storage module: add go docs and minor code quality refactors

chain/store/store.go

@@ -853,6 +853,14 @@ func (cs *ChainStore) NearestCommonAncestor(a, b *types.TipSet) (*types.TipSet,
 	return cs.LoadTipSet(l[len(l)-1].Parents())
 }
 
+// ReorgOps takes two tipsets (which can be at different heights), and walks
+// their corresponding chains backwards one step at a time until we find
+// a common ancestor. It then returns the respective chain segments that fork
+// from the identified ancestor, in reverse order, where the first element of
+// each slice is the supplied tipset, and the last element is the common
+// ancestor.
+//
+// If an error happens along the way, we return the error with nil slices.
 func (cs *ChainStore) ReorgOps(a, b *types.TipSet) ([]*types.TipSet, []*types.TipSet, error) {
 	return ReorgOps(cs.LoadTipSet, a, b)
 }
@@ -1235,6 +1243,9 @@ func (cs *ChainStore) ReadMsgMetaCids(mmc cid.Cid) ([]cid.Cid, []cid.Cid, error)
 	return blscids, secpkcids, nil
 }
 
+// GetPath returns the sequence of atomic head change operations that
+// need to be applied in order to switch the head of the chain from the `from`
+// tipset to the `to` tipset.
 func (cs *ChainStore) GetPath(ctx context.Context, from types.TipSetKey, to types.TipSetKey) ([]*api.HeadChange, error) {
 	fts, err := cs.LoadTipSet(from)
 	if err != nil {

extern/storage-sealing/precommit_policy.go

@@ -40,7 +40,10 @@ type BasicPreCommitPolicy struct {
 	duration        abi.ChainEpoch
 }
 
-// NewBasicPreCommitPolicy produces a BasicPreCommitPolicy
+// NewBasicPreCommitPolicy produces a BasicPreCommitPolicy.
+//
+// The provided duration is used as the default sector expiry when the sector
+// contains no deals. The proving boundary is used to adjust/align the sector's expiration.
 func NewBasicPreCommitPolicy(api Chain, duration abi.ChainEpoch, provingBoundary abi.ChainEpoch) BasicPreCommitPolicy {
 	return BasicPreCommitPolicy{
 		api:             api,

storage/adapter_storage_miner.go

@@ -31,10 +31,10 @@ import (
 var _ sealing.SealingAPI = new(SealingAPIAdapter)
 
 type SealingAPIAdapter struct {
-	delegate storageMinerApi
+	delegate fullNodeFilteredAPI
 }
 
-func NewSealingAPIAdapter(api storageMinerApi) SealingAPIAdapter {
+func NewSealingAPIAdapter(api fullNodeFilteredAPI) SealingAPIAdapter {
 	return SealingAPIAdapter{delegate: api}
 }
 

storage/miner.go

@@ -5,10 +5,6 @@ import (
 	"errors"
 	"time"
 
-	"github.com/filecoin-project/go-state-types/network"
-
-	"github.com/filecoin-project/go-state-types/dline"
-
 	"github.com/filecoin-project/go-bitfield"
 
 	"github.com/ipfs/go-cid"
@@ -20,9 +16,13 @@ import (
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/filecoin-project/go-state-types/crypto"
+	"github.com/filecoin-project/go-state-types/dline"
+	"github.com/filecoin-project/go-state-types/network"
+
+	"github.com/filecoin-project/specs-storage/storage"
+
 	sectorstorage "github.com/filecoin-project/lotus/extern/sector-storage"
 	"github.com/filecoin-project/lotus/extern/sector-storage/ffiwrapper"
-	"github.com/filecoin-project/specs-storage/storage"
 
 	"github.com/filecoin-project/lotus/api"
 	"github.com/filecoin-project/lotus/api/v1api"
@@ -41,8 +41,16 @@ import (
 
 var log = logging.Logger("storageminer")
 
+// Miner is the central miner entrypoint object inside Lotus. It is
+// instantiated in the node builder, along with the WindowPoStScheduler.
+//
+// This object is the owner of the sealing pipeline. Most of the actual logic
+// lives in the storage-sealing module (sealing.Sealing), and the Miner object
+// exposes it to the rest of the system by proxying calls.
+//
+// Miner#Run starts the sealing FSM.
 type Miner struct {
-	api     storageMinerApi
+	api     fullNodeFilteredAPI
 	feeCfg  config.MinerFeeConfig
 	h       host.Host
 	sealer  sectorstorage.SectorManager
@@ -70,7 +78,9 @@ type SealingStateEvt struct {
 	Error        string
 }
 
