917 lines
31 KiB
Ruby
Executable File
917 lines
31 KiB
Ruby
Executable File
require 'tempfile'
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require 'ole/base'
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require 'ole/types'
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require 'ole/ranges_io'
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module Ole # :nodoc:
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#
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# This class is the primary way the user interacts with an OLE storage file.
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#
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# = TODO
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#
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# * the custom header cruft for Header and Dirent needs some love.
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# * i have a number of classes doing load/save combos: Header, AllocationTable, Dirent,
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# and, in a manner of speaking, but arguably different, Storage itself.
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# they have differing api's which would be nice to rethink.
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# AllocationTable::Big must be created aot now, as it is used for all subsequent reads.
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#
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class Storage
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# thrown for any bogus OLE file errors.
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class FormatError < StandardError # :nodoc:
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end
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VERSION = '1.2.8.2'
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# options used at creation time
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attr_reader :params
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# The top of the ole tree structure
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attr_reader :root
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# The tree structure in its original flattened form. only valid after #load, or #flush.
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attr_reader :dirents
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# The underlying io object to/from which the ole object is serialized, whether we
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# should close it, and whether it is writeable
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attr_reader :io, :close_parent, :writeable
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# Low level internals, you probably shouldn't need to mess with these
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attr_reader :header, :bbat, :sbat, :sb_file
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# +arg+ should be either a filename, or an +IO+ object, and needs to be seekable.
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# +mode+ is optional, and should be a regular mode string.
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def initialize arg, mode=nil, params={}
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params, mode = mode, nil if Hash === mode
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params = {:update_timestamps => true}.merge(params)
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@params = params
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# get the io object
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@close_parent, @io = if String === arg
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mode ||= 'rb'
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[true, open(arg, mode)]
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else
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raise ArgumentError, 'unable to specify mode string with io object' if mode
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[false, arg]
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end
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# do we have this file opened for writing? don't know of a better way to tell
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# (unless we parse the mode string in the open case)
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# hmmm, note that in ruby 1.9 this doesn't work anymore. which is all the more
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# reason to use mode string parsing when available, and fall back to something like
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# io.writeable? otherwise.
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@writeable = begin
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if mode
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IO::Mode.new(mode).writeable?
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else
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@io.flush
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# this is for the benefit of ruby-1.9
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@io.syswrite('') if @io.respond_to?(:syswrite)
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true
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end
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rescue IOError
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false
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end
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# silence undefined warning in clear
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@sb_file = nil
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# if the io object has data, we should load it, otherwise start afresh
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# this should be based on the mode string rather.
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@io.size > 0 ? load : clear
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end
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# somewhat similar to File.open, the open class method allows a block form where
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# the Ole::Storage object is automatically closed on completion of the block.
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def self.open arg, mode=nil, params={}
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ole = new arg, mode, params
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if block_given?
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begin yield ole
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ensure; ole.close
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end
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else ole
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end
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end
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# load document from file.
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#
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# TODO: implement various allocationtable checks, maybe as a AllocationTable#fsck function :)
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#
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# 1. reterminate any chain not ending in EOC.
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# compare file size with actually allocated blocks per file.
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# 2. pass through all chain heads looking for collisions, and making sure nothing points to them
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# (ie they are really heads). in both sbat and mbat
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# 3. we know the locations of the bbat data, and mbat data. ensure that there are placeholder blocks
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# in the bat for them.
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# 4. maybe a check of excess data. if there is data outside the bbat.truncate.length + 1 * block_size,
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# (eg what is used for truncate in #flush), then maybe add some sort of message about that. it
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# will be automatically thrown away at close time.
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def load
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# we always read 512 for the header block. if the block size ends up being different,
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# what happens to the 109 fat entries. are there more/less entries?
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@io.rewind
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header_block = @io.read 512
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@header = Header.new header_block
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# create an empty bbat.
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@bbat = AllocationTable::Big.new self
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bbat_chain = header_block[Header::SIZE..-1].unpack 'V*'
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mbat_block = @header.mbat_start
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@header.num_mbat.times do
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blocks = @bbat.read([mbat_block]).unpack 'V*'
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mbat_block = blocks.pop
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bbat_chain += blocks
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end
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# am i using num_bat in the right way?
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@bbat.load @bbat.read(bbat_chain[0, @header.num_bat])
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# get block chain for directories, read it, then split it into chunks and load the
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# directory entries. semantics changed - used to cut at first dir where dir.type == 0
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@dirents = @bbat.read(@header.dirent_start).to_enum(:each_chunk, Dirent::SIZE).
