Add acltree in new package

pkg/acl/tree/aclstate.go

@@ -50,11 +50,18 @@ func newACLState() *ACLState {
 	}
 }
 
-func (st *ACLState) applyChange(change *aclpb.Change) (err error) {
+func (st *ACLState) applyChange(changeWrapper *Change) (err error) {
+	change := changeWrapper.Content
 	aclData := &aclpb.ACLChangeACLData{}
-	err = proto.Unmarshal(change.ChangesData, aclData)
-	if err != nil {
-		return
+
+	if changeWrapper.DecryptedModel != nil {
+		aclData = changeWrapper.DecryptedModel.(*aclpb.ACLChangeACLData)
+	} else {
+		err = proto.Unmarshal(change.ChangesData, aclData)
+		if err != nil {
+			return
+		}
+		changeWrapper.DecryptedModel = aclData
 	}
 
 	defer func() {

pkg/acl/tree/aclstatebuilder.go

@@ -0,0 +1,79 @@
+package tree
+
+import (
+	"fmt"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/account"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/aclchanges/aclpb"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/asymmetric/encryptionkey"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/asymmetric/signingkey"
+)
+
+type aclStateBuilder struct {
+	tree     *Tree
+	identity string
+	key      encryptionkey.PrivKey
+	decoder  signingkey.PubKeyDecoder
+}
+
+func newACLStateBuilderWithIdentity(decoder signingkey.PubKeyDecoder, accountData *account.AccountData) *aclStateBuilder {
+	return &aclStateBuilder{
+		decoder:  decoder,
+		identity: accountData.Identity,
+		key:      accountData.EncKey,
+	}
+}
+
+func newACLStateBuilder() *aclStateBuilder {
+	return &aclStateBuilder{}
+}
+
+func (sb *aclStateBuilder) Init(tree *Tree) error {
+	sb.tree = tree
+	return nil
+}
+
+func (sb *aclStateBuilder) Build() (*ACLState, error) {
+	state, _, err := sb.BuildBefore("")
+	return state, err
+}
+
+func (sb *aclStateBuilder) BuildBefore(beforeId string) (*ACLState, bool, error) {
+	var (
+		err         error
+		startChange = sb.tree.root
+		state       *ACLState
+		foundId     = false
+	)
+
+	if sb.decoder != nil {
+		state = newACLStateWithIdentity(sb.identity, sb.key, sb.decoder)
+	} else {
+		state = newACLState()
+	}
+
+	if beforeId == startChange.Id {
+		return state, true, nil
+	}
+
+	sb.tree.IterateSkip(sb.tree.root.Id, startChange.Id, func(c *Change) (isContinue bool) {
+		err = state.applyChange(c)
+		if err != nil {
+			return false
+		}
+
+		// the user can't make changes
+		if !state.hasPermission(c.Content.Identity, aclpb.ACLChange_Writer) && !state.hasPermission(c.Content.Identity, aclpb.ACLChange_Admin) {
+			err = fmt.Errorf("user %s cannot make changes", c.Content.Identity)
+			return false
+		}
+
+		if c.Id == beforeId {
+			foundId = true
+			return false
+		}
+
+		return true
+	})
+
+	return state, foundId, err
+}

