[RFC] Separate node colors

[davkal]

Node colors are procedurally generated by a node's rank. This can be a
string like tnsfork/lb-1. Now if all the nodes share the same
prefix in their rank, e.g. tnsfork/ they will all get the same
color.

An approach to separate colors a bit more would be to remove the longest
common rank prefix and set that as the color key.

Pros:

• colors are better separation for homogeneous rank values

Cons:

• if 99 nodes share a prefix and one does not, the 99 will be colored
  similarly (which is what happens now)
• if that one node appears and dissappears, the 99 nodes' colors will
  switch based on their new LCP
• Loading details panels from other topologies may yield a different
  color because that node is loaded in isolation (LCP of that
  topology's nodes is undetermined)

[rade]

The 99-1 problem is nasty; and presumably the node appearance issue would also arise for 2-1, which is also nasty.

Perhaps ranking should operate on words rather than characters, e.g. tnsfork_lb2_1 would result in three words - 'tnsfork', 'lb2', '1', which you could hash to get a series of number in MSB...LSB order for determining the colour.

[rade]

See #783 and #1539 for the issue this is meant to fix.

Network colouring already use the prefix removal algo above, and it turns out to run into the 99-1 problem for trivial examples. I have raised #1592 for that.

So back to the drawing board.

[davkal]

Closing this for inactivity.