Merge pull request 'rings: Prefix and Address factories' (#48) from pr-amery-rings into main

Reviewed-on: #48

pkg/rings/encode.go

@@ -0,0 +1,145 @@
+package rings
+
+import "net/netip"
+
+// RingZeroPrefix represents the backbone that connects gateways
+// of the different Ring 1 networks.
+//
+// The ring 0 network corresponds to what would be ring 2 for region_id 0.
+// 10.0.0.0-10.0.255.255
+func RingZeroPrefix(region RegionID, zone ZoneID) (cidr netip.Prefix, err error) {
+	switch {
+	case !region.Valid():
+		err = ErrOutOfRange(region, "region")
+	case !zone.Valid():
+		err = ErrOutOfRange(zone, "zone")
+	default:
+		addr := unsafeRingZeroAddress(region, zone, 0)
+		cidr = netip.PrefixFrom(addr, RingZeroBits)
+	}
+
+	return cidr, err
+}
+
+// RingZeroAddress returns a Ring 0 address for a particular node.
+//
+// A ring 0 address looks like 10.0.(region_id << 4 + zone_id).(node_id)/20
+func RingZeroAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr, err error) {
+	switch {
+	case !region.Valid():
+		err = ErrOutOfRange(region, "region")
+	case !zone.Valid():
+		err = ErrOutOfRange(zone, "zone")
+	case !node.ValidZero():
+		err = ErrOutOfRange(node, "node")
+	default:
+		addr = unsafeRingZeroAddress(region, zone, node)
+	}
+
+	return addr, err
+}
+
+// RingOnePrefix represents a (virtual) local network of a zone.
+//
+// Ring 1 is `10.(region_id).(zone_id << 4).(node_id)/20` network
+// grouped under what would be Ring 2 for region_id 0.
+// There are 12 bits worth of nodes but nodes under 255 are special
+// as they also get a slot on Ring 0.
+func RingOnePrefix(region RegionID, zone ZoneID) (cidr netip.Prefix, err error) {
+	switch {
+	case !region.Valid():
+		err = ErrOutOfRange(region, "region")
+	case !zone.Valid():
+		err = ErrOutOfRange(zone, "zone")
+	default:
+		addr := unsafeRingOneAddress(region, zone, 0)
+		cidr = netip.PrefixFrom(addr, RingOneBits)
+	}
+	return cidr, err
+}
+
+// RingOneAddress returns a Ring 1 address for a particular node.
+//
+// A ring 1 address is `10.(region_id).(zone_id << 4).(node_id)/20`
+// but the node_id can take up to 12 bits.
+func RingOneAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr, err error) {
+	switch {
+	case !region.Valid():
+		err = ErrOutOfRange(region, "region")
+	case !zone.Valid():
+		err = ErrOutOfRange(zone, "zone")
+	case !node.Valid():
+		err = ErrOutOfRange(node, "node")
+	default:
+		addr = unsafeRingOneAddress(region, zone, node)
+	}
+	return addr, err
+}
+
+// RingTwoPrefix represents the services of a cluster
+//
+// Ring 2 subnets are of the form `10.(region_id).0.0/20`,
+// using the address space that would belong to the ring 3
+// region_id 0.
+func RingTwoPrefix(region RegionID) (cidr netip.Prefix, err error) {
+	switch {
+	case !region.Valid():
+		err = ErrOutOfRange(region, "region")
+	default:
+		addr := unsafeRingTwoAddress(region, 0)
+		cidr = netip.PrefixFrom(addr, RingTwoBits)
+	}
+	return cidr, err
+}
+
+// RingThreePrefix returns the subnet corresponding to
+// the pods of a cluster.
+//
+// Ring 3 is a `10.(region_id << 4).0.0/12` network
+func RingThreePrefix(region RegionID) (subnet netip.Prefix, err error) {
+	switch {
+	case !region.Valid():
+		err = ErrOutOfRange(region, "region")
+	default:
+		addr := unsafeRingThreeAddress(region, 0)
+		subnet = netip.PrefixFrom(addr, RingThreeBits)
+	}
+	return subnet, err
+}
+
+func unsafeRingZeroAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr {
+	r := uint(region)
+	z := uint(zone)
+	n := uint(node)
+
+	return AddrFrom4(10, 0, r<<4+z, n)
+}
+func unsafeRingOneAddress(region RegionID, zone ZoneID, node NodeID) netip.Addr {
+	r := uint(region)
+	z := uint(zone)
+	n := uint(node)
+
+	n1 := n >> 8
+	n0 := n >> 0
+
+	return AddrFrom4(10, r, z<<4+n1, n0)
+}
+
+func unsafeRingTwoAddress(region RegionID, n uint) netip.Addr {
+	r := uint(region)
+
+	n1 := n >> 8
+	n0 := n >> 0
+
+	return AddrFrom4(10, r, n1, n0)
+}
+
+func unsafeRingThreeAddress(region RegionID, n uint) netip.Addr {
+	r := uint(region)
+
+	n2 := n >> 16
+	n1 := n >> 8
+	n0 := n >> 0
+
+	return AddrFrom4(10, r<<4+n2, n1, n0)
+}

