feat(funder):

Add egoisticChains to funder to  prioritize funding of assets.
feat(proposal):
Add SetEgoisticChain and RemoveEgoisticChain to change egoistic funder map,
when it is known which assets need to be funded first.

Signed-off-by: sophia1ch <sophia.koehler@outlook.com>

Author: sophia1ch

channel/multi/funder.go

@@ -25,18 +25,26 @@ import (
 // Funder is a multi-ledger funder.
 type Funder struct {
 	funders map[LedgerIDMapKey]channel.Funder
+	egoisticChains map[LedgerIDMapKey]bool
 }
 
 // NewFunder creates a new funder.
 func NewFunder() *Funder {
 	return &Funder{
 		funders: make(map[LedgerIDMapKey]channel.Funder),
+		egoisticChains: make(map[LedgerIDMapKey]bool),
 	}
 }
 
 // RegisterFunder registers a funder for a given ledger.
 func (f *Funder) RegisterFunder(l LedgerID, lf channel.Funder) {
 	f.funders[l.MapKey()] = lf
+	f.egoisticChains[l.MapKey()] = false
+}
+
+// SetEgoisticChain sets the egoistic chain flag for a given ledger.
+func (f *Funder) SetEgoisticChain(l LedgerID, egoistic bool) {
+	f.egoisticChains[l.MapKey()] = egoistic
 }
 
 // Fund funds a multi-ledger channel. It dispatches funding calls to all
@@ -53,12 +61,25 @@ func (f *Funder) Fund(ctx context.Context, request channel.FundingReq) error {
 		return err
 	}
 
-	n := len(ledgers)
-	errs := make(chan error, n)
+	var egoisticLedgers []LedgerID
+	var nonEgoisticLedgers []LedgerID
+
 	for _, l := range ledgers {
-		go func(l LedgerID) {
-			errs <- func() error {
-				id := l.MapKey()
+		if f.egoisticChains[l.MapKey()] {
+			egoisticLedgers = append(egoisticLedgers, l)
+		} else {
+			nonEgoisticLedgers = append(nonEgoisticLedgers, l)
+		}
+	}
+
+	
+	// First fund with Funders that are not egoistic.
+	nn := len(nonEgoisticLedgers)
+	errsN := make(chan error, nn)
+	for _, ln := range nonEgoisticLedgers {
+		go func(ln LedgerID) {
+			errsN <- func() error {
+				id := ln.MapKey()
 				lf, ok := f.funders[id]
 				if !ok {
 					return fmt.Errorf("Funder not found for ledger %v", id)
@@ -67,11 +88,34 @@ func (f *Funder) Fund(ctx context.Context, request channel.FundingReq) error {
 				err := lf.Fund(ctx, request)
 				return err
 			}()
-		}(l)
+		}(ln)
+	}
+	for i := 0; i < nn; i++ {
+		err := <-errsN
+		if err != nil {
+			return err
+		}
+	}
+	// Then fund with egoistic Funders.
+	ne := len(egoisticLedgers)
+	errsE := make(chan error, ne)
+	for _, le := range egoisticLedgers {
+		go func(le LedgerID) {
+			errsE <- func() error {
+				id := le.MapKey()
+				lf, ok := f.funders[id]
+				if !ok {
+					return fmt.Errorf("Funder not found for ledger %v", id)
+				}
+					
+				err := lf.Fund(ctx, request)
+				return err
+			}()
+		}(le)
 	}
 
-	for i := 0; i < n; i++ {
-		err := <-errs
+	for i := 0; i < ne; i++ {
+		err := <-errsE
 		if err != nil {
 			return err
 		}

client/proposal.go

@@ -127,6 +127,18 @@ func (r *ProposalResponder) Accept(ctx context.Context, acc ChannelProposalAccep
 	return r.client.handleChannelProposalAcc(ctx, r.peer, r.req, acc)
 }
 
+// SetEgoisticChain sets the egoistic chain flag for a given ledger.
+func (r *ProposalResponder) SetEgoisticChain(egoistic multi.LedgerID) {
+	mf := r.client.funder.(*multi.Funder)
+	mf.SetEgoisticChain(egoistic, true)
+}
+
+// RemoveEgoisticChain removes the egoistic chain flag for a given ledger.
+func (r *ProposalResponder) RemoveEgoisticChain(egoistic multi.LedgerID) {
+	mf := r.client.funder.(*multi.Funder)
+	mf.SetEgoisticChain(egoistic, false)
+}
+
 // Reject lets the user signal that they reject the channel proposal.
 // Returns whether the rejection message was successfully sent. Panics if the
 // proposal was already accepted or rejected.