Drop global variable hack

Add TemplatePlaceholderBuilder which only creates a `.ng_placeholder` Replace the collection of input assets in a global variable with a check for the placeholder file. This also removes the last usages of the old "transformer" internally, so we no longer generate .ng_meta.json and .ng_summary.json, both reducing the number of files per target by 1 and also improving the speed of compiles. Closes #390. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=158060754
angulardart · Jun 5, 2017 · a0db89e · a0db89e
1 parent 9201a89
commit a0db89e
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Showing 9 changed files with 48 additions and 32 deletions.
diff --git a/lib/src/source_gen/source_gen.dart b/lib/src/source_gen/source_gen.dart
@@ -6,6 +6,7 @@ import 'package:source_gen/source_gen.dart';
 import 'template_compiler/generator.dart';
 import 'template_compiler/generator_options.dart';
 
+export 'template_compiler/generator.dart' show TemplatePlaceholderBuilder;
 export 'template_compiler/generator_options.dart';
 
 Builder createSourceGenTemplateCompiler(GeneratorOptions options) =>

diff --git a/lib/src/source_gen/template_compiler/generator.dart b/lib/src/source_gen/template_compiler/generator.dart
@@ -28,14 +28,6 @@ class TemplateGenerator extends Generator {
 
   @override
   Future<String> generate(Element element, BuildStep buildStep) async {
-    // Because buildStep.hasInput() does not currently work as needed, we
-    // instead track the inputs ourselves. Thus, we await for all of the inputs
-    // to be collected, before continuing. This only works because of
-    // implementation details in package:build which will probably change, so it
-    // is recommended that you do not copy this.
-    assets.add(buildStep.inputId);
-    await new Future(() {});
-
     if (element is! LibraryElement) return null;
     return runZoned(() async {
       var config = new CompilerConfig(
@@ -44,7 +36,7 @@ class TemplateGenerator extends Generator {
           useLegacyStyleEncapsulation: _options.useLegacyStyleEncapsulation,
           profileType: codegenModeToProfileType(_options.codegenMode));
       var outputs = await processTemplates(element, buildStep, config,
-          collectAssets: _options.collectAssets);
+          usePlaceholder: _options.usePlaceholder);
       if (outputs == null) return _emptyNgDepsContents;
       return buildGeneratedCode(
         outputs,
@@ -64,3 +56,21 @@ class TemplateGenerator extends Generator {
 
 final String _emptyNgDepsContents = prettyToSource(
     new MethodBuilder.returnVoid('initReflector').buildTopLevelAst());
+
+/// Generates an empty `.ng_placeholder` file which is used as a signal to later
+/// builders which files will eventually get `.template.dart` generated.
+class TemplatePlaceholderBuilder implements Builder {
+  const TemplatePlaceholderBuilder();
+
+  @override
+  final buildExtensions = const {
+    '.dart': const ['.ng_placeholder']
+  };
+
+  @override
+  Future build(BuildStep buildStep) {
+    buildStep.writeAsString(
+        buildStep.inputId.changeExtension('.ng_placeholder'), '');
+    return new Future.value(null);
+  }
+}
diff --git a/lib/src/source_gen/template_compiler/generator_options.dart b/lib/src/source_gen/template_compiler/generator_options.dart
@@ -23,18 +23,18 @@ class GeneratorOptions {
   /// * polyfill-unscoped-rule
   final bool useLegacyStyleEncapsulation;
 
-  /// Whether to use the global set of visible assets instead of
-  /// buildStep.hasInput().
+  /// Whether to use the .ng_placeholder file instead of just the .dart file for
+  /// checks to buildStep.hasInput().
   ///
   /// For bazel workspaces, this should be [true] (default), since
   /// buildStep.hasInput() doesn't work in all cases. In other workspaces, like
   /// with build_runner, this should be [false].
-  final bool collectAssets;
+  final bool usePlaceholder;
 
   GeneratorOptions({
     this.reflectPropertiesAsAttributes: false,
     this.codegenMode: '',
     this.useLegacyStyleEncapsulation: false,
-    this.collectAssets: true,
+    this.usePlaceholder: true,
   });
 }
diff --git a/lib/src/source_gen/template_compiler/ng_deps_visitor.dart b/lib/src/source_gen/template_compiler/ng_deps_visitor.dart
@@ -28,7 +28,7 @@ import 'compile_metadata.dart';
 /// system) are required.
 Future<NgDepsModel> resolveNgDepsFor(
   LibraryElement library, {
-  @required Future<bool> hasInput(String uri),
+  @required FutureOr<bool> hasInput(String uri),
   @required bool isLibrary(String uri),
 }) async {
   // Visit and find all 'reflectables'.

diff --git a/lib/src/source_gen/template_compiler/template_processor.dart b/lib/src/source_gen/template_compiler/template_processor.dart
@@ -11,16 +11,9 @@ import 'find_components.dart';
 import 'ng_deps_visitor.dart';
 import 'template_compiler_outputs.dart';
 
