cnct: add resolver constructors

contractcourt/briefcase.go

@@ -440,7 +440,7 @@ func (b *boltArbitratorLog) CommitState(s ArbitratorState) error {
 //
 // NOTE: Part of the ContractResolver interface.
 func (b *boltArbitratorLog) FetchUnresolvedContracts() ([]ContractResolver, error) {
-	resKit := ResolverKit{
+	resolverCfg := ResolverConfig{
 		ChannelArbitratorConfig: b.cfg,
 		Checkpoint:              b.checkpointContract,
 	}
@@ -469,56 +469,38 @@ func (b *boltArbitratorLog) FetchUnresolvedContracts() ([]ContractResolver, erro
 
 			switch resType {
 			case resolverTimeout:
-				timeoutRes := &htlcTimeoutResolver{}
-				if err := timeoutRes.Decode(resReader); err != nil {
-					return err
-				}
-				timeoutRes.AttachResolverKit(resKit)
-
-				res = timeoutRes
+				res, err = newTimeoutResolverFromReader(
+					resReader, resolverCfg,
+				)
 
 			case resolverSuccess:
-				successRes := &htlcSuccessResolver{}
-				if err := successRes.Decode(resReader); err != nil {
-					return err
-				}
-
-				res = successRes
+				res, err = newSuccessResolverFromReader(
+					resReader, resolverCfg,
+				)
 
 			case resolverOutgoingContest:
-				outContestRes := &htlcOutgoingContestResolver{
-					htlcTimeoutResolver: htlcTimeoutResolver{},
-				}
-				if err := outContestRes.Decode(resReader); err != nil {
-					return err
-				}
-
-				res = outContestRes
+				res, err = newOutgoingContestResolverFromReader(
+					resReader, resolverCfg,
+				)
 
 			case resolverIncomingContest:
-				inContestRes := &htlcIncomingContestResolver{
-					htlcSuccessResolver: htlcSuccessResolver{},
-				}
-				if err := inContestRes.Decode(resReader); err != nil {
-					return err
-				}
-
-				res = inContestRes
+				res, err = newIncomingContestResolverFromReader(
+					resReader, resolverCfg,
+				)
 
 			case resolverUnilateralSweep:
-				sweepRes := &commitSweepResolver{}
-				if err := sweepRes.Decode(resReader); err != nil {
-					return err
-				}
-
-				res = sweepRes
+				res, err = newCommitSweepResolverFromReader(
+					resReader, resolverCfg,
+				)
 
 			default:
 				return fmt.Errorf("unknown resolver type: %v", resType)
 			}
 
-			resKit.Quit = make(chan struct{})
-			res.AttachResolverKit(resKit)
+			if err != nil {
+				return err
+			}
+
 			contracts = append(contracts, res)
 			return nil
 		})

contractcourt/channel_arbitrator.go

@@ -1685,7 +1685,7 @@ func (c *ChannelArbitrator) prepContractResolutions(
 
 	// We'll create the resolver kit that we'll be cloning for each
 	// resolver so they each can do their duty.
-	resKit := ResolverKit{
+	resolverCfg := ResolverConfig{
 		ChannelArbitratorConfig: c.cfg,
 		Checkpoint: func(res ContractResolver) error {
 			return c.log.InsertUnresolvedContracts(res)
@@ -1733,14 +1733,10 @@ func (c *ChannelArbitrator) prepContractResolutions(
 					continue
 				}
 
-				resKit.Quit = make(chan struct{})
-				resolver := &htlcSuccessResolver{
-					htlcResolution:  resolution,
-					broadcastHeight: height,
-					payHash:         htlc.RHash,
-					htlcAmt:         htlc.Amt,
-					ResolverKit:     resKit,
-				}
+				resolver := newSuccessResolver(
+					resolution, height,
+					htlc.RHash, htlc.Amt, resolverCfg,
+				)
 				htlcResolvers = append(htlcResolvers, resolver)
 			}
 
@@ -1761,14 +1757,10 @@ func (c *ChannelArbitrator) prepContractResolutions(
 					continue
 				}
 
-				resKit.Quit = make(chan struct{})
-				resolver := &htlcTimeoutResolver{
-					htlcResolution:  resolution,
-					broadcastHeight: height,
-					htlcIndex:       htlc.HtlcIndex,
-					htlcAmt:         htlc.Amt,
-					ResolverKit:     resKit,
-				}
+				resolver := newTimeoutResolver(
+					resolution, height, htlc.HtlcIndex,
+					htlc.Amt, resolverCfg,
+				)
 				htlcResolvers = append(htlcResolvers, resolver)
 			}
 