pkg/acl/tree/acltree.go

@@ -0,0 +1,466 @@
+package tree
+
+import (
+	"context"
+	"errors"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/account"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/aclchanges/aclpb"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/treestorage"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/treestorage/treepb"
+	"go.uber.org/zap"
+	"sync"
+)
+
+type AddResultSummary int
+
+var ErrTreeWithoutIdentity = errors.New("acl tree is created without identity")
+
+const (
+	AddResultSummaryNothing AddResultSummary = iota
+	AddResultSummaryAppend
+	AddResultSummaryRebuild
+)
+
+type AddResult struct {
+	OldHeads []string
+	Heads    []string
+	Added    []*aclpb.RawChange
+	// TODO: add summary for changes
+	Summary AddResultSummary
+}
+
+type TreeUpdateListener interface {
+	Update(tree ACLTree)
+	Rebuild(tree ACLTree)
+}
+
+type NoOpListener struct{}
+
+func (n NoOpListener) Update(tree ACLTree) {}
+
+func (n NoOpListener) Rebuild(tree ACLTree) {}
+
+type RWLocker interface {
+	sync.Locker
+	RLock()
+	RUnlock()
+}
+
+var ErrNoCommonSnapshot = errors.New("trees doesn't have a common snapshot")
+
+type ACLTree interface {
+	RWLocker
+	ID() string
+	Header() *treepb.TreeHeader
+	ACLState() *ACLState
+	AddContent(ctx context.Context, f func(builder ChangeBuilder) error) (*aclpb.RawChange, error)
+	AddRawChanges(ctx context.Context, changes ...*aclpb.RawChange) (AddResult, error)
+	Heads() []string
+	Root() *Change
+	Iterate(func(change *Change) bool)
+	IterateFrom(string, func(change *Change) bool)
+	HasChange(string) bool
+	SnapshotPath() []string
+	ChangesAfterCommonSnapshot(snapshotPath []string) ([]*aclpb.RawChange, error)
+	Storage() treestorage.TreeStorage
+	DebugDump() (string, error)
+
+	Close() error
+}
+
+type aclTree struct {
+	treeStorage    treestorage.TreeStorage
+	accountData    *account.AccountData
+	updateListener TreeUpdateListener
+
+	id       string
+	header   *treepb.TreeHeader
+	tree     *Tree
+	aclState *ACLState
+
+	treeBuilder     *treeBuilder
+	aclStateBuilder *aclStateBuilder
+	changeBuilder   *changeBuilder
+
+	sync.RWMutex
+}
+
+func BuildACLTreeWithIdentity(
+	t treestorage.TreeStorage,
+	acc *account.AccountData,
+	listener TreeUpdateListener) (ACLTree, error) {
+	treeBuilder := newTreeBuilder(t, acc.Decoder)
+	aclStateBuilder := newACLStateBuilderWithIdentity(acc.Decoder, acc)
+	changeBuilder := newChangeBuilder()
+
+	aclTree := &aclTree{
+		treeStorage:     t,
+		accountData:     acc,
+		tree:            nil,
+		aclState:        nil,
+		treeBuilder:     treeBuilder,
+		aclStateBuilder: aclStateBuilder,
+		changeBuilder:   changeBuilder,
+		updateListener:  listener,
+	}
+	err := aclTree.rebuildFromStorage()
+	if err != nil {
+		return nil, err
+	}
+	err = aclTree.removeOrphans()
+	if err != nil {
+		return nil, err
+	}
+	err = t.SetHeads(aclTree.Heads())
+	if err != nil {
+		return nil, err
+	}
+	aclTree.id, err = t.TreeID()
+	if err != nil {
+		return nil, err
+	}
+	aclTree.header, err = t.Header()
+	if err != nil {
+		return nil, err
+	}
+
+	listener.Rebuild(aclTree)
+
+	return aclTree, nil
+}
+
+func BuildACLTree(t treestorage.TreeStorage) {
+	// TODO: Add logic for building without identity
+}
+
+func (a *aclTree) removeOrphans() error {
+	// removing attached or invalid orphans
+	var toRemove []string
+
+	orphans, err := a.treeStorage.Orphans()
+	if err != nil {
+		return err
+	}
+	for _, orphan := range orphans {
+		if _, exists := a.tree.attached[orphan]; exists {
+			toRemove = append(toRemove, orphan)
+		}
+		if _, exists := a.tree.invalidChanges[orphan]; exists {
+			toRemove = append(toRemove, orphan)
+		}
+	}
+	return a.treeStorage.RemoveOrphans(toRemove...)
+}
+
+func (a *aclTree) rebuildFromStorage() (err error) {
+	a.treeBuilder.Init()
+
+	a.tree, err = a.treeBuilder.Build(true)
