos_rseg_header ⇒ Object

The position of the rollback segment header within the page.



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# File 'lib/innodb/page/sys_rseg_header.rb', line 18

def pos_rseg_header
  pos_page_body
end

#pos_undo_segment_array ⇒ Object 



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# File 'lib/innodb/page/sys_rseg_header.rb', line 27

def pos_undo_segment_array
  pos_rseg_header + size_rseg_header
end

#rseg_header ⇒ Object

Parse the rollback segment header from the page.



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# File 'lib/innodb/page/sys_rseg_header.rb', line 36

def rseg_header
  cursor(pos_rseg_header).name("rseg_header") do |c|
    Header.new(
      max_size: c.name("max_size") { c.read_uint32 },
      history_size: c.name("history_size") { c.read_uint32 },
      history_list: c.name("history_list") do
        Innodb::List::History.new(@space, Innodb::List.get_base_node(c))
      end,
      fseg: c.name("fseg") { Innodb::FsegEntry.get_inode(@space, c) }
    )
  end
end

#size_rseg_header ⇒ Object

The size of the rollback segment header.



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# File 'lib/innodb/page/sys_rseg_header.rb', line 23

def size_rseg_header
  4 + 4 + Innodb::List::BASE_NODE_SIZE + Innodb::FsegEntry::SIZE
end

#size_undo_segment_slot ⇒ Object 



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# File 'lib/innodb/page/sys_rseg_header.rb', line 31

def size_undo_segment_slot
  4
end