graph/db+sqldb: make policy migration idempotent

Finally, we make the channel-policy part of the SQL migration idempotent
by adding a migration-only policy insert query which will not error out
if the policy already exists and does not have a timestamp that is newer
than the existing records timestamp. To keep the commit simple, a
insertChanEdgePolicyMig function is added which is basically identical
to the updateChanEdgePolicy function except for the fact that it uses
the newly added query. In the next commit, it will be simplified even
more.

sqldb/sqlc/graph.sql.go

@@ -2434,6 +2434,82 @@ func (q *Queries) InsertClosedChannel(ctx context.Context, scid []byte) error {
 	return err
 }
 
+const insertEdgePolicyMig = `-- name: InsertEdgePolicyMig :one
+INSERT INTO graph_channel_policies (
+    version, channel_id, node_id, timelock, fee_ppm,
+    base_fee_msat, min_htlc_msat, last_update, disabled,
+    max_htlc_msat, inbound_base_fee_msat,
+    inbound_fee_rate_milli_msat, message_flags, channel_flags,
+    signature
+) VALUES  (
+    $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15
+)
+ON CONFLICT (channel_id, node_id, version)
+    -- If a conflict occurs, we have already migrated this policy. However, we
+    -- still need to do an "UPDATE SET" here instead of "DO NOTHING" because
+    -- otherwise, the "RETURNING id" part does not work.
+    DO UPDATE SET
+        timelock = EXCLUDED.timelock,
+        fee_ppm = EXCLUDED.fee_ppm,
+        base_fee_msat = EXCLUDED.base_fee_msat,
+        min_htlc_msat = EXCLUDED.min_htlc_msat,
+        last_update = EXCLUDED.last_update,
+        disabled = EXCLUDED.disabled,
+        max_htlc_msat = EXCLUDED.max_htlc_msat,
+        inbound_base_fee_msat = EXCLUDED.inbound_base_fee_msat,
+        inbound_fee_rate_milli_msat = EXCLUDED.inbound_fee_rate_milli_msat,
+        message_flags = EXCLUDED.message_flags,
+        channel_flags = EXCLUDED.channel_flags,
+        signature = EXCLUDED.signature
+RETURNING id
+`
+
+type InsertEdgePolicyMigParams struct {
+	Version                 int16
+	ChannelID               int64
+	NodeID                  int64
+	Timelock                int32
+	FeePpm                  int64
+	BaseFeeMsat             int64
+	MinHtlcMsat             int64
+	LastUpdate              sql.NullInt64
+	Disabled                sql.NullBool
+	MaxHtlcMsat             sql.NullInt64
+	InboundBaseFeeMsat      sql.NullInt64
+	InboundFeeRateMilliMsat sql.NullInt64
+	MessageFlags            sql.NullInt16
+	ChannelFlags            sql.NullInt16
+	Signature               []byte
+}
+
+// NOTE: This query is only meant to be used by the graph SQL migration since
+// for that migration, in order to be retry-safe, we don't want to error out if
+// we re-insert the same policy (which would error if the normal
+// UpsertEdgePolicy query is used because of the constraint in that query that
+// requires a policy update to have a newer last_update than the existing one).
+func (q *Queries) InsertEdgePolicyMig(ctx context.Context, arg InsertEdgePolicyMigParams) (int64, error) {
+	row := q.db.QueryRowContext(ctx, insertEdgePolicyMig,
+		arg.Version,
+		arg.ChannelID,
+		arg.NodeID,
+		arg.Timelock,
+		arg.FeePpm,
+		arg.BaseFeeMsat,
+		arg.MinHtlcMsat,
+		arg.LastUpdate,
+		arg.Disabled,
+		arg.MaxHtlcMsat,
+		arg.InboundBaseFeeMsat,
+		arg.InboundFeeRateMilliMsat,
+		arg.MessageFlags,
+		arg.ChannelFlags,
+		arg.Signature,
+	)
+	var id int64
+	err := row.Scan(&id)
+	return id, err
+}
+
 const insertNodeFeature = `-- name: InsertNodeFeature :exec
 /* ─────────────────────────────────────────────
    graph_node_features table queries

sqldb/sqlc/querier.go

@@ -96,6 +96,12 @@ type Querier interface {
 	// and version columns).
 	InsertChannelMig(ctx context.Context, arg InsertChannelMigParams) (int64, error)
 	InsertClosedChannel(ctx context.Context, scid []byte) error
+	// NOTE: This query is only meant to be used by the graph SQL migration since
+	// for that migration, in order to be retry-safe, we don't want to error out if
+	// we re-insert the same policy (which would error if the normal
+	// UpsertEdgePolicy query is used because of the constraint in that query that
+	// requires a policy update to have a newer last_update than the existing one).
+	InsertEdgePolicyMig(ctx context.Context, arg InsertEdgePolicyMigParams) (int64, error)
 	InsertInvoice(ctx context.Context, arg InsertInvoiceParams) (int64, error)
 	InsertInvoiceFeature(ctx context.Context, arg InsertInvoiceFeatureParams) error
 	InsertInvoiceHTLC(ctx context.Context, arg InsertInvoiceHTLCParams) (int64, error)

sqldb/sqlc/queries/graph.sql

@@ -1064,3 +1064,37 @@ INSERT INTO graph_channels (
         bitcoin_1_signature = EXCLUDED.bitcoin_1_signature,
         bitcoin_2_signature = EXCLUDED.bitcoin_2_signature
 RETURNING id;
+
+-- NOTE: This query is only meant to be used by the graph SQL migration since
+-- for that migration, in order to be retry-safe, we don't want to error out if
+-- we re-insert the same policy (which would error if the normal
+-- UpsertEdgePolicy query is used because of the constraint in that query that
+-- requires a policy update to have a newer last_update than the existing one).
+-- name: InsertEdgePolicyMig :one
+INSERT INTO graph_channel_policies (
+    version, channel_id, node_id, timelock, fee_ppm,
+    base_fee_msat, min_htlc_msat, last_update, disabled,
+    max_htlc_msat, inbound_base_fee_msat,
+    inbound_fee_rate_milli_msat, message_flags, channel_flags,
+    signature
+) VALUES  (
+    $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15
+)
+ON CONFLICT (channel_id, node_id, version)
+    -- If a conflict occurs, we have already migrated this policy. However, we
+    -- still need to do an "UPDATE SET" here instead of "DO NOTHING" because
+    -- otherwise, the "RETURNING id" part does not work.
+    DO UPDATE SET
+        timelock = EXCLUDED.timelock,
+        fee_ppm = EXCLUDED.fee_ppm,
+        base_fee_msat = EXCLUDED.base_fee_msat,
+        min_htlc_msat = EXCLUDED.min_htlc_msat,
+        last_update = EXCLUDED.last_update,
+        disabled = EXCLUDED.disabled,
+        max_htlc_msat = EXCLUDED.max_htlc_msat,
+        inbound_base_fee_msat = EXCLUDED.inbound_base_fee_msat,
+        inbound_fee_rate_milli_msat = EXCLUDED.inbound_fee_rate_milli_msat,
+        message_flags = EXCLUDED.message_flags,
+        channel_flags = EXCLUDED.channel_flags,
+        signature = EXCLUDED.signature
+RETURNING id;