Class: WimParser

Inherits:
Object
  • Object
show all
Defined in:
lib/wim_parser.rb,
lib/wim_parser/version.rb

Overview

Parser for the Windows Image Format (WIM).

Information found here:
  http://www.microsoft.com/en-us/download/details.aspx?id=13096
  http://technet.microsoft.com/en-us/library/cc749478%28WS.10%29.aspx?ITPID=win7dtp
  http://www.freepatentsonline.com/y2010/0211943.html
  http://nunobrito1981.blogspot.com/2010/12/inaccuracy-on-wim-documentation.html

TODO: Add support for processing winnt.h GUID structures for wim_guid.

http://msdn.microsoft.com/en-us/library/windows/desktop/aa373931%28v=vs.85%29.aspx
http://stackoverflow.com/questions/679381/accessing-guid-members-in-c-sharp

Constant Summary collapse

HEADER_V1_STRUCT = 
BinaryStruct.new([
  'a8',  'image_tag',          # Signature that identifies the file as a .wim file. Value is set to "MSWIM\0\0".
  'L',   'size',               # Size of the WIM header in bytes.
  'L',   'version',            # The current version of the .wim file. This number will increase if the format of the .wim file changes.
  'L',   'flags',              # Defines the custom flags (listed below).
  'L',   'compression_size',   # Size of the compressed .wim file in bytes.
  'a16', 'wim_guid',           # A unique identifier.
  'S',   'part_number',        # The part number of the current .wim file in a spanned set. This value is 1, unless the data of the .wim file was split into multiple parts (.swm).
  'S',   'total_parts',        # The total number of .wim file parts in a spanned set.
  'L',   'image_count',        # The number of images contained in the .wim file.
  'L',   'offset_table_size',  # The location of the resource lookup table.
  'L',   'offset_table_flags',
  'q',   'offset_table_offset',
  'q',   'offset_table_original_size',
  'L',   'xml_data_size',      # The location of the XML data.
  'L',   'xml_data_flags',
  'q',   'xml_data_offset',
  'q',   'xml_data_original_size',
  'L',   'boot_metadata_size', # The location of the metadata resource.
  'L',   'boot_metadata_flags',
  'q',   'boot_metadata_offset',
  'q',   'boot_metadata_original_size',
  'L',   'boot_index',         # The index of the bootable image in the .wim file. If this is zero, then there are no bootable images available.
  'L',   'integrity_size',     # The location of integrity table used to verify files.
  'L',   'integrity_flags',
  'q',   'integrity_offset',
  'q',   'integrity_original_size',
  'a60', 'unused'              # A reserved 60 bytes of additional space for future fields.
])
SIZEOF_HEADER_V1_STRUCT = 
HEADER_V1_STRUCT.size
IMAGE_TAG = 
"MSWIM\0\0\0"
FLAG_HEADER_RESERVED =

Flags values for the header struct

0x00000001
FLAG_HEADER_COMPRESSION =

Resources within the WIM (both file and metadata) are compressed.

0x00000002
FLAG_HEADER_READONLY =

The contents of this WIM should not be changed.

0x00000004
FLAG_HEADER_SPANNED =

Resource data specified by the images within this WIM may be contained in another WIM.

0x00000008
FLAG_HEADER_RESOURCE_ONLY =

This WIM contains file resources only. It does not contain any file metadata.

0x00000010
FLAG_HEADER_METADATA_ONLY =

This WIM contains file metadata only.

0x00000020
FLAG_HEADER_WRITE_IN_PROGRESS =

Limits one writer to the WIM file when opened with the WIM_FLAG_SHARE_WRITE mode, This flag is primarily used in the Windows Deployment Services (WDS) scenario.

0x00000040
FLAG_HEADER_RP_FIX =

Reparse point fixup

0x00000080
FLAG_HEADER_COMPRESS_RESERVED =

Additionally, if the FLAG_HEADER_COMPRESSION flag is set, the following flags are valid:

0x00010000
FLAG_HEADER_COMPRESS_XPRESS =

Resources within the wim are compressed using XPRESS compression.

0x00020000
FLAG_HEADER_COMPRESS_LZX =

Resources within the wim are compressed using LZX compression.

0x00040000
VERSION = 
"1.0.1"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(filename) ⇒ WimParser

Returns a new instance of WimParser.



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# File 'lib/wim_parser.rb', line 68

def initialize(filename)
  @filename = filename
end

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/wim_parser.rb', line 66

def filename
  @filename
end

Instance Method Details

#header ⇒ Object 



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# File 'lib/wim_parser.rb', line 72

def header
  data = File.open(filename, "rb") do |f|
    f.read(SIZEOF_HEADER_V1_STRUCT)
  end
  ret = HEADER_V1_STRUCT.decode(data)
  raise "#{filename} is not a WIM file" if ret["image_tag"] != IMAGE_TAG
  ret
end

#xml_data ⇒ Object 



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# File 'lib/wim_parser.rb', line 81

def xml_data
  header_data = header

  xml = File.open(filename, "rb") do |f|
    f.seek(header_data["xml_data_offset"])
    f.read(header_data["xml_data_size"])
  end
  xml.force_encoding("UTF-16")

  xml = Nokogiri::XML(xml).xpath("/WIM")

  ret = {}
  ret["total_bytes"] = xml.xpath("./TOTALBYTES").text.to_i
  ret["images"] = xml.xpath("./IMAGE").collect do |i|
    # Deal with hex time parts by removing the 0x prefix, padding with 0s to
    #   8 characters, appending the low part to the high part, converting
    #   to an integer, and then converting that to a time object.
    high_part     = i.xpath("./CREATIONTIME/HIGHPART").text[2..-1].rjust(8, '0')
    low_part      = i.xpath("./CREATIONTIME/LOWPART").text[2..-1].rjust(8, '0')
    creation_time = nt_filetime_to_ruby_time("#{high_part}#{low_part}".to_i(16))

    high_part     = i.xpath("./LASTMODIFICATIONTIME/HIGHPART").text[2..-1].rjust(8, '0')
    low_part      = i.xpath("./LASTMODIFICATIONTIME/LOWPART").text[2..-1].rjust(8, '0')
    last_mod_time = nt_filetime_to_ruby_time("#{high_part}#{low_part}".to_i(16))

    {
      "index"                  => i["INDEX"].to_i,
      "name"                   => i.xpath("./NAME").text,
      "description"            => i.xpath("./DESCRIPTION").text,
      "dir_count"              => i.xpath("./DIRCOUNT").text.to_i,
      "file_count"             => i.xpath("./FILECOUNT").text.to_i,
      "total_bytes"            => i.xpath("./TOTALBYTES").text.to_i,
      "hard_link_bytes"        => i.xpath("./HARDLINKBYTES").text.to_i,
      "creation_time"          => creation_time,
      "last_modification_time" => last_mod_time,
    }
  end
  ret
end