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2026-08-26 18:15:54 +08:00
parent 54d343b739
commit a4568d8a55
79 changed files with 11264 additions and 560 deletions
@@ -0,0 +1,285 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:crypto/crypto.dart' show sha256;
+import 'package:flutter/foundation.dart';
+import 'package:http/http.dart' as http;
+import 'package:path_provider/path_provider.dart';
+
+import '../config/app_config.dart';
+
+/// 模型目录条目（GET /api/v1/app/update 响应 data.models[]）。
+/// 服务器发布模型后随版本检查一同下发，App 按目录逐数据集下载/更新。
+class ModelCatalogItem {
+  final int datasetId;
+  final String datasetName;
+  final String version;
+  final List<String> labels;
+  final int sizeBytes;
+  final String sha256;
+  final String downloadUrl;
+
+  const ModelCatalogItem({
+    required this.datasetId,
+    required this.datasetName,
+    required this.version,
+    required this.labels,
+    required this.sizeBytes,
+    required this.sha256,
+    required this.downloadUrl,
+  });
+
+  factory ModelCatalogItem.fromJson(Map<String, dynamic> j) =>
+      ModelCatalogItem(
+        datasetId: (j['datasetId'] as num?)?.toInt() ?? 0,
+        datasetName: j['datasetName'] as String? ?? '',
+        version: j['version'] as String? ?? '',
+        labels: (j['labels'] as List? ?? const [])
+            .map((e) => e.toString())
+            .toList(),
+        sizeBytes: (j['sizeBytes'] as num?)?.toInt() ?? 0,
+        sha256: j['sha256'] as String? ?? '',
+        downloadUrl: j['downloadUrl'] as String? ?? '',
+      );
+}
+
+/// 已就绪模型（字节 + 标签，供推理 worker 加载；含内置资产回退模型）
+class ModelBundle {
+  final int datasetId;
+  final String datasetName;
+  final String version;
+  final List<String> labels;
+  final Uint8List bytes;
+
+  const ModelBundle({
+    required this.datasetId,
+    required this.datasetName,
+    required this.version,
+    required this.labels,
+    required this.bytes,
+  });
+}
+
+/// 模型热更新管理：启动时拉取模型目录（随 /app/update 公开接口下发，无需登录态），
+/// 按需下载/校验/持久化各数据集模型，供相机页多模型并行推理。
+///
+/// 存储：应用私有目录 `models/<datasetId>/`（model.tflite + labels.json + meta.json），
+/// meta 记录 {version, sha256}，服务器发布新版本时按版本+摘要重下，不重复下载旧模型。
+class ModelManager extends ChangeNotifier {
+  static final ModelManager instance = ModelManager._();
+
+  final String baseUrl;
+  final http.Client _client;
+  final Future<Directory> Function()? _rootDirOverride;
+
+  List<ModelBundle> _models = const [];
+  bool _ready = false;
+  bool _refreshing = false;
+  String? _error;
+  Future<void>? _inFlight;
+
+  ModelManager._({String? baseUrl, http.Client? client})
+      : this(baseUrl: baseUrl, client: client);
+
+  /// 可注入 baseUrl / client / 存储根目录（单测用）
+  @visibleForTesting
+  ModelManager({
+    String? baseUrl,
+    http.Client? client,
+    Future<Directory> Function()? rootDir,
+  })  : baseUrl = baseUrl ?? AppConfig.apiBaseUrl,
+        _client = client ?? http.Client(),
+        _rootDirOverride = rootDir;
+
+  /// 已就绪模型列表（空 = 无服务器模型，回退内置资产）
+  List<ModelBundle> get models => _models;
+
+  /// 是否成功拉取过目录（即使下载失败也为 true，用于区分"从未联网"与"目录为空"）
+  bool get ready => _ready;
+
+  /// 最近一次同步的错误信息（下载失败/校验失败等；目录为空不算错误）
+  String? get error => _error;
+
+  bool get refreshing => _refreshing;
+
+  /// 模型名摘要（诊断行展示）：内置 / 数据集名×n
+  String get modelsLabel {
+    if (_models.isEmpty) return '内置';
+    return _models.map((m) => m.datasetName).join(',');
+  }
+
+  /// 拉取目录并同步本地模型；并发调用共享同一进行中的刷新。
+  Future<void> refresh() {
+    if (_refreshing) return _inFlight ?? Future.value();
+    _refreshing = true;
+    _inFlight = _doRefresh().whenComplete(() {
+      _refreshing = false;
+      _inFlight = null;
+      notifyListeners();
+    });
+    return _inFlight!;
+  }
+
+  Future<void> _doRefresh() async {
+    try {
+      final res = await _client
+          .get(Uri.parse('$baseUrl/api/v1/app/update'))
+          .timeout(const Duration(seconds: 8));
+      // 服务器 Content-Type 无 charset，http 包默认按 latin1 解码会乱码 → 显式 utf8
+      final body =
+          jsonDecode(utf8.decode(res.bodyBytes)) as Map<String, dynamic>;
+      final data = body['data'] as Map<String, dynamic>? ?? const {};
+      final list = data['models'] as List? ?? const [];
+      final catalog = list
+          .map((e) => ModelCatalogItem.fromJson(e as Map<String, dynamic>))
+          .toList();
+
+      final failed = <String>[];
+      for (final item in catalog) {
+        if (!await _ensureLocal(item)) failed.add(item.datasetName);
+      }
+      await _prune(catalog);
+      _models = await _loadBundles(catalog);
+      _ready = true;
+      _error = failed.isEmpty
+          ? null
+          : '模型下载失败:${failed.join(',')}（重试旧模型或稍后再试）';
+    } catch (e) {
+      if (!_ready) _error = '模型目录拉取失败:$e';
+      // 已就绪过则保留旧模型，不覆盖 error（下载级错误优先展示）
