Merge pull request #1751 from authzed/reduce-allocations-for-wide-rel…

…ations

reduces chunking allocations for wide relations

internal/graph/check.go

@@ -383,7 +383,10 @@ func (cc *ConcurrentChecker) checkDirect(ctx context.Context, crc currentRequest
 	it.Close()
 
 	// Convert the subjects into batched requests.
-	toDispatch := make([]directDispatch, 0, subjectsToDispatch.Len())
+	// To simplify the logic, +1 is added to account for the situation where
+	// the number of elements is less than the chunk size, and spare us some annoying code.
+	expectedNumberOfChunks := subjectsToDispatch.ValueLen()/int(crc.maxDispatchCount) + 1
+	toDispatch := make([]directDispatch, 0, expectedNumberOfChunks)
 	subjectsToDispatch.ForEachType(func(rr *core.RelationReference, resourceIds []string) {
 		chunkCount := 0.0
 		slicez.ForEachChunk(resourceIds, crc.maxDispatchCount, func(resourceIdChunk []string) {
@@ -601,7 +604,10 @@ func (cc *ConcurrentChecker) checkTupleToUserset(ctx context.Context, crc curren
 	it.Close()
 
 	// Convert the subjects into batched requests.
-	toDispatch := make([]directDispatch, 0, subjectsToDispatch.Len())
+	// To simplify the logic, +1 is added to account for the situation where
+	// the number of elements is less than the chunk size, and spare us some annoying code.
+	expectedNumberOfChunks := subjectsToDispatch.ValueLen()/int(crc.maxDispatchCount) + 1
+	toDispatch := make([]directDispatch, 0, expectedNumberOfChunks)
 	subjectsToDispatch.ForEachType(func(rr *core.RelationReference, resourceIds []string) {
 		chunkCount := 0.0
 		slicez.ForEachChunk(resourceIds, crc.maxDispatchCount, func(resourceIdChunk []string) {

pkg/tuple/onrbytypeset.go

@@ -66,7 +66,17 @@ func (s *ONRByTypeSet) IsEmpty() bool {
 	return len(s.byType) == 0
 }
 
-// Len returns the number of keys in the set.
-func (s *ONRByTypeSet) Len() int {
+// KeyLen returns the number of keys in the set.
+func (s *ONRByTypeSet) KeyLen() int {
 	return len(s.byType)
 }
+
+// ValueLen returns the number of values in the set.
+func (s *ONRByTypeSet) ValueLen() int {
+	var total int
+	for _, vals := range s.byType {
+		total += len(vals)
+	}
+
+	return total
+}