+	if err != nil {
+		return err
+	}
+
+	err = a.aclStateBuilder.Init(a.tree)
+	if err != nil {
+		return err
+	}
+
+	a.aclState, err = a.aclStateBuilder.Build()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (a *aclTree) ID() string {
+	return a.id
+}
+
+func (a *aclTree) Header() *treepb.TreeHeader {
+	return a.header
+}
+
+func (a *aclTree) ACLState() *ACLState {
+	return a.aclState
+}
+
+func (a *aclTree) Storage() treestorage.TreeStorage {
+	return a.treeStorage
+}
+
+func (a *aclTree) AddContent(ctx context.Context, build func(builder ChangeBuilder) error) (*aclpb.RawChange, error) {
+	if a.accountData == nil {
+		return nil, ErrTreeWithoutIdentity
+	}
+
+	defer func() {
+		// TODO: should this be called in a separate goroutine to prevent accidental cycles (tree->updater->tree)
+		a.updateListener.Update(a)
+	}()
+
+	a.changeBuilder.Init(a.aclState, a.tree, a.accountData)
+	err := build(a.changeBuilder)
+	if err != nil {
+		return nil, err
+	}
+
+	ch, marshalled, err := a.changeBuilder.BuildAndApply()
+	if err != nil {
+		return nil, err
+	}
+	a.tree.AddFast(ch)
+	rawCh := &aclpb.RawChange{
+		Payload:   marshalled,
+		Signature: ch.Signature(),
+		Id:        ch.Id,
+	}
+
+	err = a.treeStorage.AddRawChange(rawCh)
+	if err != nil {
+		return nil, err
+	}
+
+	err = a.treeStorage.SetHeads([]string{ch.Id})
+	if err != nil {
+		return nil, err
+	}
+	return rawCh, nil
+}
+
+func (a *aclTree) AddRawChanges(ctx context.Context, rawChanges ...*aclpb.RawChange) (AddResult, error) {
+	// TODO: make proper error handling, because there are a lot of corner cases where this will break
+	var err error
+	var mode Mode
+
+	var changes []*Change // TODO: = addChangesBuf[:0] ...
+	for _, ch := range rawChanges {
+		change, err := NewFromRawChange(ch)
+		// TODO: think what if we will have incorrect signatures on rawChanges, how everything will work
+		if err != nil {
+			continue
+		}
+		changes = append(changes, change)
+	}
+
+	defer func() {
+		if err != nil {
+			return
+		}
+
+		err = a.removeOrphans()
+		if err != nil {
+			return
+		}
+
+		err = a.treeStorage.SetHeads(a.tree.Heads())
+		if err != nil {
+			return
+		}
+
+		switch mode {
+		case Append:
+			a.updateListener.Update(a)
+		case Rebuild:
+			a.updateListener.Rebuild(a)
+		default:
+			break
+		}
+	}()
+
+	getAddedChanges := func() []*aclpb.RawChange {
+		var added []*aclpb.RawChange
+		for _, ch := range rawChanges {
+			if _, exists := a.tree.attached[ch.Id]; exists {
+				added = append(added, ch)
+			}
+		}
+		return added
+	}
+
+	for _, ch := range changes {
+		err = a.treeStorage.AddChange(ch)
+		if err != nil {
+			return AddResult{}, err
+		}
+		err = a.treeStorage.AddOrphans(ch.Id)
+		if err != nil {
+			return AddResult{}, err
+		}
+	}
+
+	prevHeads := a.tree.Heads()
+	mode = a.tree.Add(changes...)
+	switch mode {
+	case Nothing:
+		return AddResult{
+			OldHeads: prevHeads,
+			Heads:    prevHeads,
+			Summary:  AddResultSummaryNothing,
+		}, nil
+
+	case Rebuild:
+		err = a.rebuildFromStorage()
+		if err != nil {
+			return AddResult{}, err
+		}
+
+		return AddResult{
+			OldHeads: prevHeads,
+			Heads:    a.tree.Heads(),
+			Added:    getAddedChanges(),
+			Summary:  AddResultSummaryRebuild,
+		}, nil
+	default:
+		// just rebuilding the state from start without reloading everything from tree storage
+		// as an optimization we could've started from current heads, but I didn't implement that
+		a.aclState, err = a.aclStateBuilder.Build()
+		if err != nil {
+			return AddResult{}, err
+		}
+
+		return AddResult{
+			OldHeads: prevHeads,
+			Heads:    a.tree.Heads(),
+			Added:    getAddedChanges(),
+			Summary:  AddResultSummaryAppend,
+		}, nil
+	}
+}
+
+func (a *aclTree) Iterate(f func(change *Change) bool) {
+	a.tree.Iterate(a.tree.RootId(), f)
+}
+