-type storageMinerApi interface {
+// fullNodeFilteredAPI is the subset of the full node API the Miner needs from
+// a Lotus full node.
+type fullNodeFilteredAPI interface {
 	// Call a read only method on actors (no interaction with the chain required)
 	StateCall(context.Context, *types.Message, types.TipSetKey) (*api.InvocResult, error)
 	StateMinerSectors(context.Context, address.Address, *bitfield.BitField, types.TipSetKey) ([]*miner.SectorOnChainInfo, error)
@@ -116,7 +126,18 @@ type storageMinerApi interface {
 	WalletHas(context.Context, address.Address) (bool, error)
 }
 
-func NewMiner(api storageMinerApi, maddr address.Address, h host.Host, ds datastore.Batching, sealer sectorstorage.SectorManager, sc sealing.SectorIDCounter, verif ffiwrapper.Verifier, gsd dtypes.GetSealingConfigFunc, feeCfg config.MinerFeeConfig, journal journal.Journal, as *AddressSelector) (*Miner, error) {
+// NewMiner creates a new Miner object.
+func NewMiner(api fullNodeFilteredAPI,
+	maddr address.Address,
+	h host.Host,
+	ds datastore.Batching,
+	sealer sectorstorage.SectorManager,
+	sc sealing.SectorIDCounter,
+	verif ffiwrapper.Verifier,
+	gsd dtypes.GetSealingConfigFunc,
+	feeCfg config.MinerFeeConfig,
+	journal journal.Journal,
+	as *AddressSelector) (*Miner, error) {
 	m := &Miner{
 		api:     api,
 		feeCfg:  feeCfg,
@@ -136,6 +157,7 @@ func NewMiner(api storageMinerApi, maddr address.Address, h host.Host, ds datast
 	return m, nil
 }
 
+// Run starts the sealing FSM in the background, running preliminary checks first.
 func (m *Miner) Run(ctx context.Context) error {
 	if err := m.runPreflightChecks(ctx); err != nil {
 		return xerrors.Errorf("miner preflight checks failed: %w", err)
@@ -152,17 +174,37 @@ func (m *Miner) Run(ctx context.Context) error {
 		MaxTerminateGasFee: abi.TokenAmount(m.feeCfg.MaxTerminateGasFee),
 	}
 
-	evts := events.NewEvents(ctx, m.api)
-	adaptedAPI := NewSealingAPIAdapter(m.api)
-	// TODO: Maybe we update this policy after actor upgrades?
-	pcp := sealing.NewBasicPreCommitPolicy(adaptedAPI, policy.GetMaxSectorExpirationExtension()-(md.WPoStProvingPeriod*2), md.PeriodStart%md.WPoStProvingPeriod)
+	var (
+		// consumer of chain head changes.
+		evts        = events.NewEvents(ctx, m.api)
+		evtsAdapter = NewEventsAdapter(evts)
 
-	as := func(ctx context.Context, mi miner.MinerInfo, use api.AddrUse, goodFunds, minFunds abi.TokenAmount) (address.Address, abi.TokenAmount, error) {
-		return m.addrSel.AddressFor(ctx, m.api, mi, use, goodFunds, minFunds)
-	}
+		// Create a shim to glue the API required by the sealing component
+		// with the API that Lotus is capable of providing.
+		// The shim translates between "tipset tokens" and tipset keys, and
+		// provides extra methods.
+		adaptedAPI = NewSealingAPIAdapter(m.api)
+
+		// Instantiate a precommit policy.
+		defaultDuration = policy.GetMaxSectorExpirationExtension() - (md.WPoStProvingPeriod * 2)
+		provingBoundary = md.PeriodStart % md.WPoStProvingPeriod
+
+		// TODO: Maybe we update this policy after actor upgrades?
+		pcp = sealing.NewBasicPreCommitPolicy(adaptedAPI, defaultDuration, provingBoundary)
+
+		// address selector.
+		as = func(ctx context.Context, mi miner.MinerInfo, use api.AddrUse, goodFunds, minFunds abi.TokenAmount) (address.Address, abi.TokenAmount, error) {
+			return m.addrSel.AddressFor(ctx, m.api, mi, use, goodFunds, minFunds)
+		}
+
+		// sealing configuration.
+		cfg = sealing.GetSealingConfigFunc(m.getSealConfig)
+	)
 
-	m.sealing = sealing.New(adaptedAPI, fc, NewEventsAdapter(evts), m.maddr, m.ds, m.sealer, m.sc, m.verif, &pcp, sealing.GetSealingConfigFunc(m.getSealConfig), m.handleSealingNotifications, as)
+	// Instantiate the sealing FSM.
+	m.sealing = sealing.New(adaptedAPI, fc, evtsAdapter, m.maddr, m.ds, m.sealer, m.sc, m.verif, &pcp, cfg, m.handleSealingNotifications, as)
 
