Event driven AutoNAT

addrset/addrset.go

@@ -0,0 +1,106 @@
+package addrset
+
+import (
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+// AddrState describes the state of a dialable addresses as seen by AutoNAT.
+type AddrState int
+
+const (
+	// StateUnknown is used for new entries.
+	StateUnknown AddrState = iota
+	// UnconfirmedListenUnknown applies to interface listen addresses that have unknown reachability.
+	UnconfirmedListenUnknown
+
+	//  UnconfirmedExternalUnknown applies to external observed addresses with unknown reachability.
+	UnconfirmedExternalUnknown
+
+	// Private is applied to addresses that have been deemed to have private reachability by AutoNAT.
+	Private
+
+	// Confirmed is applied to peers that have been confirmed to be dialable by AutoNAT.
+	Confirmed
+)
+
+// DialAddrsSet maintains the state of a dialable addresses as seen by AutoNAT.
+// The state is a set of  multi-addresses, each labeled with a AddrState.
+type DialAddrsSet struct {
+	// all known addresses
+	all []dialAddrState
+}
+
+type dialAddrState struct {
+	addr  ma.Multiaddr
+	state AddrState
+}
+
+// DialAddrsSet creates a new empty set of dial addresses.
+func NewDialAddrsSet() *DialAddrsSet {
+	return &DialAddrsSet{
+		all: []dialAddrState{},
+	}
+}
+
+func (ds *DialAddrsSet) find(a ma.Multiaddr) int {
+	for i := range ds.all {
+		if ds.all[i].addr.Equal(a) {
+			return i
+		}
+	}
+	return -1
+}
+
+// TryAdd adds the address a to the address set.
+// If the address is already present, no action is taken.
+// Otherwise, the address is added with state set to StateUnknown.
+// TryAdd returns true if the address was not already present.
+func (ds *DialAddrsSet) TryAdd(a ma.Multiaddr) bool {
+	if ds.find(a) >= 0 {
+		return false
+	} else {
+		ds.all = append(ds.all,
+			dialAddrState{addr: a, state: StateUnknown})
+		return true
+	}
+}
+
+// SetState sets the state of address a to s.
+// If a  is not in the address set, SetState panics.
+func (ds *DialAddrsSet) SetState(a ma.Multiaddr, s AddrState) {
+	ds.all[ds.find(a)].state = s
+}
+
+// GetState returns the state of address a.
+// If a is not in the address set, GetState panics.
+func (ds *DialAddrsSet) GetState(a ma.Multiaddr) AddrState {
+	return ds.all[ds.find(a)].state
+}
+
+// GetAddrsInState returns multiaddrs which are in one of the given states
+func (ds *DialAddrsSet) GetAddrsInStates(states ...AddrState) []ma.Multiaddr {
+	var addrs []ma.Multiaddr
+	for _, a := range ds.all {
+		for _, s := range states {
+			if a.state == s {
+				addrs = append(addrs, a.addr)
+			}
+		}
+	}
+
+	return addrs
+}
+
+// AssertStateAndRemove aserts that address a is in the given state s (panics if is NOT).
+// It then remove the address from the address set.
+// AssertStateAndRemove will panic if a is NOT in the address set.
+func (ds *DialAddrsSet) AssertStateAndRemove(a ma.Multiaddr, s AddrState) {
+	index := ds.find(a)
+
+	if ds.all[index].state != s {
+		panic("unexpected state")
+	}
+
+	ds.all[index] = ds.all[len(ds.all)-1]
+	ds.all = ds.all[:len(ds.all)-1]
+}

addrset/addrset_test.go

@@ -0,0 +1,9 @@
+package addrset
+
+import (
+	"testing"
+)
+
+func TestAddrsSet(t *testing.T) {
+
+}