X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/feda522eba3e2a27c91741c77d0d01f1840c0004..b961d7cdc59213673c3e4f86d3dae99daf0a1935:/tree.go

diff --git a/tree.go b/tree.go
index 9fb033f..4309597 100644
--- a/tree.go
+++ b/tree.go
@@ -19,23 +19,6 @@ import (
 // few bytes over it, because the view measures the real sizes.
 const nodeBytes = 512
 
-// Node is one line of the summary tree. Node (l, i) covers the 2^l messages
-// from i*2^l on. A node of level 0 holds one message. A node of a higher level
-// merges its two children, (l-1, 2i) and (l-1, 2i+1). Size is the UTF-8 byte
-// length of Text.
-type Node struct {
-	Level int    `json:"l"`
-	Index int    `json:"i"`
-	Text  string `json:"text"`
-	Size  int    `json:"size"`
-}
-
-// nodeKey names the node (l, i).
-type nodeKey struct {
-	level int
-	index int
-}
-
 // treeRecordBytes is the size of a record of index/tree.idx: the position of
 // the node line, the node index, and the node level.
 const treeRecordBytes = 32
@@ -54,13 +37,30 @@ const treeRecordBytes = 32
 // built again from the day files.
 type Tree struct {
 	clock   func() time.Time
-	journal journal
+	journal Journal
 	dir     string
-	order   *records
-	levels  map[int]*records
+	order   *Records
+	levels  map[int]*Records
 	failure error
 }
 
+// Node is one line of the summary tree. Node (l, i) covers the 2^l messages
+// from i*2^l on. A node of level 0 holds one message. A node of a higher level
+// merges its two children, (l-1, 2i) and (l-1, 2i+1). Size is the UTF-8 byte
+// length of Text.
+type Node struct {
+	Level int    `json:"l"`
+	Index int    `json:"i"`
+	Text  string `json:"text"`
+	Size  int    `json:"size"`
+}
+
+// NodeKey names the node (l, i).
+type NodeKey struct {
+	level int
+	index int
+}
+
 // openTree opens the tree of the chat in root and indexes its new lines. A chat
 // of total messages cannot have a node that covers a later message.
 func openTree(ctx context.Context, root string, total int, clock func() time.Time) (*Tree, error) {
@@ -73,11 +73,11 @@ func openTree(ctx context.Context, root string, total int, clock func() time.Tim
 
 	t := &Tree{
 		clock: clock,
-		journal: journal{
+		journal: Journal{
 			dir: filepath.Join(root, "tree"),
 		},
 		dir:    filepath.Join(root, "index"),
-		levels: make(map[int]*records),
+		levels: make(map[int]*Records),
 	}
 
 	err := t.open(ctx, total)
@@ -90,12 +90,13 @@ func openTree(ctx context.Context, root string, total int, clock func() time.Tim
 
 func (t *Tree) open(ctx context.Context, total int) error {
 	var err error
+
 	t.order, err = openRecords(filepath.Join(t.dir, "tree.idx"), treeRecordBytes)
 	if err != nil {
 		return err
 	}
 
-	start := position{}
+	start := Position{}
 	if t.order.count == 0 {
 		err = t.removeLevels()
 		if err != nil {
@@ -109,23 +110,24 @@ func (t *Tree) open(ctx context.Context, total int) error {
 
 		// A crash can stop an add between the two index writes, so the
 		// last node gets its level record again.
-		node, last := decodeTreeRecord(record)
+		node, last := treeDecodeRecord(record)
 		err = t.writeLevel(node, last)
 		if err != nil {
 			return err
 		}
 
-		start = position{
+		start = Position{
 			day:    last.day,
 			offset: last.offset + uint64(last.length),
 		}
 	}
 
-	return t.journal.Scan(ctx, start, func(line []byte, place position) error {
+	return t.journal.Scan(ctx, start, func(line []byte, place Position) error {
 		var node Node
+
 		err := json.Unmarshal(line, &node)
 		if err != nil {
-			return err
+			return fmt.Errorf("decode tree node: %w", err)
 		}
 
 		err = t.check(node)
@@ -137,10 +139,27 @@ func (t *Tree) open(ctx context.Context, total int) error {
 			return fmt.Errorf("node (%d, %d) covers messages after the log", node.Level, node.Index)
 		}
 
-		return t.addIndex(nodeKey{node.Level, node.Index}, place)
+		return t.addIndex(NodeKey{node.Level, node.Index}, place)
 	})
 }
 
