Add a sequence number to advertisements

ingest/schema/envelope.go

@@ -12,6 +12,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/libp2p/go-libp2p/core/record"
 	"github.com/multiformats/go-multihash"
+	"github.com/multiformats/go-varint"
 )
 
 var log = logging.Logger("indexer/schema")
@@ -93,9 +94,14 @@ func signaturePayload(ad *Advertisement, oldFormat bool) ([]byte, error) {
 		addrsLen += len(addr)
 	}
 
+	var seqLen int
+	if ad.SeqNum != nil {
+		seqLen = varint.UvarintSize(*ad.SeqNum)
+	}
+
 	// Signature data is previousID+entries+metadata+isRm
 	var sigBuf bytes.Buffer
-	sigBuf.Grow(len(bindex) + len(ent) + len(ad.Provider) + addrsLen + len(ad.Metadata) + 1)
+	sigBuf.Grow(len(bindex) + len(ent) + len(ad.Provider) + addrsLen + len(ad.Metadata) + 1 + seqLen)
 	sigBuf.Write(bindex)
 	sigBuf.Write(ent)
 	sigBuf.WriteString(ad.Provider)
@@ -108,6 +114,9 @@ func signaturePayload(ad *Advertisement, oldFormat bool) ([]byte, error) {
 	} else {
 		sigBuf.WriteByte(0)
 	}
+	if ad.SeqNum != nil {
+		sigBuf.Write(varint.ToUvarint(*ad.SeqNum))
+	}
 
 	// Generates the old (incorrect) data payload used for signature.  This is
 	// only for compatibility with existing advertisements that have the old
@@ -147,8 +156,11 @@ func extendedProviderSignaturePayload(ad *Advertisement, p *Provider) ([]byte, e
 	for _, addr := range p.Addresses {
 		addrsLen += len(addr)
 	}
-
-	sigBuf.Grow(len(bindex) + len(ent) + len(ad.Provider) + len(ad.ContextID) + len(p.ID) + addrsLen + len(p.Metadata) + 1)
+	var seqLen int
+	if ad.SeqNum != nil {
+		seqLen = varint.UvarintSize(*ad.SeqNum)
+	}
+	sigBuf.Grow(len(bindex) + len(ent) + len(ad.Provider) + len(ad.ContextID) + len(p.ID) + addrsLen + len(p.Metadata) + 1 + seqLen)
 	sigBuf.Write(bindex)
 	sigBuf.Write(ent)
 	sigBuf.WriteString(ad.Provider)
@@ -163,6 +175,9 @@ func extendedProviderSignaturePayload(ad *Advertisement, p *Provider) ([]byte, e
 	} else {
 		sigBuf.WriteByte(0)
 	}
+	if ad.SeqNum != nil {
+		sigBuf.Write(varint.ToUvarint(*ad.SeqNum))
+	}
 
 	return multihash.Sum(sigBuf.Bytes(), multihash.SHA2_256, -1)
 }

ingest/schema/envelope_test.go

@@ -51,7 +51,7 @@ func testSignAndVerify(t *testing.T, signer func(*stischema.Advertisement, crypt
 	require.NoError(t, err)
 	elnk, err := lsys.Store(ipld.LinkContext{}, stischema.Linkproto, node)
 	require.NoError(t, err)
-
+	seq := uint64(123)
 	adv := stischema.Advertisement{
 		Provider: "12D3KooWKRyzVWW6ChFjQjK4miCty85Niy48tpPV95XdKu1BcvMA",
 		Addresses: []string{
@@ -60,6 +60,7 @@ func testSignAndVerify(t *testing.T, signer func(*stischema.Advertisement, crypt
 		Entries:   elnk,
 		ContextID: []byte("test-context-id"),
 		Metadata:  []byte("test-metadata"),
+		SeqNum:    &seq,
 	}
 	err = signer(&adv, priv)
 	require.NoError(t, err)

ingest/schema/schema.ipldsch

@@ -64,6 +64,8 @@ type Advertisement struct {
     Metadata Bytes
     # IsRm specifies whether this advertisement represents the content are no longer retrievalbe fom the provider.
     IsRm Bool
+    # SeqNum is a monotonically increasing sequence number that gives the advertisement's distance in the chain.
+    SeqNum optional Int
     # ExtendedProvider might optionally specify a set of providers where the ad entries are available from. 
     # See: https://github.com/ipni/storetheindex/blob/main/doc/ingest.md#extendedprovider
     ExtendedProvider optional ExtendedProvider

ingest/schema/types.go

@@ -40,6 +40,7 @@ type (
 		ContextID        []byte
 		Metadata         []byte
 		IsRm             bool
+		SeqNum           *uint64
 		ExtendedProvider *ExtendedProvider
 	}
 	EntryChunk struct {
@@ -100,6 +101,13 @@ func (a Advertisement) PreviousCid() cid.Cid {
 	return a.PreviousID.(cidlink.Link).Cid
 }
 
+func (a Advertisement) Sequence() uint64 {
+	if a.SeqNum == nil {
+		return 0
+	}
+	return uint64(*a.SeqNum)
+}
+
 func (a Advertisement) Validate() error {
 	if len(a.ContextID) > MaxContextIDLen {
 		return errors.New("context id too long")

ingest/schema/types_test.go

@@ -269,6 +269,7 @@ func Test_LinkLoadNoEntries(t *testing.T) {
 func generateAdvertisement() *stischema.Advertisement {
 	mhs := test.RandomMultihashes(7)
 	prev := ipld.Link(cidlink.Link{Cid: cid.NewCidV1(cid.Raw, mhs[0])})
+	seq := uint64(54321)
 	return &stischema.Advertisement{
 		PreviousID: prev,
 		Provider:   mhs[1].String(),
@@ -280,6 +281,7 @@ func generateAdvertisement() *stischema.Advertisement {
 		Metadata:  mhs[5],
 		Signature: mhs[6],
 		IsRm:      false,
+		SeqNum:    &seq,
 	}
 }