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map { |str| Dirent.new self, str }.reject { |d| d.type_id == 0 }
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# now reorder from flat into a tree
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# links are stored in some kind of balanced binary tree
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# check that everything is visited at least, and at most once
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# similarly with the blocks of the file.
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# was thinking of moving this to Dirent.to_tree instead.
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class << @dirents
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def to_tree idx=0
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return [] if idx == Dirent::EOT
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d = self[idx]
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d.children = to_tree d.child
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raise FormatError, "directory #{d.inspect} used twice" if d.idx
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d.idx = idx
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to_tree(d.prev) + [d] + to_tree(d.next)
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end
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end
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@root = @dirents.to_tree.first
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Log.warn "root name was #{@root.name.inspect}" unless @root.name == 'Root Entry'
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unused = @dirents.reject(&:idx).length
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Log.warn "#{unused} unused directories" if unused > 0
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# FIXME i don't currently use @header.num_sbat which i should
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# hmm. nor do i write it. it means what exactly again?
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# which mode to use here?
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@sb_file = RangesIOResizeable.new @bbat, :first_block => @root.first_block, :size => @root.size
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@sbat = AllocationTable::Small.new self
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@sbat.load @bbat.read(@header.sbat_start)
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end
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def close
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@sb_file.close
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flush if @writeable
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@io.close if @close_parent
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end
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# the flush method is the main "save" method. all file contents are always
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# written directly to the file by the RangesIO objects, all this method does
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# is write out all the file meta data - dirents, allocation tables, file header
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# etc.
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#
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# maybe add an option to zero the padding, and any remaining avail blocks in the
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# allocation table.
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#
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# TODO: long and overly complex. simplify and test better. eg, perhaps move serialization
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# of bbat to AllocationTable::Big.
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def flush
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# update root dirent, and flatten dirent tree
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@root.name = 'Root Entry'
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@root.first_block = @sb_file.first_block
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@root.size = @sb_file.size
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@dirents = @root.flatten
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# serialize the dirents using the bbat
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RangesIOResizeable.open @bbat, 'w', :first_block => @header.dirent_start do |io|
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@dirents.each { |dirent| io.write dirent.to_s }
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padding = (io.size / @bbat.block_size.to_f).ceil * @bbat.block_size - io.size
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io.write 0.chr * padding
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@header.dirent_start = io.first_block
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end
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# serialize the sbat
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# perhaps the blocks used by the sbat should be marked with BAT?
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RangesIOResizeable.open @bbat, 'w', :first_block => @header.sbat_start do |io|
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io.write @sbat.to_s
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@header.sbat_start = io.first_block
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@header.num_sbat = @bbat.chain(@header.sbat_start).length
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end
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# create RangesIOResizeable hooked up to the bbat. use that to claim bbat blocks using
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# truncate. then when its time to write, convert that chain and some chunk of blocks at
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# the end, into META_BAT blocks. write out the chain, and those meta bat blocks, and its
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# done.
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# this is perhaps not good, as we reclaim all bat blocks here, which
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# may include the sbat we just wrote. FIXME
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@bbat.map! do |b|
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b == AllocationTable::BAT || b == AllocationTable::META_BAT ? AllocationTable::AVAIL : b
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end
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# currently we use a loop. this could be better, but basically,
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# the act of writing out the bat, itself requires blocks which get
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# recorded in the bat.
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#
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# i'm sure that there'd be some simpler closed form solution to this. solve
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# recursive func:
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#
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# num_mbat_blocks = ceil(max((mbat_len - 109) * 4 / block_size, 0))
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# bbat_len = initial_bbat_len + num_mbat_blocks
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# mbat_len = ceil(bbat_len * 4 / block_size)
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#
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# the actual bbat allocation table is itself stored throughout the file, and that chain
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# is stored in the initial blocks, and the mbat blocks.
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num_mbat_blocks = 0
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io = RangesIOResizeable.new @bbat, 'w', :first_block => AllocationTable::EOC
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# truncate now, so that we can simplify size calcs - the mbat blocks will be appended in a
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# contiguous chunk at the end.
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# hmmm, i think this truncate should be matched with a truncate of the underlying io. if you
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# delete a lot of stuff, and free up trailing blocks, the file size never shrinks. this can
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# be fixed easily, add an io truncate
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@bbat.truncate!
