channeldb: FetchPermAndTempPeers to load access perms on startup

We introduce a new func FetchPermAndTempPeers that returns two maps.
The first map indicates the nodes that will have "protected" access
to the server. The second map indicates the nodes that have
"temporary" access to the server. This will be used in a future
commit in the server.go code.

channeldb/db_test.go

@@ -721,6 +721,91 @@ func TestFetchHistoricalChannel(t *testing.T) {
 	}
 }
 
+// TestFetchPermTempPeer tests that we're able to call FetchPermAndTempPeers
+// successfully.
+func TestFetchPermTempPeer(t *testing.T) {
+	t.Parallel()
+
+	fullDB, err := MakeTestDB(t)
+	require.NoError(t, err, "unable to make test database")
+
+	cdb := fullDB.ChannelStateDB()
+
+	// Create an open channel.
+	privKey1, err := btcec.NewPrivateKey()
+	require.NoError(t, err, "unable to generate new private key")
+
+	pubKey1 := privKey1.PubKey()
+
+	channelState1 := createTestChannel(
+		t, cdb, openChannelOption(), pubKeyOption(pubKey1),
+	)
+
+	// Next, assert that the channel exists in the database.
+	_, err = cdb.FetchChannel(channelState1.FundingOutpoint)
+	require.NoError(t, err, "unable to fetch channel")
+
+	// Create a pending channel.
+	privKey2, err := btcec.NewPrivateKey()
+	require.NoError(t, err, "unable to generate private key")
+
+	pubKey2 := privKey2.PubKey()
+	channelState2 := createTestChannel(t, cdb, pubKeyOption(pubKey2))
+
+	// Assert that the channel exists in the database.
+	_, err = cdb.FetchChannel(channelState2.FundingOutpoint)
+	require.NoError(t, err, "unable to fetch channel")
+
+	// Create a closed channel.
+	privKey3, err := btcec.NewPrivateKey()
+	require.NoError(t, err, "unable to generate new private key")
+
+	pubKey3 := privKey3.PubKey()
+
+	_ = createTestChannel(
+		t, cdb, pubKeyOption(pubKey3), openChannelOption(),
+		closedChannelOption(),
+	)
+
+	// Fetch the ChanCount for our peers.
+	peerCounts, err := cdb.FetchPermAndTempPeers(key[:])
+	require.NoError(t, err, "unable to fetch perm and temp peers")
+
+	// There should only be three entries.
+	require.Len(t, peerCounts, 3)
+
+	// The first entry should have OpenClosed set to true and Pending set
+	// to 0.
+	count1, found := peerCounts[string(pubKey1.SerializeCompressed())]
+	require.True(t, found, "unable to find peer 1 in peerCounts")
+	require.True(
+		t, count1.HasOpenOrClosedChan,
+		"couldn't find peer 1's channels",
+	)
+	require.Zero(
+		t, count1.PendingOpenCount,
+		"peer 1 doesn't have 0 pending-open",
+	)
+
+	count2, found := peerCounts[string(pubKey2.SerializeCompressed())]
+	require.True(t, found, "unable to find peer 2 in peerCounts")
+	require.False(
+		t, count2.HasOpenOrClosedChan, "found erroneous channels",
+	)
+	require.Equal(t, uint64(1), count2.PendingOpenCount)
+
+	count3, found := peerCounts[string(pubKey3.SerializeCompressed())]
+	require.True(t, found, "unable to find peer 3 in peerCounts")
+	require.True(
+		t, count3.HasOpenOrClosedChan,
+		"couldn't find peer 3's channels",
+	)
+	require.Zero(
+		t, count3.PendingOpenCount,
+		"peer 3 doesn't have 0 pending-open",
+	)
+}
+
 func createLightningNode(priv *btcec.PrivateKey) *models.LightningNode {
 	updateTime := rand.Int63()