+func (a *aclTree) IterateFrom(s string, f func(change *Change) bool) {
+	a.tree.Iterate(s, f)
+}
+
+func (a *aclTree) HasChange(s string) bool {
+	_, attachedExists := a.tree.attached[s]
+	_, unattachedExists := a.tree.unAttached[s]
+	_, invalidExists := a.tree.invalidChanges[s]
+	return attachedExists || unattachedExists || invalidExists
+}
+
+func (a *aclTree) Heads() []string {
+	return a.tree.Heads()
+}
+
+func (a *aclTree) Root() *Change {
+	return a.tree.Root()
+}
+
+func (a *aclTree) Close() error {
+	return nil
+}
+
+func (a *aclTree) SnapshotPath() []string {
+	// TODO: think about caching this
+
+	var path []string
+	// TODO: think that the user may have not all of the snapshots locally
+	currentSnapshotId := a.tree.RootId()
+	for currentSnapshotId != "" {
+		sn, err := a.treeBuilder.loadChange(currentSnapshotId)
+		if err != nil {
+			break
+		}
+		path = append(path, currentSnapshotId)
+		currentSnapshotId = sn.SnapshotId
+	}
+	return path
+}
+
+func (a *aclTree) ChangesAfterCommonSnapshot(theirPath []string) ([]*aclpb.RawChange, error) {
+	// TODO: think about when the clients will have their full acl tree and thus full snapshots
+	//  but no changes after some of the snapshots
+
+	var (
+		isNewDocument = len(theirPath) == 0
+		ourPath       = a.SnapshotPath()
+		// by default returning everything we have
+		commonSnapshot = ourPath[len(ourPath)-1] // TODO: root snapshot, probably it is better to have a specific method in treestorage
+		err            error
+	)
+
+	// if this is non-empty request
+	if !isNewDocument {
+		commonSnapshot, err = a.commonSnapshotForTwoPaths(ourPath, theirPath)
+		if err != nil {
+			return nil, err
+		}
+	}
+	var rawChanges []*aclpb.RawChange
+	// using custom load function to skip verification step and save raw changes
+	load := func(id string) (*Change, error) {
+		raw, err := a.treeStorage.GetChange(context.Background(), id)
+		if err != nil {
+			return nil, err
+		}
+
+		aclChange, err := a.treeBuilder.makeUnverifiedACLChange(raw)
+		if err != nil {
+			return nil, err
+		}
+
+		ch := NewChange(id, aclChange)
+		rawChanges = append(rawChanges, raw)
+		return ch, nil
+	}
+	// we presume that we have everything after the common snapshot, though this may not be the case in case of clients and only ACL tree changes
+	log.With(
+		zap.Strings("heads", a.tree.Heads()),
+		zap.String("breakpoint", commonSnapshot),
+		zap.String("id", a.id)).
+		Debug("getting all changes from common snapshot")
+	_, err = a.treeBuilder.dfs(a.tree.Heads(), commonSnapshot, load)
+	if err != nil {
+		return nil, err
+	}
+	if isNewDocument {
+		// adding snapshot to raw changes
+		_, err = load(commonSnapshot)
+		if err != nil {
+			return nil, err
+		}
+	}
+	log.With(
+		zap.Int("len(changes)", len(rawChanges)),
+		zap.String("id", a.id)).
+		Debug("returning all changes after common snapshot")
+
+	return rawChanges, nil
+}
+
+func (a *aclTree) DebugDump() (string, error) {
+	return a.tree.Graph(ACLDescriptionParser)
+}
+
+func (a *aclTree) commonSnapshotForTwoPaths(ourPath []string, theirPath []string) (string, error) {
+	var i int
+	var j int
+	log.With(zap.Strings("our path", ourPath), zap.Strings("their path", theirPath)).
+		Debug("finding common snapshot for two paths")
+OuterLoop:
+	// find starting point from the right
+	for i = len(ourPath) - 1; i >= 0; i-- {
+		for j = len(theirPath) - 1; j >= 0; j-- {
+			// most likely there would be only one comparison, because mostly the snapshot path will start from the root for nodes
+			if ourPath[i] == theirPath[j] {
+				break OuterLoop
+			}
+		}
+	}
+	if i < 0 || j < 0 {
+		return "", ErrNoCommonSnapshot
+	}
+	// find last common element of the sequence moving from right to left
+	for i >= 0 && j >= 0 {
+		if ourPath[i] == theirPath[j] {
+			i--
+			j--
+		}
+	}
+	return ourPath[i+1], nil
+}

