Re: [PATCH] udevd: de-duplicate strings in rules

[Alan Jenkins <alan-jenkins@tuffmail.co.uk>]

Kay Sievers wrote:
> On Tue, Nov 11, 2008 at 22:23, Kay Sievers <kay.sievers@vrfy.org> wrote:
>   
>> On Tue, Nov 11, 2008 at 21:20, Alan Jenkins <alan-jenkins@tuffmail.co.uk> wrote:
>>     
>>> On my Ubuntu installation this removes 15k of duplicate strings,
>>> using a temporary index of about 25k.
>>>       
>> Great. That looks nice.
>>
>> Thats's the diff of the rule dump before and after the patch:
>>  ...
>>  -[] shrunk to 64896 bytes tokens (5408 * 12 bytes), 57298 bytes buffer
>>  -[] dumping 5408 (64896 bytes) tokens, 5818 (57298 bytes) strings
>>  +[] shrunk to 64896 bytes tokens (5408 * 12 bytes), 18204 bytes buffer
>>  +[] used 40512 bytes of string index nodes (844 * 48 bytes)
>>  +[] dumping 5408 (64896 bytes) tokens, 1369 (18204 bytes) strings
>>     
>
> I split the nodes and the childs in two independent arrays, so we got
> rid of the limit of 10 childs per node. I've got ~200 fully uses slots
> with the huge rules set here. Unlimited childs in the index removes
> another 3 kB of duplicates, and the temporary index seems also a bit
> smaller:
>   shrunk to 64896 bytes tokens (5408 * 12 bytes), 15324 bytes buffer
>   used 29456 bytes for index (1076 * 16 bytes nodes, 1020 * 12 bytes
> child links)
>
> Would be great, if you can check if it still works for you as expected. :)
>   

Did you have a particular reason to keep the trie_root array?  Now
there's no fixed limit on children, you could just use trie[1] as the
root node.  Remove the special case for depth = 0.  And initialize it's
value and length to 0, then you can remove the special case for len = 0.

Alan