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before = @io.size
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@io.truncate @bbat.block_size * (@bbat.length + 1)
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while true
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# get total bbat size. equivalent to @bbat.to_s.length, but for the factoring in of
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# the mbat blocks. we can't just add the mbat blocks directly to the bbat, as as this iteration
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# progresses, more blocks may be needed for the bat itself (if there are no more gaps), and the
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# mbat must remain contiguous.
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bbat_data_len = ((@bbat.length + num_mbat_blocks) * 4 / @bbat.block_size.to_f).ceil * @bbat.block_size
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# now storing the excess mbat blocks also increases the size of the bbat:
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new_num_mbat_blocks = ([bbat_data_len / @bbat.block_size - 109, 0].max * 4 / (@bbat.block_size.to_f - 4)).ceil
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if new_num_mbat_blocks != num_mbat_blocks
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# need more space for the mbat.
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num_mbat_blocks = new_num_mbat_blocks
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elsif io.size != bbat_data_len
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# need more space for the bat
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# this may grow the bbat, depending on existing available blocks
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io.truncate bbat_data_len
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else
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break
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end
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end
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# now extract the info we want:
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ranges = io.ranges
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bbat_chain = @bbat.chain io.first_block
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io.close
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bbat_chain.each { |b| @bbat[b] = AllocationTable::BAT }
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# tack on the mbat stuff
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@header.num_bat = bbat_chain.length
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mbat_blocks = (0...num_mbat_blocks).map do
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block = @bbat.free_block
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@bbat[block] = AllocationTable::META_BAT
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block
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end
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@header.mbat_start = mbat_blocks.first || AllocationTable::EOC
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# now finally write the bbat, using a not resizable io.
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# the mode here will be 'r', which allows write atm.
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RangesIO.open(@io, :ranges => ranges) { |f| f.write @bbat.to_s }
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# this is the mbat. pad it out.
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bbat_chain += [AllocationTable::AVAIL] * [109 - bbat_chain.length, 0].max
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@header.num_mbat = num_mbat_blocks
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if num_mbat_blocks != 0
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# write out the mbat blocks now. first of all, where are they going to be?
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mbat_data = bbat_chain[109..-1]
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# expand the mbat_data to include the linked list forward pointers.
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mbat_data = mbat_data.to_enum(:each_slice, @bbat.block_size / 4 - 1).to_a.
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zip(mbat_blocks[1..-1] + [nil]).map { |a, b| b ? a + [b] : a }
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# pad out the last one.
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mbat_data.last.push(*([AllocationTable::AVAIL] * (@bbat.block_size / 4 - mbat_data.last.length)))
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RangesIO.open @io, :ranges => @bbat.ranges(mbat_blocks) do |f|
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f.write mbat_data.flatten.pack('V*')
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end
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end
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# now seek back and write the header out
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@io.seek 0
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@io.write @header.to_s + bbat_chain[0, 109].pack('V*')
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@io.flush
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end
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def clear
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# initialize to equivalent of loading an empty ole document.
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Log.warn 'creating new ole storage object on non-writable io' unless @writeable
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@header = Header.new
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@bbat = AllocationTable::Big.new self
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@root = Dirent.new self, :type => :root, :name => 'Root Entry'
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@dirents = [@root]
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@root.idx = 0
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@sb_file.close if @sb_file
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@sb_file = RangesIOResizeable.new @bbat, :first_block => AllocationTable::EOC
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@sbat = AllocationTable::Small.new self
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# throw everything else the hell away
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@io.truncate 0
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end
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# could be useful with mis-behaving ole documents. or to just clean them up.
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def repack temp=:file
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case temp
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when :file
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Tempfile.open 'ole-repack' do |io|
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io.binmode
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repack_using_io io
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end
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when :mem; StringIO.open('', &method(:repack_using_io))
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else raise ArgumentError, "unknown temp backing #{temp.inspect}"
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end
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end
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def repack_using_io temp_io
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@io.rewind
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IO.copy @io, temp_io
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clear
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Storage.open temp_io, nil, @params do |temp_ole|
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#temp_ole.root.type = :dir
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Dirent.copy temp_ole.root, root
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end
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end
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def bat_for_size size
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# note >=, not > previously.
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size >= @header.threshold ? @bbat : @sbat
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end
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def inspect
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"#<#{self.class} io=#{@io.inspect} root=#{@root.inspect}>"
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end
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#
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# A class which wraps the ole header
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#
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# Header.new can be both used to load from a string, or to create from
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# defaults. Serialization is accomplished with the #to_s method.
