fix edge case related to startUid = 1

hypermodeinc · Nov 11, 2021 · a56d6c4 · a56d6c4
1 parent 0756963
commit a56d6c4
Show file tree

Hide file tree

Showing 2 changed files with 14 additions and 11 deletions.
diff --git a/go.sum b/go.sum
@@ -182,12 +182,6 @@ github.com/dgraph-io/ristretto v0.1.1-0.20210824115121-89e99415887a h1:2+hTlwc5y
 github.com/dgraph-io/ristretto v0.1.1-0.20210824115121-89e99415887a/go.mod h1:fux0lOrBhrVCJd3lcTHsIJhq1T2rokOu6v9Vcb3Q9ug=
 github.com/dgraph-io/simdjson-go v0.3.0 h1:h71LO7vR4LHMPUhuoGN8bqGm1VNfGOlAG8BI6iDUKw0=
 github.com/dgraph-io/simdjson-go v0.3.0/go.mod h1:Otpysdjaxj9OGaJusn4pgQV7OFh2bELuHANq0I78uvY=
-github.com/dgraph-io/sroar v0.0.0-20210930201544-8a9a0351f20f h1:/7NA7mug98b6QkBU+3BEfun5EpegFVx7cRZU86vTouQ=
-github.com/dgraph-io/sroar v0.0.0-20210930201544-8a9a0351f20f/go.mod h1:bdNPtQmcxoIQVkZEWZvX0n0/IDlHFab397xdBlP4OoE=
-github.com/dgraph-io/sroar v0.0.0-20211109162404-04042b4dc6bf h1:8MALpTCcxt9Th2Zg1SoIKd8JiVQxNmRMu82eoRm6ilY=
-github.com/dgraph-io/sroar v0.0.0-20211109162404-04042b4dc6bf/go.mod h1:bdNPtQmcxoIQVkZEWZvX0n0/IDlHFab397xdBlP4OoE=
-github.com/dgraph-io/sroar v0.0.0-20211109183029-fd981ce5e705 h1:kTbqbQw7mo5AUf8V0u04BjUndA9eFiApin0+vjPO3Qk=
-github.com/dgraph-io/sroar v0.0.0-20211109183029-fd981ce5e705/go.mod h1:bdNPtQmcxoIQVkZEWZvX0n0/IDlHFab397xdBlP4OoE=
 github.com/dgraph-io/sroar v0.0.0-20211110072951-f8373db427cd h1:qfO1q+M7gc9zLb0N69QbO8OkfrSAszhqo0zCbGKD0o8=
 github.com/dgraph-io/sroar v0.0.0-20211110072951-f8373db427cd/go.mod h1:bdNPtQmcxoIQVkZEWZvX0n0/IDlHFab397xdBlP4OoE=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=

diff --git a/posting/list.go b/posting/list.go
@@ -912,6 +912,11 @@ func (l *List) Rollup(alloc *z.Allocator) ([]*bpb.KV, error) {
 	}
 	// defer out.free()
 
+	if len(out.parts) > 0 {
+		out.plist.Postings = nil
+		out.plist.Bitmap = nil
+	}
+
 	var kvs []*bpb.KV
 	kv := MarshalPostingList(out.plist, alloc)
 	// We set kv.Version to newMinTs + 1 because if we write the rolled up keys at the same ts as
@@ -1120,20 +1125,24 @@ func (ro *rollupOutput) split(startUid uint64) error {
 	// Provide a 30% cushion, because NSplit doesn't do equal splitting based on maxListSize.
 	bms := r.NSplit(f, uint64(0.7*float64(maxListSize)))
 
-	for _, bm := range bms {
+	for i, bm := range bms {
 		if bm.GetCardinality() == 0 {
 			continue
 		}
-		startUid, err := bm.Select(0)
+		start, err := bm.Select(0)
 		x.Check(err)
-		endUid, err := bm.Select(uint64(bm.GetCardinality()) - 1)
+		end, err := bm.Select(uint64(bm.GetCardinality()) - 1)
 		x.Check(err)
 
 		newpl := &pb.PostingList{}
 		newpl.Bitmap = bm.ToBuffer()
-		newpl.Postings = getPostings(startUid, endUid)
+		newpl.Postings = getPostings(start, end)
+		// startUid = 1 is a special case. ro.parts should always have UID 1
+		if i == 0 && startUid == 1 {
+			start = 1
+		}
 
-		ro.parts[startUid] = newpl
+		ro.parts[start] = newpl
 	}
 
 	return nil