Use EthHash compatible type for subscription and filter IDs

api/docgen/docgen.go

@@ -378,8 +378,11 @@ func init() {
 	ethFeeHistoryReward := [][]api.EthBigInt{}
 	addExample(&ethFeeHistoryReward)
 
-	addExample(api.EthFilterID("c5564560217c43e4bc0484df655e9019"))
-	addExample(api.EthSubscriptionID("b62df77831484129adf6682332ad0725"))
+	filterid, _ := api.EthHashFromHex("0x5CbEeC012345673f25E309Cc264f240bb0664031")
+	addExample(api.EthFilterID(filterid))
+
+	subid, _ := api.EthHashFromHex("0x5CbEeCF99d3fDB301234567c264f240bb0664031")
+	addExample(api.EthSubscriptionID(subid))
 
 	pstring := func(s string) *string { return &s }
 	addExample(&api.EthFilterSpec{

api/eth_types.go

@@ -417,11 +417,10 @@ type EthFeeHistory struct {
 	Reward        *[][]EthBigInt `json:"reward,omitempty"`
 }
 
-// An opaque identifier generated by the Lotus node to refer to an installed filter.
-type EthFilterID string
+type EthFilterID EthHash
 
 // An opaque identifier generated by the Lotus node to refer to an active subscription.
-type EthSubscriptionID string
+type EthSubscriptionID EthHash
 
 type EthFilterSpec struct {
 	// Interpreted as an epoch or one of "latest" for last mined block, "earliest" for first,

api/eth_types_test.go

@@ -176,7 +176,7 @@ func TestEthFilterResultMarshalJSON(t *testing.T) {
 		BlockHash:        hash2,
 		BlockNumber:      53,
 		Topics:           []EthBytes{hash1[:]},
-		Data:             hash1[:],
+		Data:             EthBytes(hash1[:]),
 		Address:          addr,
 	}
 	logjson, err := json.Marshal(log)

chain/events/filter/event.go

@@ -7,7 +7,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/google/uuid"
 	"github.com/ipfs/go-cid"
 	cbg "github.com/whyrusleeping/cbor-gen"
 	"golang.org/x/xerrors"
@@ -24,7 +23,7 @@ import (
 const indexed uint8 = 0x01
 
 type EventFilter struct {
-	id         string
+	id         types.FilterID
 	minHeight  abi.ChainEpoch // minimum epoch to apply filter or -1 if no minimum
 	maxHeight  abi.ChainEpoch // maximum epoch to apply filter or -1 if no maximum
 	tipsetCid  cid.Cid
@@ -51,7 +50,7 @@ type CollectedEvent struct {
 	MsgCid      cid.Cid         // cid of message that produced event
 }
 
-func (f *EventFilter) ID() string {
+func (f *EventFilter) ID() types.FilterID {
 	return f.id
 }
 
@@ -290,7 +289,7 @@ type EventFilterManager struct {
 	EventIndex       *EventIndex
 
 	mu            sync.Mutex // guards mutations to filters
-	filters       map[string]*EventFilter
+	filters       map[types.FilterID]*EventFilter
 	currentHeight abi.ChainEpoch
 }
 
@@ -365,13 +364,13 @@ func (m *EventFilterManager) Install(ctx context.Context, minHeight, maxHeight a
 		return nil, xerrors.Errorf("historic event index disabled")
 	}
 
-	id, err := uuid.NewRandom()
+	id, err := newFilterID()
 	if err != nil {
-		return nil, xerrors.Errorf("new uuid: %w", err)
+		return nil, xerrors.Errorf("new filter id: %w", err)
 	}
 
 	f := &EventFilter{
-		id:         id.String(),
+		id:         id,
 		minHeight:  minHeight,
 		maxHeight:  maxHeight,
 		tipsetCid:  tipsetCid,
@@ -389,15 +388,15 @@ func (m *EventFilterManager) Install(ctx context.Context, minHeight, maxHeight a
 
