extract kdbx_file.dart into it's own file. cache recycleBin, and do not resolve it every time by uuid.

example/pubspec.lock

@@ -117,7 +117,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.3.0"
+    version: "0.3.1"
   logging:
     dependency: transitive
     description:

lib/kdbx.dart

@@ -8,6 +8,7 @@ export 'src/kdbx_consts.dart';
 export 'src/kdbx_custom_data.dart';
 export 'src/kdbx_dao.dart' show KdbxDao;
 export 'src/kdbx_entry.dart';
+export 'src/kdbx_file.dart';
 export 'src/kdbx_format.dart';
 export 'src/kdbx_group.dart';
 export 'src/kdbx_header.dart'

lib/src/kdbx_dao.dart

@@ -1,4 +1,5 @@
 import 'package:kdbx/kdbx.dart';
+import 'package:kdbx/src/kdbx_file.dart';
 import 'package:logging/logging.dart';
 import 'package:meta/meta.dart';
 
@@ -32,28 +33,6 @@ extension KdbxDao on KdbxFile {
     return group;
   }
 
-  /// Returns the recycle bin, if it exists, null otherwise.
-  KdbxGroup get recycleBin {
-    final uuid = body.meta.recycleBinUUID.get();
-    if (uuid?.isNil != false) {
-      return null;
-    }
-    try {
-      return findGroupByUuid(uuid);
-    } catch (e, stackTrace) {
-      _logger.warning(() {
-        final groupDebug = body.rootGroup
-            .getAllGroups()
-            .map((g) => '${g.uuid}: ${g.name}')
-            .join('\n');
-        return 'All Groups: $groupDebug';
-      });
-      _logger.severe('Inconsistency error, uuid $uuid not found in groups.', e,
-          stackTrace);
-      rethrow;
-    }
-  }
-
   KdbxGroup getRecycleBinOrCreate() {
     return recycleBin ?? _createRecycleBin();
   }

lib/src/kdbx_entry.dart

@@ -1,6 +1,6 @@
 import 'package:kdbx/src/crypto/protected_value.dart';
 import 'package:kdbx/src/kdbx_consts.dart';
-import 'package:kdbx/src/kdbx_format.dart';
+import 'package:kdbx/src/kdbx_file.dart';
 import 'package:kdbx/src/kdbx_group.dart';
 import 'package:kdbx/src/kdbx_object.dart';
 import 'package:kdbx/src/kdbx_xml.dart';

