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lib/cfpropertylist/rbBinaryCFPropertyList.rb

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+# -*- coding: utf-8 -*-
+#
+# CFPropertyList implementation
+# parser class to read, manipulate and write binary property list files (plist(5)) as defined by Apple
+#
+# Author::    Christian Kruse (mailto:cjk@wwwtech.de)
+# Copyright:: Copyright (c) 2010
+# License::   Distributes under the same terms as Ruby
+
+module CFPropertyList
+  class Binary
+    # Read a binary plist file
+    def load(opts)
+      @unique_table = {}
+      @count_objects = 0
+      @string_size = 0
+      @int_size = 0
+      @misc_size = 0
+      @object_refs = 0
+
+      @written_object_count = 0
+      @object_table = []
+      @object_ref_size = 0
+
+      @offsets = []
+
+      fd = nil
+      if(opts.has_key?(:file)) then
+        fd = File.open(opts[:file],"rb")
+        file = opts[:file]
+      else
+        fd = StringIO.new(opts[:data],"rb")
+        file = "<string>"
+      end
+
+      # first, we read the trailer: 32 byte from the end
+      fd.seek(-32,IO::SEEK_END)
+      buff = fd.read(32)
+
+      offset_size, object_ref_size, number_of_objects, top_object, table_offset = buff.unpack "x6CCx4Nx4Nx4N"
+
+      # after that, get the offset table
+      fd.seek(table_offset, IO::SEEK_SET)
+      coded_offset_table = fd.read(number_of_objects * offset_size)
+      raise CFFormatError.new("#{file}: Format error!") unless coded_offset_table.bytesize == number_of_objects * offset_size
+
+      @count_objects = number_of_objects
+
+      # decode offset table
+      formats = ["","C*","n*","(H6)*","N*"]
+      @offsets = coded_offset_table.unpack(formats[offset_size])
+      if(offset_size == 3) then
+        0.upto(@offsets.count-1) { |i| @offsets[i] = @offsets[i].to_i(16) }
+      end
+
+      @object_ref_size = object_ref_size
+      val = read_binary_object_at(file,fd,top_object)
+
+      fd.close
+      return val
+    end
+
+
+    # Convert CFPropertyList to binary format; since we have to count our objects we simply unique CFDictionary and CFArray
+    def to_str(opts={})
+      @unique_table = {}
+      @count_objects = 0
+      @string_size = 0
+      @int_size = 0
+      @misc_size = 0
+      @object_refs = 0
+
+      @written_object_count = 0
+      @object_table = []
+      @object_ref_size = 0
+
+      @offsets = []
+
+      binary_str = "bplist00"
+      unique_and_count_values(opts[:root])
+
+      @count_objects += @unique_table.count
+      @object_ref_size = Binary.bytes_needed(@count_objects)
+
+      file_size = @string_size + @int_size + @misc_size + @object_refs * @object_ref_size + 40
+      offset_size = Binary.bytes_needed(file_size)
+      table_offset = file_size - 32
+
+      @object_table = []
+      @written_object_count = 0
+      @unique_table = {} # we needed it to calculate several values, but now we need an empty table
+
+      opts[:root].to_binary(self)
+
+      object_offset = 8
+      offsets = []
+
+      0.upto(@object_table.count-1) do |i|
+        binary_str += @object_table[i]
+        offsets[i] = object_offset
+        object_offset += @object_table[i].bytesize
+      end
+
+      offsets.each do |offset|
+        binary_str += Binary.pack_it_with_size(offset_size,offset)
+      end
+
+      binary_str += [offset_size, @object_ref_size].pack("x6CC")
+      binary_str += [@count_objects].pack("x4N")
+      binary_str += [0].pack("x4N")
+      binary_str += [table_offset].pack("x4N")
+
+      return binary_str
+    end
+
+    # read a „null” type (i.e. null byte, marker byte, bool value)
+    def read_binary_null_type(length)
+      case length
+      when 0 then return 0 # null byte
+      when 8 then return CFBoolean.new(false)
+      when 9 then return CFBoolean.new(true)
+      when 15 then return 15 # fill type
+      end
+
+      raise CFFormatError.new("unknown null type: #{length}")
+    end
+    protected :read_binary_null_type
+
+    # read a binary int value
+    def read_binary_int(fname,fd,length)
+      raise CFFormatError.new("Integer greater than 8 bytes: #{length}") if length > 3
+
+      nbytes = 1 << length
+
+      val = nil
+      buff = fd.read(nbytes)
+
+      case length
+      when 0 then
+        val = buff.unpack("C")
+        val = val[0]
+      when 1 then
+        val = buff.unpack("n")
+        val = val[0]
+      when 2 then
+        val = buff.unpack("N")
+        val = val[0]
+      when 3
+        hiword,loword = buff.unpack("NN")
+        val = hiword << 32 | loword
+      end
+
+      return CFInteger.new(val);
+    end
+    protected :read_binary_int
+
+    # read a binary real value
+    def read_binary_real(fname,fd,length)
+      raise CFFormatError.new("Real greater than 8 bytes: #{length}") if length > 3
+
+      nbytes = 1 << length
+      val = nil
+      buff = fd.read(nbytes)
+
+      case length
+      when 0 then # 1 byte float? must be an error
+        raise CFFormatError.new("got #{length+1} byte float, must be an error!")