pkg/acl/tree/change.go

@@ -22,12 +22,18 @@ type Change struct {
 	Id              string
 	SnapshotId      string
 	IsSnapshot      bool
-	DecryptedChange []byte
+	DecryptedChange []byte // TODO: check if we need it
+	DecryptedModel  interface{}
 
 	Content *aclpb.Change
 	Sign    []byte
 }
 
+func (ch *Change) ProtoChange() *aclpb.ACLChange {
+	//TODO implement me
+	panic("implement me")
+}
+
 func (ch *Change) DecryptContents(key *symmetric.Key) error {
 	// if the document is already decrypted
 	if ch.Content.CurrentReadKeyHash == 0 {
@@ -65,10 +71,6 @@ func NewChange(id string, ch *aclpb.Change) *Change {
 	}
 }
 
-func (ch *Change) ProtoChange() *aclpb.Change {
-	return ch.Content
-}
-
 func (ch *Change) DecryptedChangeContent() []byte {
 	return ch.DecryptedChange
 }

pkg/acl/tree/changebuilder.go

@@ -0,0 +1,163 @@
+package tree
+
+import (
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/account"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/aclchanges/aclpb"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/cid"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/asymmetric/encryptionkey"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/keys/symmetric"
+	"github.com/gogo/protobuf/proto"
+	"hash/fnv"
+	"time"
+)
+
+type MarshalledChange = []byte
+
+type ACLChangeBuilder interface {
+	UserAdd(identity string, encryptionKey encryptionkey.PubKey, permissions aclpb.ACLChangeUserPermissions) error
+	AddId(id string)      // TODO: this is only for testing
+	SetMakeSnapshot(bool) // TODO: who should decide this? probably ACLTree so we can delete it
+}
+
+type ChangeBuilder interface {
+	ACLChangeBuilder
+	AddChangeContent(marshaler proto.Marshaler) // user code should be responsible for making regular snapshots
+}
+
+type changeBuilder struct {
+	aclState *ACLState
+	tree     *Tree
+	acc      *account.AccountData
+
+	aclData       *aclpb.ACLChangeACLData
+	changeContent proto.Marshaler
+	id            string
+	makeSnapshot  bool
+	readKey       *symmetric.Key
+	readKeyHash   uint64
+}
+
+func newChangeBuilder() *changeBuilder {
+	return &changeBuilder{}
+}
+
+func (c *changeBuilder) Init(state *ACLState, tree *Tree, acc *account.AccountData) {
+	c.aclState = state
+	c.tree = tree
+	c.acc = acc
+
+	c.aclData = &aclpb.ACLChangeACLData{}
+	// setting read key for further encryption etc
+	if state.currentReadKeyHash == 0 {
+		c.readKey, _ = symmetric.NewRandom()
+
+		hasher := fnv.New64()
+		hasher.Write(c.readKey.Bytes())
+		c.readKeyHash = hasher.Sum64()
+	} else {
+		c.readKey = c.aclState.userReadKeys[c.aclState.currentReadKeyHash]
+		c.readKeyHash = c.aclState.currentReadKeyHash
+	}
+}
+
+func (c *changeBuilder) AddId(id string) {
+	c.id = id
+}
+
+func (c *changeBuilder) SetMakeSnapshot(b bool) {
+	c.makeSnapshot = b
+}
+
+func (c *changeBuilder) UserAdd(identity string, encryptionKey encryptionkey.PubKey, permissions aclpb.ACLChangeUserPermissions) error {
+	var allKeys []*symmetric.Key
+	if c.aclState.currentReadKeyHash != 0 {
+		for _, key := range c.aclState.userReadKeys {
+			allKeys = append(allKeys, key)
+		}
+	} else {
+		allKeys = append(allKeys, c.readKey)
+	}
+
+	var encryptedKeys [][]byte
+	for _, k := range allKeys {
+		res, err := encryptionKey.Encrypt(k.Bytes())
+		if err != nil {
+			return err
+		}
+
+		encryptedKeys = append(encryptedKeys, res)
+	}
+	rawKey, err := encryptionKey.Raw()
+	if err != nil {
+		return err
+	}
+	ch := &aclpb.ACLChangeACLContentValue{
+		Value: &aclpb.ACLChangeACLContentValueValueOfUserAdd{
+			UserAdd: &aclpb.ACLChangeUserAdd{
+				Identity:          identity,
+				EncryptionKey:     rawKey,
+				EncryptedReadKeys: encryptedKeys,
+				Permissions:       permissions,
+			},
+		},
+	}
+	c.aclData.AclContent = append(c.aclData.AclContent, ch)
+	return nil
+}
+
+func (c *changeBuilder) BuildAndApply() (*Change, []byte, error) {
+	aclChange := &aclpb.ACLChange{
+		TreeHeadIds:        c.tree.Heads(),
+		AclHeadIds:         c.tree.ACLHeads(),
+		SnapshotBaseId:     c.tree.RootId(),
+		AclData:            c.aclData,
+		CurrentReadKeyHash: c.readKeyHash,
+		Timestamp:          int64(time.Now().Nanosecond()),
+		Identity:           c.acc.Identity,
+	}
+	err := c.aclState.applyChange(aclChange)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if c.makeSnapshot {
+		c.aclData.AclSnapshot = c.aclState.makeSnapshot()
+	}
+
+	var marshalled []byte
+	if c.changeContent != nil {
+		marshalled, err = c.changeContent.Marshal()
+		if err != nil {
+			return nil, nil, err
+		}
+
+		encrypted, err := c.aclState.userReadKeys[c.aclState.currentReadKeyHash].
+			Encrypt(marshalled)
+		if err != nil {
+			return nil, nil, err
+		}
+		aclChange.ChangesData = encrypted
+	}
+
+	fullMarshalledChange, err := proto.Marshal(aclChange)
+	if err != nil {
+		return nil, nil, err
+	}
+	signature, err := c.acc.SignKey.Sign(fullMarshalledChange)
+	if err != nil {
+		return nil, nil, err
+	}
+	id, err := cid.NewCIDFromBytes(fullMarshalledChange)
+	if err != nil {
+		return nil, nil, err
+	}
+	ch := NewChange(id, aclChange)
+	ch.DecryptedDocumentChange = marshalled
+	ch.Sign = signature
+
+	return ch, fullMarshalledChange, nil
+}
+
+func (c *changeBuilder) AddChangeContent(marshaler proto.Marshaler) {
+	c.changeContent = marshaler
+}

