lotus/chain/events/events_called.go
2019-09-18 13:01:52 +02:00

333 lines
8.2 KiB
Go

package events
import (
"context"
"math"
"sync"
"github.com/ipfs/go-cid"
"github.com/filecoin-project/go-lotus/chain/address"
"github.com/filecoin-project/go-lotus/chain/types"
)
const NoTimeout = math.MaxUint64
type triggerId = uint64
// msgH is the block height at which a message was present / event has happened
type msgH = uint64
// triggerH is the block height at which the listener will be notified about the
// message (msgH+confidence)
type triggerH = uint64
// `ts` is the tipset, in which the `msg` is included.
// `curH`-`ts.Height` = `confidence`
type CalledHandler func(msg *types.Message, ts *types.TipSet, curH uint64) (bool, error)
// CheckFunc is used for atomicity guarantees. If the condition the callbacks
// wait for has already happened in tipset `ts`
//
// If `done` is true, timeout won't be triggered
// If `more` is false, no messages will be sent to CalledHandler (RevertHandler
// may still be called)
type CheckFunc func(ts *types.TipSet) (done bool, more bool, err error)
type callHandler struct {
confidence int
timeout uint64
disabled bool // TODO: GC after gcConfidence reached
handle CalledHandler
revert RevertHandler
}
type queuedEvent struct {
trigger triggerId
h uint64
msg *types.Message
called bool
}
type calledEvents struct {
cs eventApi
tsc *tipSetCache
gcConfidence uint64
lk sync.Mutex
ctr triggerId
triggers map[triggerId]*callHandler
callTuples map[callTuple][]triggerId
// maps block heights to events
// [triggerH][msgH][event]
confQueue map[triggerH]map[msgH][]*queuedEvent
// [msgH][triggerH]
revertQueue map[msgH][]triggerH
// [timeoutH+confidence][triggerId]{calls}
timeouts map[uint64]map[triggerId]int
}
type callTuple struct {
actor address.Address
method uint64
}
func (e *calledEvents) headChangeCalled(rev, app []*types.TipSet) error {
e.lk.Lock()
defer e.lk.Unlock()
for _, ts := range rev {
e.handleReverts(ts)
}
tail := len(app) - 1
for i := range app {
ts := app[tail-i]
// called triggers
e.checkNewCalls(ts)
e.applyWithConfidence(ts)
e.applyTimeouts(ts)
}
return nil
}
func (e *calledEvents) handleReverts(ts *types.TipSet) {
reverts, ok := e.revertQueue[ts.Height()]
if !ok {
return // nothing to do
}
for _, triggerH := range reverts {
toRevert := e.confQueue[triggerH][ts.Height()]
for _, event := range toRevert {
if !event.called {
continue // event wasn't apply()-ied yet
}
trigger := e.triggers[event.trigger]
if err := trigger.revert(ts); err != nil {
log.Errorf("reverting chain trigger (call %s.%d() @H %d, called @ %d) failed: %s", event.msg.To, event.msg.Method, ts.Height(), triggerH, err)
}
}
delete(e.confQueue[triggerH], ts.Height())
}
delete(e.revertQueue, ts.Height())
}
func (e *calledEvents) checkNewCalls(ts *types.TipSet) {
e.messagesForTs(ts, func(msg *types.Message) {
// TODO: do we have to verify the receipt, or are messages on chain
// guaranteed to be successful?
ct := callTuple{
actor: msg.To,
method: msg.Method,
}
triggers, ok := e.callTuples[ct]
if !ok {
return
}
for _, tid := range triggers {
e.queueForConfidence(tid, msg, ts)
}
})
}
func (e *calledEvents) queueForConfidence(triggerId uint64, msg *types.Message, ts *types.TipSet) {
trigger := e.triggers[triggerId]
triggerH := ts.Height() + uint64(trigger.confidence)
byOrigH, ok := e.confQueue[triggerH]
if !ok {
byOrigH = map[uint64][]*queuedEvent{}
e.confQueue[triggerH] = byOrigH
}
byOrigH[ts.Height()] = append(byOrigH[ts.Height()], &queuedEvent{
trigger: triggerId,
h: ts.Height(),
msg: msg,
})
e.revertQueue[ts.Height()] = append(e.revertQueue[ts.Height()], triggerH) // todo: dedupe?
