Use sync.Pool for Relation slices.

cache/cache.go

@@ -3,6 +3,8 @@ package cache
 import (
 	"sync"
 
+	"github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/internal/mempool"
 	"github.com/aserto-dev/azm/model"
 	"github.com/aserto-dev/azm/model/diff"
 	stts "github.com/aserto-dev/azm/stats"
@@ -17,15 +19,17 @@ type (
 )
 
 type Cache struct {
-	model *model.Model
-	mtx   sync.RWMutex
+	model    *model.Model
+	mtx      sync.RWMutex
+	relsPool *graph.RelationsPool
 }
 
 // New, create new model cache instance.
 func New(m *model.Model) *Cache {
 	return &Cache{
-		model: m,
-		mtx:   sync.RWMutex{},
+		model:    m,
+		mtx:      sync.RWMutex{},
+		relsPool: mempool.NewSlicePool[*dsc.Relation](),
 	}
 }
 

cache/check.go

@@ -9,7 +9,10 @@ import (
 )
 
 func (c *Cache) Check(req *dsr.CheckRequest, relReader graph.RelationReader) (*dsr.CheckResponse, error) {
-	checker := graph.NewCheck(c.model, req, relReader)
+	c.mtx.RLock()
+	defer c.mtx.RUnlock()
+
+	checker := graph.NewCheck(c.model, req, relReader, c.relsPool)
 
 	ctx := pb.NewStruct()
 
@@ -26,15 +29,18 @@ type graphSearch interface {
 }
 
 func (c *Cache) GetGraph(req *dsr.GetGraphRequest, relReader graph.RelationReader) (*dsr.GetGraphResponse, error) {
+	c.mtx.RLock()
+	defer c.mtx.RUnlock()
+
 	var (
 		search graphSearch
 		err    error
 	)
 
 	if req.ObjectId == "" {
-		search, err = graph.NewObjectSearch(c.model, req, relReader)
+		search, err = graph.NewObjectSearch(c.model, req, relReader, c.relsPool)
 	} else {
-		search, err = graph.NewSubjectSearch(c.model, req, relReader)
+		search, err = graph.NewSubjectSearch(c.model, req, relReader, c.relsPool)
 	}
 
 	if err != nil {

graph/check.go

@@ -15,9 +15,10 @@ type Checker struct {
 	getRels RelationReader
 
 	memo *checkMemo
+	pool *RelationsPool
 }
 
-func NewCheck(m *model.Model, req *dsr.CheckRequest, reader RelationReader) *Checker {
+func NewCheck(m *model.Model, req *dsr.CheckRequest, reader RelationReader, pool *RelationsPool) *Checker {
 	return &Checker{
 		m: m,
 		params: &relation{
@@ -29,6 +30,7 @@ func NewCheck(m *model.Model, req *dsr.CheckRequest, reader RelationReader) *Che
 		},
 		getRels: reader,
 		memo:    newCheckMemo(req.Trace),
+		pool:    pool,
 	}
 }
 
@@ -88,7 +90,16 @@ func (c *Checker) checkRelation(params *relation) (checkStatus, error) {
 	r := c.m.Objects[params.ot].Relations[params.rel]
 	steps := c.m.StepRelation(r, params.st)
 
+	// Reuse the same slice in all steps.
+	relsPtr := c.pool.Get()
+	defer func() {
+		*relsPtr = (*relsPtr)[:0]
+		c.pool.Put(relsPtr)
+	}()
+
 	for _, step := range steps {
+		*relsPtr = (*relsPtr)[:0]
+
 		req := &dsc.Relation{
 			ObjectType:  params.ot.String(),
 			ObjectId:    params.oid.String(),
@@ -103,27 +114,26 @@ func (c *Checker) checkRelation(params *relation) (checkStatus, error) {
 			req.SubjectRelation = step.Relation.String()
 		}
 