+      when 1 then # 2 byte float? must be an error
+        raise CFFormatError.new("got #{length+1} byte float, must be an error!")
+      when 2 then
+        val = buff.reverse.unpack("f")
+        val = val[0]
+      when 3 then
+        val = buff.reverse.unpack("d")
+        val = val[0]
+      end
+
+      return CFReal.new(val)
+    end
+    protected :read_binary_real
+
+    # read a binary date value
+    def read_binary_date(fname,fd,length)
+      raise CFFormatError.new("Date greater than 8 bytes: #{length}") if length > 3
+
+      nbytes = 1 << length
+      val = nil
+      buff = fd.read(nbytes)
+
+      case length
+      when 0 then # 1 byte CFDate is an error
+        raise CFFormatError.new("#{length+1} byte CFDate, error")
+      when 1 then # 2 byte CFDate is an error
+        raise CFFormatError.new("#{length+1} byte CFDate, error")
+      when 2 then
+        val = buff.reverse.unpack("f")
+        val = val[0]
+      when 3 then
+        val = buff.reverse.unpack("d")
+        val = val[0]
+      end
+
+      return CFDate.new(val,CFDate::TIMESTAMP_APPLE)
+    end
+    protected :read_binary_date
+
+    # Read a binary data value
+    def read_binary_data(fname,fd,length)
+      buff = "";
+      buff = fd.read(length) if length > 0
+      return CFData.new(buff,CFData::DATA_RAW)
+    end
+    protected :read_binary_data
+
+    # Read a binary string value
+    def read_binary_string(fname,fd,length)
+      buff = ""
+      buff = fd.read(length) if length > 0
+
+      @unique_table[buff] = true unless @unique_table.has_key?(buff)
+      return CFString.new(buff)
+    end
+    protected :read_binary_string
+
+    # Convert the given string from one charset to another
+    def Binary.charset_convert(str,from,to="UTF-8")
+      return str.clone.force_encoding(from).encode(to) if str.respond_to?("encode")
+      return Iconv.conv(to,from,str)
+    end
+
+    # Count characters considering character set
+    def Binary.charset_strlen(str,charset="UTF-8")
+      return str.length if str.respond_to?("encode")
+
+      str = Iconv.conv("UTF-8",charset,str) if charset != "UTF-8"
+      return str.scan(/./mu).size
+    end
+
+    # Read a unicode string value, coded as UTF-16BE
+    def read_binary_unicode_string(fname,fd,length)
+      # The problem is: we get the length of the string IN CHARACTERS;
+      # since a char in UTF-16 can be 16 or 32 bit long, we don't really know
+      # how long the string is in bytes
+      buff = fd.read(2*length)
+
+      @unique_table[buff] = true unless @unique_table.has_key?(buff)
+      return CFString.new(Binary.charset_convert(buff,"UTF-16BE","UTF-8"))
+    end
+    protected :read_binary_unicode_string
+
+    # Read an binary array value, including contained objects
+    def read_binary_array(fname,fd,length)
+      ary = []
+
+      # first: read object refs
+      if(length != 0) then
+        buff = fd.read(length * @object_ref_size)
+        objects = buff.unpack(@object_ref_size == 1 ? "C*" : "n*")
+
+        # now: read objects
+        0.upto(length-1) do |i|
+          object = read_binary_object_at(fname,fd,objects[i])
+          ary.push object
+        end
+      end
+
+      return CFArray.new(ary)
+    end
+    protected :read_binary_array
+
+    # Read a dictionary value, including contained objects
+    def read_binary_dict(fname,fd,length)
+      dict = {}
+
+      # first: read keys
