Split out AssetTracker, create AssetGraphLoader and BuildPhases. (#3928)

* Move `AssetTracker` to its own file.

* Add `AssetGraphLoader` and `BuildPhases`.

Author: davidmorgan

build_runner/lib/src/daemon/change_providers.dart

@@ -8,7 +8,7 @@ import 'package:build_daemon/change_provider.dart';
 // ignore: implementation_imports
 import 'package:build_runner_core/src/asset_graph/graph.dart';
 // ignore: implementation_imports
-import 'package:build_runner_core/src/generate/build_definition.dart';
+import 'package:build_runner_core/src/generate/asset_tracker.dart';
 import 'package:watcher/watcher.dart' show WatchEvent;
 
 /// Continually updates the [changes] stream as watch events are seen on the

build_runner/lib/src/daemon/daemon_builder.dart

@@ -17,7 +17,7 @@ import 'package:build_runner_core/build_runner_core.dart'
 import 'package:build_runner_core/build_runner_core.dart'
     hide BuildResult, BuildStatus;
 // ignore: implementation_imports
-import 'package:build_runner_core/src/generate/build_definition.dart';
+import 'package:build_runner_core/src/generate/asset_tracker.dart';
 // ignore: implementation_imports
 import 'package:build_runner_core/src/generate/build_series.dart';
 import 'package:stream_transform/stream_transform.dart';

build_runner/test/generate/watch_test.dart

@@ -14,6 +14,7 @@ import 'package:build_runner/src/generate/watch_impl.dart' as watch_impl;
 import 'package:build_runner_core/build_runner_core.dart';
 import 'package:build_runner_core/src/asset_graph/graph.dart';
 import 'package:build_runner_core/src/asset_graph/node.dart';
+import 'package:build_runner_core/src/generate/build_phases.dart';
 import 'package:build_test/src/in_memory_reader_writer.dart';
 import 'package:logging/logging.dart';
 import 'package:path/path.dart' as path;
@@ -354,7 +355,7 @@ void main() {
         );
 
         var expectedGraph = await AssetGraph.build(
-          [],
+          BuildPhases([]),
           <AssetId>{},
           {packageConfigId},
           buildPackageGraph({rootPackage('a'): []}),

build_runner/test/server/asset_handler_test.dart

@@ -10,6 +10,7 @@ import 'package:build_runner/src/server/server.dart';
 import 'package:build_runner_core/build_runner_core.dart';
 import 'package:build_runner_core/src/asset_graph/graph.dart';
 import 'package:build_runner_core/src/asset_graph/node.dart';
+import 'package:build_runner_core/src/generate/build_phases.dart';
 import 'package:build_runner_core/src/generate/options.dart';
 import 'package:build_runner_core/src/package_graph/target_graph.dart';
 import 'package:shelf/shelf.dart';
@@ -23,7 +24,7 @@ void main() {
 
   setUp(() async {
     graph = await AssetGraph.build(
-      [],
+      BuildPhases([]),
       <AssetId>{},
       <AssetId>{},
       buildPackageGraph({rootPackage('a'): []}),
@@ -38,7 +39,7 @@ void main() {
         packageGraph,
         defaultRootPackageSources: defaultRootPackageSources,
       ),
-      [],
+      BuildPhases([]),
       'a',
     );
     handler = AssetHandler(reader, 'a');

build_runner/test/server/serve_handler_test.dart

@@ -15,6 +15,7 @@ import 'package:build_runner/src/server/server.dart';
 import 'package:build_runner_core/build_runner_core.dart';
 import 'package:build_runner_core/src/asset_graph/graph.dart';
 import 'package:build_runner_core/src/asset_graph/node.dart';
+import 'package:build_runner_core/src/generate/build_phases.dart';
 import 'package:build_runner_core/src/generate/options.dart';
 import 'package:build_runner_core/src/generate/performance_tracker.dart';
 import 'package:build_runner_core/src/package_graph/target_graph.dart';
@@ -107,7 +108,7 @@ void main() {
     final packageGraph = buildPackageGraph({rootPackage('a'): []});
     readerWriter = TestReaderWriter(rootPackage: packageGraph.root.name);
     assetGraph = await AssetGraph.build(
-      [],
+      BuildPhases([]),
       <AssetId>{},
       <AssetId>{},
       packageGraph,
@@ -122,7 +123,7 @@ void main() {
             packageGraph,
             defaultRootPackageSources: defaultRootPackageSources,
           ),
-          [],
+          BuildPhases([]),
           'a',
         ),
       ),

build_runner_core/lib/src/asset/finalized_reader.dart

@@ -15,7 +15,7 @@ import '../../build_runner_core.dart';
 import '../asset_graph/graph.dart';
 import '../asset_graph/node.dart';
 import '../asset_graph/optional_output_tracker.dart';
-import '../generate/phase.dart';
+import '../generate/build_phases.dart';
 import '../package_graph/target_graph.dart';
 
 /// A view of the build output.
@@ -30,7 +30,7 @@ class FinalizedReader {
   final TargetGraph _targetGraph;
   OptionalOutputTracker? _optionalOutputTracker;
   final String _rootPackage;
-  final List<BuildPhase> _buildPhases;
+  final BuildPhases _buildPhases;
 
   void reset(Set<String> buildDirs, Set<BuildFilter> buildFilters) {
     _optionalOutputTracker = OptionalOutputTracker(

build_runner_core/lib/src/asset_graph/graph.dart

@@ -11,14 +11,15 @@ import 'package:build/build.dart';
 import 'package:build/experiments.dart' as experiments_zone;
 // ignore: implementation_imports
 import 'package:build/src/internal.dart';
-import 'package:convert/convert.dart';
+import 'package:built_collection/built_collection.dart';
 import 'package:crypto/crypto.dart';
 import 'package:glob/glob.dart';
 import 'package:package_config/package_config.dart';
 import 'package:watcher/watcher.dart';
 