-		rels, err := c.getRels(req)
-		if err != nil {
+		if err := c.getRels(req, relsPtr); err != nil {
 			return checkStatusFalse, err
 		}
 
 		switch {
 		case step.IsDirect():
-			for _, rel := range rels {
+			for _, rel := range *relsPtr {
 				if rel.SubjectId == params.sid.String() {
 					return checkStatusTrue, nil
 				}
 			}
 
 		case step.IsWildcard():
-			if len(rels) > 0 {
+			if len(*relsPtr) > 0 {
 				// We have a wildcard match.
 				return checkStatusTrue, nil
 			}
 
 		case step.IsSubject():
-			for _, rel := range rels {
+			for _, rel := range *relsPtr {
 				if status, err := c.check(&relation{
 					ot:  step.Object,
 					oid: ObjectID(rel.SubjectId),
@@ -190,17 +200,21 @@ func (c *Checker) checkPermission(params *relation) (checkStatus, error) {
 
 func (c *Checker) expandTerm(pt *model.PermissionTerm, params *relation) (relations, error) {
 	if pt.IsArrow() {
-		// Resolve the base of the arrow.
-		rels, err := c.getRels(&dsc.Relation{
+		query := &dsc.Relation{
 			ObjectType: params.ot.String(),
 			ObjectId:   params.oid.String(),
 			Relation:   pt.Base.String(),
-		})
+		}
+
+		relsPtr := c.pool.Get()
+
+		// Resolve the base of the arrow.
+		err := c.getRels(query, relsPtr)
 		if err != nil {
 			return relations{}, err
 		}
 
-		expanded := lo.Map(rels, func(rel *dsc.Relation, _ int) *relation {
+		expanded := lo.Map(*relsPtr, func(rel *dsc.Relation, _ int) *relation {
 			return &relation{
 				ot:  model.ObjectName(rel.SubjectType),
 				oid: ObjectID(rel.SubjectId),
@@ -210,6 +224,9 @@ func (c *Checker) expandTerm(pt *model.PermissionTerm, params *relation) (relati
 			}
 		})
 
+		*relsPtr = (*relsPtr)[:0]
+		c.pool.Put(relsPtr)
+
 		return expanded, nil
 	}
 

graph/check_test.go

@@ -5,7 +5,9 @@ import (
 	"testing"
 
 	azmgraph "github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/internal/mempool"
 	v3 "github.com/aserto-dev/azm/v3"
+	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -67,11 +69,13 @@ func TestCheck(t *testing.T) {
 	assert.NoError(t, err)
 	assert.NotNil(t, m)
 
+	pool := mempool.NewSlicePool[*dsc.Relation]()
+
 	for _, test := range tests {
 		t.Run(test.check, func(tt *testing.T) {
 			assert := assert.New(tt)
 
-			checker := azmgraph.NewCheck(m, checkReq(test.check), rels.GetRelations)
+			checker := azmgraph.NewCheck(m, checkReq(test.check), rels.GetRelations, pool)
 
 			res, err := checker.Check()
 			assert.NoError(err)

graph/objects.go

@@ -16,7 +16,7 @@ type ObjectSearch struct {
 	wildcardSearch *SubjectSearch
 }
 
-func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationReader) (*ObjectSearch, error) {
+func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationReader, pool *RelationsPool) (*ObjectSearch, error) {
 	params := searchParams(req)
 	if err := validate(m, params); err != nil {
 		return nil, err
@@ -40,13 +40,15 @@ func NewObjectSearch(m *model.Model, req *dsr.GetGraphRequest, reader RelationRe
 			getRels: invertedRelationReader(im, reader),
 			memo:    newSearchMemo(req.Trace),
 			explain: req.Explain,
+			pool:    pool,
 		}},
 		wildcardSearch: &SubjectSearch{graphSearch{
 			m:       im,
 			params:  wildcardParams(iParams),
 			getRels: invertedRelationReader(im, reader),
 			memo:    newSearchMemo(req.Trace),
 			explain: req.Explain,
+			pool:    pool,
 		}},
 	}, nil
 }
@@ -125,22 +127,24 @@ func wildcardParams(params *relation) *relation {
 }
 