-// Because buildStep.canRead() does not currently work as needed, we instead
-// track the inputs ourselves. Thus, we await for all of the inputs to be
-// collected, before continuing. This only works because of implementation
-// details in package:build which will probably change, so it is recommended
-// that you do not copy this.
-final Set<AssetId> assets = new Set();
-
 Future<TemplateCompilerOutputs> processTemplates(
     LibraryElement element, BuildStep buildStep, CompilerConfig config,
-    {bool collectAssets: true}) async {
+    {bool usePlaceholder: true}) async {
   final templateCompiler = createTemplateCompiler(buildStep, config);
   final resolver = await buildStep.resolver;
   final ngDepsModel = await logElapsedAsync(
@@ -34,10 +27,16 @@ Future<TemplateCompilerOutputs> processTemplates(
         // a.dart, and a.dart imports b.dart, we can assume that there will be
         // a generated b.template.dart that we need to import/initReflector().
         hasInput: (uri) async {
-          final asset = new AssetId.resolve(uri, from: buildStep.inputId);
-          return collectAssets
-              ? assets.contains(asset)
-              : await buildStep.canRead(asset);
+          if (usePlaceholder) {
+            final placeholder = ''
+                '${uri.substring(0, uri.length - '.dart'.length)}'
+                '.ng_placeholder';
+            return await buildStep.canRead(
+                new AssetId.resolve(placeholder, from: buildStep.inputId));
+          } else {
+            return await buildStep
+                .canRead(new AssetId.resolve(uri, from: buildStep.inputId));
+          }
         },
         // For a given import or export directive, return whether a generated
         // .template.dart file already exists. If it does we will need to link

diff --git a/lib/src/transform/common/names.dart b/lib/src/transform/common/names.dart
@@ -24,6 +24,7 @@ const ALL_EXTENSIONS = const [
   META_EXTENSION,
   SUMMARY_META_EXTENSION,
   TEMPLATE_EXTENSION,
+  '.ng_placeholder',
   '.dart'
 ];
 
@@ -40,6 +41,7 @@ bool isGenerated(String uri) {
     SHIMMED_STYLESHEET_EXTENSION,
     SUMMARY_META_EXTENSION,
     TEMPLATE_EXTENSION,
+    '.ng_placeholder',
   ].any((ext) => uri.endsWith(ext));
 }
 

diff --git a/lib/src/transform/transformer.dart b/lib/src/transform/transformer.dart
@@ -38,13 +38,16 @@ class AngularTransformerGroup extends TransformerGroup {
             'using the Dart analyzer. See https://goo.gl/68VhMa for details.');
       }
       phases = [
+        [new BuilderTransformer(new TemplatePlaceholderBuilder())],
+        [new ReflectionRemover(options)],
         [
+          new DeferredRewriter(),
+          new StylesheetCompiler(options),
           new BuilderTransformer(createSourceGenTemplateCompiler(
               new GeneratorOptions(
                   codegenMode: options.codegenMode,
                   useLegacyStyleEncapsulation:
-                      options.useLegacyStyleEncapsulation,
-                  collectAssets: false)))
+                      options.useLegacyStyleEncapsulation)))
         ]
       ];
     } else if (options.inlineViews) {

diff --git a/lib/transform/codegen.dart b/lib/transform/codegen.dart
@@ -46,13 +46,14 @@ class CodegenTransformer extends TransformerGroup {
       }
       phases = [
         [new AssetConsumer()],
+        [new BuilderTransformer(new TemplatePlaceholderBuilder())],
         [
+          new StylesheetCompiler(options),
           new BuilderTransformer(createSourceGenTemplateCompiler(
               new GeneratorOptions(
                   codegenMode: options.codegenMode,
                   useLegacyStyleEncapsulation:
-                      options.useLegacyStyleEncapsulation,
-                  collectAssets: false)))
+                      options.useLegacyStyleEncapsulation)))
         ]
       ];
     } else if (options.inlineViews) {

diff --git a/test/source_gen/template_compiler/generate.dart b/test/source_gen/template_compiler/generate.dart
@@ -28,7 +28,7 @@ Future main(List<String> args) async {
       ..addAction(
           new GeneratorBuilder([
             new TemplateGenerator(new GeneratorOptions(
-                codegenMode: 'release', collectAssets: false))
+                codegenMode: 'release', usePlaceholder: false))
           ],
               generatedExtension: updateGoldens
                   ? '.template_release.golden'
@@ -38,7 +38,7 @@ Future main(List<String> args) async {
       ..addAction(
           new GeneratorBuilder([
             new TemplateGenerator(new GeneratorOptions(
-                codegenMode: 'debug', collectAssets: false))
+                codegenMode: 'debug', usePlaceholder: false))
           ],
               generatedExtension: updateGoldens
                   ? '.template_debug.golden'