+import '../../build_runner_core.dart';
+import '../generate/build_phases.dart';
 import '../generate/phase.dart';
-import '../package_graph/package_graph.dart';
 import '../util/constants.dart';
 import 'exceptions.dart';
 import 'node.dart';
@@ -41,9 +42,9 @@ class AssetGraph implements GeneratedAssetHider {
 
   /// The Dart language experiments that were enabled when this graph was
   /// originally created from the [build] constructor.
-  final List<String> enabledExperiments;
+  final BuiltList<String> enabledExperiments;
 
-  final Map<String, LanguageVersion?> packageLanguageVersions;
+  final BuiltMap<String, LanguageVersion?> packageLanguageVersions;
 
   AssetGraph._(
     this.buildPhasesDigest,
@@ -57,21 +58,17 @@ class AssetGraph implements GeneratedAssetHider {
       _AssetGraphDeserializer(serializedGraph).deserialize();
 
   static Future<AssetGraph> build(
-    List<BuildPhase> buildPhases,
+    BuildPhases buildPhases,
     Set<AssetId> sources,
     Set<AssetId> internalSources,
     PackageGraph packageGraph,
     AssetReader digestReader,
   ) async {
-    var packageLanguageVersions = {
-      for (var pkg in packageGraph.allPackages.values)
-        pkg.name: pkg.languageVersion,
-    };
     var graph = AssetGraph._(
-      computeBuildPhasesDigest(buildPhases),
+      buildPhases.digest,
       Platform.version,
-      packageLanguageVersions,
-      experiments_zone.enabledExperiments,
+      packageGraph.languageVersions,
+      experiments_zone.enabledExperiments.build(),
     );
     var placeholders = graph._addPlaceHolderNodes(packageGraph);
     graph._addSources(sources);
@@ -191,7 +188,7 @@ class AssetGraph implements GeneratedAssetHider {
   }
 
   /// Adds [AssetNode.builderOptions] for all [buildPhases] to this graph.
-  void _addBuilderOptionsNodes(List<BuildPhase> buildPhases) {
+  void _addBuilderOptionsNodes(BuildPhases buildPhases) {
     for (var phaseNum = 0; phaseNum < buildPhases.length; phaseNum++) {
       var phase = buildPhases[phaseNum];
       if (phase is InBuildPhase) {
@@ -335,7 +332,7 @@ class AssetGraph implements GeneratedAssetHider {
   ///
   /// Returns the list of [AssetId]s that were invalidated.
   Future<Set<AssetId>> updateAndInvalidate(
-    List<BuildPhase> buildPhases,
+    BuildPhases buildPhases,
     Map<AssetId, ChangeType> updates,
     String rootPackage,
     Future Function(AssetId id) delete,
@@ -531,7 +528,7 @@ class AssetGraph implements GeneratedAssetHider {
   /// If [placeholders] is supplied they will be added to [newSources] to create
   /// the full input set.
   Set<AssetId> _addOutputsForSources(
-    List<BuildPhase> buildPhases,
+    BuildPhases buildPhases,
     Set<AssetId> newSources,
     String rootPackage, {
     Set<AssetId>? placeholders,
@@ -570,7 +567,7 @@ class AssetGraph implements GeneratedAssetHider {
     InBuildPhase phase,
     int phaseNum,
     Set<AssetId> allInputs,
-    List<BuildPhase> buildPhases,
+    BuildPhases buildPhases,
     String rootPackage,
   ) {
     var phaseOutputs = <AssetId>{};
@@ -640,7 +637,7 @@ class AssetGraph implements GeneratedAssetHider {
     Iterable<AssetId> outputs,
     int phaseNumber,
     AssetNode builderOptionsNode,
-    List<BuildPhase> buildPhases,
+    BuildPhases buildPhases,
     String rootPackage, {
     required AssetId primaryInput,
     required bool isHidden,
@@ -733,17 +730,35 @@ class AssetGraph implements GeneratedAssetHider {
     }
     return id;
   }
-}
 
-/// Computes a [Digest] for [buildPhases] which can be used to compare one set
-/// of [BuildPhase]s against another.
-Digest computeBuildPhasesDigest(Iterable<BuildPhase> buildPhases) {
-  var digestSink = AccumulatorSink<Digest>();
-  md5.startChunkedConversion(digestSink)
-    ..add(buildPhases.map((phase) => phase.identity).toList())
-    ..close();
-  assert(digestSink.events.length == 1);
-  return digestSink.events.first;
+  /// Deletes outputs that were written to the source tree.
+  ///
+  /// Returns the assets that were deleted.
+  Future<Iterable<AssetId>> deleteOutputs(
+    PackageGraph packageGraph,
+    RunnerAssetWriter writer,
+  ) async {
+    var deletedSources = <AssetId>[];
+    // Delete all the non-hidden outputs.
+    for (final id in outputs) {
+      var node = get(id)!;
+      final nodeConfiguration = node.generatedNodeConfiguration!;
+      final nodeState = node.generatedNodeState!;
+      if (nodeState.wasOutput && !nodeConfiguration.isHidden) {
+        var idToDelete = id;
+        // If the package no longer exists, then the user must have
+        // renamed the root package.
+        //
+        // In that case we change `idToDelete` to be in the root package.
+        if (packageGraph[id.package] == null) {
+          idToDelete = AssetId(packageGraph.root.name, id.path);
+        }
+        deletedSources.add(idToDelete);
+        await writer.delete(idToDelete);
+      }
+    }
+    return deletedSources;
+  }
 }
 
 Digest computeBuilderOptionsDigest(BuilderOptions options) =>