feat: add ChainGetTipSetAfterHeight

This is identical to ChainGetTipSetByHeight, but returns the tipset
following any null tipsets. This is what the user usually wants anyways.

(and I need it for another PR)

api/api_full.go

@@ -113,6 +113,11 @@ type FullNode interface {
 	// will be returned.
 	ChainGetTipSetByHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error) //perm:read
 
+	// ChainGetTipSetAfterHeight looks back for a tipset at the specified epoch.
+	// If there are no blocks at the specified epoch, the first non-nil tipset at a later epoch
+	// will be returned.
+	ChainGetTipSetAfterHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error) //perm:read
+
 	// ChainReadObj reads ipld nodes referenced by the specified CID from chain
 	// blockstore and returns raw bytes.
 	ChainReadObj(context.Context, cid.Cid) ([]byte, error) //perm:read

api/api_gateway.go

@@ -35,6 +35,7 @@ type Gateway interface {
 	ChainGetMessage(ctx context.Context, mc cid.Cid) (*types.Message, error)
 	ChainGetTipSet(ctx context.Context, tsk types.TipSetKey) (*types.TipSet, error)
 	ChainGetTipSetByHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error)
+	ChainGetTipSetAfterHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error)
 	ChainNotify(context.Context) (<-chan []*HeadChange, error)
 	ChainReadObj(context.Context, cid.Cid) ([]byte, error)
 	GasEstimateMessageGas(ctx context.Context, msg *types.Message, spec *MessageSendSpec, tsk types.TipSetKey) (*types.Message, error)

api/mocks/mock_full.go

@@ -343,6 +343,21 @@ func (mr *MockFullNodeMockRecorder) ChainGetTipSet(arg0, arg1 interface{}) *gomo
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ChainGetTipSet", reflect.TypeOf((*MockFullNode)(nil).ChainGetTipSet), arg0, arg1)
 }
 
+// ChainGetTipSetAfterHeight mocks base method.
+func (m *MockFullNode) ChainGetTipSetAfterHeight(arg0 context.Context, arg1 abi.ChainEpoch, arg2 types.TipSetKey) (*types.TipSet, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "ChainGetTipSetAfterHeight", arg0, arg1, arg2)
+	ret0, _ := ret[0].(*types.TipSet)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// ChainGetTipSetAfterHeight indicates an expected call of ChainGetTipSetAfterHeight.
+func (mr *MockFullNodeMockRecorder) ChainGetTipSetAfterHeight(arg0, arg1, arg2 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "ChainGetTipSetAfterHeight", reflect.TypeOf((*MockFullNode)(nil).ChainGetTipSetAfterHeight), arg0, arg1, arg2)
+}
+
 // ChainGetTipSetByHeight mocks base method.
 func (m *MockFullNode) ChainGetTipSetByHeight(arg0 context.Context, arg1 abi.ChainEpoch, arg2 types.TipSetKey) (*types.TipSet, error) {
 	m.ctrl.T.Helper()

api/proxy_gen.go

@@ -132,6 +132,8 @@ type FullNodeStruct struct {
 
 		ChainGetTipSet func(p0 context.Context, p1 types.TipSetKey) (*types.TipSet, error) `perm:"read"`
 
+		ChainGetTipSetAfterHeight func(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) `perm:"read"`
+
 		ChainGetTipSetByHeight func(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) `perm:"read"`
 
 		ChainHasObj func(p0 context.Context, p1 cid.Cid) (bool, error) `perm:"read"`
@@ -474,6 +476,8 @@ type GatewayStruct struct {
 
 		ChainGetTipSet func(p0 context.Context, p1 types.TipSetKey) (*types.TipSet, error) ``
 
+		ChainGetTipSetAfterHeight func(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) ``
+
 		ChainGetTipSetByHeight func(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) ``
 
 		ChainHasObj func(p0 context.Context, p1 cid.Cid) (bool, error) ``
@@ -1171,6 +1175,17 @@ func (s *FullNodeStub) ChainGetTipSet(p0 context.Context, p1 types.TipSetKey) (*
 	return nil, ErrNotSupported
 }
 