 	m.mu.Lock()
 	if m.filters == nil {
-		m.filters = make(map[string]*EventFilter)
+		m.filters = make(map[types.FilterID]*EventFilter)
 	}
-	m.filters[id.String()] = f
+	m.filters[id] = f
 	m.mu.Unlock()
 
 	return f, nil
 }
 
-func (m *EventFilterManager) Remove(ctx context.Context, id string) error {
+func (m *EventFilterManager) Remove(ctx context.Context, id types.FilterID) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	if _, found := m.filters[id]; !found {

chain/events/filter/mempool.go

@@ -5,7 +5,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/google/uuid"
 	"github.com/ipfs/go-cid"
 	"golang.org/x/xerrors"
 
@@ -14,7 +13,7 @@ import (
 )
 
 type MemPoolFilter struct {
-	id         string
+	id         types.FilterID
 	maxResults int // maximum number of results to collect, 0 is unlimited
 	ch         chan<- interface{}
 
@@ -25,7 +24,7 @@ type MemPoolFilter struct {
 
 var _ Filter = (*MemPoolFilter)(nil)
 
-func (f *MemPoolFilter) ID() string {
+func (f *MemPoolFilter) ID() types.FilterID {
 	return f.id
 }
 
@@ -79,7 +78,7 @@ type MemPoolFilterManager struct {
 	MaxFilterResults int
 
 	mu      sync.Mutex // guards mutations to filters
-	filters map[string]*MemPoolFilter
+	filters map[types.FilterID]*MemPoolFilter
 }
 
 func (m *MemPoolFilterManager) WaitForMpoolUpdates(ctx context.Context, ch <-chan api.MpoolUpdate) {
@@ -113,27 +112,27 @@ func (m *MemPoolFilterManager) processUpdate(ctx context.Context, u api.MpoolUpd
 }
 
 func (m *MemPoolFilterManager) Install(ctx context.Context) (*MemPoolFilter, error) {
-	id, err := uuid.NewRandom()
+	id, err := newFilterID()
 	if err != nil {
-		return nil, xerrors.Errorf("new uuid: %w", err)
+		return nil, xerrors.Errorf("new filter id: %w", err)
 	}
 
 	f := &MemPoolFilter{
-		id:         id.String(),
+		id:         id,
 		maxResults: m.MaxFilterResults,
 	}
 
 	m.mu.Lock()
 	if m.filters == nil {
-		m.filters = make(map[string]*MemPoolFilter)
+		m.filters = make(map[types.FilterID]*MemPoolFilter)
 	}
-	m.filters[id.String()] = f
+	m.filters[id] = f
 	m.mu.Unlock()
 
 	return f, nil
 }
 
-func (m *MemPoolFilterManager) Remove(ctx context.Context, id string) error {
+func (m *MemPoolFilterManager) Remove(ctx context.Context, id types.FilterID) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	if _, found := m.filters[id]; !found {

chain/events/filter/store.go

@@ -5,19 +5,24 @@ import (
 	"errors"
 	"sync"
 	"time"
+
+	"github.com/google/uuid"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/lotus/chain/types"
 )
 
 type Filter interface {
-	ID() string
+	ID() types.FilterID
 	LastTaken() time.Time
 	SetSubChannel(chan<- interface{})
 	ClearSubChannel()
 }
 
 type FilterStore interface {
 	Add(context.Context, Filter) error
-	Get(context.Context, string) (Filter, error)
-	Remove(context.Context, string) error
+	Get(context.Context, types.FilterID) (Filter, error)
+	Remove(context.Context, types.FilterID) error
 	NotTakenSince(when time.Time) []Filter // returns a list of filters that have not had their collected results taken
 }
 
@@ -27,18 +32,28 @@ var (
 	ErrMaximumNumberOfFilters  = errors.New("maximum number of filters registered")
 )
 
