Re: [Qemu-devel] [PATCH v1 01/10] qdict: implement a qdict_crumple method for un-flattening a dict

[Eric Blake <eblake@redhat.com>]

[-- Attachment #1: Type: text/plain, Size: 1792 bytes --]

On 02/19/2016 09:47 AM, Daniel P. Berrange wrote:
> The qdict_flatten() method will take a dict whose elements are
> further nested dicts/lists and flatten them by concatenating
> keys.
> 
> The qdict_crumple() method aims todo the reverse, taking a flat

s/todo/to do/

> qdict, and turning it into a set of nested dicts/lists. It will
> apply nesting based on the key name, with a '.' indicating a
> new level in the hierarchy. If the keys in the nested structure
> are all numeric, it will create a list, otherwise it will create
> a dict.
> 

Interesting idea. I haven't closely reviewed the patch yet, but do have
a comment on the commit message:

> 
> If the key is intended to contain a literal '.', then it must
> be escaped as '..'. ie a flat dict

Hmm. We forbid the use of '.' inside QAPI key names in most places, but
have an exception that downstream extensions use '.'.  So, I guess the
only place you'd really use this is trying to target a
downstream-extension key name:

> 
>   {
>      'foo..bar': 'wizz',
>      'bar.foo..bar': 'eek',

as in '__com..example_bar': 'eek' to set the downstream key-name of
'__com.example_bar'.  I'm not sure the special casing of '.' is worth
it, particularly since qdict_flatten() doesn't have it in the reverse
direction.

> The intent of this function is that it allows a set of QemuOpts
> to be turned into a nested data structure that mirrors the nested
> used when the same object is defined over QMP.
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---

I hope to offer a more detailed review next week (I'm trying to get some
of my own patches polished today).

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 604 bytes --]