[#92] Refactor policer and add some unit tests

Signed-off-by: Alejandro Lopez <a.lopez@yadro.com>

cmd/frostfs-node/keyspaceiterator.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	objectcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/engine"
+)
+
+type keySpaceIterator struct {
+	ng  *engine.StorageEngine
+	cur *engine.Cursor
+}
+
+func (it *keySpaceIterator) Next(ctx context.Context, batchSize uint32) ([]objectcore.AddressWithType, error) {
+	var prm engine.ListWithCursorPrm
+	prm.WithCursor(it.cur)
+	prm.WithCount(batchSize)
+
+	res, err := it.ng.ListWithCursor(ctx, prm)
+	if err != nil {
+		return nil, fmt.Errorf("cannot list objects in engine: %w", err)
+	}
+
+	it.cur = res.Cursor()
+	return res.AddressList(), nil
+}

cmd/frostfs-node/object.go

@@ -38,6 +38,7 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/replicator"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
 	eaclSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/eacl"
+	netmapSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
 	objectSDK "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
 	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
 	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
@@ -211,15 +212,30 @@ func addPolicer(c *cfg, keyStorage *util.KeyStorage, clientConstructor *cache.Cl
 
 	ls := c.cfgObject.cfgLocalStorage.localStorage
 
+	buryFn := func(ctx context.Context, addr oid.Address) error {
+		var prm engine.InhumePrm
+		prm.MarkAsGarbage(addr)
+		prm.WithForceRemoval()
+
+		_, err := ls.Inhume(ctx, prm)
+		return err
+	}
+
+	remoteHeader := headsvc.NewRemoteHeader(keyStorage, clientConstructor)
+
 	pol := policer.New(
 		policer.WithLogger(c.log),
-		policer.WithLocalStorage(ls),
+		policer.WithKeySpaceIterator(&keySpaceIterator{ng: ls}),
+		policer.WithBuryFunc(buryFn),
 		policer.WithContainerSource(c.cfgObject.cnrSource),
 		policer.WithPlacementBuilder(
 			placement.NewNetworkMapSourceBuilder(c.netMapSource),
 		),
-		policer.WithRemoteHeader(
-			headsvc.NewRemoteHeader(keyStorage, clientConstructor),
+		policer.WithRemoteObjectHeaderFunc(
+			func(ctx context.Context, ni netmapSDK.NodeInfo, a oid.Address) (*objectSDK.Object, error) {
+				prm := new(headsvc.RemoteHeadPrm).WithNodeInfo(ni).WithObjectAddress(a)
+				return remoteHeader.Head(ctx, prm)
+			},
 		),
 		policer.WithNetmapKeys(c),
 		policer.WithHeadTimeout(