+func newFilterID() (types.FilterID, error) {
+	rawid, err := uuid.NewRandom()
+	if err != nil {
+		return types.FilterID{}, xerrors.Errorf("new uuid: %w", err)
+	}
+	id := types.FilterID{}
+	copy(id[:], rawid[:]) // uuid is 16 bytes, the last 16 bytes are zeroed
+	return id, nil
+}
+
 type memFilterStore struct {
 	max     int
 	mu      sync.Mutex
-	filters map[string]Filter
+	filters map[types.FilterID]Filter
 }
 
 var _ FilterStore = (*memFilterStore)(nil)
 
 func NewMemFilterStore(maxFilters int) FilterStore {
 	return &memFilterStore{
 		max:     maxFilters,
-		filters: make(map[string]Filter),
+		filters: make(map[types.FilterID]Filter),
 	}
 }
 
@@ -57,7 +72,7 @@ func (m *memFilterStore) Add(_ context.Context, f Filter) error {
 	return nil
 }
 
-func (m *memFilterStore) Get(_ context.Context, id string) (Filter, error) {
+func (m *memFilterStore) Get(_ context.Context, id types.FilterID) (Filter, error) {
 	m.mu.Lock()
 	f, found := m.filters[id]
 	m.mu.Unlock()
@@ -67,7 +82,7 @@ func (m *memFilterStore) Get(_ context.Context, id string) (Filter, error) {
 	return f, nil
 }
 
-func (m *memFilterStore) Remove(_ context.Context, id string) error {
+func (m *memFilterStore) Remove(_ context.Context, id types.FilterID) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 

chain/events/filter/tipset.go

@@ -5,14 +5,13 @@ import (
 	"sync"
 	"time"
 
-	"github.com/google/uuid"
 	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/lotus/chain/types"
 )
 
 type TipSetFilter struct {
-	id         string
+	id         types.FilterID
 	maxResults int // maximum number of results to collect, 0 is unlimited
 	ch         chan<- interface{}
 
@@ -23,7 +22,7 @@ type TipSetFilter struct {
 
 var _ Filter = (*TipSetFilter)(nil)
 
-func (f *TipSetFilter) ID() string {
+func (f *TipSetFilter) ID() types.FilterID {
 	return f.id
 }
 
@@ -77,7 +76,7 @@ type TipSetFilterManager struct {
 	MaxFilterResults int
 
 	mu      sync.Mutex // guards mutations to filters
-	filters map[string]*TipSetFilter
+	filters map[types.FilterID]*TipSetFilter
 }
 
 func (m *TipSetFilterManager) Apply(ctx context.Context, from, to *types.TipSet) error {
@@ -100,27 +99,27 @@ func (m *TipSetFilterManager) Revert(ctx context.Context, from, to *types.TipSet
 }
 
 func (m *TipSetFilterManager) Install(ctx context.Context) (*TipSetFilter, error) {
-	id, err := uuid.NewRandom()
+	id, err := newFilterID()
 	if err != nil {
-		return nil, xerrors.Errorf("new uuid: %w", err)
+		return nil, xerrors.Errorf("new filter id: %w", err)
 	}
 
 	f := &TipSetFilter{
-		id:         id.String(),
+		id:         id,
 		maxResults: m.MaxFilterResults,
 	}
 
 	m.mu.Lock()
 	if m.filters == nil {
-		m.filters = make(map[string]*TipSetFilter)
+		m.filters = make(map[types.FilterID]*TipSetFilter)
 	}
-	m.filters[id.String()] = f
+	m.filters[id] = f
 	m.mu.Unlock()
 
 	return f, nil
 }
 
-func (m *TipSetFilterManager) Remove(ctx context.Context, id string) error {
+func (m *TipSetFilterManager) Remove(ctx context.Context, id types.FilterID) error {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	if _, found := m.filters[id]; !found {

chain/types/event.go

@@ -22,3 +22,5 @@ type EventEntry struct {
 	// Any DAG-CBOR encodeable type.
 	Value []byte
 }
+
+type FilterID [32]byte // compatible with EthHash