pkg/rings/encode_test.go

@@ -0,0 +1,63 @@
+package rings
+
+import (
+	"fmt"
+	"net/netip"
+	"testing"
+)
+
+func TestRingZeroAddress(t *testing.T) {
+	RZNTest(t, "RingZeroAddress", RingZeroAddress, []RZNTestCase{
+		{1, 1, 50, MustParseAddr("10.0.17.50")},
+		{1, 2, 50, MustParseAddr("10.0.18.50")},
+		{2, 3, 1, MustParseAddr("10.0.35.1")},
+		{2, 3, 300, netip.Addr{}},
+	})
+}
+
+func TestRingOneAddress(t *testing.T) {
+	RZNTest(t, "RingOneAddress", RingOneAddress, []RZNTestCase{
+		{1, 1, 50, MustParseAddr("10.1.16.50")},
+		{1, 2, 50, MustParseAddr("10.1.32.50")},
+		{2, 3, 300, MustParseAddr("10.2.49.44")},
+		{1, 20, 50, netip.Addr{}},
+	})
+}
+
+type RZNTestCase struct {
+	region RegionID
+	zone   ZoneID
+	node   NodeID
+	addr   netip.Addr
+}
+
+func RZNTest(t *testing.T,
+	fnName string, fn func(RegionID, ZoneID, NodeID) (netip.Addr, error),
+	cases []RZNTestCase) {
+	//
+	for i, tc := range cases {
+		s := fmt.Sprintf("%s(%v, %v, %v)", fnName,
+			tc.region,
+			tc.zone,
+			tc.node,
+		)
+
+		addr, err := fn(tc.region, tc.zone, tc.node)
+
+		switch {
+		case !tc.addr.IsValid():
+			// expect error
+			if err != nil {
+				t.Logf("[%v/%v]: %s → %s", i, len(cases), s, err)
+			} else {
+				t.Errorf("ERROR: [%v/%v]: %s → %s (expected %s)", i, len(cases), s, addr, "error")
+			}
+		case err != nil:
+			t.Errorf("ERROR: [%v/%v]: %s → %s (expected %s)", i, len(cases), s, err, tc.addr)
+		case addr.Compare(tc.addr) != 0:
+			t.Errorf("ERROR: [%v/%v]: %s → %s (expected %s)", i, len(cases), s, addr, tc.addr)
+		default:
+			t.Logf("[%v/%v]: %s → %s", i, len(cases), s, addr)
+		}
+	}
+}

pkg/rings/one.go

@@ -1,42 +0,0 @@
-package rings
-
-import "net/netip"
-
-// RingOnePrefix represents a (virtual) local network of a zone.
-//
-// Ring 1 is `10.(region_id).(zone_id << 4).(node_id)/20` network
-// grouped under what would be Ring 2 for region_id 0.
-// There are 12 bits worth of nodes but nodes under 255 are special
-// as they also get a slot on Ring 0.
-func RingOnePrefix(region RegionID, zone ZoneID) (cidr netip.Prefix, err error) {
-	switch {
-	case !region.Valid():
-		err = ErrOutOfRange(region, "region")
-	case !zone.Valid():
-		err = ErrOutOfRange(zone, "zone")
-	default:
-		addr := AddrFrom4(10, uint(region), uint(zone)<<4, 0)
-		cidr = netip.PrefixFrom(addr, RingOneBits)
-	}
-	return cidr, err
-}
-
-// RingOneAddress returns a Ring 1 address for a particular node.
-//
-// A ring 1 address is `10.(region_id).(zone_id << 4).(node_id)/20`
-// but the node_id can take up to 12 bits.
-func RingOneAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr, err error) {
-	switch {
-	case !region.Valid():
-		err = ErrOutOfRange(region, "region")
-	case !zone.Valid():
-		err = ErrOutOfRange(zone, "zone")
-	case !node.Valid():
-		err = ErrOutOfRange(node, "node")
-	default:
-		n1 := uint(node) / 8
-		n2 := uint(node) % 8
-		addr = AddrFrom4(10, uint(region), (uint(zone)<<4)+n1, n2)
-	}
-	return addr, err
-}