pkg/acl/tree/descriptionparser.go

@@ -0,0 +1,45 @@
+package tree
+
+import (
+	"fmt"
+	"github.com/anytypeio/go-anytype-infrastructure-experiments/pkg/acl/aclchanges/aclpb"
+	"github.com/gogo/protobuf/proto"
+	"strings"
+	"unicode"
+)
+
+type DescriptionParser interface {
+	ParseChange(*Change) ([]string, error)
+}
+
+var ACLDescriptionParser = aclDescriptionParser{}
+
+type aclDescriptionParser struct{}
+
+func (a aclDescriptionParser) ParseChange(changeWrapper *Change) (res []string, err error) {
+	change := changeWrapper.Content
+	aclData := &aclpb.ACLChangeACLData{}
+
+	if changeWrapper.DecryptedModel != nil {
+		aclData = changeWrapper.DecryptedModel.(*aclpb.ACLChangeACLData)
+	} else {
+		err = proto.Unmarshal(change.ChangesData, aclData)
+		if err != nil {
+			return
+		}
+	}
+
+	var chSymbs []string
+	for _, chc := range aclData.AclContent {
+		tp := fmt.Sprintf("%T", chc.Value)
+		tp = strings.Replace(tp, "ACLChangeACLContentValueValueOf", "", 1)
+		res := ""
+		for _, ts := range tp {
+			if unicode.IsUpper(ts) {
+				res += string(ts)
+			}
+		}
+		chSymbs = append(chSymbs, res)
+	}
+	return chSymbs, nil
+}

pkg/acl/tree/tree.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"crypto/md5"
 	"fmt"
-	"github.com/anytypeio/go-anytype-infrastructure-experiments/util/slice"
 	"sort"
 )
 
@@ -289,34 +288,6 @@ func (t *Tree) updateHeads() {
 	sort.Strings(t.metaHeadIds)
 }
 
-func (t *Tree) ACLHeads() []string {
-	var aclTreeHeads []string
-	for _, head := range t.Heads() {
-		if slice.FindPos(aclTreeHeads, head) != -1 { // do not scan known heads
-			continue
-		}
-		precedingHeads := t.getPrecedingACLHeads(head)
-
-		for _, aclHead := range precedingHeads {
-			if slice.FindPos(aclTreeHeads, aclHead) != -1 {
-				continue
-			}
-			aclTreeHeads = append(aclTreeHeads, aclHead)
-		}
-	}
-	return aclTreeHeads
-}
-
-func (t *Tree) getPrecedingACLHeads(head string) []string {
-	headChange := t.attached[head]
-
-	if headChange.Content.GetAclData() != nil {
-		return []string{head}
-	} else {
-		return headChange.Content.AclHeadIds
-	}
-}
-
 func (t *Tree) iterate(start *Change, f func(c *Change) (isContinue bool)) {
 	it := newIterator()
 	defer freeIterator(it)

pkg/acl/tree/treebuilder.go

@@ -223,8 +223,8 @@ func (tb *treeBuilder) makeVerifiedChange(change *aclpb.RawChange) (aclChange *a
 	return
 }
 
