rings: DecodeRingZeroAddress() and DecodeRingOneAddress()

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/rings/rings.go

@@ -97,6 +97,25 @@ func RingZeroAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr
 	return addr, err
 }
 
+// DecodeRingZeroAddress attempts to extract region, zone and node identifiers
+// from a given ring 0 address.
+//
+// revive:disable:function-result-limit
+func DecodeRingZeroAddress(addr netip.Addr) (RegionID, ZoneID, NodeID, bool) {
+	// revive:enable:function-result-limit
+	if addr.IsValid() {
+		if addr.Is4In6() {
+			addr = addr.Unmap()
+		}
+
+		if addr.Is4() {
+			return unsafeDecodeRingZeroAddress(addr.As4())
+		}
+	}
+
+	return 0, 0, 0, false
+}
+
 // RingOnePrefix represents a (virtual) local network of a zone.
 //
 // Ring 1 is `10.(region_id).(zone_id << 4).(node_id)/20` network
@@ -134,6 +153,25 @@ func RingOneAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr,
 	return addr, err
 }
 
+// DecodeRingOneAddress attempts to extract region, zone and node identifiers
+// from a given ring 1 address.
+//
+// revive:disable:function-result-limit
+func DecodeRingOneAddress(addr netip.Addr) (RegionID, ZoneID, NodeID, bool) {
+	// revive:enable:function-result-limit
+	if addr.IsValid() {
+		if addr.Is4In6() {
+			addr = addr.Unmap()
+		}
+
+		if addr.Is4() {
+			return unsafeDecodeRingOneAddress(addr.As4())
+		}
+	}
+
+	return 0, 0, 0, false
+}
+
 // RingTwoPrefix represents the services of a cluster
 //
 // Ring 2 subnets are of the form `10.(region_id).0.0/20`,
@@ -173,6 +211,20 @@ func unsafeRingZeroAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr
 	return AddrFrom4(10, 0, r<<4+z, n)
 }
 
+// revive:disable:function-result-limit
+func unsafeDecodeRingZeroAddress(a4 [4]byte) (RegionID, ZoneID, NodeID, bool) {
+	// revive:enable:function-result-limit
+	if a4[0] == 10 && a4[1] == 0 {
+		r := a4[2] >> 4
+		z := a4[2] & 0x0f
+		n := a4[3]
+
+		return RegionID(r), ZoneID(z), NodeID(n), true
+	}
+
+	return 0, 0, 0, false
+}
+
 func unsafeRingOneAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr {
 	r := uint(region)
 	z := uint(zone)
@@ -184,6 +236,23 @@ func unsafeRingOneAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr
 	return AddrFrom4(10, r, z<<4+n1, n0)
 }
 
+// revive:disable:function-result-limit
+func unsafeDecodeRingOneAddress(a4 [4]byte) (RegionID, ZoneID, NodeID, bool) {
+	// revive:enable:function-result-limit
+	if a4[0] == 10 && (a4[1]>>4) == 0 {
+		n1 := uint(a4[2] & 0x0f)
+		n0 := uint(a4[3])
+
+		r := a4[1]
+		z := a4[2] >> 4
+		n := n1<<8 + n0
+
+		return RegionID(r), ZoneID(z), NodeID(n), true
+	}
+
+	return 0, 0, 0, false
+}
+
 func unsafeRingTwoAddress(region RegionID, n uint) netip.Addr {
 	r := uint(region)
 

pkg/rings/rings_test.go

@@ -61,3 +61,49 @@ func RZNTest(t *testing.T,
 		}
 	}
 }
+
+func TestDecodeRingZeroAddress(t *testing.T) {
+	RZNDecodeTest(t, "DecodeRingZeroAddress", DecodeRingZeroAddress, []RZNDecodeTestCase{
+		{1, 1, 50, MustParseAddr("10.0.17.50"), true},
+		{1, 2, 50, MustParseAddr("10.0.18.50"), true},
+		{2, 3, 1, MustParseAddr("10.0.35.1"), true},
+	})
+}
+
+func TesDecodetRingOneAddress(t *testing.T) {
+	RZNDecodeTest(t, "DecodeRingOneAddress", DecodeRingOneAddress, []RZNDecodeTestCase{
+		{1, 1, 50, MustParseAddr("10.1.16.50"), true},
+		{1, 2, 50, MustParseAddr("10.1.32.50"), true},
+		{2, 3, 300, MustParseAddr("10.2.49.44"), true},
+	})
+}
+
+type RZNDecodeTestCase struct {
+	region RegionID
+	zone   ZoneID
+	node   NodeID
+	addr   netip.Addr
+	ok     bool
+}
+
+func RZNDecodeTest(t *testing.T,
+	fnName string, fn func(netip.Addr) (RegionID, ZoneID, NodeID, bool),
+	cases []RZNDecodeTestCase) {
+	//
+	for i, tc := range cases {
+		s := fmt.Sprintf("%s(%q)", fnName, tc.addr)
+
+		r, z, n, ok := fn(tc.addr)
+
+		switch {
+		case ok != tc.ok, r != tc.region, z != tc.zone, n != tc.node:
+			t.Errorf("ERROR: [%v/%v]: %s → %v %v %v %v (expected %v %v %v %v)",
+				i, len(cases), s,
+				r, z, n, ok,
+				tc.region, tc.zone, tc.node, tc.ok)
+		default:
+			t.Logf("[%v/%v]: %s → %v %v %v %v", i, len(cases), s,
+				r, z, n, ok)
+		}
+	}
+}