@@ -1798,18 +1790,11 @@ func (c *ChannelArbitrator) prepContractResolutions(
 					ChanID: c.cfg.ShortChanID,
 				}
 
-				resKit.Quit = make(chan struct{})
-				resolver := &htlcIncomingContestResolver{
-					htlcExpiry: htlc.RefundTimeout,
-					circuitKey: circuitKey,
-					htlcSuccessResolver: htlcSuccessResolver{
-						htlcResolution:  resolution,
-						broadcastHeight: height,
-						payHash:         htlc.RHash,
-						htlcAmt:         htlc.Amt,
-						ResolverKit:     resKit,
-					},
-				}
+				resolver := newIncomingContestResolver(
+					htlc.RefundTimeout, circuitKey,
+					resolution, height, htlc.RHash,
+					htlc.Amt, resolverCfg,
+				)
 				htlcResolvers = append(htlcResolvers, resolver)
 			}
 
@@ -1831,16 +1816,10 @@ func (c *ChannelArbitrator) prepContractResolutions(
 					continue
 				}
 
-				resKit.Quit = make(chan struct{})
-				resolver := &htlcOutgoingContestResolver{
-					htlcTimeoutResolver: htlcTimeoutResolver{
-						htlcResolution:  resolution,
-						broadcastHeight: height,
-						htlcIndex:       htlc.HtlcIndex,
-						htlcAmt:         htlc.Amt,
-						ResolverKit:     resKit,
-					},
-				}
+				resolver := newOutgoingContestResolver(
+					resolution, height, htlc.HtlcIndex,
+					htlc.Amt, resolverCfg,
+				)
 				htlcResolvers = append(htlcResolvers, resolver)
 			}
 		}
@@ -1850,14 +1829,10 @@ func (c *ChannelArbitrator) prepContractResolutions(
 	// a resolver to sweep our commitment output (but only if it wasn't
 	// trimmed).
 	if contractResolutions.CommitResolution != nil {
-		resKit.Quit = make(chan struct{})
-		resolver := &commitSweepResolver{
-			commitResolution: *contractResolutions.CommitResolution,
-			broadcastHeight:  height,
-			chanPoint:        c.cfg.ChanPoint,
-			ResolverKit:      resKit,
-		}
-
+		resolver := newCommitSweepResolver(
+			*contractResolutions.CommitResolution,
+			height, c.cfg.ChanPoint, resolverCfg,
+		)
 		htlcResolvers = append(htlcResolvers, resolver)
 	}
 

contractcourt/commit_sweep_resolver.go

@@ -36,7 +36,20 @@ type commitSweepResolver struct {
 	// chanPoint is the channel point of the original contract.
 	chanPoint wire.OutPoint
 
-	ResolverKit
+	contractResolverKit
+}
+
+// newCommitSweepResolver instantiates a new direct commit output resolver.
+func newCommitSweepResolver(res lnwallet.CommitOutputResolution,
+	broadcastHeight uint32,
+	chanPoint wire.OutPoint, resCfg ResolverConfig) *commitSweepResolver {
+
+	return &commitSweepResolver{
+		contractResolverKit: *newContractResolverKit(resCfg),
+		commitResolution:    res,
+		broadcastHeight:     broadcastHeight,
+		chanPoint:           chanPoint,
+	}
 }
 
 // ResolverKey returns an identifier which should be globally unique for this
@@ -80,7 +93,7 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 			return nil, errResolverShuttingDown
 		}
 
-	case <-c.Quit:
+	case <-c.quit:
 		return nil, errResolverShuttingDown
 	}
 
@@ -138,7 +151,7 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 
 			log.Infof("ChannelPoint(%v) commit tx is fully resolved by "+
 				"sweep tx: %v", c.chanPoint, sweepResult.Tx.TxHash())
-		case <-c.Quit:
+		case <-c.quit:
 			return nil, errResolverShuttingDown
 		}
 
@@ -180,7 +193,7 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 			log.Errorf("unable to Checkpoint: %v", err)
 			return nil, err
 		}
-	case <-c.Quit:
+	case <-c.quit:
 		return nil, errResolverShuttingDown
 	}
 
@@ -206,7 +219,7 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 		log.Infof("ChannelPoint(%v) commit tx is fully resolved, at height: %v",
 			c.chanPoint, confInfo.BlockHeight)
 
