Split acceptance tests into separate files

tests/acceptance/file_writer.rb

@@ -0,0 +1,123 @@
+# Noddy test class for writing files to disc in predictable patterns
+# in order to test FlexNBD.
+#
+class FileWriter
+  def initialize(filename, blocksize)
+    @fh = File.open(filename, "w+")
+    @blocksize = blocksize
+    @pattern = ""
+  end
+
+  # We write in fixed block sizes, given by "blocksize"
+  #    _ means skip a block
+  #    0 means write a block full of zeroes
+  #    f means write a block with the file offset packed every 4 bytes
+  #
+  def write(data)
+    @pattern += data
+
+    data.split("").each do |code|
+      if code == "_"
+        @fh.seek(@blocksize, IO::SEEK_CUR)
+      else
+        @fh.write(data(code))
+      end
+    end
+    @fh.flush
+    self
+  end
+
+
+  # Returns what the data ought to be at the given offset and length
+  #
+  def read_original( off, len )
+    patterns = @pattern.split( "" )
+    patterns.zip( (0...patterns.length).to_a ).
+      map { |blk, blk_off|
+      data(blk, blk_off)
+    }.join[off...(off+len)]
+  end
+
+  # Read what's actually in the file
+  #
+  def read(off, len)
+    @fh.seek(off, IO::SEEK_SET)
+    @fh.read(len)
+  end
+
+  def untouched?(offset, len)
+    read(offset, len) == read_original(offset, len)
+  end
+
+  def close
+    @fh.close
+    nil
+  end
+
+  protected
+
+  def data(code, at=@fh.tell)
+    case code
+      when "0", "_"
+        "\0" * @blocksize
+      when "X"
+        "X" * @blocksize
+      when "f"
+        r = ""
+        (@blocksize/4).times do
+          r += [at].pack("I")
+          at += 4
+        end
+        r
+      else
+        raise "Unknown character '#{block}'"
+    end
+  end
+
+end
+
+if __FILE__==$0
+  require 'tempfile'
+  require 'test/unit'
+
+  class FileWriterTest < Test::Unit::TestCase
+    def test_read_original_zeros
+      Tempfile.open("test_read_original_zeros") do |tempfile|
+        tempfile.close
+        file = FileWriter.new( tempfile.path, 4096 )
+        file.write( "0" )
+        assert_equal file.read( 0, 4096 ), file.read_original( 0, 4096 )
+        assert( file.untouched?(0,4096) , "Untouched file was touched." )
+      end
+    end
+
+    def test_read_original_offsets
+      Tempfile.open("test_read_original_offsets") do |tempfile|
+        tempfile.close
+        file = FileWriter.new( tempfile.path, 4096 )
+        file.write( "f" )
+        assert_equal file.read( 0, 4096 ), file.read_original( 0, 4096 )
+        assert( file.untouched?(0,4096) , "Untouched file was touched." )
+      end
+    end
+
+    def test_file_size
+      Tempfile.open("test_file_size") do |tempfile|
+        tempfile.close
+        file = FileWriter.new( tempfile.path, 4096 )
+        file.write( "f" )
+        assert_equal 4096, File.stat( tempfile.path ).size
+      end
+    end
+
+    def test_read_original_size
+      Tempfile.open("test_read_original_offsets") do |tempfile|
+        tempfile.close
+        file = FileWriter.new( tempfile.path, 4)
+        file.write( "f"*4 )
+        assert_equal 4, file.read_original(0, 4).length
+      end
+    end
+  end
+end
+