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#
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class Header < Struct.new(
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:magic, :clsid, :minor_ver, :major_ver, :byte_order, :b_shift, :s_shift,
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:reserved, :csectdir, :num_bat, :dirent_start, :transacting_signature, :threshold,
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:sbat_start, :num_sbat, :mbat_start, :num_mbat
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)
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PACK = 'a8 a16 v2 a2 v2 a6 V3 a4 V5'
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SIZE = 0x4c
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# i have seen it pointed out that the first 4 bytes of hex,
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# 0xd0cf11e0, is supposed to spell out docfile. hmmm :)
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MAGIC = "\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1" # expected value of Header#magic
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# what you get if creating new header from scratch.
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# AllocationTable::EOC isn't available yet. meh.
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EOC = 0xfffffffe
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DEFAULT = [
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MAGIC, 0.chr * 16, 59, 3, "\xfe\xff", 9, 6,
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0.chr * 6, 0, 1, EOC, 0.chr * 4,
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4096, EOC, 0, EOC, 0
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]
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def initialize values=DEFAULT
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values = values.unpack(PACK) if String === values
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super(*values)
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validate!
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end
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def to_s
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to_a.pack PACK
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end
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def validate!
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raise FormatError, "OLE2 signature is invalid" unless magic == MAGIC
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if num_bat == 0 or # is that valid for a completely empty file?
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# not sure about this one. basically to do max possible bat given size of mbat
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num_bat > 109 && num_bat > 109 + num_mbat * (1 << b_shift - 2) or
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# shouldn't need to use the mbat as there is enough space in the header block
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num_bat < 109 && num_mbat != 0 or
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# given the size of the header is 76, if b_shift <= 6, blocks address the header.
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s_shift > b_shift or b_shift <= 6 or b_shift >= 31 or
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# we only handle little endian
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byte_order != "\xfe\xff"
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raise FormatError, "not valid OLE2 structured storage file"
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end
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# relaxed this, due to test-msg/qwerty_[1-3]*.msg they all had
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# 3 for this value.
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# transacting_signature != "\x00" * 4 or
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if threshold != 4096 or
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num_mbat == 0 && mbat_start != AllocationTable::EOC or
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reserved != "\x00" * 6
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Log.warn "may not be a valid OLE2 structured storage file"
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end
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true
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end
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end
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#
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# +AllocationTable+'s hold the chains corresponding to files. Given
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# an initial index, <tt>AllocationTable#chain</tt> follows the chain, returning
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# the blocks that make up that file.
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#
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# There are 2 allocation tables, the bbat, and sbat, for big and small
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# blocks respectively. The block chain should be loaded using either
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# <tt>Storage#read_big_blocks</tt> or <tt>Storage#read_small_blocks</tt>
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# as appropriate.
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#
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# Whether or not big or small blocks are used for a file depends on
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# whether its size is over the <tt>Header#threshold</tt> level.
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#
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# An <tt>Ole::Storage</tt> document is serialized as a series of directory objects,
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# which are stored in blocks throughout the file. The blocks are either
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# big or small, and are accessed using the <tt>AllocationTable</tt>.
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#
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# The bbat allocation table's data is stored in the spare room in the header
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# block, and in extra blocks throughout the file as referenced by the meta
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# bat. That chain is linear, as there is no higher level table.
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#
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# AllocationTable.new is used to create an empty table. It can parse a string
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# with the #load method. Serialization is accomplished with the #to_s method.
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#
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class AllocationTable < Array
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# a free block (I don't currently leave any blocks free), although I do pad out
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# the allocation table with AVAIL to the block size.
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AVAIL = 0xffffffff
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EOC = 0xfffffffe # end of a chain
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# these blocks are used for storing the allocation table chains
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BAT = 0xfffffffd
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META_BAT = 0xfffffffc
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attr_reader :ole, :io, :block_size
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def initialize ole
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@ole = ole
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@sparse = true
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super()
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end
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def load data
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replace data.unpack('V*')
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end
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def truncate
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# this strips trailing AVAILs. come to think of it, this has the potential to break
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# bogus ole. if you terminate using AVAIL instead of EOC, like I did before. but that is
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# very broken. however, if a chain ends with AVAIL, it should probably be fixed to EOC
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# at load time.