pkg/rings/rings.go

@@ -56,5 +56,5 @@ func (n NodeID) ValidZero() bool { return n > 0 && n <= NodeZeroMax }
 // ErrOutOfRange is an error indicating the value of a field
 // is out of range.
 func ErrOutOfRange[T ~int | ~uint32](value T, field string) error {
-	return core.Wrap(syscall.EINVAL, "%v: %s out of range", value, field)
+	return core.Wrap(syscall.EINVAL, "%s out of range (%v)", field, value)
 }

pkg/rings/three.go

@@ -1,18 +0,0 @@
-package rings
-
-import "net/netip"
-
-// RingThreePrefix returns the subnet corresponding to
-// the pods of a cluster.
-//
-// Ring 3 is a `10.(region_id << 4).0.0/12` network
-func RingThreePrefix(region RegionID) (subnet netip.Prefix, err error) {
-	switch {
-	case !region.Valid():
-		err = ErrOutOfRange(region, "region")
-	default:
-		addr := AddrFrom4(10, uint(region)<<4, 0, 0)
-		subnet = netip.PrefixFrom(addr, RingThreeBits)
-	}
-	return subnet, err
-}

pkg/rings/two.go

@@ -1,19 +0,0 @@
-package rings
-
-import "net/netip"
-
-// RingTwoPrefix represents the services of a cluster
-//
-// Ring 2 subnets are of the form `10.(region_id).0.0/20`,
-// using the address space that would belong to the ring 3
-// region_id 0.
-func RingTwoPrefix(region RegionID) (cidr netip.Prefix, err error) {
-	switch {
-	case !region.Valid():
-		err = ErrOutOfRange(region, "region")
-	default:
-		addr := AddrFrom4(10, uint(region), 0, 0)
-		cidr = netip.PrefixFrom(addr, RingTwoBits)
-	}
-	return cidr, err
-}

pkg/rings/zero.go

@@ -1,40 +0,0 @@
-package rings
-
-import "net/netip"
-
-// RingZeroPrefix represents the backbone that connects gateways
-// of the different Ring 1 networks.
-//
-// The ring 0 network corresponds to what would be ring 2 for region_id 0.
-// 10.0.0.0-10.0.255.255
-func RingZeroPrefix(region RegionID, zone ZoneID) (cidr netip.Prefix, err error) {
-	switch {
-	case !region.Valid():
-		err = ErrOutOfRange(region, "region")
-	case !zone.Valid():
-		err = ErrOutOfRange(zone, "zone")
-	default:
-		addr := AddrFrom4(10, 0, uint(region)<<4+uint(zone), 0)
-		cidr = netip.PrefixFrom(addr, RingZeroBits)
-	}
-
-	return cidr, err
-}
-
-// RingZeroAddress returns a Ring 0 address for a particular node.
-//
-// A ring 0 address looks like 10.0.(region_id << 4 + zone_id).(node_id)/20
-func RingZeroAddress(region RegionID, zone ZoneID, node NodeID) (addr netip.Addr, err error) {
-	switch {
-	case !region.Valid():
-		err = ErrOutOfRange(region, "region")
-	case !zone.Valid():
-		err = ErrOutOfRange(zone, "zone")
-	case !node.ValidZero():
-		err = ErrOutOfRange(node, "node")
-	default:
-		addr = AddrFrom4(10, 0, uint(region)<<4+uint(zone), uint(node))
-	}
-
-	return addr, err
-}