Re: [PATCH for-5.0 v2 18/23] iotests: Add VM.assert_block_path()

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

11.11.2019 19:02, Max Reitz wrote:
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>   tests/qemu-iotests/iotests.py | 59 +++++++++++++++++++++++++++++++++++
>   1 file changed, 59 insertions(+)
> 
> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
> index d34305ce69..3e03320ce3 100644
> --- a/tests/qemu-iotests/iotests.py
> +++ b/tests/qemu-iotests/iotests.py
> @@ -681,6 +681,65 @@ class VM(qtest.QEMUQtestMachine):
>   
>           return fields.items() <= ret.items()
>   
> +    """
> +    Check whether the node under the given path in the block graph is
> +    @expected_node.
> +
> +    @root is the node name of the node where the @path is rooted.
> +
> +    @path is a string that consists of child names separated by
> +    slashes.  It must begin with a slash.
> +
> +    Examples for @root + @path:
> +      - root="qcow2-node", path="/backing/file"
> +      - root="quorum-node", path="/children.2/file"
> +
> +    Hypothetically, @path could be empty, in which case it would point
> +    to @root.  However, in practice this case is not useful and hence
> +    not allowed.
> +
> +    @expected_node may be None.
> +
> +    @graph may be None or the result of an x-debug-query-block-graph
> +    call that has already been performed.
> +    """
> +    def assert_block_path(self, root, path, expected_node, graph=None):
> +        if graph is None:
> +            graph = self.qmp('x-debug-query-block-graph')['return']
> +
> +        iter_path = iter(path.split('/'))
> +
> +        # Must start with a /
> +        assert next(iter_path) == ''
> +
> +        node = next((node for node in graph['nodes'] if node['name'] == root),
> +                    None)
> +
> +        for path_node in iter_path:

I'd rename path_node to child or edge, to not interfere with block nodes here.

> +            assert node is not None, 'Cannot follow path %s' % path
> +
> +            try:
> +                node_id = next(edge['child'] for edge in graph['edges'] \
> +                                             if edge['parent'] == node['id'] and
> +                                                edge['name'] == path_node)
> +
> +                node = next(node for node in graph['nodes'] \
> +                                 if node['id'] == node_id)
> +            except StopIteration:
> +                node = None
> +
> +        assert node is not None or expected_node is None, \
> +               'No node found under %s (but expected %s)' % \
> +               (path, expected_node)
> +
> +        assert expected_node is not None or node is None, \
> +               'Found node %s under %s (but expected none)' % \
> +               (node['name'], path)
> +
> +        if node is not None and expected_node is not None:
> +            assert node['name'] == expected_node, \
> +                   'Found node %s under %s (but expected %s)' % \
> +                   (node['name'], path, expected_node)
>   
>   index_re = re.compile(r'([^\[]+)\[([^\]]+)\]')
>   
> 


-- 
Best regards,
Vladimir