Fix incomplete match loops and improve mem alloc for str builder and key sorting. (bd8a620c) · Commits · public-projects / Nakama

server/matchmaker_process.go

+56 −10

Original line number	Diff line number	Diff line
		@@ -713,6 +713,7 @@ func combineIndexesRandom(from []*MatchmakerIndex, min, max int, done <-chan str
		combination := make([]*MatchmakerIndex, 0, max)
		selectedIndexes := make([]int, 0, max)
		seenIndex := make(map[int]struct{}, max)
		stackFrames := make([]stackFrame, 0, max*2)

		// Number of possible combinations.
		limit := new(big.Int).Binomial(int64(length), int64(max))
		@@ -728,7 +729,7 @@ func combineIndexesRandom(from []*MatchmakerIndex, min, max int, done <-chan str
		var key string

		combinationLoop:
		for len(combination) <= max {
		for len(combination) <= max && len(seenIndex) < length {
		unique := false
		for !unique {
		i = rand.Intn(length)
		@@ -740,7 +741,7 @@ func combineIndexesRandom(from []*MatchmakerIndex, min, max int, done <-chan str
		entryCount += element.Count
		if entryCount > max {
		if entryCount >= min {
		key = generateKey(selectedIndexes)
		key = generateKey(selectedIndexes, stackFrames)
		if seenCombination[key] {
		break combinationLoop
		}
		@@ -760,7 +761,7 @@ func combineIndexesRandom(from []*MatchmakerIndex, min, max int, done <-chan str
		selectedIndexes = append(selectedIndexes, i)
		seenIndex[i] = struct{}{}
		if entryCount == max {
		key = generateKey(selectedIndexes)
		key = generateKey(selectedIndexes, stackFrames)
		if seenCombination[key] {
		break combinationLoop
		}
		@@ -783,16 +784,61 @@ func combineIndexesRandom(from []*MatchmakerIndex, min, max int, done <-chan str
		return c
		}

		var builder strings.Builder
		var keyBuilder strings.Builder

		func generateKey(indices []int) string {
		builder.Reset()
		sort.Ints(indices)
		func generateKey(indices []int, stack []stackFrame) string {
		keyBuilder.Reset()
		keyBuilder.Grow(len(indices) * 4)
		quicksort(indices, stack)
		for _, index := range indices {
		builder.WriteString(strconv.Itoa(index))
		builder.WriteString(",")
		keyBuilder.WriteString(strconv.Itoa(index))
		keyBuilder.WriteString(",")
		}
		return builder.String()
		return keyBuilder.String()
		}

		type stackFrame struct {
		low, high int
		}

		func quicksort(indices []int, stack []stackFrame) {
		if len(indices) <= 1 {
		return
		}

		stack = stack[:0]
		stack = append(stack, stackFrame{0, len(indices) - 1})

		for len(stack) > 0 {
		frame := stack[len(stack)-1]
		stack = stack[:len(stack)-1]

		low, high := frame.low, frame.high
		if low >= high {
		continue
		}

		pivot := partition(indices, low, high)
		if pivot > 0 {
		stack = append(stack, stackFrame{low, pivot - 1})
		}
		stack = append(stack, stackFrame{pivot + 1, high})
		}
		}

		func partition(indices []int, low, high int) int {
		pivot := indices[high]
		i := low - 1

		for j := low; j < high; j++ {
		if indices[j] <= pivot {
		i++
		indices[i], indices[j] = indices[j], indices[i]
		}
		}

		indices[i+1], indices[high] = indices[high], indices[i+1]
		return i + 1
		}

		func combineIndexes(from []MatchmakerIndex, min, max int, done <-chan struct{}) <-chan []MatchmakerIndex {