courgette/internal/workflow/dependencies.go

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979 B
Go
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package workflow
// Splits a flat map representing a graph's parent > children relationships
// into an ordered slice of levels.
func SplitFlatTreeIntoGroups(flatTree map[string][]string) [][]string {
type TreeNode struct {
name string
level int
}
nodes := map[string]TreeNode{}
deepestLevel := 0
next := []string{""}
for len(next) > 0 {
current := next[0]
next = next[1:]
children := flatTree[current]
currentNode, found := nodes[current]
// The negative value represents the graph root.
currentLevel := -1
if found {
currentLevel = currentNode.level
}
for _, child := range children {
nodes[child] = TreeNode{
name: child,
level: currentLevel + 1,
}
}
if deepestLevel < currentLevel {
deepestLevel = currentLevel
}
next = append(next, children...)
}
levels := make([][]string, deepestLevel+1)
for _, node := range nodes {
levels[node.level] = append(levels[node.level], node.name)
}
return levels
}