 func invertedRelationReader(m *model.Model, reader RelationReader) RelationReader {
-	return func(r *dsc.Relation) ([]*dsc.Relation, error) {
+	return func(r *dsc.Relation, out *Relations) error {
 		ir := uninvertRelation(m, relationFromProto(r))
-		res, err := reader(ir.asProto())
-		if err != nil {
-			return nil, err
+		if err := reader(ir.asProto(), out); err != nil {
+			return err
 		}
 
-		return lo.Map(res, func(r *dsc.Relation, _ int) *dsc.Relation {
-			return &dsc.Relation{
+		res := *out
+		for i, r := range res {
+			res[i] = &dsc.Relation{
 				ObjectType:  r.SubjectType,
 				ObjectId:    r.SubjectId,
 				Relation:    r.Relation,
 				SubjectType: r.ObjectType,
 				SubjectId:   r.ObjectId,
 			}
-		}), nil
+		}
+
+		return nil
 	}
 }
 

graph/objects_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/aserto-dev/azm/graph"
+	"github.com/aserto-dev/azm/internal/mempool"
 	"github.com/aserto-dev/azm/model"
 	v3 "github.com/aserto-dev/azm/v3"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
@@ -35,11 +36,13 @@ func TestSearchObjects(t *testing.T) {
 		im.Validate(model.SkipNameValidation, model.AllowPermissionInArrowBase),
 	)
 
+	pool := mempool.NewSlicePool[*dsc.Relation]()
+
 	for _, test := range searchObjectsTests {
 		t.Run(test.search, func(tt *testing.T) {
 			assert := assert.New(tt)
 
-			objSearch, err := graph.NewObjectSearch(m, graphReq(test.search), rels.GetRelations)
+			objSearch, err := graph.NewObjectSearch(m, graphReq(test.search), rels.GetRelations, pool)
 			assert.NoError(err)
 
 			res, err := objSearch.Search()

graph/search.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/aserto-dev/azm/internal/mempool"
 	"github.com/aserto-dev/azm/model"
 	dsc "github.com/aserto-dev/go-directory/aserto/directory/common/v3"
 	dsr "github.com/aserto-dev/go-directory/aserto/directory/reader/v3"
@@ -12,21 +13,27 @@ import (
 	"google.golang.org/protobuf/types/known/structpb"
 )
 
-type ObjectID = model.ObjectID
+type (
+	ObjectID = model.ObjectID
 
-// RelationReader retrieves relations that match the given filter.
-type RelationReader func(*dsc.Relation) ([]*dsc.Relation, error)
+	Relations = []*dsc.Relation
 
-type searchPath relations
+	// RelationReader retrieves relations that match the given filter.
+	RelationReader func(*dsc.Relation, *Relations) error
 
-type object struct {
-	Type model.ObjectName
-	ID   ObjectID
-}
+	RelationsPool = mempool.Pool[*Relations]
+
+	searchPath relations
 
-// The results of a search is a map where the key is a matching relations
-// and the value is a list of paths that connect the search object and subject.
-type searchResults map[object][]searchPath
+	object struct {
+		Type model.ObjectName
+		ID   ObjectID
+	}
+
+	// The results of a search is a map where the key is a matching relations
+	// and the value is a list of paths that connect the search object and subject.
+	searchResults map[object][]searchPath
+)
 
 // Objects returns the objects from the search results.
 func (r searchResults) Objects() []*dsc.ObjectIdentifier {
@@ -92,6 +99,7 @@ type graphSearch struct {
 
 	memo    *searchMemo
 	explain bool
+	pool    *RelationsPool
 }
 
 func validate(m *model.Model, params *relation) error {