Class Ole::Storage::RangesIOMigrateable
In: lib/ole/storage/base.rb
Parent: RangesIOResizeable
String Data Lpstr Clsid Lpwstr Section Enumerable DateTime FileTime Constants Variant::Constants Storage\n[lib/ole/storage/base.rb\nlib/ole/storage/file_system.rb\nlib/ole/storage/meta_data.rb] PropertySet lib/ole/storage/file_system.rb lib/ole/types/property_set.rb lib/ole/types/base.rb Constants Constants Variant Types Ole dot/m_9_0.png

like RangesIOResizeable, but Ole::Storage::Dirent specific. provides for migration between bats based on size, and updating the dirent.

Methods

first_block   first_block=   new   truncate  

Attributes

dirent  [R] 

Public Class methods

new(dirent, mode='r')

[Source]

     # File lib/ole/storage/base.rb, line 626
626:                         def initialize dirent, mode='r'
627:                                 @dirent = dirent
628:                                 super @dirent.ole.bat_for_size(@dirent.size), mode,
629:                                         :first_block => @dirent.first_block, :size => @dirent.size
630:                         end

Public Instance methods

first_block()

forward this to the dirent

[Source]

     # File lib/ole/storage/base.rb, line 661
661:                         def first_block
662:                                 @dirent.first_block
663:                         end
first_block=(val)

[Source]

     # File lib/ole/storage/base.rb, line 665
665:                         def first_block= val
666:                                 @dirent.first_block = val
667:                         end
truncate(size)

[Source]

     # File lib/ole/storage/base.rb, line 632
632:                         def truncate size
633:                                 bat = @dirent.ole.bat_for_size size
634:                                 if bat.class != @bat.class
635:                                         # bat migration needed! we need to backup some data. the amount of data
636:                                         # should be <= @ole.header.threshold, so we can just hold it all in one buffer.
637:                                         # backup this
638:                                         pos = [@pos, size].min
639:                                         self.pos = 0
640:                                         keep = read [@size, size].min
641:                                         # this does a normal truncate to 0, removing our presence from the old bat, and
642:                                         # rewrite the dirent's first_block
643:                                         super 0
644:                                         @bat = bat
645:                                         # just change the underlying io from right under everyone :)
646:                                         @io = bat.io
647:                                         # important to do this now, before the write. as the below write will always
648:                                         # migrate us back to sbat! this will now allocate us +size+ in the new bat.
649:                                         super
650:                                         self.pos = 0
651:                                         write keep
652:                                         self.pos = pos
653:                                 else
654:                                         super
655:                                 end
656:                                 # now just update the file
657:                                 @dirent.size = size
658:                         end

[Validate]