-func (tb *treeBuilder) makeUnverifiedACLChange(change *aclpb.RawChange) (aclChange *aclpb.ACLChange, err error) {
-	aclChange = new(aclpb.ACLChange)
+func (tb *treeBuilder) makeUnverifiedACLChange(change *aclpb.RawChange) (aclChange *aclpb.Change, err error) {
+	aclChange = new(aclpb.Change)
 	err = proto.Unmarshal(change.Payload, aclChange)
 	return
 }

pkg/acl/tree/treegraph.go

@@ -0,0 +1,11 @@
+//go:build ((!linux && !darwin) || android || ios || nographviz) && !amd64
+// +build !linux,!darwin android ios nographviz
+// +build !amd64
+
+package tree
+
+import "fmt"
+
+func (t *Tree) Graph(parser DescriptionParser) (data []string, err error) {
+	return "", fmt.Errorf("not supported")
+}

pkg/acl/tree/treegraph_nix.go

@@ -0,0 +1,121 @@
+//go:build (linux || darwin) && !android && !ios && !nographviz && (amd64 || arm64)
+// +build linux darwin
+// +build !android
+// +build !ios
+// +build !nographviz
+// +build amd64 arm64
+
+package tree
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/goccy/go-graphviz"
+	"github.com/goccy/go-graphviz/cgraph"
+	"strings"
+	"time"
+)
+
+func (t *Tree) Graph(parser DescriptionParser) (data string, err error) {
+	var order = make(map[string]string)
+	var seq = 0
+	t.Iterate(t.RootId(), func(c *Change) (isContinue bool) {
+		v := order[c.Id]
+		if v == "" {
+			order[c.Id] = fmt.Sprint(seq)
+		} else {
+			order[c.Id] = fmt.Sprintf("%s,%d", v, seq)
+		}
+		seq++
+		return true
+	})
+	g := graphviz.New()
+	defer g.Close()
+	graph, err := g.Graph()
+	if err != nil {
+		return
+	}
+	defer func() {
+		err = graph.Close()
+	}()
+	var nodes = make(map[string]*cgraph.Node)
+	var addChange = func(c *Change) error {
+		n, e := graph.CreateNode(c.Id)
+		if e != nil {
+			return e
+		}
+		n.SetStyle(cgraph.FilledNodeStyle)
+		nodes[c.Id] = n
+		ord := order[c.Id]
+		if ord == "" {
+			ord = "miss"
+		}
+		chSymbs, err := parser.ParseChange(c)
+		if err != nil {
+			return err
+		}
+
+		shortId := c.Id
+		label := fmt.Sprintf("Id: %s\nOrd: %s\nTime: %s\nChanges: %s\n",
+			shortId,
+			ord,
+			time.Unix(c.Content.Timestamp, 0).Format("02.01.06 15:04:05"),
+			strings.Join(chSymbs, ","),
+		)
+		n.SetLabel(label)
+		return nil
+	}
+	for _, c := range t.attached {
+		if err = addChange(c); err != nil {
+			return
+		}
+	}
+	for _, c := range t.unAttached {
+		if err = addChange(c); err != nil {
+			return
+		}
+	}
+	var getNode = func(id string) (*cgraph.Node, error) {
+		if n, ok := nodes[id]; ok {
+			return n, nil
+		}
+		n, err := graph.CreateNode(fmt.Sprintf("%s: not in Tree", id))
+		if err != nil {
+			return nil, err
+		}
+		nodes[id] = n
+		return n, nil
+	}
+	var addLinks = func(c *Change) error {
+		for _, prevId := range c.PreviousIds {
+			self, e := getNode(c.Id)
+			if e != nil {
+				return e
+			}
+			prev, e := getNode(prevId)
+			if e != nil {
+				return e
+			}
+			_, e = graph.CreateEdge("", self, prev)
+			if e != nil {
+				return e
+			}
+		}
+		return nil
+	}
+	for _, c := range t.attached {
+		if err = addLinks(c); err != nil {
+			return
+		}
+	}
+	for _, c := range t.unAttached {
+		if err = addLinks(c); err != nil {
+			return
+		}
+	}
+	var buf bytes.Buffer
+	if err = g.Render(graph, "dot", &buf); err != nil {
+		return
+	}
+	return buf.String(), nil
+}