+// Close closes the files of the tree.
+func (t *Tree) Close() error {
+	err := t.journal.Close()
+	if t.order != nil {
+		err = errors.Join(err, t.order.Close())
+		t.order = nil
+	}
+
+	for level, index := range t.levels {
+		err = errors.Join(err, index.Close())
+
+		delete(t.levels, level)
+	}
+
+	return err
+}
+
 // removeLevels removes the level indexes, which are not valid without the order
 // index.
 func (t *Tree) removeLevels() error {
@@ -160,7 +179,7 @@ func (t *Tree) removeLevels() error {
 }
 
 // writeLevel writes the position of node to its level index.
-func (t *Tree) writeLevel(node nodeKey, place position) error {
+func (t *Tree) writeLevel(node NodeKey, place Position) error {
 	level, err := t.level(node.level)
 	if err != nil {
 		return err
@@ -172,23 +191,6 @@ func (t *Tree) writeLevel(node nodeKey, place position) error {
 	return level.Write(node.index, record)
 }
 
-// level returns the index of level, and opens it at first use.
-func (t *Tree) level(level int) (*records, error) {
-	index, open := t.levels[level]
-	if open {
-		return index, nil
-	}
-
-	index, err := openRecords(filepath.Join(t.dir, fmt.Sprintf("tree-%d.idx", level)), positionBytes)
-	if err != nil {
-		return nil, err
-	}
-
-	t.levels[level] = index
-
-	return index, nil
-}
-
 // check makes sure that node is valid and can join the tree now.
 func (t *Tree) check(node Node) error {
 	if node.Level < 0 || node.Level >= bits.UintSize-2 || node.Index < 0 {
@@ -227,7 +229,7 @@ func (t *Tree) check(node Node) error {
 }
 
 // addIndex adds the node line at place to both indexes.
-func (t *Tree) addIndex(node nodeKey, place position) error {
+func (t *Tree) addIndex(node NodeKey, place Position) error {
 	record := make([]byte, treeRecordBytes)
 	encodePosition(record, place)
 	binary.LittleEndian.PutUint64(record[positionBytes:], uint64(node.index))
@@ -241,20 +243,48 @@ func (t *Tree) addIndex(node nodeKey, place position) error {
 	return t.writeLevel(node, place)
 }
 
-// Close closes the files of the tree.
-func (t *Tree) Close() error {
-	err := t.journal.Close()
-	if t.order != nil {
-		err = errors.Join(err, t.order.Close())
-		t.order = nil
+// level returns the index of level, and opens it at first use.
+func (t *Tree) level(level int) (*Records, error) {
+	index, open := t.levels[level]
+	if open {
+		return index, nil
 	}
 
-	for level, index := range t.levels {
-		err = errors.Join(err, index.Close())
-		delete(t.levels, level)
+	index, err := openRecords(filepath.Join(t.dir, fmt.Sprintf("tree-%d.idx", level)), positionBytes)
+	if err != nil {
+		return nil, err
 	}
 
-	return err
+	t.levels[level] = index
+
+	return index, nil
+}
+
+// Built tells if the node (l, i) is built.
+func (t *Tree) Built(level, index int) (bool, error) {
+	_, built, err := t.place(level, index)
+	return built, err
+}
+
+// place returns the position of the node (l, i) if it is built.
+func (t *Tree) place(level, index int) (Position, bool, error) {
+	if level < 0 || level >= bits.UintSize-2 || index < 0 {
+		return Position{}, false, nil
+	}
+
+	records, err := t.level(level)
+	if err != nil {
+		return Position{}, false, err
+	}
+
+	record, found, err := records.Read(index)
+	if err != nil || !found {
+		return Position{}, false, err
+	}
+
+	place := decodePosition(record)
+
+	return place, place.length > 0, nil
 }
 
 // Add writes a new node to the tree.
@@ -275,7 +305,7 @@ func (t *Tree) Add(node Node) error {
 
 	place, err := t.journal.Write(t.clock().Format(time.DateOnly), append(line, '\n'))
 	if err == nil {
-		err = t.addIndex(nodeKey{node.Level, node.Index}, place)
+		err = t.addIndex(NodeKey{node.Level, node.Index}, place)
 	}
 
 	if err != nil {
@@ -286,33 +316,6 @@ func (t *Tree) Add(node Node) error {
 	return nil
 }
 