+      if(length != 0) then
+        buff = fd.read(length * @object_ref_size)
+        keys = buff.unpack(@object_ref_size == 1 ? "C*" : "n*")
+
+        # second: read object refs
+        buff = fd.read(length * @object_ref_size)
+        objects = buff.unpack(@object_ref_size == 1 ? "C*" : "n*")
+
+        # read real keys and objects
+        0.upto(length-1) do |i|
+          key = read_binary_object_at(fname,fd,keys[i])
+          object = read_binary_object_at(fname,fd,objects[i])
+          dict[key.value] = object
+        end
+      end
+
+      return CFDictionary.new(dict)
+    end
+    protected :read_binary_dict
+
+    # Read an object type byte, decode it and delegate to the correct reader function
+    def read_binary_object(fname,fd)
+      # first: read the marker byte
+      buff = fd.read(1)
+
+      object_length = buff.unpack("C*")
+      object_length = object_length[0]  & 0xF
+
+      buff = buff.unpack("H*")
+      object_type = buff[0][0].chr
+
+      if(object_type != "0" && object_length == 15) then
+        object_length = read_binary_object(fname,fd)
+        object_length = object_length.value
+      end
+
+      retval = nil
+      case object_type
+      when '0' then # null, false, true, fillbyte
+        retval = read_binary_null_type(object_length)
+      when '1' then # integer
+        retval = read_binary_int(fname,fd,object_length)
+      when '2' then # real
+        retval = read_binary_real(fname,fd,object_length)
+      when '3' then # date
+        retval = read_binary_date(fname,fd,object_length)
+      when '4' then # data
+        retval = read_binary_data(fname,fd,object_length)
+      when '5' then # byte string, usually utf8 encoded
+        retval = read_binary_string(fname,fd,object_length)
+      when '6' then # unicode string (utf16be)
+        retval = read_binary_unicode_string(fname,fd,object_length)
+      when 'a' then # array
+        retval = read_binary_array(fname,fd,object_length)
+      when 'd' then # dictionary
+        retval = read_binary_dict(fname,fd,object_length)
+      end
+
+      return retval
+    end
+    protected :read_binary_object
+
+    # Read an object type byte at position $pos, decode it and delegate to the correct reader function
+    def read_binary_object_at(fname,fd,pos)
+      position = @offsets[pos]
+      fd.seek(position,IO::SEEK_SET)
+      return read_binary_object(fname,fd)
+    end
+    protected :read_binary_object_at
+
+    # calculate the bytes needed for a size integer value
+    def Binary.bytes_size_int(int)
+      nbytes = 0
+
+      nbytes += 2 if int > 0xE # 2 bytes int
+      nbytes += 2 if int > 0xFF # 3 bytes int
+      nbytes += 2 if int > 0xFFFF # 5 bytes int
+
+      return nbytes
+    end
+
+    # Calculate the byte needed for a „normal” integer value
+    def Binary.bytes_int(int)
+      nbytes = 1
+
+      nbytes += 1 if int > 0xFF # 2 byte int
+      nbytes += 2 if int > 0xFFFF # 4 byte int
+      nbytes += 4 if int > 0xFFFFFFFF # 8 byte int
+      nbytes += 7 if int < 0 # 8 byte int (since it is signed)
+
+      return nbytes + 1 # one „marker” byte
+    end
+
+    # pack an +int+ of +nbytes+ with size
+    def Binary.pack_it_with_size(nbytes,int)
+      format = ["C", "n", "N", "N"][nbytes-1]
+
+      if(nbytes == 3) then
+        val = [int].pack(format)
+        return val.slice(-3)
+      end
+
+      return [int].pack(format)
+    end
+
