lotus/chain/events/events.go
2020-07-10 15:51:45 +01:00

180 lines
4.2 KiB
Go

package events
import (
"context"
"sync"
"time"
"github.com/filecoin-project/specs-actors/actors/abi"
"github.com/ipfs/go-cid"
logging "github.com/ipfs/go-log/v2"
"golang.org/x/xerrors"
"github.com/filecoin-project/go-address"
"github.com/filecoin-project/lotus/api"
"github.com/filecoin-project/lotus/build"
"github.com/filecoin-project/lotus/chain/store"
"github.com/filecoin-project/lotus/chain/types"
)
var log = logging.Logger("events")
// HeightHandler `curH`-`ts.Height` = `confidence`
type HeightHandler func(ctx context.Context, ts *types.TipSet, curH abi.ChainEpoch) error
type RevertHandler func(ctx context.Context, ts *types.TipSet) error
type heightHandler struct {
confidence int
called bool
handle HeightHandler
revert RevertHandler
}
type eventAPI interface {
ChainNotify(context.Context) (<-chan []*api.HeadChange, error)
ChainGetBlockMessages(context.Context, cid.Cid) (*api.BlockMessages, error)
ChainGetTipSetByHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error)
StateGetReceipt(context.Context, cid.Cid, types.TipSetKey) (*types.MessageReceipt, error)
ChainGetTipSet(context.Context, types.TipSetKey) (*types.TipSet, error)
StateGetActor(ctx context.Context, actor address.Address, tsk types.TipSetKey) (*types.Actor, error) // optional / for CalledMsg
}
type Events struct {
api eventAPI
tsc *tipSetCache
lk sync.Mutex
ready sync.WaitGroup
readyOnce sync.Once
heightEvents
*hcEvents
}
func NewEvents(ctx context.Context, api eventAPI) *Events {
gcConfidence := 2 * build.ForkLengthThreshold
tsc := newTSCache(gcConfidence, api.ChainGetTipSetByHeight)
e := &Events{
api: api,
tsc: tsc,
heightEvents: heightEvents{
tsc: tsc,
ctx: ctx,
gcConfidence: gcConfidence,
heightTriggers: map[uint64]*heightHandler{},
htTriggerHeights: map[abi.ChainEpoch][]uint64{},
htHeights: map[abi.ChainEpoch][]uint64{},
},
hcEvents: newHCEvents(ctx, api, tsc, uint64(gcConfidence)),
}
e.ready.Add(1)
go e.listenHeadChanges(ctx)
e.ready.Wait()
// TODO: cleanup/gc goroutine
return e
}
func (e *Events) listenHeadChanges(ctx context.Context) {
for {
if err := e.listenHeadChangesOnce(ctx); err != nil {
log.Errorf("listen head changes errored: %s", err)
} else {
log.Warn("listenHeadChanges quit")
}
if ctx.Err() != nil {
log.Warnf("not restarting listenHeadChanges: context error: %s", ctx.Err())
return
}
build.Clock.Sleep(time.Second)
log.Info("restarting listenHeadChanges")
}
}
func (e *Events) listenHeadChangesOnce(ctx context.Context) error {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
notifs, err := e.api.ChainNotify(ctx)
if err != nil {
// TODO: retry
return xerrors.Errorf("listenHeadChanges ChainNotify call failed: %w", err)
}
cur, ok := <-notifs // TODO: timeout?
if !ok {
return xerrors.Errorf("notification channel closed")
}
if len(cur) != 1 {
return xerrors.Errorf("unexpected initial head notification length: %d", len(cur))
}
if cur[0].Type != store.HCCurrent {
return xerrors.Errorf("expected first head notification type to be 'current', was '%s'", cur[0].Type)
}
if err := e.tsc.add(cur[0].Val); err != nil {
log.Warn("tsc.add: adding current tipset failed: %w", err)
}
e.readyOnce.Do(func() {
e.lastTs = cur[0].Val
e.ready.Done()
})
for notif := range notifs {
var rev, app []*types.TipSet
for _, notif := range notif {
switch notif.Type {
case store.HCRevert:
rev = append(rev, notif.Val)
case store.HCApply:
app = append(app, notif.Val)
default:
log.Warnf("unexpected head change notification type: '%s'", notif.Type)
}
}
if err := e.headChange(rev, app); err != nil {
log.Warnf("headChange failed: %s", err)
}
// sync with fake chainstore (for tests)
if fcs, ok := e.api.(interface{ notifDone() }); ok {
fcs.notifDone()
}
}
return nil
}
func (e *Events) headChange(rev, app []*types.TipSet) error {
if len(app) == 0 {
return xerrors.New("events.headChange expected at least one applied tipset")
}
e.lk.Lock()
defer e.lk.Unlock()
if err := e.headChangeAt(rev, app); err != nil {
return err
}
return e.processHeadChangeEvent(rev, app)
}