Implement webhook branch filter (#7791)

* Fix validate() function to handle errors in embedded anon structs

* Implement webhook branch filter

See #2025, #3998.

vendor/github.com/gobwas/glob/match/segments.go

@@ -0,0 +1,91 @@
+package match
+
+import (
+	"sync"
+)
+
+type SomePool interface {
+	Get() []int
+	Put([]int)
+}
+
+var segmentsPools [1024]sync.Pool
+
+func toPowerOfTwo(v int) int {
+	v--
+	v |= v >> 1
+	v |= v >> 2
+	v |= v >> 4
+	v |= v >> 8
+	v |= v >> 16
+	v++
+
+	return v
+}
+
+const (
+	cacheFrom             = 16
+	cacheToAndHigher      = 1024
+	cacheFromIndex        = 15
+	cacheToAndHigherIndex = 1023
+)
+
+var (
+	segments0 = []int{0}
+	segments1 = []int{1}
+	segments2 = []int{2}
+	segments3 = []int{3}
+	segments4 = []int{4}
+)
+
+var segmentsByRuneLength [5][]int = [5][]int{
+	0: segments0,
+	1: segments1,
+	2: segments2,
+	3: segments3,
+	4: segments4,
+}
+
+func init() {
+	for i := cacheToAndHigher; i >= cacheFrom; i >>= 1 {
+		func(i int) {
+			segmentsPools[i-1] = sync.Pool{New: func() interface{} {
+				return make([]int, 0, i)
+			}}
+		}(i)
+	}
+}
+
+func getTableIndex(c int) int {
+	p := toPowerOfTwo(c)
+	switch {
+	case p >= cacheToAndHigher:
+		return cacheToAndHigherIndex
+	case p <= cacheFrom:
+		return cacheFromIndex
+	default:
+		return p - 1
+	}
+}
+
+func acquireSegments(c int) []int {
+	// make []int with less capacity than cacheFrom
+	// is faster than acquiring it from pool
+	if c < cacheFrom {
+		return make([]int, 0, c)
+	}
+
+	return segmentsPools[getTableIndex(c)].Get().([]int)[:0]
+}
+
+func releaseSegments(s []int) {
+	c := cap(s)
+
+	// make []int with less capacity than cacheFrom
+	// is faster than acquiring it from pool
+	if c < cacheFrom {
+		return
+	}
+
+	segmentsPools[getTableIndex(c)].Put(s)
+}