+    # calculate how many bytes are needed to save +count+
+    def Binary.bytes_needed(count)
+      nbytes = 0
+
+      while count >= 1 do
+        nbytes += 1
+        count /= 256
+      end
+
+      return nbytes
+    end
+
+    # create integer bytes of +int+
+    def Binary.int_bytes(int)
+      intbytes = ""
+
+      if(int > 0xFFFF) then
+        intbytes = "\x12"+[int].pack("N") # 4 byte integer
+      elsif(int > 0xFF) then
+        intbytes = "\x11"+[int].pack("n") # 2 byte integer
+      else
+        intbytes = "\x10"+[int].pack("C") # 8 byte integer
+      end
+
+      return intbytes;
+    end
+
+    # Create a type byte for binary format as defined by apple
+    def Binary.type_bytes(type,type_len)
+      optional_int = ""
+
+      if(type_len < 15) then
+        type += sprintf("%x",type_len)
+      else
+        type += "f"
+        optional_int = Binary.int_bytes(type_len)
+      end
+
+      return [type].pack("H*") + optional_int
+    end
+
+    # „unique” and count values. „Unique” means, several objects (e.g. strings)
+    # will only be saved once and referenced later
+    def unique_and_count_values(value)
+      # no uniquing for other types than CFString and CFData
+      if(value.is_a?(CFInteger) || value.is_a?(CFReal)) then
+        val = value.value
+        if(value.is_a?(CFInteger)) then
+          @int_size += Binary.bytes_int(val)
+        else
+          @misc_size += 9 # 9 bytes (8 + marker byte) for real
+        end
+
+        @count_objects += 1
+        return
+      elsif(value.is_a?(CFDate)) then
+        @misc_size += 9
+        @count_objects += 1
+        return
+      elsif(value.is_a?(CFBoolean)) then
+        @count_objects += 1
+        @misc_size += 1
+        return
+      elsif(value.is_a?(CFArray)) then
+        cnt = 0
+
+        value.value.each do |v|
+          cnt += 1
+          unique_and_count_values(v)
+          @object_refs += 1 # each array member is a ref
+        end
+
+        @count_objects += 1
+        @int_size += Binary.bytes_size_int(cnt)
+        @misc_size += 1 # marker byte for array
+        return
+      elsif(value.is_a?(CFDictionary)) then
+        cnt = 0
+
+        value.value.each_pair do |k,v|
+          cnt += 1
+
+          if(!@unique_table.has_key?(k))
+            @unique_table[k] = 0
+            @string_size += Binary.binary_strlen(k) + 1
+            @int_size += Binary.bytes_size_int(Binary.charset_strlen(k,'UTF-8'))
+          end
+
+          @object_refs += 2 # both, key and value, are refs
+          @unique_table[k] += 1
+          unique_and_count_values(v)
+        end
+
+        @count_objects += 1
+        @misc_size += 1 # marker byte for dict
+        @int_size += Binary.bytes_size_int(cnt)
+        return
+      elsif(value.is_a?(CFData)) then
+        val = value.decoded_value
+        @int_size += Binary.bytes_size_int(val.length)
+        @misc_size += val.length
+        @count_objects += 1
+        return
+      end
+
+      val = value.value
+      if(!@unique_table.has_key?(val)) then
+        @unique_table[val] = 0
+        @string_size += Binary.binary_strlen(val) + 1
+        @int_size += Binary.bytes_size_int(Binary.charset_strlen(val,'UTF-8'))
+      end
+
+      @unique_table[val] += 1
+    end
+    protected :unique_and_count_values
+
+    # Counts the number of bytes the string will have when coded; utf-16be if non-ascii characters are present.
