Add min amount

README.md

@@ -48,6 +48,7 @@ rebalance-lnd](https://github.com/accumulator/rebalance-lnd).
   -a, --amount=              amount to rebalance
       --econ-ratio=          economical ratio for fee limit calculation as a multiple of target channel fee (for example, 0.5 means you want to pay at max half the fee you might earn for routing out of the target channel)
   -b, --probe=               if the payment fails at the last hop try to probe lower amount using binary search
+      --min-amount=          if probing is enabled this will be the minimum amount to try
   -i, --exclude-channel-in=  don't use this channel as incoming (can be specified multiple times)
   -o, --exclude-channel-out= don't use this channel as outgoing (can be specified multiple times)
   -e, --exclude-channel=     don't use this channel at all (can be specified multiple times)

config.json.sample

@@ -6,6 +6,7 @@
     "perc": 20,
     "econ_ratio": 0.5,
     "amount": 100000,
+    "min_amount": 50000,
     "probe_steps": 5,
     "pfrom": 10,
     "pto": 30,

main.go

@@ -31,6 +31,7 @@ var params struct {
 	Amount             int64    `short:"a" long:"amount" description:"amount to rebalance" json:"amount"`
 	EconRatio          float64  `long:"econ-ratio" description:"economical ratio for fee limit calculation as a multiple of target channel fee (for example, 0.5 means you want to pay at max half the fee you might earn for routing out of the target channel)" json:"econ_ratio"`
 	ProbeSteps         int      `short:"b" long:"probe-steps" description:"if the payment fails at the last hop try to probe lower amount using this many steps" json:"probe_steps"`
+	MinAmount          int64    `long:"min-amount" description:"if probing is enabled this will be the minimum amount to try" json:"min_amount"`
 	ExcludeChannelsIn  []uint64 `short:"i" long:"exclude-channel-in" description:"don't use this channel as incoming (can be specified multiple times)" json:"exclude_channels_in"`
 	ExcludeChannelsOut []uint64 `short:"o" long:"exclude-channel-out" description:"don't use this channel as outgoing (can be specified multiple times)" json:"exclude_channels_out"`
 	ExcludeChannels    []uint64 `short:"e" long:"exclude-channel" description:"don't use this channel at all (can be specified multiple times)" json:"exclude_channels"`
@@ -104,7 +105,7 @@ func tryRebalance(ctx context.Context, r *regolancer, invoice **lnrpc.AddInvoice
 		log.Printf("Attempt %s, amount: %s (max fee: %s)", hiWhiteColorF("#%d", *attempt),
 			hiWhiteColor(amt), hiWhiteColor(fee/1000))
 		r.printRoute(ctx, route)
-		err = r.pay(ctx, *invoice, amt, route, params.ProbeSteps)
+		err = r.pay(ctx, *invoice, amt, params.MinAmount, route, params.ProbeSteps)
 		if err == nil {
 			return nil, false
 		}
@@ -120,7 +121,7 @@ func tryRebalance(ctx context.Context, r *regolancer, invoice **lnrpc.AddInvoice
 			if err != nil {
 				log.Printf("Error rebuilding the route for probed payment: %s", errColor(err))
 			} else {
-				err = r.pay(ctx, probedInvoice, amt, probedRoute, 0)
+				err = r.pay(ctx, probedInvoice, amt, 0, probedRoute, 0)
 				if err == nil {
 					return nil, false
 				} else {
@@ -162,6 +163,9 @@ func main() {
 		params.FromPerc = params.Perc
 		params.ToPerc = params.Perc
 	}
+	if params.MinAmount > 0 && params.MinAmount > params.Amount {
+		log.Fatal("Minimum amount should be more than amount")
+	}
 	conn, err := lndclient.NewBasicConn(params.Connect, params.TLSCert, params.MacaroonDir, params.Network,
 		lndclient.MacFilename(params.MacaroonFilename))
 	if err != nil {

payment.go

@@ -26,7 +26,8 @@ func (r *regolancer) createInvoice(ctx context.Context, from, to uint64, amount
 		Expiry: int64(time.Hour.Seconds() * 24)})
 }
 
-func (r *regolancer) pay(ctx context.Context, invoice *lnrpc.AddInvoiceResponse, amount int64, route *lnrpc.Route, probeSteps int) error {
+func (r *regolancer) pay(ctx context.Context, invoice *lnrpc.AddInvoiceResponse, amount int64,
+	minAmount int64, route *lnrpc.Route, probeSteps int) error {
 	fmt.Println()
 	defer fmt.Println()
 	lastHop := route.Hops[len(route.Hops)-1]
@@ -63,7 +64,13 @@ func (r *regolancer) pay(ctx context.Context, invoice *lnrpc.AddInvoiceResponse,
 			cyanColor(node1name), cyanColor(node2name))
 		if int(result.Failure.FailureSourceIndex) == len(route.Hops)-2 && probeSteps > 0 {
 			fmt.Println("Probing route...")
-			maxAmount, err := r.probeRoute(ctx, route, 0, amount, amount/2, probeSteps, params.EconRatio)
+			min := int64(0)
+			start := amount / 2
+			if minAmount > 0 && minAmount < amount {
+				min = -minAmount - 1
+				start = minAmount
+			}
+			maxAmount, err := r.probeRoute(ctx, route, min, amount, start, probeSteps, params.EconRatio)
 			if err != nil {
 				return err
 			}