From: Joe Van Dyk <joevandyk@...>
Date: 2005-08-14T09:09:37+09:00
Subject: Re: no clue

On 8/13/05, Simon Kr�ger <SimonKroeger@gmx.de> wrote:
> 
> data.each{ |j, line|
>    k, v = -2, 0
>    while (v = line.index(58, k))
>      h5[j][line[(k+2)...v].intern] =
>        line[(v+2)...(k = line.index(44, v) || line.length)]
>    end
> }
> 
> Ok, lets walk this trough:
> 
> j is just the key in the outer hash.
> 
> line looks like:
> "x_position: 200, y_position: 400, z_position: 300"
> 
> k is the index of the key (like 'x_position') in the line
> v is the index of the value (like '200') in the line
> 
> 58 is the ascii number of the char ':'
> 44 is the ascii number of the char ','
> 
> #index returns the index of the char in the string or nil
> if no such char exists (after the index given as second
> parameter)
> 
> while there is another ':' in the string
>    add key from last ',' to ':' => value from ':' to next ','
> end
> 
> the +2 is there to skip the (',' or ':') and the space.
> 
> the initial k = -2 is there because no ',' is there to skip
> at the beginning.
> 
> One is loosing readability of code if optimizing for speed
> has top priority - even in ruby.
> 
> data.each{|j, line|
>    line.split(',').each{|kv|
>      k, v = kv.split(':')
>      h6[j][k.strip.intern] = v.strip
>    }
> }
> 
> is much nicer, but look at the numbers:
> 
>                            user     system      total        real
> inject                4.672000   0.015000   4.687000 (  5.281000)
> scan                  5.250000   0.063000   5.313000 (  5.312000)
> eval                  6.140000   0.047000   6.187000 (  6.219000)
> tmp                   4.407000   0.062000   4.469000 (  4.469000)
> index                 0.375000   0.000000   0.375000 (  0.375000)
> split                10.625000   0.141000  10.766000 ( 10.781000)
> true

Ah, ok.  In my application, there's a bunch more than 3 possible keys
and they are of differing length.  I am in control of the format of
the incoming strings though, and so could modify their format to make
them easier/faster to parse.  Any ideas on what would be a more
efficient format for transporting the data?

(for reference, the original string format was "id: 3, x_position: 39,
y_position: 209, z_position: 39" and in my real application, there's
about twenty different attributes that are in the string.)

Perhaps it would be more efficient to not convert the string into a hash?

All I really need to be able to do is access/display a player's data
via some mechanism, and a player's data should be updated once a
second, and there's up to 400 players.  The above was the best way I
could come up with transporting and accessing the data, but perhaps
there's a better way of doing it.