lib/src/kdbx_file.dart

@@ -0,0 +1,111 @@
+import 'dart:async';
+import 'dart:typed_data';
+
+import 'package:kdbx/src/crypto/protected_value.dart';
+import 'package:kdbx/src/kdbx_format.dart';
+import 'package:kdbx/src/kdbx_group.dart';
+import 'package:kdbx/src/kdbx_header.dart';
+import 'package:kdbx/src/kdbx_object.dart';
+import 'package:logging/logging.dart';
+import 'package:xml/xml.dart' as xml;
+import 'package:kdbx/src/kdbx_dao.dart';
+
+final _logger = Logger('kdbx_file');
+
+class KdbxFile {
+  KdbxFile(this.kdbxFormat, this.credentials, this.header, this.body) {
+    for (final obj in _allObjects) {
+      obj.file = this;
+    }
+  }
+
+  static final protectedValues = Expando<ProtectedValue>();
+
+  static ProtectedValue protectedValueForNode(xml.XmlElement node) {
+    return protectedValues[node];
+  }
+
+  static void setProtectedValueForNode(
+      xml.XmlElement node, ProtectedValue value) {
+    protectedValues[node] = value;
+  }
+
+  final KdbxFormat kdbxFormat;
+  final Credentials credentials;
+  final KdbxHeader header;
+  final KdbxBody body;
+  final Set<KdbxObject> dirtyObjects = {};
+  final StreamController<Set<KdbxObject>> _dirtyObjectsChanged =
+      StreamController<Set<KdbxObject>>.broadcast();
+
+  Stream<Set<KdbxObject>> get dirtyObjectsChanged =>
+      _dirtyObjectsChanged.stream;
+
+  Future<Uint8List> save() async {
+    return kdbxFormat.save(this);
+  }
+
+  /// Marks all dirty objects as clean. Called by [KdbxFormat.save].
+  void onSaved() {
+    dirtyObjects.clear();
+    _dirtyObjectsChanged.add(dirtyObjects);
+  }
+
+  Iterable<KdbxObject> get _allObjects => body.rootGroup
+      .getAllGroups()
+      .cast<KdbxObject>()
+      .followedBy(body.rootGroup.getAllEntries());
+
+  void dirtyObject(KdbxObject kdbxObject) {
+    dirtyObjects.add(kdbxObject);
+    _dirtyObjectsChanged.add(dirtyObjects);
+  }
+
+  void dispose() {
+    _dirtyObjectsChanged.close();
+  }
+
+  KdbxGroup _recycleBin;
+
+  /// Returns the recycle bin, if it exists, null otherwise.
+  KdbxGroup get recycleBin => _recycleBin ??= _findRecycleBin();
+
+  KdbxGroup _findRecycleBin() {
+    final uuid = body.meta.recycleBinUUID.get();
+    if (uuid?.isNil != false) {
+      return null;
+    }
+    try {
+      return findGroupByUuid(uuid);
+    } catch (e, stackTrace) {
+      _logger.warning(() {
+        final groupDebug = body.rootGroup
+            .getAllGroups()
+            .map((g) => '${g.uuid}: ${g.name}')
+            .join('\n');
+        return 'All Groups: $groupDebug';
+      });
+      _logger.severe('Inconsistency error, uuid $uuid not found in groups.', e,
+          stackTrace);
+      rethrow;
+    }
+  }
+
+//  void _subscribeToChildren() {
+//    final allObjects = _allObjects;
+//    for (final obj in allObjects) {
+//      _subscriptions.handle(obj.changes.listen((event) {
+//        if (event.isDirty) {
+//          isDirty = true;
+//          if (event.object is KdbxGroup) {
+//            Future(() {
+//              // resubscribe, just in case some child groups/entries have changed.
+//              _subscriptions.cancelSubscriptions();
+//              _subscribeToChildren();
+//            });
+//          }
+//        }
+//      }));
+//    }
+//  }
+}

lib/src/kdbx_format.dart

@@ -14,6 +14,7 @@ import 'package:kdbx/src/crypto/protected_value.dart';
 import 'package:kdbx/src/internal/byte_utils.dart';
 import 'package:kdbx/src/internal/consts.dart';
 import 'package:kdbx/src/internal/crypto_utils.dart';
+import 'package:kdbx/src/kdbx_file.dart';
 import 'package:kdbx/src/kdbx_group.dart';
 import 'package:kdbx/src/kdbx_header.dart';
 import 'package:kdbx/src/kdbx_meta.dart';
@@ -120,98 +121,6 @@ class HashCredentials implements Credentials {
   Uint8List getHash() => hash;
 }
 
