Revert "Add API for discovering assets (#118410)" (#119273)

This reverts commit 2b8f2d0.

Author: christopherfujino

dev/benchmarks/microbenchmarks/lib/foundation/decode_and_parse_asset_manifest.dart

@@ -2,7 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:flutter/services.dart' show AssetManifest, PlatformAssetBundle, rootBundle;
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart' show PlatformAssetBundle;
 import 'package:flutter/widgets.dart';
 
 import '../common.dart';
@@ -15,12 +18,16 @@ void main() async {
   final BenchmarkResultPrinter printer = BenchmarkResultPrinter();
   WidgetsFlutterBinding.ensureInitialized();
   final Stopwatch watch = Stopwatch();
-  final PlatformAssetBundle bundle = rootBundle as PlatformAssetBundle;
+  final PlatformAssetBundle bundle = PlatformAssetBundle();
 
+  final ByteData assetManifestBytes = await bundle.load('money_asset_manifest.json');
   watch.start();
   for (int i = 0; i < _kNumIterations; i++) {
-    await AssetManifest.loadFromAssetBundle(bundle);
     bundle.clear();
+    final String json = utf8.decode(assetManifestBytes.buffer.asUint8List());
+    // This is a test, so we don't need to worry about this rule.
+    // ignore: invalid_use_of_visible_for_testing_member
+    await AssetImage.manifestParser(json);
   }
   watch.stop();
 

packages/flutter/lib/services.dart

@@ -11,7 +11,6 @@
 library services;
 
 export 'src/services/asset_bundle.dart';
-export 'src/services/asset_manifest.dart';
 export 'src/services/autofill.dart';
 export 'src/services/binary_messenger.dart';
 export 'src/services/binding.dart';

packages/flutter/lib/src/services/asset_bundle.dart

@@ -96,22 +96,12 @@ abstract class AssetBundle {
   }
 
   /// Retrieve a string from the asset bundle, parse it with the given function,
-  /// and return that function's result.
+  /// and return the function's result.
   ///
   /// Implementations may cache the result, so a particular key should only be
   /// used with one parser for the lifetime of the asset bundle.
   Future<T> loadStructuredData<T>(String key, Future<T> Function(String value) parser);
 
-  /// Retrieve [ByteData] from the asset bundle, parse it with the given function,
-  /// and return that function's result.
-  ///
-  /// Implementations may cache the result, so a particular key should only be
-  /// used with one parser for the lifetime of the asset bundle.
-  Future<T> loadStructuredBinaryData<T>(String key, FutureOr<T> Function(ByteData data) parser) async {
-    final ByteData data = await load(key);
-    return parser(data);
-  }
-
   /// If this is a caching asset bundle, and the given key describes a cached
   /// asset, then evict the asset from the cache so that the next time it is
   /// loaded, the cache will be reread from the asset bundle.
@@ -164,16 +154,6 @@ class NetworkAssetBundle extends AssetBundle {
     return parser(await loadString(key));
   }
 
-  /// Retrieve [ByteData] from the asset bundle, parse it with the given function,
-  /// and return the function's result.
-  ///
-  /// The result is not cached. The parser is run each time the resource is
-  /// fetched.
-  @override
-  Future<T> loadStructuredBinaryData<T>(String key, FutureOr<T> Function(ByteData data) parser) async {
-    return parser(await load(key));
-  }
-
   // TODO(ianh): Once the underlying network logic learns about caching, we
   // should implement evict().
 
@@ -193,7 +173,6 @@ abstract class CachingAssetBundle extends AssetBundle {
   // TODO(ianh): Replace this with an intelligent cache, see https://github.com/flutter/flutter/issues/3568
   final Map<String, Future<String>> _stringCache = <String, Future<String>>{};
   final Map<String, Future<dynamic>> _structuredDataCache = <String, Future<dynamic>>{};
-  final Map<String, Future<dynamic>> _structuredBinaryDataCache = <String, Future<dynamic>>{};
 
   @override
   Future<String> loadString(String key, { bool cache = true }) {
@@ -242,66 +221,16 @@ abstract class CachingAssetBundle extends AssetBundle {
     return completer.future;
   }
 
-  /// Retrieve bytedata from the asset bundle, parse it with the given function,
-  /// and return the function's result.
-  ///
-  /// The result of parsing the bytedata is cached (the bytedata itself is not).
-  /// For any given `key`, the `parser` is only run the first time.
-  ///
-  /// Once the value has been parsed, the future returned by this function for
-  /// subsequent calls will be a [SynchronousFuture], which resolves its
-  /// callback synchronously.
-  @override
-  Future<T> loadStructuredBinaryData<T>(String key, FutureOr<T> Function(ByteData data) parser) {
-    if (_structuredBinaryDataCache.containsKey(key)) {
-      return _structuredBinaryDataCache[key]! as Future<T>;
-    }
-
-    // load can return a SynchronousFuture in certain cases, like in the
-    // flutter_test framework. So, we need to support both async and sync flows.
-    Completer<T>? completer; // For async flow.
-    SynchronousFuture<T>? result; // For sync flow.
-
-    load(key)
-      .then<T>(parser)
-      .then<void>((T value) {
-        result = SynchronousFuture<T>(value);
-        if (completer != null) {
-          // The load and parse operation ran asynchronously. We already returned
-          // from the loadStructuredBinaryData function and therefore the caller
-          // was given the future of the completer.
-          completer.complete(value);
-        }
-      }, onError: (Object error, StackTrace stack) {
-        completer!.completeError(error, stack);
-      });
-
-    if (result != null) {
-      // The above code ran synchronously. We can synchronously return the result.
-      _structuredBinaryDataCache[key] = result!;
-      return result!;
-    }
-
-    // Since the above code is being run asynchronously and thus hasn't run its
-    // `then` handler yet, we'll return a completer that will be completed
-    // when the handler does run.
-    completer = Completer<T>();
-    _structuredBinaryDataCache[key] = completer.future;
-    return completer.future;
-  }
-
   @override
   void evict(String key) {
     _stringCache.remove(key);
     _structuredDataCache.remove(key);
-    _structuredBinaryDataCache.remove(key);
   }
 
   @override
   void clear() {
     _stringCache.clear();
     _structuredDataCache.clear();
-    _structuredBinaryDataCache.clear();
   }
 
   @override
@@ -343,7 +272,7 @@ class PlatformAssetBundle extends CachingAssetBundle {
     bool debugUsePlatformChannel = false;
     assert(() {
       // dart:io is safe to use here since we early return for web
-      // above. If that code is changed, this needs to be guarded on
+      // above. If that code is changed, this needs to be gaurded on
       // web presence. Override how assets are loaded in tests so that
       // the old loader behavior that allows tests to load assets from
       // the current package using the package prefix.