databricks-cli/bundle/schema/tracker.go

54 lines
1.2 KiB
Go
Raw Permalink Normal View History

package schema
import (
"container/list"
"fmt"
)
type tracker struct {
// Nodes encountered in current path during the recursive traversal. Used to
// check for cycles
seenNodes map[interface{}]struct{}
// List of node names encountered in order in current path during the recursive traversal.
// Used to hydrate errors with path to the exact node where error occured.
//
// NOTE: node and node names can be the same
listOfNodes *list.List
}
func newTracker() *tracker {
return &tracker{
seenNodes: map[interface{}]struct{}{},
listOfNodes: list.New(),
}
}
func (t *tracker) errWithTrace(prefix string, initTrace string) error {
traceString := initTrace
curr := t.listOfNodes.Front()
for curr != nil {
if curr.Value.(string) != "" {
traceString += " -> " + curr.Value.(string)
}
curr = curr.Next()
}
return fmt.Errorf(prefix + ". traversal trace: " + traceString)
}
func (t *tracker) hasCycle(node interface{}) bool {
_, ok := t.seenNodes[node]
return ok
}
func (t *tracker) push(node interface{}, name string) {
t.seenNodes[node] = struct{}{}
t.listOfNodes.PushBack(name)
}
func (t *tracker) pop(nodeType interface{}) {
back := t.listOfNodes.Back()
t.listOfNodes.Remove(back)
delete(t.seenNodes, nodeType)
}