-class KdbxFile {
-  KdbxFile(this.kdbxFormat, this.credentials, this.header, this.body) {
-    for (final obj in _allObjects) {
-      obj.file = this;
-    }
-  }
-
-  static final protectedValues = Expando<ProtectedValue>();
-
-  static ProtectedValue protectedValueForNode(xml.XmlElement node) {
-    return protectedValues[node];
-  }
-
-  static void setProtectedValueForNode(
-      xml.XmlElement node, ProtectedValue value) {
-    protectedValues[node] = value;
-  }
-
-  final KdbxFormat kdbxFormat;
-  final Credentials credentials;
-  final KdbxHeader header;
-  final KdbxBody body;
-  final Set<KdbxObject> dirtyObjects = {};
-  final StreamController<Set<KdbxObject>> _dirtyObjectsChanged =
-      StreamController<Set<KdbxObject>>.broadcast();
-
-  Stream<Set<KdbxObject>> get dirtyObjectsChanged =>
-      _dirtyObjectsChanged.stream;
-
-  Future<Uint8List> save() async {
-    final output = BytesBuilder();
-    final writer = WriterHelper(output);
-    header.generateSalts();
-    header.write(writer);
-    final headerHash =
-        (crypto.sha256.convert(writer.output.toBytes()).bytes as Uint8List);
-
-    if (header.versionMajor <= 3) {
-      final streamKey = header.fields[HeaderFields.ProtectedStreamKey].bytes;
-      final gen = ProtectedSaltGenerator(streamKey);
-
-      body.meta.headerHash.set(headerHash.buffer);
-      await body.writeV3(writer, this, gen);
-    } else if (header.versionMajor <= 4) {
-      final headerBytes = writer.output.toBytes();
-      writer.writeBytes(headerHash);
-      final gen = kdbxFormat._createProtectedSaltGenerator(header);
-      final keys = await kdbxFormat._computeKeysV4(header, credentials);
-      final headerHmac = kdbxFormat._getHeaderHmac(headerBytes, keys.hmacKey);
-      writer.writeBytes(headerHmac.bytes as Uint8List);
-      body.writeV4(writer, this, gen, keys);
-    } else {
-      throw UnsupportedError('Unsupported version ${header.versionMajor}');
-    }
-    dirtyObjects.clear();
-    _dirtyObjectsChanged.add(dirtyObjects);
-    return output.toBytes();
-  }
-
-  Iterable<KdbxObject> get _allObjects => body.rootGroup
-      .getAllGroups()
-      .cast<KdbxObject>()
-      .followedBy(body.rootGroup.getAllEntries());
-
-  void dirtyObject(KdbxObject kdbxObject) {
-    dirtyObjects.add(kdbxObject);
-    _dirtyObjectsChanged.add(dirtyObjects);
-  }
-
-  void dispose() {
-    _dirtyObjectsChanged.close();
-  }
-
-//  void _subscribeToChildren() {
-//    final allObjects = _allObjects;
-//    for (final obj in allObjects) {
-//      _subscriptions.handle(obj.changes.listen((event) {
-//        if (event.isDirty) {
-//          isDirty = true;
-//          if (event.object is KdbxGroup) {
-//            Future(() {
-//              // resubscribe, just in case some child groups/entries have changed.
-//              _subscriptions.cancelSubscriptions();
-//              _subscribeToChildren();
-//            });
-//          }
-//        }
-//      }));
-//    }
-//  }
-}
-
 class KdbxBody extends KdbxNode {
   KdbxBody.create(this.meta, this.rootGroup) : super.create('KeePassFile') {
     node.children.add(meta.node);
@@ -379,6 +288,39 @@ class KdbxFormat {
     }
   }
 
+  Future<Uint8List> save(KdbxFile file) async {
+    final body = file.body;
+    final header = file.header;
+
+    final output = BytesBuilder();
+    final writer = WriterHelper(output);
+    header.generateSalts();
+    header.write(writer);
+    final headerHash =
+        (crypto.sha256.convert(writer.output.toBytes()).bytes as Uint8List);
+
+    if (file.header.versionMajor <= 3) {
+      final streamKey =
+          file.header.fields[HeaderFields.ProtectedStreamKey].bytes;
+      final gen = ProtectedSaltGenerator(streamKey);
+
+      body.meta.headerHash.set(headerHash.buffer);
+      await body.writeV3(writer, file, gen);
+    } else if (header.versionMajor <= 4) {
+      final headerBytes = writer.output.toBytes();
+      writer.writeBytes(headerHash);
+      final gen = _createProtectedSaltGenerator(header);
+      final keys = await _computeKeysV4(header, file.credentials);
+      final headerHmac = _getHeaderHmac(headerBytes, keys.hmacKey);
+      writer.writeBytes(headerHmac.bytes as Uint8List);
+      body.writeV4(writer, file, gen, keys);
+    } else {
+      throw UnsupportedError('Unsupported version ${header.versionMajor}');
+    }
+    file.onSaved();
+    return output.toBytes();
+  }
+
   Future<KdbxFile> _loadV3(
       KdbxHeader header, ReaderHelper reader, Credentials credentials) async {
 //    _getMasterKeyV3(header, credentials);