pkg/acl/tree/treeiterator.go

@@ -0,0 +1,158 @@
+package tree
+
+import "sync"
+
+var itPool = &sync.Pool{
+	New: func() interface{} {
+		return &iterator{}
+	},
+}
+
+func newIterator() *iterator {
+	return itPool.Get().(*iterator)
+}
+
+func freeIterator(i *iterator) {
+	itPool.Put(i)
+}
+
+type iterator struct {
+	compBuf    []*Change
+	queue      []*Change
+	doneMap    map[*Change]struct{}
+	breakpoint *Change
+	f          func(c *Change) bool
+}
+
+func (i *iterator) iterateSkip(start *Change, skipBefore *Change, f func(c *Change) (isContinue bool)) {
+	skipping := true
+	i.iterate(start, func(c *Change) (isContinue bool) {
+		if skipping && c != skipBefore {
+			return true
+		}
+		skipping = false
+		return f(c)
+	})
+}
+
+func (i *iterator) iterate(start *Change, f func(c *Change) (isContinue bool)) {
+	if start == nil {
+		return
+	}
+	// reset
+	i.queue = i.queue[:0]
+	i.compBuf = i.compBuf[:0]
+	i.doneMap = make(map[*Change]struct{})
+	i.queue = append(i.queue, start)
+	i.breakpoint = nil
+	i.f = f
+
+	for len(i.queue) > 0 {
+		c := i.queue[0]
+		i.queue = i.queue[1:]
+		nl := len(c.Next)
+		if nl == 1 {
+			if !i.iterateLin(c) {
+				return
+			}
+			if i.breakpoint != nil {
+				i.toQueue(i.breakpoint)
+				i.breakpoint = nil
+			}
+		} else {
+			_, done := i.doneMap[c]
+			if !done {
+				if !f(c) {
+					return
+				}
+				i.doneMap[c] = struct{}{}
+			}
+			if nl != 0 {
+				for _, next := range c.Next {
+					i.toQueue(next)
+				}
+			}
+		}
+	}
+}
+
+func (i *iterator) iterateLin(c *Change) bool {
+	for len(c.Next) == 1 {
+		_, done := i.doneMap[c]
+		if !done {
+			if !i.f(c) {
+				return false
+			}
+			i.doneMap[c] = struct{}{}
+		}
+
+		c = c.Next[0]
+		if len(c.PreviousIds) > 1 {
+			break
+		}
+	}
+	if len(c.Next) == 0 && len(c.PreviousIds) <= 1 {
+		if !i.f(c) {
+			return false
+		}
+		i.doneMap[c] = struct{}{}
+	} else {
+		i.breakpoint = c
+	}
+
+	return true
+}
+
+func (i *iterator) comp(c1, c2 *Change) uint8 {
+	if c1.Id == c2.Id {
+		return 0
+	}
+	i.compBuf = i.compBuf[:0]
+	i.compBuf = append(i.compBuf, c1.Next...)
+	var uniq = make(map[*Change]struct{})
+	var appendUniqueToBuf = func(next []*Change) {
+		for _, n := range next {
+			if _, ok := uniq[n]; !ok {
+				i.compBuf = append(i.compBuf, n)
+				uniq[n] = struct{}{}
+			}
+		}
+	}
+	var used int
+	for len(i.compBuf)-used > 0 {
+		l := len(i.compBuf) - used
+		for _, n := range i.compBuf[used:] {
+			delete(uniq, n)
+			if n.Id == c2.Id {
+				return 1
+			} else {
+				appendUniqueToBuf(n.Next)
+			}
+		}
+		used += l
+	}
+	return 2
+}
+
+func (i *iterator) toQueue(c *Change) {
+	var pos = -1
+For:
+	for idx, qc := range i.queue {
+		switch i.comp(c, qc) {
+		// exists
+		case 0:
+			return
+		//
+		case 1:
+			pos = idx
+			break For
+		}
+	}
+	if pos == -1 {
+		i.queue = append(i.queue, c)
+	} else if pos == 0 {
+		i.queue = append([]*Change{c}, i.queue...)
+	} else {
+		i.queue = append(i.queue[:pos], append([]*Change{c}, i.queue[pos:]...)...)
+	}
+}