On 10.07.19 03:05, John Snow wrote:
> 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>
> ---
>  tests/qemu-iotests/257 | 125 +++++++++++++++++++++++++----------------
>  1 file changed, 76 insertions(+), 49 deletions(-)
> 
> diff --git a/tests/qemu-iotests/257 b/tests/qemu-iotests/257
> index f576a35a5c..2ff4aa8695 100755
> --- a/tests/qemu-iotests/257
> +++ b/tests/qemu-iotests/257
> @@ -85,6 +85,60 @@ GROUPS = [
>          Pattern('0xdd', 0x3fc0000)]), # New; leaving a gap to the right
>  ]
>  
> +
> +class EmulatedBitmap:
> +    def __init__(self, granularity=GRANULARITY):
> +        self._bits = set()
> +        self.groups = set()
> +        self.granularity = granularity
> +
> +    def dirty_bits(self, bits):
> +        self._bits |= set(bits)
> +
> +    def dirty_group(self, n):
> +        self.dirty_bits(GROUPS[n].bits(self.granularity))
> +
> +    def clear(self):
> +        self._bits = set()
> +
> +    def clear_bits(self, bits):
> +        self._bits = self._bits - set(bits)

Does -= not work here?

No real complaints.  Sorry.

Reviewed-by: Max Reitz <mreitz@redhat.com>