-// Built tells if the node (l, i) is built.
-func (t *Tree) Built(level, index int) (bool, error) {
-	_, built, err := t.place(level, index)
-	return built, err
-}
-
-// place returns the position of the node (l, i) if it is built.
-func (t *Tree) place(level, index int) (position, bool, error) {
-	if level < 0 || level >= bits.UintSize-2 || index < 0 {
-		return position{}, false, nil
-	}
-
-	records, err := t.level(level)
-	if err != nil {
-		return position{}, false, err
-	}
-
-	record, found, err := records.Read(index)
-	if err != nil || !found {
-		return position{}, false, err
-	}
-
-	place := decodePosition(record)
-
-	return place, place.length > 0, nil
-}
-
 // Node reads the node (l, i) if it is built.
 func (t *Tree) Node(level, index int) (Node, bool, error) {
 	place, built, err := t.place(level, index)
@@ -326,6 +329,7 @@ func (t *Tree) Node(level, index int) (Node, bool, error) {
 	}
 
 	var node Node
+
 	err = json.Unmarshal(line, &node)
 	if err != nil {
 		return Node{}, false, fmt.Errorf("decode node (%d, %d): %w", level, index, err)
@@ -338,41 +342,52 @@ func (t *Tree) Node(level, index int) (Node, bool, error) {
 	return node, true, nil
 }
 
-// Count returns the number of built nodes.
-func (t *Tree) Count() int {
-	return t.order.count
-}
-
 // Keys returns the keys of the built nodes, ordered by level and then by index.
-func (t *Tree) Keys() ([]nodeKey, error) {
-	keys := make([]nodeKey, 0, t.order.count)
+func (t *Tree) Keys() ([]NodeKey, error) {
+	keys := make([]NodeKey, 0, t.order.count)
 	for n := range t.order.count {
 		record, _, err := t.order.Read(n)
 		if err != nil {
 			return nil, err
 		}
 
-		key, _ := decodeTreeRecord(record)
+		key, _ := treeDecodeRecord(record)
 		keys = append(keys, key)
 	}
 
-	slices.SortFunc(keys, func(a, b nodeKey) int {
+	slices.SortFunc(keys, func(a, b NodeKey) int {
 		return cmp.Or(cmp.Compare(a.level, b.level), cmp.Compare(a.index, b.index))
 	})
 
 	return keys, nil
 }
 
-// leafSource returns the text that the leaf of message holds or summarizes.
-func leafSource(message Message) string {
-	return message.Kind + ": " + message.Text
+// Count returns the number of built nodes.
+func (t *Tree) Count() int {
+	return t.order.count
 }
 
-// freeLeaf returns the leaf of message when its source fits in a node. Such a
-// leaf holds the source word for word and needs no model call.
+// treeDecodeRecord reads the key and the position of a record of
+// index/tree.idx.
+func treeDecodeRecord(record []byte) (NodeKey, Position) {
+	key := NodeKey{
+		level: int(binary.LittleEndian.Uint32(record[positionBytes+8:])),
+		index: int(binary.LittleEndian.Uint64(record[positionBytes:])),
+	}
+
+	return key, decodePosition(record)
+}
+
+// nodeEnd returns the ID after the last message of node (l, i).
+func nodeEnd(level, index int) int {
+	return (index + 1) << level
+}
+
+// freeLeaf returns a text-only leaf when its source fits in a node. Images need
+// a model description even when their text fits.
 func freeLeaf(message Message) (Node, bool) {
 	text := leafSource(message)
-	if len(text) > nodeBytes {
+	if len(text) > nodeBytes || len(imageFiles(message.Text)) > 0 {
 		return Node{}, false
 	}
 
@@ -384,6 +399,11 @@ func freeLeaf(message Message) (Node, bool) {
 	}, true
 }
 
+// leafSource returns the text that the leaf of message holds or summarizes.
+func leafSource(message Message) string {
+	return message.Kind + ": " + message.Text
+}
+
 // freeMerge returns the parent of two sibling nodes when both texts, joined by
 // a newline, fit in a node. Such a parent needs no model call.
 func freeMerge(left, right Node) (Node, bool) {
@@ -400,19 +420,3 @@ func freeMerge(left, right Node) (Node, bool) {
 		Size:  len(text),
 	}, true
 }
-
-// decodeTreeRecord reads the key and the position of a record of
-// index/tree.idx.
-func decodeTreeRecord(record []byte) (nodeKey, position) {
-	key := nodeKey{
-		level: int(binary.LittleEndian.Uint32(record[positionBytes+8:])),
-		index: int(binary.LittleEndian.Uint64(record[positionBytes:])),
-	}
-
-	return key, decodePosition(record)
-}
-
-// nodeEnd returns the ID after the last message of node (l, i).
-func nodeEnd(level, index int) int {
-	return (index + 1) << level
-}