}
func (e *calledEvents) applyWithConfidence(ts *types.TipSet) {
byOrigH, ok := e.confQueue[ts.Height()]
if !ok {
return // no triggers at thin height
}
for origH, events := range byOrigH {
triggerTs, err := e.tsc.get(origH)
if err != nil {
log.Errorf("events: applyWithConfidence didn't find tipset for event; wanted %d; current %d", origH, ts.Height())
}
for _, event := range events {
trigger := e.triggers[event.trigger]
if trigger.disabled {
continue
}
more, err := trigger.handle(event.msg, triggerTs, ts.Height())
if err != nil {
log.Errorf("chain trigger (call %s.%d() @H %d, called @ %d) failed: %s", event.msg.To, event.msg.Method, origH, ts.Height(), err)
continue // don't revert failed calls
}
event.called = true
touts, ok := e.timeouts[trigger.timeout]
if ok {
touts[event.trigger]++
}
trigger.disabled = !more
}
}
}
func (e *calledEvents) applyTimeouts(ts *types.TipSet) {
triggers, ok := e.timeouts[ts.Height()]
if !ok {
return // nothing to do
}
for triggerId, calls := range triggers {
if calls > 0 {
continue // don't timeout if the method was called
}
trigger := e.triggers[triggerId]
if trigger.disabled {
continue
}
timeoutTs, err := e.tsc.get(ts.Height() - uint64(trigger.confidence))
if err != nil {
log.Errorf("events: applyTimeouts didn't find tipset for event; wanted %d; current %d", ts.Height()-uint64(trigger.confidence), ts.Height())
}
more, err := trigger.handle(nil, timeoutTs, ts.Height())
if err != nil {
log.Errorf("chain trigger (call @H %d, called @ %d) failed: %s", timeoutTs.Height(), ts.Height(), err)
continue // don't revert failed calls
}
trigger.disabled = !more // allows messages after timeout
}
}
func (e *calledEvents) messagesForTs(ts *types.TipSet, consume func(*types.Message)) {
seen := map[cid.Cid]struct{}{}
for _, tsb := range ts.Blocks() {
msgs, err := e.cs.ChainGetBlockMessages(context.TODO(), tsb.Messages)
if err != nil {
log.Errorf("messagesForTs MessagesForBlock failed (ts.H=%d, Bcid:%s, B.Mcid:%s): %s", ts.Height(), tsb.Cid(), tsb.Messages, err)
// this is quite bad, but probably better than missing all the other updates
continue
}
for _, m := range msgs.BlsMessages {
_, ok := seen[m.Cid()]
if ok {
continue
}
seen[m.Cid()] = struct{}{}
consume(m)
}
for _, m := range msgs.SecpkMessages {
_, ok := seen[m.Message.Cid()]
if ok {
continue
}
seen[m.Message.Cid()] = struct{}{}
consume(&m.Message)
}
}
}
// Called registers a callbacks which are triggered when a specified method is
// called on an actor, or a timeout is reached.
//
// * `CheckFunc` callback is invoked immediately with a recent tipset, it
// returns two booleans - `done`, and `more`.
//
// * `done` should be true when some on-chain action we are waiting for has
// happened. When `done` is set to true, timeout trigger is disabled.
//
// * `more` should be false when we don't want to receive new notifications
// through CalledHandler. Note that notifications may still be delivered to
// RevertHandler
//
// * `CalledHandler` is called when the specified event was observed on-chain,
// and a confidence threshold was reached, or the specified `timeout` height
// was reached with no events observed. When this callback is invoked on a
// timeout, `msg` is set to nil. This callback returns a boolean specifying
// whether further notifications should be sent, like `more` return param
// from `CheckFunc` above.
//
// * `RevertHandler` is called after apply handler, when we drop the tipset
// containing the message. The tipset passed as the argument is the tipset
// that is being dropped. Note that the message dropped may be re-applied
// in a different tipset in small amount of time.
func (e *calledEvents) Called(check CheckFunc, hnd CalledHandler, rev RevertHandler, confidence int, timeout uint64, actor address.Address, method uint64) error {
e.lk.Lock()
defer e.lk.Unlock()
done, more, err := check(e.tsc.best())
if err != nil {
return err
}
if done {
timeout = NoTimeout
}
id := e.ctr
e.ctr++
e.triggers[id] = &callHandler{
confidence: confidence,
timeout: timeout + uint64(confidence),
disabled: !more,
handle: hnd,
revert: rev,
}
ct := callTuple{
actor: actor,
method: method,
}
e.callTuples[ct] = append(e.callTuples[ct], id)
if timeout != NoTimeout {
if e.timeouts[timeout+uint64(confidence)] == nil {
e.timeouts[timeout+uint64(confidence)] = map[uint64]int{}
}
e.timeouts[timeout+uint64(confidence)][id] = 0
}
return nil
}