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temp = reverse
|
|
not_avail = temp.find { |b| b != AVAIL } and temp = temp[temp.index(not_avail)..-1]
|
|
temp.reverse
|
|
end
|
|
|
|
def truncate!
|
|
replace truncate
|
|
end
|
|
|
|
def to_s
|
|
table = truncate
|
|
# pad it out some
|
|
num = @ole.bbat.block_size / 4
|
|
# do you really use AVAIL? they probably extend past end of file, and may shortly
|
|
# be used for the bat. not really good.
|
|
table += [AVAIL] * (num - (table.length % num)) if (table.length % num) != 0
|
|
table.pack 'V*'
|
|
end
|
|
|
|
# rewrote this to be non-recursive as it broke on a large attachment
|
|
# chain with a stack error
|
|
def chain idx
|
|
a = []
|
|
until idx >= META_BAT
|
|
raise FormatError, "broken allocationtable chain" if idx < 0 || idx > length
|
|
a << idx
|
|
idx = self[idx]
|
|
end
|
|
Log.warn "invalid chain terminator #{idx}" unless idx == EOC
|
|
a
|
|
end
|
|
|
|
# Turn a chain (an array given by +chain+) of blocks (optionally
|
|
# truncated to +size+) into an array of arrays describing the stretches of
|
|
# bytes in the file that it belongs to.
|
|
#
|
|
# The blocks are Big or Small blocks depending on the table type.
|
|
def blocks_to_ranges chain, size=nil
|
|
# truncate the chain if required
|
|
chain = chain[0...(size.to_f / block_size).ceil] if size
|
|
# convert chain to ranges of the block size
|
|
ranges = chain.map { |i| [block_size * i, block_size] }
|
|
# truncate final range if required
|
|
ranges.last[1] -= (ranges.length * block_size - size) if ranges.last and size
|
|
ranges
|
|
end
|
|
|
|
def ranges chain, size=nil
|
|
chain = self.chain(chain) unless Array === chain
|
|
blocks_to_ranges chain, size
|
|
end
|
|
|
|
# quick shortcut. chain can be either a head (in which case the table is used to
|
|
# turn it into a chain), or a chain. it is converted to ranges, then to rangesio.
|
|
def open chain, size=nil, &block
|
|
RangesIO.open @io, :ranges => ranges(chain, size), &block
|
|
end
|
|
|
|
def read chain, size=nil
|
|
open chain, size, &:read
|
|
end
|
|
|
|
# catch any method that may add an AVAIL somewhere in the middle, thus invalidating
|
|
# the @sparse speedup for free_block. annoying using eval, but define_method won't
|
|
# work for this.
|
|
# FIXME
|
|
[:map!, :collect!].each do |name|
|
|
eval <<-END
|
|
def #{name}(*args, &block)
|
|
@sparse = true
|
|
super
|
|
end
|
|
END
|
|
end
|
|
|
|
def []= idx, val
|
|
@sparse = true if val == AVAIL
|
|
super
|
|
end
|
|
|
|
def free_block
|
|
if @sparse
|
|
i = index(AVAIL) and return i
|
|
end
|
|
@sparse = false
|
|
push AVAIL
|
|
length - 1
|
|
end
|
|
|
|
# must return first_block. modifies +blocks+ in place
|
|
def resize_chain blocks, size
|
|
new_num_blocks = (size / block_size.to_f).ceil
|
|
old_num_blocks = blocks.length
|
|
if new_num_blocks < old_num_blocks
|
|
# de-allocate some of our old blocks. TODO maybe zero them out in the file???
|
|
(new_num_blocks...old_num_blocks).each { |i| self[blocks[i]] = AVAIL }
|
|
self[blocks[new_num_blocks-1]] = EOC if new_num_blocks > 0
|
|
blocks.slice! new_num_blocks..-1
|
|
elsif new_num_blocks > old_num_blocks
|
|
# need some more blocks.
|
|
last_block = blocks.last
|
|
(new_num_blocks - old_num_blocks).times do
|
|
block = free_block
|
|
# connect the chain. handle corner case of blocks being [] initially
|
|
self[last_block] = block if last_block
|
|
blocks << block
|
|
last_block = block
|
|
self[last_block] = EOC
|
|
end
|
|
end
|
|
# update ranges, and return that also now
|
|
blocks
|
|
end
|
|
|
|
class Big < AllocationTable
|
|
def initialize(*args)
