Fasta targets and loaders.

pkg/fasta/lib/src/loader.dart

Index: pkg/fasta/lib/src/loader.dart
diff --git a/pkg/fasta/lib/src/loader.dart b/pkg/fasta/lib/src/loader.dart
new file mode 100644
index 0000000000000000000000000000000000000000..18081ab420bb6fdc2c7282148a75db51da4ca7e3
--- /dev/null
+++ b/pkg/fasta/lib/src/loader.dart
@@ -0,0 +1,132 @@
+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library fasta.loader;
+
+import 'dart:async' show
+    Future;
+
+import 'dart:collection' show
+    Queue;
+
+import 'ast_kind.dart' show
+    AstKind;
+
+import 'builder/builder.dart' show
+    LibraryBuilder;
+
+import 'errors.dart' show
+    InputError,
+    firstSourceUri;
+
+import 'target_implementation.dart' show
+    TargetImplementation;
+
+import 'ticker.dart' show
+    Ticker;
+
+abstract class Loader<L> {
+  final Map<Uri, LibraryBuilder> builders = <Uri, LibraryBuilder>{};
+
+  final Queue<LibraryBuilder> unparsedLibraries = new Queue<LibraryBuilder>();
+
+  final List<L> libraries = <L>[];
+
+  final TargetImplementation target;
+
+  LibraryBuilder coreLibrary;
+
+  LibraryBuilder first;
+
+  int byteCount = 0;
+
+  Uri currentUriForCrashReporting;
+
+  Loader(this.target);
+
+  Ticker get ticker => target.ticker;
+
+  LibraryBuilder read(Uri uri) {
+    firstSourceUri ??= uri;
+    LibraryBuilder builder = builders.putIfAbsent(uri, () {
+      LibraryBuilder library = target.createLibraryBuilder(uri);
+      if (uri.scheme == "dart" && uri.path == "core") {
+        coreLibrary = library;
+      }
+      first ??= library;
+      if (library.loader == this) {
+        unparsedLibraries.addLast(library);
+      }
+      return library;
+    });
+    return builder;
+  }
+
+  void ensureCoreLibrary() {
+    if (coreLibrary == null) {
+      read(Uri.parse("dart:core"));
+      assert(coreLibrary != null);
+    }
+  }
+
+  Future<Null> buildBodies(AstKind astKind) async {
+    assert(coreLibrary != null);
+    for (LibraryBuilder library in builders.values) {
+      currentUriForCrashReporting = library.uri;
+      await buildBody(library, astKind);
+    }
+    currentUriForCrashReporting = null;
+    ticker.log((Duration elapsed, Duration sinceStart) {
+      int libraryCount = builders.length;
+      double ms =
+          elapsed.inMicroseconds / Duration.MICROSECONDS_PER_MILLISECOND;
+      String message = "Built $libraryCount compilation units";
+      print("""
+$sinceStart: $message ($byteCount bytes) in ${format(ms, 3, 0)}ms, that is,
+${format(byteCount / ms, 3, 12)} bytes/ms, and
+${format(ms / libraryCount, 3, 12)} ms/compilation unit.""");
+    });
+  }
+
+  Future<Null> buildOutlines() async {
+    ensureCoreLibrary();
+    while (unparsedLibraries.isNotEmpty) {
+      LibraryBuilder library = unparsedLibraries.removeFirst();
+      currentUriForCrashReporting = library.uri;
+      await buildOutline(library);
+    }
+    currentUriForCrashReporting = null;
+    ticker.log((Duration elapsed, Duration sinceStart) {
+      int libraryCount = builders.length;
+      double ms =
+          elapsed.inMicroseconds / Duration.MICROSECONDS_PER_MILLISECOND;
+      String message = "Built outlines for $libraryCount compilation units";
+      // TODO(ahe): Share this message with [buildBodies]. Also make it easy to
+      // tell the difference between outlines read from a dill file or source
+      // files. Currently, [libraryCount] is wrong for dill files.
+      print("""
+$sinceStart: $message ($byteCount bytes) in ${format(ms, 3, 0)}ms, that is,
+${format(byteCount / ms, 3, 12)} bytes/ms, and
+${format(ms / libraryCount, 3, 12)} ms/compilation unit.""");
+    });
+  }
+
+  Future<Null> buildOutline(LibraryBuilder library);
+
+  Future<Null> buildBody(LibraryBuilder library, AstKind astKind);
+
+  List<InputError> collectCompileTimeErrors() {
+    List<InputError> errors = <InputError>[];
+    for (LibraryBuilder library in builders.values) {
+      if (library.loader == this) {
+        errors.addAll(library.compileTimeErrors);
+      }
+    }
+    return errors;
+  }
+}
+
+String format(double d, int fractionDigits, int width) {
+  return d.toStringAsFixed(fractionDigits).padLeft(width);
+}