Having 6 lists of topolgies in the same file is a bit much:
1. consts for topology names
2. Report type definition
3. MakeReport() Report initialisation
4. Report.Topology(name) lookup
5. Report.TopologyMap() mapping of names to topology references
6. Report.WalkPairedTopologies() iterator over topology references
We get rid of 5 and 6 by introducing a topologyNames slice. So we
are down to 5.
We replace Report.TopologyMap() with a new function,
WalkNamedTopologies, that uses topologyNames. WalkPairedTopologies()
is updated to operate in a similar fashion. Likewise for
WalkTopologies() and Topologies() - these were previously calling
Walk[Paired]Topologies, but it is clearer to simply implement them
directly.
Previously this was buidling a fresh map of all topologies, just so it
could look up the one given as an argument.
Node summarisation (via detailed.Summaries) in particular was badly
affected by that.
This doesn't make any difference to the outcome - we were simply
setting the shape in the NodeSummary to "", which is what it starts
out as - but looks less weird in the code.
Report.Copy() shallow-copies the nodes in Report.Nodes. Hence
Node.Metrics is shared between the original and the copy. Hence bad
things happen when modifying it.
This bug has laid dormant because by luck other tests in detailed_test
involving metrics are executed first.
Any existing list would be mutated by result(), which is bad.
Note that all the existing newJoinResults() call sites pass in nodes
with no adjacencies, so this is purely a safety measure.
Since we seed the joinResult with the nodes from the topology we are
mapping to, we know the 'create' function is only called when there is
no node with the specified id.
This neatly makes the 'create' function only do what it says,
i.e. return _new_ nodes.
It is unused and none of the adjacency mapping code in the renderer
takes any notice of it. Removing this shrinks the report size.
Edges were introduced in #838. At the time we had an experimental
packet sniffer under experimental/sniff/sniffer.go. That got removed
in #1646.
We can resurrect this if we ever decide to add meta data to edges.
We used to ignore source endpoints that are associated with multiple
destination endpoints, which is a partial workaround for our inability
to correctly represent two connections from the same source ip/port
but different processes, or the same destination ip/port but different
processes. See #2665.
However, that condition is too coarse. In particular, we end up
ignoring endpoints that are connected to NATed destinations, since the
latter are represented by two (or more) endpoints.
The change here corrects that.