|
|
super
|
|
@block_size = 1 << @ole.header.b_shift
|
|
@io = @ole.io
|
|
end
|
|
|
|
# Big blocks are kind of -1 based, in order to not clash with the header.
|
|
def blocks_to_ranges blocks, size
|
|
super blocks.map { |b| b + 1 }, size
|
|
end
|
|
end
|
|
|
|
class Small < AllocationTable
|
|
def initialize(*args)
|
|
super
|
|
@block_size = 1 << @ole.header.s_shift
|
|
@io = @ole.sb_file
|
|
end
|
|
end
|
|
end
|
|
|
|
# like normal RangesIO, but Ole::Storage specific. the ranges are backed by an
|
|
# AllocationTable, and can be resized. used for read/write to 2 streams:
|
|
# 1. serialized dirent data
|
|
# 2. sbat table data
|
|
# 3. all dirents but through RangesIOMigrateable below
|
|
#
|
|
# Note that all internal access to first_block is through accessors, as it is sometimes
|
|
# useful to redirect it.
|
|
class RangesIOResizeable < RangesIO
|
|
attr_reader :bat
|
|
attr_accessor :first_block
|
|
def initialize bat, mode='r', params={}
|
|
mode, params = 'r', mode if Hash === mode
|
|
first_block, size = params.values_at :first_block, :size
|
|
raise ArgumentError, 'must specify first_block' unless first_block
|
|
@bat = bat
|
|
self.first_block = first_block
|
|
# we now cache the blocks chain, for faster resizing.
|
|
@blocks = @bat.chain first_block
|
|
super @bat.io, mode, :ranges => @bat.ranges(@blocks, size)
|
|
end
|
|
|
|
def truncate size
|
|
# note that old_blocks is != @ranges.length necessarily. i'm planning to write a
|
|
# merge_ranges function that merges sequential ranges into one as an optimization.
|
|
@bat.resize_chain @blocks, size
|
|
@ranges = @bat.ranges @blocks, size
|
|
@pos = @size if @pos > size
|
|
self.first_block = @blocks.empty? ? AllocationTable::EOC : @blocks.first
|
|
|
|
# don't know if this is required, but we explicitly request our @io to grow if necessary
|
|
# we never shrink it though. maybe this belongs in allocationtable, where smarter decisions
|
|
# can be made.
|
|
# maybe its ok to just seek out there later??
|
|
max = @ranges.map { |pos, len| pos + len }.max || 0
|
|
@io.truncate max if max > @io.size
|
|
|
|
@size = size
|
|
end
|
|
end
|
|
|
|
# like RangesIOResizeable, but Ole::Storage::Dirent specific. provides for migration
|
|
# between bats based on size, and updating the dirent.
|
|
class RangesIOMigrateable < RangesIOResizeable
|
|
attr_reader :dirent
|
|
def initialize dirent, mode='r'
