Switch to new resolver, remove old resolver.

Author: davidmorgan

build/lib/src/library_cycle_graph/phased_reader.dart

@@ -29,4 +29,14 @@ abstract class PhasedReader {
   /// its content. Note that generation might output nothing, in which case an
   /// empty string is returned for its content.
   Future<PhasedValue<String>> readPhased(AssetId id);
+
+  /// Whether [id] is a generated asset that changes between [phase] and
+  /// [comparedToPhase].
+  ///
+  /// Returns `true` iff the generated file is hidden to one of the two phases
+  /// and not hidden to the other. Do not check actual file content or
+  /// generation state.
+  ///
+  /// Returns `false` for all other types of asset, including unknown assets.
+  bool hasChanged(AssetId id, {required int comparedToPhase});
 }

build_resolvers/lib/builder.dart

@@ -4,12 +4,12 @@
 
 import 'dart:async';
 
+import 'package:analyzer/dart/analysis/utilities.dart';
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:build/build.dart';
 import 'package:convert/convert.dart';
 import 'package:crypto/crypto.dart';
 
-import 'src/build_asset_uri_resolver.dart';
-
 const transitiveDigestExtension = '.transitive_digest';
 
 Builder transitiveDigestsBuilder(BuilderOptions _) =>
@@ -64,7 +64,7 @@ https://github.com/dart-lang/build/blob/master/docs/faq.md#unable-to-read-asset-
       byteSink.add((await buildStep.digest(next)).bytes);
 
       // We know this isn't null since we already checked if we can read `next`.
-      final deps = (await dependenciesOf(next, buildStep))!;
+      final deps = _parseDependencies(await buildStep.readAsString(next), next);
 
       // Add all previously unseen deps to the queue.
       for (final dep in deps) {
@@ -83,3 +83,17 @@ https://github.com/dart-lang/build/blob/master/docs/faq.md#unable-to-read-asset-
     '.dart': ['.dart$transitiveDigestExtension'],
   };
 }
+
+const _ignoredSchemes = ['dart', 'dart-ext'];
+
+Iterable<AssetId> _parseDependencies(String content, AssetId from) =>
+    parseString(content: content, throwIfDiagnostics: false).unit.directives
+        .whereType<UriBasedDirective>()
+        .map((directive) => directive.uri.stringValue)
+        // Filter out nulls. uri.stringValue can be null for strings that use
+        // interpolation.
+        .whereType<String>()
+        .where(
+          (uriContent) => !_ignoredSchemes.any(Uri.parse(uriContent).isScheme),
+        )
+        .map((content) => AssetId.resolve(Uri.parse(content), from: from));

build_resolvers/lib/src/analysis_driver.dart

@@ -7,13 +7,12 @@ import 'dart:io';
 import 'package:analyzer/file_system/file_system.dart' show ResourceProvider;
 // ignore: implementation_imports
 import 'package:analyzer/src/clients/build_resolvers/build_resolvers.dart';
-import 'package:build/build.dart';
 import 'package:package_config/package_config.dart' show PackageConfig;
 import 'package:path/path.dart' as p;
 import 'package:pub_semver/pub_semver.dart';
 
+import 'analysis_driver_filesystem.dart';
 import 'analysis_driver_model.dart';
-import 'build_asset_uri_resolver.dart';
 
 /// Builds an [AnalysisDriverForPackageBuild] backed by a summary SDK.
 ///
@@ -55,10 +54,20 @@ Packages _buildAnalyzerPackages(
       // make them match the paths that we give it, so we use the
       // `assetPath` function to create those.
       rootFolder: resourceProvider.getFolder(
-        p.url.normalize(assetPath(AssetId(package.name, ''))),
+        p.url.normalize(
+          AnalysisDriverFilesystem.assetPathFor(
+            package: package.name,
+            path: '',
+          ),
+        ),
       ),
       libFolder: resourceProvider.getFolder(
-        p.url.normalize(assetPath(AssetId(package.name, 'lib'))),
+        p.url.normalize(
+          AnalysisDriverFilesystem.assetPathFor(
+            package: package.name,
+            path: 'lib',
+          ),
+        ),
       ),
     ),
 });

build_resolvers/lib/src/analysis_driver_filesystem.dart

@@ -100,6 +100,10 @@ class AnalysisDriverFilesystem implements UriResolver, ResourceProvider {
   static String assetPath(AssetId assetId) =>
       '/${assetId.package}/${assetId.path}';
 
+  /// Path of the asset with [package] and [path] for the in-memory filesystem.
+  static String assetPathFor({required String package, required String path}) =>
+      '/$package/$path';
+
   /// Attempts to parse [uri] into an [AssetId].
   ///
   /// Handles 'package:' or 'asset:' URIs, as well as 'file:' URIs that have the

build_resolvers/lib/src/analysis_driver_model.dart

@@ -29,6 +29,9 @@ import 'analysis_driver_filesystem.dart';
 /// anywhere; finish it. See `build_asset_uri_resolver.dart` for the current
 /// implementation.
 class AnalysisDriverModel {
+  /// The instance used by the shared `AnalyzerResolvers` instance.
+  static AnalysisDriverModel sharedInstance = AnalysisDriverModel();
+
   /// In-memory filesystem for the analyzer.
   final AnalysisDriverFilesystem filesystem = AnalysisDriverFilesystem();
 
