add support for a header of AssetBundle on the last in the file

lib/mikunyan/asset_bundle.rb

@@ -73,7 +73,7 @@ module Mikunyan
             ui_block_size = br.i32u
             flags = br.i32u
 
-            head = BinaryReader.new(uncompress(br.read(ci_block_size), ui_block_size, flags))
+            head = BinaryReader.new(uncompress(flags & 0x80 == 0 ? br.read(ci_block_size) : br.read_abs(ci_block_size, file_size - ci_block_size), ui_block_size, flags))
             guid = head.read(16)
 
             blocks = []

lib/mikunyan/binary_reader.rb

@@ -51,6 +51,14 @@ module Mikunyan
             data
         end
 
+        # Read given size of binary string from specified position. This method does not seek.
+        # @param [Integer] size size
+        # @param [Integer] pos position
+        # @return [String] data
+        def read_abs(size, pos)
+            @data.byteslice(pos, size)
+        end
+
         # Read string until null character
         # @return [String] string
         def cstr