Yield combinations one by one instead of storing all of them. (141e027b) · Commits · public-projects / Nakama

server/matchmaker_process.go

+23 −19

Original line number	Diff line number	Diff line
		@@ -489,8 +489,7 @@ func (m LocalMatchmaker) processCustom() [][]MatchmakerEntry {
		hitIndexes = append(hitIndexes, hitIndex)
		}

		hitIndexesCombinations := combinationsMinMax(hitIndexes, 1, index.MaxCount-index.Count)
		for _, hitIndexes := range hitIndexesCombinations {
		for hitIndexes := range combinationsMinMax(hitIndexes, 1, index.MaxCount-index.Count) {
		// Check the min and max counts are met across the hit.
		var hitCount int
		for _, hitIndex := range hitIndexes {
		@@ -653,7 +652,11 @@ func (m LocalMatchmaker) processCustom() [][]MatchmakerEntry {
		return finalMatchedEntries
		}

		func combinationsMinMax[T any](from []T, min, max int) (combinations [][]T) {
		func combinationsMinMax[T any](from []T, min, max int) <-chan []T {
		c := make(chan []T)

		go func() {
		defer close(c)
		length := uint(len(from))

		// Go through all possible combinations of from 1 (only first element in subset) to 2^length (all objects in subset)
		@@ -671,7 +674,8 @@ func combinationsMinMax[T any](from []T, min, max int) (combinations [][]T) {
		combination = append(combination, from[element])
		}
		}
		combinations = append(combinations, combination)
		c <- combination
		}
		return combinations
		}()
		return c
		}