Class: Innodb::Page::Inode

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

Overview

A specialized class for handling INODE pages, which contain index FSEG (file segment) information. This allows all extents and individual pages assigned to each index to be found.

Constant Summary

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

#calculate_checksum, #checksum, #corrupt?, #cursor, #data, #fil_header, handle, #initialize, #inspect, #lsn, maybe_undefined, #next, #offset, parse, #pos_fil_header, #pos_fil_trailer, #pos_page_body, #prev, #size, #size_fil_header, #size_fil_trailer, #type

Constructor Details

This class inherits a constructor from Innodb::Page

Instance Method Details

#dump ⇒ Object

Dump the contents of a page for debugging purposes.



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# File 'lib/innodb/page/inode.rb', line 72

def dump
  super

  puts "list entry:"
  pp list_entry
  puts

  puts "inodes:"
  each_inode do |inode|
    inode.dump
  end
  puts
end

#each_inode ⇒ Object

Iterate through all Inodes in the inode array.



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# File 'lib/innodb/page/inode.rb', line 57

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

  inode_cursor = cursor(pos_inode_array)
  inodes_per_page.times do |n|
    inode_cursor.name("inode[#{n}]") do |c|
      this_inode = Innodb::Inode.new_from_cursor(@space, c)
      yield this_inode if this_inode.allocated?
    end
  end
end

#inode_at(cursor) ⇒ Object

Read a single Inode entry from the provided byte offset by creating a cursor and reading the inode using the inode method.



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# File 'lib/innodb/page/inode.rb', line 52

def inode_at(cursor)
  cursor.name("inode") { |c| Innodb::Inode.new_from_cursor(@space, c) }
end

#inodes_per_page ⇒ Object

The number of Inode entries that fit on a page.



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

def inodes_per_page
  (size - pos_inode_array - 10) / Innodb::Inode::SIZE
end

#list_entry ⇒ Object

Return the list entry.



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# File 'lib/innodb/page/inode.rb', line 32

def list_entry
  cursor(pos_list_entry).name("list") do |c|
    Innodb::List.get_node(c)
  end
end

#next_address ⇒ Object

Return the “next” address pointer from the list entry. This is used by Innodb::List::Inode to iterate through Inode lists.



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# File 'lib/innodb/page/inode.rb', line 46

def next_address
  list_entry[:next]
end

#pos_inode_array ⇒ Object

Return the byte offset of the Inode array in the page, which immediately follows the list entry.



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# File 'lib/innodb/page/inode.rb', line 22

def pos_inode_array
  pos_list_entry + size_list_entry
end

#pos_list_entry ⇒ Object

Return the byte offset of the list node, which immediately follows the FIL header.



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# File 'lib/innodb/page/inode.rb', line 11

def pos_list_entry
  pos_fil_header + size_fil_header
end

#prev_address ⇒ Object

Return the “previous” address pointer from the list entry. This is used by Innodb::List::Inode to iterate through Inode lists.



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# File 'lib/innodb/page/inode.rb', line 40

def prev_address
  list_entry[:prev]
end

#size_list_entry ⇒ Object

Return the size of the list node.



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# File 'lib/innodb/page/inode.rb', line 16

def size_list_entry
  Innodb::List::NODE_SIZE
end