Is QMap efficient in case of frequent read access ?

[lauranger]

Hi
As far as I can tell from few tests, if you look after performance of search,
size matters :
Under approximately 50 items, an array/vector of pairs is better
Between 50 and 400 items, an ordered map (like QMap) works better
Over 400, a hash map shows better performance.
But if the usage is running through each item, array/vector of pairs
will be the optimum.
Hth.

[yellowmat]

How did you test performances ?

[lauranger]

Hi,
I am a bit late with my answer.
I don't have the code anymore, I guess. But this is what I remember :
I tested by filling randomly generated longs in a container
and in a vector for randomly selecting the ones to search for
and repeated the search tests for some times and measured the times
it had taken.
Hth

[lauranger]

Ouch, I read your first post too quickly !
It appears that the set of your key has no hole,
as it grows from zero without a gap, and you use
every entry of your virtual map.
Here, obviously, anything more complicated than a "vector"
(an array would suffice, as it is static data --the keys are known
at compile time--) is overkill and
brings its overhead in time and memory consumption.
So my advice is : stick to an array.
Hth