|
|
@dirent = dirent
|
|
super @dirent.ole.bat_for_size(@dirent.size), mode,
|
|
:first_block => @dirent.first_block, :size => @dirent.size
|
|
end
|
|
|
|
def truncate size
|
|
bat = @dirent.ole.bat_for_size size
|
|
if bat.class != @bat.class
|
|
# bat migration needed! we need to backup some data. the amount of data
|
|
# should be <= @ole.header.threshold, so we can just hold it all in one buffer.
|
|
# backup this
|
|
pos = @pos
|
|
@pos = 0
|
|
keep = read [@size, size].min
|
|
# this does a normal truncate to 0, removing our presence from the old bat, and
|
|
# rewrite the dirent's first_block
|
|
super 0
|
|
@bat = bat
|
|
# just change the underlying io from right under everyone :)
|
|
@io = bat.io
|
|
# important to do this now, before the write. as the below write will always
|
|
# migrate us back to sbat! this will now allocate us +size+ in the new bat.
|
|
super
|
|
@pos = 0
|
|
write keep
|
|
@pos = pos
|
|
else
|
|
super
|
|
end
|
|
# now just update the file
|
|
@dirent.size = size
|
|
end
|
|
|
|
# forward this to the dirent
|
|
def first_block
|
|
@dirent.first_block
|
|
end
|
|
|
|
def first_block= val
|
|
@dirent.first_block = val
|
|
end
|
|
end
|
|
|
|
#
|
|
# A class which wraps an ole directory entry. Can be either a directory
|
|
# (<tt>Dirent#dir?</tt>) or a file (<tt>Dirent#file?</tt>)
|
|
#
|
|
# Most interaction with <tt>Ole::Storage</tt> is through this class.
|
|
# The 2 most important functions are <tt>Dirent#children</tt>, and
|
|
# <tt>Dirent#data</tt>.
|
|
#
|
|
# was considering separate classes for dirs and files. some methods/attrs only
|
|
# applicable to one or the other.
|
|
#
|
|
# As with the other classes, #to_s performs the serialization.
|
|
#
|
|
class Dirent < Struct.new(
|
|
:name_utf16, :name_len, :type_id, :colour, :prev, :next, :child,
|
|
:clsid, :flags, # dirs only
|
|
:create_time_str, :modify_time_str, # files only
|
|
:first_block, :size, :reserved
|
|
)
|
|
include RecursivelyEnumerable
|
|
|
|
PACK = 'a64 v C C V3 a16 V a8 a8 V2 a4'
|
|
SIZE = 128
|
|
TYPE_MAP = {
|
|
# this is temporary
|
|
0 => :empty,
|
|
1 => :dir,
|
|
2 => :file,
|
|
5 => :root
|
|
}
|
|
# something to do with the fact that the tree is supposed to be red-black
|
|
COLOUR_MAP = {
|
|
0 => :red,
|
|
1 => :black
|
|
}
|
|
# used in the next / prev / child stuff to show that the tree ends here.
|
|
# also used for first_block for directory.
|
|
EOT = 0xffffffff
|
|
DEFAULT = [
|
|
0.chr * 2, 2, 0, # will get overwritten
|
|
1, EOT, EOT, EOT,
|
|
0.chr * 16, 0, nil, nil,
|
|
AllocationTable::EOC, 0, 0.chr * 4
|
|
]
|
|
|
|
# i think its just used by the tree building
|
|
attr_accessor :idx
|
|
# This returns all the children of this +Dirent+. It is filled in
|
|
# when the tree structure is recreated.
|
|
attr_accessor :children
|
|
attr_accessor :name
|
|
attr_reader :ole, :type, :create_time, :modify_time
|
|
def initialize ole, values=DEFAULT, params={}
|
|
@ole = ole
|
|
values, params = DEFAULT, values if Hash === values
|
|
values = values.unpack(PACK) if String === values
|
|
super(*values)
|
|
|
|
# extra parsing from the actual struct values
|
|
@name = params[:name] || Types::Variant.load(Types::VT_LPWSTR, name_utf16[0...name_len])
|
|
@type = if params[:type]
|
|
unless TYPE_MAP.values.include?(params[:type])
|
|
raise ArgumentError, "unknown type #{params[:type].inspect}"
|
|
end
|
|
params[:type]
|
|
else
|
|
TYPE_MAP[type_id] or raise FormatError, "unknown type_id #{type_id.inspect}"
|
|
end
|
|
|
|
# further extra type specific stuff
|
|
if file?
|
|
default_time = @ole.params[:update_timestamps] ? Time.now : nil
|
|
@create_time ||= default_time
|
|
@modify_time ||= default_time
|
|
@create_time = Types::Variant.load(Types::VT_FILETIME, create_time_str) if create_time_str
|
|
@modify_time = Types::Variant.load(Types::VT_FILETIME, create_time_str) if modify_time_str
|
|
@children = nil
|
|
else
|
|
@create_time = nil
|
|
@modify_time = nil
|
|
self.size = 0 unless @type == :root
|
|
@children = []
|
|
end
|
|
|
|
# to silence warnings. used for tree building at load time
|
|
# only.
|
|
@idx = nil
|
|
end
|
|
|
|
def open mode='r'
|
|
raise Errno::EISDIR unless file?
|
|
io = RangesIOMigrateable.new self, mode
|
|
# TODO work on the mode string stuff a bit more.
|
|
# maybe let the io object know about the mode, so it can refuse
|
|
# to work for read/write appropriately. maybe redefine all unusable
|
|
# methods using singleton class to throw errors.
|
|
# for now, i just want to implement truncation on use of 'w'. later,
|
|
# i need to do 'a' etc.
|
|
case mode
|
|
when 'r', 'r+'
|
|
# as i don't enforce reading/writing, nothing changes here. kind of
|
|
# need to enforce tt if i want modify times to work better.
|
|
@modify_time = Time.now if mode == 'r+'
|
|
when 'w'
|
|
@modify_time = Time.now
|
|
# io.truncate 0
|
|
#else
|
|
# raise NotImplementedError, "unsupported mode - #{mode.inspect}"
|
|
end
|
|
if block_given?
|
|
begin yield io
|
|
ensure; io.close
|
|
end
|
|
else io
|
|
end
|
|
end
|
|
|
|
def read limit=nil
|
|
open { |io| io.read limit }
|
|
end
|
|
|
|
def file?
|
|
type == :file
|
|
end
|
|
|
|
def dir?
|
|
# to count root as a dir.
|
|
!file?
