Class: Innodb::Page::SysRsegHeader

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

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, SPECIALIZED_CLASSES

Instance Attribute Summary

Attributes inherited from Innodb::Page

#space

Instance Method Summary collapse

Methods inherited from Innodb::Page

#checksum, #checksum_crc32, #checksum_crc32?, #checksum_innodb, #checksum_innodb?, #checksum_invalid?, #checksum_trailer, #checksum_type, #checksum_valid?, #corrupt?, #cursor, #each_page_body_byte_as_uint8, #each_page_header_byte_as_uint8, #fil_header, #fil_trailer, handle, #in_doublewrite_buffer?, #initialize, #inspect, #lsn, #lsn_low32_header, #lsn_low32_trailer, maybe_undefined, #misplaced?, #misplaced_offset?, #misplaced_space?, #name, #next, #offset, parse, #pos_fil_header, #pos_fil_trailer, #pos_page_body, #pos_partial_page_header, #prev, #size, #size_fil_header, #size_fil_trailer, #size_page_body, #size_partial_page_header, #space_id, #torn?, #type

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 86

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 {|{ :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 58

def each_region
  unless block_given?
    return enum_for(:each_region)
  end

  super do |region|
    yield region
  end

  yield({
    :offset => pos_rseg_header,
    :length => size_rseg_header,
    :name => :rseg_header,
    :info => "Rollback Segment Header",
  })

  (0...UNDO_SEGMENT_SLOTS).each do |slot|
    yield({
      :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 43

def each_undo_segment
  unless block_given?
    return enum_for(:each_undo_segment)
  end

  cursor(pos_undo_segment_array).name("undo_segment_array") do |c|
    (0...UNDO_SEGMENT_SLOTS).each do |slot|
      page_number = c.name("slot[#{slot}]") {
        Innodb::Page.maybe_undefined(c.get_uint32)
      }
      yield slot, page_number
    end
  end
end

#history_list ⇒ Object 



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# File 'lib/innodb/page/sys_rseg_header.rb', line 39

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 8

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 17

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 26

def rseg_header
  cursor(pos_rseg_header).name("rseg_header") do |c|
    {
      :max_size => c.name("max_size") { c.get_uint32 },
      :history_size => c.name("history_size") { c.get_uint32 },
      :history_list => c.name("history_list") {
        Innodb::List::History.new(@space, Innodb::List.get_base_node(c))
      },
      :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 13

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 21

def size_undo_segment_slot
  4
end