+    }
+  }
+
+  /// 保证目录条目在本地可用：meta 匹配且文件在 → 跳过；否则下载并校验 sha256。
+  Future<bool> _ensureLocal(ModelCatalogItem item) async {
+    final dir = await _modelDir(item.datasetId);
+    try {
+      final meta = await _readMeta(dir);
+      final file = File('${dir.path}/model.tflite');
+      if (meta != null &&
+          meta['version'] == item.version &&
+          meta['sha256'] == item.sha256 &&
+          await file.exists()) {
+        return true;
+      }
+      // 版本更新或文件缺失：下载校验（失败重试一次）
+      for (var attempt = 0; attempt < 2; attempt++) {
+        final ok = await _downloadAndVerify(item, dir, file);
+        if (ok) return true;
+        await file.delete().catchError((_) => file);
+        await File('${dir.path}/model.tflite.part')
+            .delete()
+            .catchError((_) => file);
+      }
+      debugPrint('[ModelManager] 下载失败: ${item.datasetName} ${item.version}');
+      return false;
+    } catch (e) {
+      debugPrint('[ModelManager] _ensureLocal ${item.datasetName}: $e');
+      return false;
+    }
+  }
+
+  Future<bool> _downloadAndVerify(
+      ModelCatalogItem item, Directory dir, File file) async {
+    final part = File('${file.path}.part');
+    final sink = part.openWrite();
+    try {
+      final res = await _client
+          .send(http.Request('GET', Uri.parse('$baseUrl${item.downloadUrl}')))
+          .timeout(const Duration(minutes: 3));
+      if (res.statusCode != 200) return false;
+      await res.stream.pipe(sink);
+      await sink.close();
+      final bytes = await part.readAsBytes();
+      final hex = sha256.convert(bytes).toString();
+      if (item.sha256.isNotEmpty && hex != item.sha256) {
+        debugPrint('[ModelManager] sha256 不匹配: ${item.datasetName} '
+            'want=${item.sha256} got=$hex');
+        return false;
+      }
+      await part.rename(file.path);
+      await dir.create(recursive: true);
+      await File('${dir.path}/labels.json')
+          .writeAsString(jsonEncode(item.labels));
+      await File('${dir.path}/meta.json').writeAsString(jsonEncode({
+        'version': item.version,
+        'sha256': item.sha256,
+      }));
+      debugPrint('[ModelManager] 已下载 ${item.datasetName} '
+          '${bytes.length}B -> ${file.path}');
+      return true;
+    } catch (e) {
+      await sink.close().catchError((_) {});
+      debugPrint('[ModelManager] 下载异常 ${item.datasetName}: $e');
+      return false;
+    }
+  }
+
+  /// 清理服务器目录中已下线的数据集模型（不再发布则删本地）
+  Future<void> _prune(List<ModelCatalogItem> catalog) async {
+    final root = await _rootDir();
+    if (!await root.exists()) return;
+    final keep = catalog.map((c) => '${c.datasetId}').toSet();
+    await for (final e in root.list()) {
+      if (e is Directory) {
+        // 目录 URI 末尾带 '/'，pathSegments 末位为空串 → 过滤后取目录名
+        final name = e.uri.pathSegments.where((s) => s.isNotEmpty).last;
+        if (!keep.contains(name)) {
+          await e.delete(recursive: true).catchError((_) => e);
+        }
+      }
+    }
+  }
+
+  Future<List<ModelBundle>> _loadBundles(
+      List<ModelCatalogItem> catalog) async {
+    final bundles = <ModelBundle>[];
+    for (final item in catalog) {
+      try {
+        final dir = await _modelDir(item.datasetId);
+        final file = File('${dir.path}/model.tflite');
+        if (!await file.exists()) continue;
+        final labels = await File('${dir.path}/labels.json').exists()
+            ? (jsonDecode(
+                    await File('${dir.path}/labels.json').readAsString())
+                as List)
+                .map((e) => e.toString())
+                .toList()
+            : item.labels;
+        bundles.add(ModelBundle(
+          datasetId: item.datasetId,
+          datasetName: item.datasetName,
+          version: item.version,
+          labels: labels,
+          bytes: await file.readAsBytes(),
+        ));
+      } catch (e) {
+        debugPrint('[ModelManager] 读取 ${item.datasetName} 失败: $e');
+      }
+    }
+    return bundles;
+  }
+
+  Future<Map<String, dynamic>?> _readMeta(Directory dir) async {
+    final f = File('${dir.path}/meta.json');
+    if (!await f.exists()) return null;
+    try {
+      return jsonDecode(await f.readAsString()) as Map<String, dynamic>;
+    } catch (_) {
+      return null;
+    }
+  }
+
+  Future<Directory> _rootDir() async {
+    if (_rootDirOverride != null) return _rootDirOverride();
+    final support = await getApplicationSupportDirectory();
+    return Directory('${support.path}/models');
+  }
+
+  Future<Directory> _modelDir(int datasetId) async {
+    final root = await _rootDir();
+    final dir = Directory('${root.path}/$datasetId');
+    await dir.create(recursive: true);
+    return dir;
+  }
+}