|
|
end
|
|
|
|
# maybe need some options regarding case sensitivity.
|
|
def / name
|
|
children.find { |child| name === child.name }
|
|
end
|
|
|
|
def [] idx
|
|
if String === idx
|
|
#warn 'String form of Dirent#[] is deprecated'
|
|
self / idx
|
|
else
|
|
super
|
|
end
|
|
end
|
|
|
|
# move to ruby-msg. and remove from here
|
|
def time
|
|
#warn 'Dirent#time is deprecated'
|
|
create_time || modify_time
|
|
end
|
|
|
|
def each_child(&block)
|
|
@children.each(&block)
|
|
end
|
|
|
|
# flattens the tree starting from here into +dirents+. note it modifies its argument.
|
|
def flatten dirents=[]
|
|
@idx = dirents.length
|
|
dirents << self
|
|
if file?
|
|
self.prev = self.next = self.child = EOT
|
|
else
|
|
children.each { |child| child.flatten dirents }
|
|
self.child = Dirent.flatten_helper children
|
|
end
|
|
dirents
|
|
end
|
|
|
|
# i think making the tree structure optimized is actually more complex than this, and
|
|
# requires some intelligent ordering of the children based on names, but as long as
|
|
# it is valid its ok.
|
|
# actually, i think its ok. gsf for example only outputs a singly-linked-list, where
|
|
# prev is always EOT.
|
|
def self.flatten_helper children
|
|
return EOT if children.empty?
|
|
i = children.length / 2
|
|
this = children[i]
|
|
this.prev, this.next = [(0...i), (i+1..-1)].map { |r| flatten_helper children[r] }
|
|
this.idx
|
|
end
|
|
|
|
def to_s
|
|
tmp = Types::Variant.dump(Types::VT_LPWSTR, name)
|
|
tmp = tmp[0, 62] if tmp.length > 62
|
|
tmp += 0.chr * 2
|
|
self.name_len = tmp.length
|
|
self.name_utf16 = tmp + 0.chr * (64 - tmp.length)
|
|
# type_id can perhaps be set in the initializer, as its read only now.
|
|
self.type_id = TYPE_MAP.to_a.find { |id, name| @type == name }.first
|
|
# for the case of files, it is assumed that that was handled already
|
|
# note not dir?, so as not to override root's first_block
|
|
self.first_block = Dirent::EOT if type == :dir
|
|
if file?
|
|
# this is messed up. it changes the time stamps regardless of whether the file
|
|
# was actually touched. instead, any open call with a writeable mode, should update
|
|
# the modify time. create time would be set in new.
|
|
if @ole.params[:update_timestamps]
|
|
self.create_time_str = Types::Variant.dump Types::VT_FILETIME, @create_time
|
|
self.modify_time_str = Types::Variant.dump Types::VT_FILETIME, @modify_time
|
|
end
|
|
else
|
|
self.create_time_str = 0.chr * 8
|
|
self.modify_time_str = 0.chr * 8
|
|
end
|
|
to_a.pack PACK
|
|
end
|
|
|
|
def inspect
|
|
str = "#<Dirent:#{name.inspect}"
|
|
# perhaps i should remove the data snippet. its not that useful anymore.
|
|
# there is also some dir specific stuff. like clsid, flags, that i should
|
|
# probably include
|
|
if file?
|
|
tmp = read 9
|
|
data = tmp.length == 9 ? tmp[0, 5] + '...' : tmp
|
|
str << " size=#{size}" +
|
|
"#{modify_time ? ' modify_time=' + modify_time.to_s.inspect : nil}" +
|
|
" data=#{data.inspect}"
|
|
end
|
|
str + '>'
|
|
end
|
|
|
|
def delete child
|
|
# remove from our child array, so that on reflatten and re-creation of @dirents, it will be gone
|
|
raise ArgumentError, "#{child.inspect} not a child of #{self.inspect}" unless @children.delete child
|
|
# free our blocks
|
|
child.open { |io| io.truncate 0 }
|
|
end
|
|
|
|
def self.copy src, dst
|
|
# copies the contents of src to dst. must be the same type. this will throw an
|
|
# error on copying to root. maybe this will recurse too much for big documents??
|
|
raise ArgumentError, 'differing types' if src.file? and !dst.file?
|
|
dst.name = src.name
|
|
if src.dir?
|
|
src.children.each do |src_child|
|
|
dst_child = Dirent.new dst.ole, :type => src_child.type
|
|
dst.children << dst_child
|
|
Dirent.copy src_child, dst_child
|
|
end
|
|
else
|
|
src.open do |src_io|
|
|
dst.open { |dst_io| IO.copy src_io, dst_io }
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|