+    def Binary.binary_strlen(val)
+      val.each_byte do |b|
+        if(b > 127) then
+          val = Binary.charset_convert(val, 'UTF-8', 'UTF-16BE')
+          return val.bytesize
+        end
+      end
+
+      return val.bytesize
+    end
+
+    # Uniques and transforms a string value to binary format and adds it to the object table
+    def string_to_binary(val)
+      saved_object_count = -1
+
+      unless(@unique_table.has_key?(val)) then
+        saved_object_count = @written_object_count
+        @written_object_count += 1
+
+        @unique_table[val] = saved_object_count
+        utf16 = false
+
+        val.each_byte do |b|
+          if(b > 127) then
+            utf16 = true
+            break
+          end
+        end
+
+        if(utf16) then
+          bdata = Binary.type_bytes("6",Binary.charset_strlen(val,"UTF-8")) # 6 is 0110, unicode string (utf16be)
+          val = Binary.charset_convert(val,"UTF-8","UTF-16BE")
+
+          val.force_encoding("ASCII-8BIT") if val.respond_to?("encode")
+          @object_table[saved_object_count] = bdata + val
+        else
+          bdata = Binary.type_bytes("5",val.bytesize) # 5 is 0101 which is an ASCII string (seems to be ASCII encoded)
+          @object_table[saved_object_count] = bdata + val
+        end
+      else
+        saved_object_count = @unique_table[val]
+      end
+
+      return saved_object_count
+    end
+
+    # Codes an integer to binary format
+    def int_to_binary(value)
+      nbytes = 0
+      nbytes = 1 if value > 0xFF # 1 byte integer
+      nbytes += 1 if value > 0xFFFF # 4 byte integer
+      nbytes += 1 if value > 0xFFFFFFFF # 8 byte integer
+      nbytes = 3 if value < 0 # 8 byte integer, since signed
+
+      bdata = Binary.type_bytes("1", nbytes) # 1 is 0001, type indicator for integer
+      buff = ""
+
+      if(nbytes < 3) then
+        fmt = "N"
+
+        if(nbytes == 0) then
+          fmt = "C"
+        elsif(nbytes == 1)
+          fmt = "n"
+        end
+
+        buff = [value].pack(fmt)
+      else
+        # 64 bit signed integer; we need the higher and the lower 32 bit of the value
+        high_word = value >> 32
+        low_word = value & 0xFFFFFFFF
+        buff = [high_word,low_word].pack("NN")
+      end
+
+      return bdata + buff
+    end
+
+    # Codes a real value to binary format
+    def real_to_binary(val)
+      bdata = Binary.type_bytes("2",3) # 2 is 0010, type indicator for reals
+      buff = [val].pack("d")
+      return bdata + buff.reverse
+    end
+
+    # Converts a numeric value to binary and adds it to the object table
+    def num_to_binary(value)
+      saved_object_count = @written_object_count
+      @written_object_count += 1
+
+      val = ""
+      if(value.is_a?(CFInteger)) then
+        val = int_to_binary(value.value)
+      else
+        val = real_to_binary(value.value)
+      end
+
+      @object_table[saved_object_count] = val
+      return saved_object_count
+    end
+
+    # Convert date value (apple format) to binary and adds it to the object table
+    def date_to_binary(val)
+      saved_object_count = @written_object_count
+      @written_object_count += 1
+
+      val = val.getutc.to_f - CFDate::DATE_DIFF_APPLE_UNIX # CFDate is a real, number of seconds since 01/01/2001 00:00:00 GMT
+
+      bdata = Binary.type_bytes("3", 3) # 3 is 0011, type indicator for date
+      @object_table[saved_object_count] = bdata + [val].pack("d").reverse
+
+      return saved_object_count
+    end
+
+    # Convert a bool value to binary and add it to the object table
+    def bool_to_binary(val)
+      saved_object_count = @written_object_count
+      @written_object_count += 1
+
+      @object_table[saved_object_count] = val ? "\x9" : "\x8" # 0x9 is 1001, type indicator for true; 0x8 is 1000, type indicator for false
+      return saved_object_count
+    end
+
+    # Convert data value to binary format and add it to the object table
+    def data_to_binary(val)
+      saved_object_count = @written_object_count
+      @written_object_count += 1
+
+      bdata = Binary.type_bytes("4", val.bytesize) # a is 1000, type indicator for data
+      @object_table[saved_object_count] = bdata + val
+
+      return saved_object_count
+    end
+
+    # Convert array to binary format and add it to the object table
+    def array_to_binary(val)
+      saved_object_count = @written_object_count
+      @written_object_count += 1
+
+      bdata = Binary.type_bytes("a", val.value.count) # a is 1010, type indicator for arrays
+
+      val.value.each do |v|
+        bdata += Binary.pack_it_with_size(@object_ref_size,  v.to_binary(self));
+      end
+
+      @object_table[saved_object_count] = bdata
+      return saved_object_count
+    end
+
+    # Convert dictionary to binary format and add it to the object table
+    def dict_to_binary(val)
+      saved_object_count = @written_object_count
+      @written_object_count += 1
+
+      bdata = Binary.type_bytes("d",val.value.count) # d=1101, type indicator for dictionary
+
+      val.value.each_key do |k|
+        str = CFString.new(k)
+        key = str.to_binary(self)
+        bdata += Binary.pack_it_with_size(@object_ref_size,key)
+      end
+
+      val.value.each_value do |v|
+        bdata += Binary.pack_it_with_size(@object_ref_size,v.to_binary(self))
+      end
+
+      @object_table[saved_object_count] = bdata
+      return saved_object_count
+    end
+  end
+end
+
+# eof