-	case <-c.Quit:
+	case <-c.quit:
 		return nil, errResolverShuttingDown
 	}
 
@@ -221,7 +234,7 @@ func (c *commitSweepResolver) Resolve() (ContractResolver, error) {
 //
 // NOTE: Part of the ContractResolver interface.
 func (c *commitSweepResolver) Stop() {
-	close(c.Quit)
+	close(c.quit)
 }
 
 // IsResolved returns true if the stored state in the resolve is fully
@@ -262,44 +275,40 @@ func (c *commitSweepResolver) Encode(w io.Writer) error {
 	return nil
 }
 
-// Decode attempts to decode an encoded ContractResolver from the passed Reader
-// instance, returning an active ContractResolver instance.
-//
-// NOTE: Part of the ContractResolver interface.
-func (c *commitSweepResolver) Decode(r io.Reader) error {
+// newCommitSweepResolverFromReader attempts to decode an encoded
+// ContractResolver from the passed Reader instance, returning an active
+// ContractResolver instance.
+func newCommitSweepResolverFromReader(r io.Reader, resCfg ResolverConfig) (
+	*commitSweepResolver, error) {
+
+	c := &commitSweepResolver{
+		contractResolverKit: *newContractResolverKit(resCfg),
+	}
+
 	if err := decodeCommitResolution(r, &c.commitResolution); err != nil {
-		return err
+		return nil, err
 	}
 
 	if err := binary.Read(r, endian, &c.resolved); err != nil {
-		return err
+		return nil, err
 	}
 	if err := binary.Read(r, endian, &c.broadcastHeight); err != nil {
-		return err
+		return nil, err
 	}
 	_, err := io.ReadFull(r, c.chanPoint.Hash[:])
 	if err != nil {
-		return err
+		return nil, err
 	}
 	err = binary.Read(r, endian, &c.chanPoint.Index)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	// Previously a sweep tx was deserialized at this point. Refactoring
 	// removed this, but keep in mind that this data may still be present in
 	// the database.
 
-	return nil
-}
-
-// AttachResolverKit should be called once a resolved is successfully decoded
-// from its stored format. This struct delivers a generic tool kit that
-// resolvers need to complete their duty.
-//
-// NOTE: Part of the ContractResolver interface.
-func (c *commitSweepResolver) AttachResolverKit(r ResolverKit) {
-	c.ResolverKit = r
+	return c, nil
 }
 
 // A compile time assertion to ensure commitSweepResolver meets the

contractcourt/contract_resolvers.go

@@ -46,16 +46,6 @@ type ContractResolver interface {
 	// passed Writer.
 	Encode(w io.Writer) error
 
-	// Decode attempts to decode an encoded ContractResolver from the
-	// passed Reader instance, returning an active ContractResolver
-	// instance.
-	Decode(r io.Reader) error
-
-	// AttachResolverKit should be called once a resolved is successfully
-	// decoded from its stored format. This struct delivers a generic tool
-	// kit that resolvers need to complete their duty.
-	AttachResolverKit(ResolverKit)
-
 	// Stop signals the resolver to cancel any current resolution
 	// processes, and suspend.
 	Stop()
@@ -69,10 +59,9 @@ type reportingContractResolver interface {
 	report() *ContractReport
 }
 
-// ResolverKit is meant to be used as a mix-in struct to be embedded within a
-// given ContractResolver implementation. It contains all the items that a
-// resolver requires to carry out its duties.
-type ResolverKit struct {
+// ResolverConfig contains the externally supplied configuration items that are
+// required by a ContractResolver implementation.
+type ResolverConfig struct {
 	// ChannelArbitratorConfig contains all the interfaces and closures
 	// required for the resolver to interact with outside sub-systems.
 	ChannelArbitratorConfig
@@ -81,8 +70,23 @@ type ResolverKit struct {
 	// should write the state of the resolver to persistent storage, and
 	// return a non-nil error upon success.
 	Checkpoint func(ContractResolver) error
+}
+
+// contractResolverKit is meant to be used as a mix-in struct to be embedded within a
+// given ContractResolver implementation. It contains all the common items that
+// a resolver requires to carry out its duties.
+type contractResolverKit struct {
+	ResolverConfig
+
+	quit chan struct{}
+}
 
-	Quit chan struct{}
+// newContractResolverKit instantiates the mix-in struct.
+func newContractResolverKit(cfg ResolverConfig) *contractResolverKit {
+	return &contractResolverKit{
+		ResolverConfig: cfg,
+		quit:           make(chan struct{}),
+	}
 }
 
 var (