lib/src/kdbx_header.dart

@@ -150,7 +150,7 @@ class KdbxHeader {
   }
 
   void _validate() {
-    for (HeaderFields required in _requiredFields(versionMajor)) {
+    for (final required in _requiredFields(versionMajor)) {
       if (fields[required] == null) {
         throw KdbxCorruptedFileException('Missing header $required');
       }
@@ -351,14 +351,14 @@ class KdbxHeader {
       List<TE> fields, T createField(TE field, Uint8List bytes)) sync* {
     while (true) {
       final headerId = reader.readUint8();
-      final int bodySize =
+      final bodySize =
           versionMajor >= 4 ? reader.readUint32() : reader.readUint16();
 //      _logger.fine('Reading header with id $headerId (size: $bodySize)}');
       final bodyBytes = bodySize > 0 ? reader.readBytes(bodySize) : null;
 //      _logger.finer(
 //          'Read header ${fields[headerId]}: ${ByteUtils.toHexList(bodyBytes)}');
       if (headerId > 0) {
-        final TE field = fields[headerId];
+        final field = fields[headerId];
         yield createField(field, bodyBytes);
         /* else {
           if (field == InnerHeaderFields.InnerRandomStreamID) {
@@ -448,7 +448,7 @@ class HashedBlockReader {
       Uint8List.fromList(readNextBlock(reader).expand((x) => x).toList());
 
   static Iterable<Uint8List> readNextBlock(ReaderHelper reader) sync* {
-    int expectedBlockIndex = 0;
+    var expectedBlockIndex = 0;
     while (true) {
       // ignore: unused_local_variable
       final blockIndex = reader.readUint32();
@@ -471,7 +471,7 @@ class HashedBlockReader {
 //  static Uint8List writeBlocks(WriterHelper writer) =>
 
   static void writeBlocks(ReaderHelper reader, WriterHelper writer) {
-    for (int blockIndex = 0;; blockIndex++) {
+    for (var blockIndex = 0;; blockIndex++) {
       final block = reader.readBytesUpTo(BLOCK_SIZE);
       if (block.lengthInBytes == 0) {
         // written all data, write a last empty block.

lib/src/kdbx_object.dart

@@ -2,7 +2,7 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
-import 'package:kdbx/src/kdbx_format.dart';
+import 'package:kdbx/src/kdbx_file.dart';
 import 'package:kdbx/src/kdbx_group.dart';
 import 'package:kdbx/src/kdbx_times.dart';
 import 'package:kdbx/src/kdbx_xml.dart';

lib/src/kdbx_xml.dart

@@ -200,12 +200,12 @@ class XmlUtils {
 
 class DateTimeUtils {
   static String toIso8601StringSeconds(DateTime dateTime) {
-    final String y = _fourDigits(dateTime.year);
+    final y = _fourDigits(dateTime.year);
-    final String m = _twoDigits(dateTime.month);
+    final m = _twoDigits(dateTime.month);
-    final String d = _twoDigits(dateTime.hour);
+    final d = _twoDigits(dateTime.hour);
-    final String h = _twoDigits(dateTime.hour);
+    final h = _twoDigits(dateTime.hour);
-    final String min = _twoDigits(dateTime.minute);
+    final min = _twoDigits(dateTime.minute);
-    final String sec = _twoDigits(dateTime.second);
+    final sec = _twoDigits(dateTime.second);
     return '$y-$m-${d}T$h:$min:${sec}Z';
   }