nnvirtual: M-x <number> gnus-topic-select-group

nnvirtual: M-x <number> gnus-topic-select-group

[Christoph Conrad]

Hi!

What is the algorithm used when fetching n Articles from a nnvirtual
group? I am wondering about this. How many articles are fetched from
each group and which ones? Is it possible to fetch the last n articles
from the matching groups, so that all articles are chronologically
sorted, regardless of the group?

i. A.
Christoph Conrad
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Re: nnvirtual: M-x <number> gnus-topic-select-group

[ShengHuo ZHU]

Christoph Conrad <C.Conrad@cli.de> writes:

> What is the algorithm used when fetching n Articles from a nnvirtual
> group? I am wondering about this. How many articles are fetched from
> each group and which ones? Is it possible to fetch the last n articles
> from the matching groups, so that all articles are chronologically
> sorted, regardless of the group?

A nnvirtual group contains all active articles from component groups.


,----
| Convert component -> virtual:
| set num = num - Offset(group)
| find first row in Mapping where num <= 'a'
| num = (num-'b')*c + Position(group) + 'e'
`----

Convert virtual -> component:
find first row in Mapping where num <= 'd'
num = num - 'e'
group_pos = num mod 'c'
num = (num / 'c') + 'b' + Offset(group_pos)

ShengHuo

Re: nnvirtual: M-x <number> gnus-topic-select-group

[ShengHuo ZHU]

[Accidently typed C-c C-c.]

ShengHuo ZHU <zsh@cs.rochester.edu> writes:

> Christoph Conrad <C.Conrad@cli.de> writes:
> 
> > What is the algorithm used when fetching n Articles from a nnvirtual
> > group? I am wondering about this. How many articles are fetched from
> > each group and which ones? Is it possible to fetch the last n articles
> > from the matching groups, so that all articles are chronologically
> > sorted, regardless of the group?
> 
> A nnvirtual group contains all active articles from component groups.
>
> ,----
> | Convert component -> virtual:
> | set num = num - Offset(group)
> | find first row in Mapping where num <= 'a'
> | num = (num-'b')*c + Position(group) + 'e'
> `----
> 
> Convert virtual -> component:
> find first row in Mapping where num <= 'd'
> num = num - 'e'
> group_pos = num mod 'c'
> num = (num / 'c') + 'b' + Offset(group_pos)

In another word, the articles from the same component group are listed
together.  Only the active numbers are used and no date info is
available when generating a nnvirtual group map, so the chronological
sort is not possible with the current scheme.

ShengHuo