Add detailed scanner metrics (#15161)

internal/pubsub/mask.go

@@ -0,0 +1,66 @@
+package pubsub
+
+import (
+	"math"
+	"math/bits"
+)
+
+// Mask allows filtering by a bitset mask.
+type Mask uint64
+
+const (
+	// MaskAll is the mask for all entries.
+	MaskAll Mask = math.MaxUint64
+)
+
+// MaskFromMaskable extracts mask from an interface.
+func MaskFromMaskable(m Maskable) Mask {
+	return Mask(m.Mask())
+}
+
+// Contains returns whether *all* flags in other is present in t.
+func (t Mask) Contains(other Mask) bool {
+	return t&other == other
+}
+
+// Overlaps returns whether *any* flags in t overlaps with other.
+func (t Mask) Overlaps(other Mask) bool {
+	return t&other != 0
+}
+
+// SingleType returns whether t has a single type set.
+func (t Mask) SingleType() bool {
+	return bits.OnesCount64(uint64(t)) == 1
+}
+
+// FromUint64 will set a mask to the uint64 value.
+func (t *Mask) FromUint64(m uint64) {
+	*t = Mask(m)
+}
+
+// Merge will merge other into t.
+func (t *Mask) Merge(other Mask) {
+	*t |= other
+}
+
+// MergeMaskable will merge other into t.
+func (t *Mask) MergeMaskable(other Maskable) {
+	*t |= Mask(other.Mask())
+}
+
+// SetIf will add other if b is true.
+func (t *Mask) SetIf(b bool, other Mask) {
+	if b {
+		*t |= other
+	}
+}
+
+// Mask returns the mask as a uint64.
+func (t Mask) Mask() uint64 {
+	return uint64(t)
+}
+
+// Maskable implementations must return their mask as a 64 bit uint.
+type Maskable interface {
+	Mask() uint64
+}