@@ -37,7 +40,7 @@ class AnalysisDriverModel {
 
   /// Assets that have been synced into the in-memory filesystem
   /// [filesystem].
-  final _syncedOntoFilesystem = <AssetId>{};
+  final _syncedOntoFilesystemAtPhase = <AssetId, int>{};
 
   /// Notifies that [step] has completed.
   ///
@@ -49,7 +52,7 @@ class AnalysisDriverModel {
   /// Clear cached information specific to an individual build.
   void reset() {
     _graphLoader.clear();
-    _syncedOntoFilesystem.clear();
+    _syncedOntoFilesystemAtPhase.clear();
   }
 
   /// Attempts to parse [uri] into an [AssetId] and returns it if it is cached.
@@ -86,25 +89,17 @@ class AnalysisDriverModel {
     withDriverResource, {
     required bool transitive,
   }) async {
-    // Immediately take the lock on `driver` so that the whole class state,
-    // is only mutated by one build step at a time.
-    await withDriverResource((driver) async {
-      // TODO(davidmorgan): it looks like this is only ever called with a single
-      // entrypoint, consider doing a breaking release to simplify the API.
-      for (final entrypoint in entrypoints) {
-        await _performResolve(
-          driver,
-          buildStep as BuildStepImpl,
-          entrypoint,
-          withDriverResource,
-          transitive: transitive,
-        );
-      }
-    });
+    for (final entrypoint in entrypoints) {
+      await _performResolve(
+        buildStep as BuildStepImpl,
+        entrypoint,
+        withDriverResource,
+        transitive: transitive,
+      );
+    }
   }
 
   Future<void> _performResolve(
-    AnalysisDriverForPackageBuild driver,
     BuildStepImpl buildStep,
     AssetId entrypoint,
     Future<void> Function(
@@ -113,17 +108,18 @@ class AnalysisDriverModel {
     withDriverResource, {
     required bool transitive,
   }) async {
-    var idsToSyncOntoFilesystem = [entrypoint];
+    Iterable<AssetId> idsToSyncOntoFilesystem = [entrypoint];
     Iterable<AssetId> inputIds = [entrypoint];
 
     // If requested, find transitive imports.
     if (transitive) {
+      // Note: `transitiveDepsOf` can cause loads that cause builds that cause a
+      // recursive `_performResolve` on this same `AnalysisDriver` instance.
       final nodeLoader = AssetDepsLoader(buildStep.phasedReader);
-      idsToSyncOntoFilesystem =
-          (await _graphLoader.transitiveDepsOf(
-            nodeLoader,
-            entrypoint,
-          )).toList();
+      idsToSyncOntoFilesystem = await _graphLoader.transitiveDepsOf(
+        nodeLoader,
+        entrypoint,
+      );
       inputIds = idsToSyncOntoFilesystem;
     }
 
@@ -133,27 +129,45 @@ class AnalysisDriverModel {
       inputs: inputIds,
     );
 
-    // Sync changes onto the "URI resolver", the in-memory filesystem.
-    for (final id in idsToSyncOntoFilesystem) {
-      if (!_syncedOntoFilesystem.add(id)) {
-        continue;
-      }
-      final content =
-          await buildStep.canRead(id) ? await buildStep.readAsString(id) : null;
-      if (content == null) {
-        filesystem.deleteFile(id.asPath);
-      } else {
-        filesystem.writeFile(id.asPath, content);
+    await withDriverResource((driver) async {
+      // Sync changes onto the "URI resolver", the in-memory filesystem.
+      final phase = buildStep.phasedReader.phase;
+      for (final id in idsToSyncOntoFilesystem) {
+        final wasSyncedAt = _syncedOntoFilesystemAtPhase[id];
+        if (wasSyncedAt != null) {
+          // Skip if already synced at this phase.
+          if (wasSyncedAt == phase) {
+            continue;
+          }
+          // Skip if synced at an equivalent other phase.
+          if (!buildStep.phasedReader.hasChanged(
+            id,
+            comparedToPhase: wasSyncedAt,
+          )) {
+            continue;
+          }
+        }
+
+        _syncedOntoFilesystemAtPhase[id] = phase;
+        final content =
+            await buildStep.canRead(id)
+                ? await buildStep.readAsString(id)
+                : null;
+        if (content == null) {
+          filesystem.deleteFile(id.asPath);
+        } else {
+          filesystem.writeFile(id.asPath, content);
+        }
       }
-    }
 
-    // Notify the analyzer of changes and wait for it to update its internal
-    // state.
-    for (final path in filesystem.changedPaths) {
-      driver.changeFile(path);
-    }
-    filesystem.clearChangedPaths();
-    await driver.applyPendingFileChanges();
+      // Notify the analyzer of changes and wait for it to update its internal
+      // state.
+      for (final path in filesystem.changedPaths) {
+        driver.changeFile(path);
+      }
+      filesystem.clearChangedPaths();
+      await driver.applyPendingFileChanges();
+    });
   }
 }