+	// Run the sealing FSM.
 	go m.sealing.Run(ctx) //nolint:errcheck // logged intside the function
 
 	return nil
@@ -184,6 +226,7 @@ func (m *Miner) Stop(ctx context.Context) error {
 	return m.sealing.Stop(ctx)
 }
 
+// runPreflightChecks verifies that preconditions to run the miner are satisfied.
 func (m *Miner) runPreflightChecks(ctx context.Context) error {
 	mi, err := m.api.StateMinerInfo(ctx, m.maddr, types.EmptyTSK)
 	if err != nil {

storage/wdpost_changehandler.go

@@ -21,22 +21,25 @@ const (
 type CompleteGeneratePoSTCb func(posts []miner.SubmitWindowedPoStParams, err error)
 type CompleteSubmitPoSTCb func(err error)
 
-type changeHandlerAPI interface {
+// wdPoStCommands is the subset of the WindowPoStScheduler + full node APIs used
+// by the changeHandler to execute actions and query state.
+type wdPoStCommands interface {
 	StateMinerProvingDeadline(context.Context, address.Address, types.TipSetKey) (*dline.Info, error)
+
 	startGeneratePoST(ctx context.Context, ts *types.TipSet, deadline *dline.Info, onComplete CompleteGeneratePoSTCb) context.CancelFunc
 	startSubmitPoST(ctx context.Context, ts *types.TipSet, deadline *dline.Info, posts []miner.SubmitWindowedPoStParams, onComplete CompleteSubmitPoSTCb) context.CancelFunc
 	onAbort(ts *types.TipSet, deadline *dline.Info)
-	failPost(err error, ts *types.TipSet, deadline *dline.Info)
+	recordPoStFailure(err error, ts *types.TipSet, deadline *dline.Info)
 }
 
 type changeHandler struct {
-	api        changeHandlerAPI
+	api        wdPoStCommands
 	actor      address.Address
 	proveHdlr  *proveHandler
 	submitHdlr *submitHandler
 }
 
-func newChangeHandler(api changeHandlerAPI, actor address.Address) *changeHandler {
+func newChangeHandler(api wdPoStCommands, actor address.Address) *changeHandler {
 	posts := newPostsCache()
 	p := newProver(api, posts)
 	s := newSubmitter(api, posts)
@@ -146,7 +149,7 @@ type postResult struct {
 
 // proveHandler generates proofs
 type proveHandler struct {
-	api   changeHandlerAPI
+	api   wdPoStCommands
 	posts *postsCache
 
 	postResults chan *postResult
@@ -163,7 +166,7 @@ type proveHandler struct {
 }
 
 func newProver(
-	api changeHandlerAPI,
+	api wdPoStCommands,
 	posts *postsCache,
 ) *proveHandler {
 	ctx, cancel := context.WithCancel(context.Background())
@@ -248,7 +251,7 @@ func (p *proveHandler) processPostResult(res *postResult) {
 	di := res.currPost.di
 	if res.err != nil {
 		// Proving failed so inform the API
-		p.api.failPost(res.err, res.ts, di)
+		p.api.recordPoStFailure(res.err, res.ts, di)
 		log.Warnf("Aborted window post Proving (Deadline: %+v)", di)
 		p.api.onAbort(res.ts, di)
 
@@ -295,7 +298,7 @@ type postInfo struct {
 
 // submitHandler submits proofs on-chain
 type submitHandler struct {
-	api   changeHandlerAPI
+	api   wdPoStCommands
 	posts *postsCache
 
 	submitResults chan *submitResult
@@ -319,7 +322,7 @@ type submitHandler struct {
 }
 
 func newSubmitter(
-	api changeHandlerAPI,
+	api wdPoStCommands,
 	posts *postsCache,
 ) *submitHandler {
 	ctx, cancel := context.WithCancel(context.Background())
@@ -488,7 +491,7 @@ func (s *submitHandler) submitIfReady(ctx context.Context, advance *types.TipSet
 func (s *submitHandler) processSubmitResult(res *submitResult) {
 	if res.err != nil {
 		// Submit failed so inform the API and go back to the start state
-		s.api.failPost(res.err, res.pw.ts, res.pw.di)
+		s.api.recordPoStFailure(res.err, res.pw.ts, res.pw.di)
 		log.Warnf("Aborted window post Submitting (Deadline: %+v)", res.pw.di)
 		s.api.onAbort(res.pw.ts, res.pw.di)
 

storage/wdpost_changehandler_test.go

@@ -191,7 +191,7 @@ func (m *mockAPI) wasAbortCalled() bool {
 	return m.abortCalled
 }
 
-func (m *mockAPI) failPost(err error, ts *types.TipSet, deadline *dline.Info) {
+func (m *mockAPI) recordPoStFailure(err error, ts *types.TipSet, deadline *dline.Info) {
 }
 
 func (m *mockAPI) setChangeHandler(ch *changeHandler) {