Refactored and Included Tests for TopoSortFromBfsNodeMap

[nathannaveen]

Description of the PR

• Refactored the code for TopoSortFromBfsNodeMap for readability and time complexity purposes.
• Included tests for TopoSortFromBfsNodeMap

In regards of improving the time complexity here is what I did:

I changed parentsMap from a map[string] []string to a map[string] parent, with parent being:

type parent struct {  
	parents map[string]bool // Consider the map[string]bool as a set, the value doesn't matter just the key  
}

So basically now parentsMap = map[string] map[string] bool. This so that we don't have to loop through every value in parentsMap. Doing this change will improve the time complexity by a lot, instead of looping through every value, we will only be doing an O(1) operation to remove each id from the maps.

I also added a map[string] []string called childrensMap, it is a map of parents to a list of children. This makes it so that we know which children have which parents. We can use this to only loop through the nodes that have a certain parent and not just loop through each and every node.

This may be affected by: #1132

PR Checklist

• All commits have a Developer Certificate of Origin (DCO) -- they are generated using -s flag to git commit.
• All new changes are covered by tests
• If GraphQL schema is changed, make generate has been run
• If collectsub protobuf has been changed, make proto has been run
• All CI checks are passing (tests and formatting)
• All dependent PRs have already been merged

[pxp928]

@rmetzman Did you want to review this one as well?

[rmetzman]

Thank you! LGTM

[pxp928]

LGTM

[nathannaveen]

@lumjjb, @mihaimaruseac 👀

[pxp928]

@nathannaveen rebase will auto merge.

[nathannaveen]

@nathannaveen rebase will auto merge.

Done, Thanks!