Class: OLEWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/writeexcel/olewriter.rb

Overview

:nodoc:

Constant Summary collapse

MaxSize =

Not meant for public consumption

7087104
BlockSize =

Use WriteExcel::Big to exceed this

4096
BlockDiv =
512
ListBlocks =
127

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(arg) ⇒ OLEWriter

Accept an IO or IO-like object or a filename (as a String)


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# File 'lib/writeexcel/olewriter.rb', line 29

def initialize(arg)
  if arg.respond_to?(:to_str)
    @io = File.open(arg, "w")
  else
    @io = arg
  end
  @io.binmode if @io.respond_to?(:binmode)

  @filehandle    = ""
  @fileclosed    = false
  @internal_fh   = 0
  @biff_only     = 0
  @size_allowed  = true
  @biff_size     = 0
  @book_size     = 0
  @big_blocks    = 0
  @list_blocks   = 0
  @root_start    = 0
  @block_count   = 4
end

Instance Attribute Details

#biff_onlyObject

Returns the value of attribute biff_only


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# File 'lib/writeexcel/olewriter.rb', line 26

def biff_only
  @biff_only
end

#biff_sizeObject (readonly)

Returns the value of attribute biff_size


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# File 'lib/writeexcel/olewriter.rb', line 24

def biff_size
  @biff_size
end

#big_blocksObject (readonly)

Returns the value of attribute big_blocks


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# File 'lib/writeexcel/olewriter.rb', line 24

def big_blocks
  @big_blocks
end

#book_sizeObject (readonly)

Returns the value of attribute book_size


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# File 'lib/writeexcel/olewriter.rb', line 24

def book_size
  @book_size
end

#internal_fhObject

Returns the value of attribute internal_fh


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# File 'lib/writeexcel/olewriter.rb', line 26

def internal_fh
  @internal_fh
end

#list_blocksObject (readonly)

Returns the value of attribute list_blocks


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# File 'lib/writeexcel/olewriter.rb', line 24

def list_blocks
  @list_blocks
end

#root_startObject (readonly)

Returns the value of attribute root_start


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# File 'lib/writeexcel/olewriter.rb', line 25

def root_start
  @root_start
end

#size_allowedObject (readonly)

Returns the value of attribute size_allowed


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# File 'lib/writeexcel/olewriter.rb', line 25

def size_allowed
  @size_allowed
end

Class Method Details

.open(arg) ⇒ Object


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# File 'lib/writeexcel/olewriter.rb', line 78

def self.open(arg)
  if block_given?
    ole = self.new(arg)
    result = yield(ole)
    ole.close
    result
  else
    self.new(arg)
  end
end

Instance Method Details

#_initializeObject

_initialize()

Create a new filehandle or use the provided filehandle.


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# File 'lib/writeexcel/olewriter.rb', line 58

def _initialize
  olefile = @olefilename

  # If the filename is a reference it is assumed that it is a valid
  # filehandle, if not we create a filehandle.
  #

  # Create a new file, open for writing
  fh = open(olefile, "wb")

  # Workbook.pm also checks this but something may have happened since
  # then.
  raise "Can't open olefile. It may be in use or protected.\n" unless fh

  @internal_fh = 1

  # Store filehandle
  @filehandle = fh
end

#calculate_sizesObject

_calculate_sizes()

Calculate various sizes needed for the OLE stream


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# File 'lib/writeexcel/olewriter.rb', line 125

def calculate_sizes
  @big_blocks  = (@book_size.to_f/BlockDiv.to_f).ceil
  @list_blocks = (@big_blocks / ListBlocks) + 1
  @root_start  = @big_blocks
end

#closeObject

close()

Write root entry, big block list and close the filehandle. This routine is used to explicitly close the open filehandle without having to wait for DESTROY.


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# File 'lib/writeexcel/olewriter.rb', line 139

def close
  if @size_allowed == true
    write_padding          if @biff_only == 0
    write_property_storage if @biff_only == 0
    write_big_block_depot  if @biff_only == 0
  end
  @io.close
end

#set_size(size = BlockSize) ⇒ Object

set_size(biffsize)

Set the size of the data to be written to the OLE stream

$big_blocks = (109 depot block x (128 -1 marker word)
              - (1 x end words)) = 13842
$maxsize    = $big_blocks * 512 bytes = 7087104

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# File 'lib/writeexcel/olewriter.rb', line 109

def set_size(size = BlockSize)
  if size > MaxSize
    return @size_allowed = false
  end

  @biff_size = size
  @book_size = [size, BlockSize].max
  @size_allowed = true
end

#write(data) ⇒ Object

write($data)

Write BIFF data to OLE file.


