iotests/257: add EmulatedBitmap class

Represent a bitmap with an object that we can mark and clear bits in.
This makes it easier to manage partial writes when we don't write a
full group's worth of patterns before an error.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190716000117.25219-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
1 file changed