[pve-devel] [PATCH v2 common] cli-formatter: avoid warning when trying to sort on undefined key

[Thomas Lamprecht]

On 11/28/19 10:08 AM, Fabian Grünbichler wrote:
> On November 27, 2019 4:59 pm, Thomas Lamprecht wrote:
>> On 11/26/19 1:10 PM, Christian Ebner wrote:
>>> Example:
>>>     pvesh get /nodes/{node}/qemu/{vmid}/rrddata --timeframe day
>>>
>>> If the sorting key is not defined in the dataset, e.g. when a VM was not running
>>> for some time within the given timeframe, this resulted in several ugly warnings.
>>>
>>> Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
>>> ---
>>>
>>> v2: Oops, v1 is nonsense and breaks sorting.
>>>
>>>  src/PVE/CLIFormatter.pm | 6 ++++--
>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/src/PVE/CLIFormatter.pm b/src/PVE/CLIFormatter.pm
>>> index 0e9cbe6..21fa2df 100644
>>> --- a/src/PVE/CLIFormatter.pm
>>> +++ b/src/PVE/CLIFormatter.pm
>>> @@ -175,9 +175,11 @@ sub print_text_table {
>>>      if (defined($sort_key) && $sort_key ne 0) {
>>>  	my $type = $returnprops->{$sort_key}->{type} // 'string';
>>>  	if ($type eq 'integer' || $type eq 'number') {
>>> -	    @$data = sort { $a->{$sort_key} <=> $b->{$sort_key} } @$data;
>>> +	    @$data = sort { $a->{$sort_key} <=> $b->{$sort_key}
>>> +		if defined $a->{$sort_key} && defined $b->{$sort_key} } @$data;
>>>  	} else {
>>> -	    @$data = sort { $a->{$sort_key} cmp $b->{$sort_key} } @$data;
>>> +	    @$data = sort { $a->{$sort_key} cmp $b->{$sort_key}
>>> +		if defined $a->{$sort_key} && defined $b->{$sort_key} } @$data;
>>
>>
>> a post-if in a sort condition feels a bit awkward and does not
>> clearly tells a reader what the behavior for undefined cases is, IMO
>>
>> Maybe use a ternary operation here:
>> sort {
>>     defined $a->{$sort_key} && defined $b->{$sort_key}
>>         ? $a->{$sort_key} cmp $b->{$sort_key}
>>         : 1
>> }
>>
>>
>> or as alternative a sorter method:
>>
>> my $hashsort = sub {
>>     my ($a, $b, $key) = @_;
>>     return 1 if !(defined $a->{$key} && defined $b->{$key});
>>     return $a->{$key} cmp $b->{$key};
>> }
>>
>> and use that?
>>
>> Or even:
>>
>> return 1 if defined $a->{$key} && !defined $b->{$key});
>> return -1 if !defined $a->{$key} && defined $b->{$key};
>> return 0 if defined $a->{$key} && defined $b->{$key};
>>
>> ?? that stuff confuses me after a longer day, sorry ^^
> 
> complete would actually be, with the (hopefully) most likely  case up 
> front, and the assumption that undef is less than anything defined ;)
> could of course also be written as if / elsif / elsif / else, to make it 
> more obvious that all cases are handled.
> 
> return $a->{$key} cmp $b->{key} if defined($a->{key}) && defined($b->{key});
> return 1 if defined($a->{$key}) && !defined($b->{$key});
> return -1 if !defined($a->{$key}) && defined($b->{$key});
> return 0 if !(defined($a->{$key}) && defined($b->{$key}));
> 

That's the exact same I proposed?? or do I miss something?