+func (s *FullNodeStruct) ChainGetTipSetAfterHeight(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) {
+	if s.Internal.ChainGetTipSetAfterHeight == nil {
+		return nil, ErrNotSupported
+	}
+	return s.Internal.ChainGetTipSetAfterHeight(p0, p1, p2)
+}
+
+func (s *FullNodeStub) ChainGetTipSetAfterHeight(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) {
+	return nil, ErrNotSupported
+}
+
 func (s *FullNodeStruct) ChainGetTipSetByHeight(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) {
 	if s.Internal.ChainGetTipSetByHeight == nil {
 		return nil, ErrNotSupported
@@ -2997,6 +3012,17 @@ func (s *GatewayStub) ChainGetTipSet(p0 context.Context, p1 types.TipSetKey) (*t
 	return nil, ErrNotSupported
 }
 
+func (s *GatewayStruct) ChainGetTipSetAfterHeight(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) {
+	if s.Internal.ChainGetTipSetAfterHeight == nil {
+		return nil, ErrNotSupported
+	}
+	return s.Internal.ChainGetTipSetAfterHeight(p0, p1, p2)
+}
+
+func (s *GatewayStub) ChainGetTipSetAfterHeight(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) {
+	return nil, ErrNotSupported
+}
+
 func (s *GatewayStruct) ChainGetTipSetByHeight(p0 context.Context, p1 abi.ChainEpoch, p2 types.TipSetKey) (*types.TipSet, error) {
 	if s.Internal.ChainGetTipSetByHeight == nil {
 		return nil, ErrNotSupported