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# File 'lib/writeexcel/olewriter.rb', line 95

def write(data)
  @io.write(data)
end

#write_big_block_depotObject

_write_big_block_depot()

Write big block depot.


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# File 'lib/writeexcel/olewriter.rb', line 202

def write_big_block_depot
  num_blocks   = @big_blocks
  num_lists    = @list_blocks
  total_blocks = num_lists * 128
  used_blocks  = num_blocks + num_lists + 2

  marker          = [-3].pack("V")
  end_of_chain    = [-2].pack("V")
  unused          = [-1].pack("V")

  1.upto(num_blocks-1){|n|
    write([n].pack("V"))
  }

  write end_of_chain
  write end_of_chain

  1.upto(num_lists){ write(marker) }

  used_blocks.upto(total_blocks){ write(unused) }

end

#write_headerObject

write_header()

Write OLE header block.


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# File 'lib/writeexcel/olewriter.rb', line 154

def write_header
  return if @biff_only == 1
  calculate_sizes
  root_start = @root_start
  num_lists  = @list_blocks

  id              = [0xD0CF11E0, 0xA1B11AE1].pack("NN")
  unknown1        = [0x00, 0x00, 0x00, 0x00].pack("VVVV")
  unknown2        = [0x3E, 0x03].pack("vv")
  unknown3        = [-2].pack("v")
  unknown4        = [0x09].pack("v")
  unknown5        = [0x06, 0x00, 0x00].pack("VVV")
  num_bbd_blocks  = [num_lists].pack("V")
  root_startblock = [root_start].pack("V")
  unknown6        = [0x00, 0x1000].pack("VV")
  sbd_startblock  = [-2].pack("V")
  unknown7        = [0x00, -2 ,0x00].pack("VVV")

  write(id)
  write(unknown1)
  write(unknown2)
  write(unknown3)
  write(unknown4)
  write(unknown5)
  write(num_bbd_blocks)
  write(root_startblock)
  write(unknown6)
  write(sbd_startblock)
  write(unknown7)

  unused = [-1].pack("V")

  1.upto(num_lists){
    root_start += 1
    write([root_start].pack("V"))
  }

  num_lists.upto(108){
    write(unused)
  }
end

#write_paddingObject

_write_padding()

Pad the end of the file


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# File 'lib/writeexcel/olewriter.rb', line 296

def write_padding
  min_size = 512
  min_size = BlockSize if @biff_size < BlockSize

  if @biff_size % min_size != 0
    padding = min_size - (@biff_size % min_size)
    write("\0" * padding)
  end
end

#write_pps(name, type, dir, start, size) ⇒ Object

_write_pps()

Write property sheet in property storage


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# File 'lib/writeexcel/olewriter.rb', line 246

def write_pps(name, type, dir, start, size)
  length = 0
  ord_name = []
  unless name.empty?
    name = name + "\0"
    ord_name = name.unpack("c*")
    length = name.bytesize * 2
  end

  rawname        = ord_name.pack("v*")
  zero           = [0].pack("C")

  pps_sizeofname = [length].pack("v")   #0x40
  pps_type       = [type].pack("v")     #0x42
  pps_prev       = [-1].pack("V")       #0x44
  pps_next       = [-1].pack("V")       #0x48
  pps_dir        = [dir].pack("V")      #0x4c

  unknown = [0].pack("V")

  pps_ts1s       = [0].pack("V")        #0x64
  pps_ts1d       = [0].pack("V")        #0x68
  pps_ts2s       = [0].pack("V")        #0x6c
  pps_ts2d       = [0].pack("V")        #0x70
  pps_sb         = [start].pack("V")    #0x74
  pps_size       = [size].pack("V")     #0x78

  write(rawname)
  write(zero * (64 - length)) if 64 - length >= 1
  write(pps_sizeofname)
  write(pps_type)
  write(pps_prev)
  write(pps_next)
  write(pps_dir)
  write(unknown * 5)
  write(pps_ts1s)
  write(pps_ts1d)
  write(pps_ts2s)
  write(pps_ts2d)
  write(pps_sb)
  write(pps_size)
  write(unknown)
end

#write_property_storageObject

_write_property_storage()

Write property storage. TODO: add summary sheets


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# File 'lib/writeexcel/olewriter.rb', line 231

def write_property_storage

  #########  name         type  dir start size
  write_pps('Root Entry', 0x05,  1,   -2, 0x00)
  write_pps('Workbook',   0x02, -1, 0x00, @book_size)
  write_pps("",           0x00, -1, 0x00, 0x0000)
  write_pps("",           0x00, -1, 0x00, 0x0000)
end