documentation/en/api-v1-unstable-methods.md

@@ -27,6 +27,7 @@
   * [ChainGetRandomnessFromBeacon](#ChainGetRandomnessFromBeacon)
   * [ChainGetRandomnessFromTickets](#ChainGetRandomnessFromTickets)
   * [ChainGetTipSet](#ChainGetTipSet)
+  * [ChainGetTipSetAfterHeight](#ChainGetTipSetAfterHeight)
   * [ChainGetTipSetByHeight](#ChainGetTipSetByHeight)
   * [ChainHasObj](#ChainHasObj)
   * [ChainHead](#ChainHead)
@@ -766,6 +767,38 @@ Response:
 }
 ```
 
+### ChainGetTipSetAfterHeight
+ChainGetTipSetAfterHeight looks back for a tipset at the specified epoch.
+If there are no blocks at the specified epoch, the first non-nil tipset at a later epoch
+will be returned.
+
+
+Perms: read
+
+Inputs:
+```json
+[
+  10101,
+  [
+    {
+      "/": "bafy2bzacea3wsdh6y3a36tb3skempjoxqpuyompjbmfeyf34fi3uy6uue42v4"
+    },
+    {
+      "/": "bafy2bzacebp3shtrn43k7g3unredz7fxn4gj533d3o43tqn2p2ipxxhrvchve"
+    }
+  ]
+]
+```
+
+Response:
+```json
+{
+  "Cids": null,
+  "Blocks": null,
+  "Height": 0
+}
+```
+
 ### ChainGetTipSetByHeight
 ChainGetTipSetByHeight looks back for a tipset at the specified epoch.
 If there are no blocks at the specified epoch, a tipset at an earlier epoch

gateway/node.go

@@ -36,6 +36,7 @@ type TargetAPI interface {
 	ChainGetNode(ctx context.Context, p string) (*api.IpldObject, error)
 	ChainGetTipSet(ctx context.Context, tsk types.TipSetKey) (*types.TipSet, error)
 	ChainGetTipSetByHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error)
+	ChainGetTipSetAfterHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error)
 	ChainHasObj(context.Context, cid.Cid) (bool, error)
 	ChainHead(ctx context.Context) (*types.TipSet, error)
 	ChainNotify(context.Context) (<-chan []*api.HeadChange, error)
@@ -163,32 +164,48 @@ func (gw *Node) ChainGetTipSet(ctx context.Context, tsk types.TipSetKey) (*types
 }
 
 func (gw *Node) ChainGetTipSetByHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error) {
+	if err := gw.checkTipSetHeight(ctx, h, tsk); err != nil {
+		return nil, err
+	}
+
+	return gw.target.ChainGetTipSetByHeight(ctx, h, tsk)
+}
+
+func (gw *Node) ChainGetTipSetAfterHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error) {
+	if err := gw.checkTipSetHeight(ctx, h, tsk); err != nil {
+		return nil, err
+	}
+
+	return gw.target.ChainGetTipSetAfterHeight(ctx, h, tsk)
+}
+
+func (gw *Node) checkTipSetHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) error {
 	var ts *types.TipSet
 	if tsk.IsEmpty() {
 		head, err := gw.target.ChainHead(ctx)
 		if err != nil {
-			return nil, err
+			return err
 		}
 		ts = head
 	} else {
 		gts, err := gw.target.ChainGetTipSet(ctx, tsk)
 		if err != nil {
-			return nil, err
+			return err
 		}
 		ts = gts
 	}
 
 	// Check if the tipset key refers to gw tipset that's too far in the past
 	if err := gw.checkTipset(ts); err != nil {
-		return nil, err
+		return err
 	}
 
 	// Check if the height is too far in the past
 	if err := gw.checkTipsetHeight(ts, h); err != nil {
-		return nil, err
+		return err
 	}
 
-	return gw.target.ChainGetTipSetByHeight(ctx, h, tsk)
+	return nil
 }
 
 func (gw *Node) ChainGetNode(ctx context.Context, p string) (*api.IpldObject, error) {

node/impl/full/chain.go

@@ -50,6 +50,7 @@ type ChainModuleAPI interface {
 	ChainGetMessage(ctx context.Context, mc cid.Cid) (*types.Message, error)
 	ChainGetTipSet(ctx context.Context, tsk types.TipSetKey) (*types.TipSet, error)
 	ChainGetTipSetByHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error)
+	ChainGetTipSetAfterHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error)
 	ChainReadObj(context.Context, cid.Cid) ([]byte, error)
 }
 
@@ -266,6 +267,14 @@ func (m *ChainModule) ChainGetTipSetByHeight(ctx context.Context, h abi.ChainEpo
 	return m.Chain.GetTipsetByHeight(ctx, h, ts, true)
 }
 
+func (m *ChainModule) ChainGetTipSetAfterHeight(ctx context.Context, h abi.ChainEpoch, tsk types.TipSetKey) (*types.TipSet, error) {
+	ts, err := m.Chain.GetTipSetFromKey(tsk)
+	if err != nil {
+		return nil, xerrors.Errorf("loading tipset %s: %w", tsk, err)
+	}
+	return m.Chain.GetTipsetByHeight(ctx, h, ts, false)
+}
+
 func (m *ChainModule) ChainReadObj(ctx context.Context, obj cid.Cid) ([]byte, error) {
 	blk, err := m.ExposedBlockstore.Get(obj)
 	if err != nil {

storage/miner.go

@@ -113,6 +113,7 @@ type fullNodeFilteredAPI interface {
 	ChainGetRandomnessFromTickets(ctx context.Context, tsk types.TipSetKey, personalization crypto.DomainSeparationTag, randEpoch abi.ChainEpoch, entropy []byte) (abi.Randomness, error)
 	ChainGetRandomnessFromBeacon(ctx context.Context, tsk types.TipSetKey, personalization crypto.DomainSeparationTag, randEpoch abi.ChainEpoch, entropy []byte) (abi.Randomness, error)
 	ChainGetTipSetByHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error)
+	ChainGetTipSetAfterHeight(context.Context, abi.ChainEpoch, types.TipSetKey) (*types.TipSet, error)
 	ChainGetBlockMessages(context.Context, cid.Cid) (*api.BlockMessages, error)
 	ChainGetMessage(ctx context.Context, mc cid.Cid) (*types.Message, error)
 	ChainReadObj(context.Context, cid.Cid) ([]byte, error)