Move package summary reading code into analyzer.

pkg/analyzer/lib/src/summary/package_bundle_reader.dart

Index: pkg/analyzer/lib/src/summary/package_bundle_reader.dart
diff --git a/pkg/analyzer/lib/src/summary/package_bundle_reader.dart b/pkg/analyzer/lib/src/summary/package_bundle_reader.dart
new file mode 100644
index 0000000000000000000000000000000000000000..a58bfd3757f9c02e09ded69f10270924a0bc7311
--- /dev/null
+++ b/pkg/analyzer/lib/src/summary/package_bundle_reader.dart
@@ -0,0 +1,224 @@
+import 'dart:io' as io;
+
+import 'package:analyzer/dart/element/element.dart';
+import 'package:analyzer/src/context/cache.dart';
+import 'package:analyzer/src/context/context.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/resolver.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/summary/idl.dart';
+import 'package:analyzer/src/summary/resynthesize.dart';
+import 'package:analyzer/src/summary/summary_sdk.dart';
+import 'package:analyzer/src/task/dart.dart';
+import 'package:analyzer/task/dart.dart';
+import 'package:analyzer/task/model.dart';
+import 'package:path/path.dart' as pathos;
+
+/**
+ * If [uri] has the `package` scheme in form of `package:pkg/file.dart`,
+ * return the `pkg` name.  Otherwise return `null`.
+ */
+String _getPackageName(Uri uri) {
+  if (uri.scheme != 'package') {
+    return null;
+  }
+  String path = uri.path;
+  int index = path.indexOf('/');
+  if (index == -1) {
+    return null;
+  }
+  return path.substring(0, index);
+}
+
+/**
+ * The [ResultProvider] that provides results from input package summaries.
+ */
+class InputPackagesResultProvider extends ResultProvider {
+  final InternalAnalysisContext _context;
+  final Map<String, String> _packageSummaryInputs;
+
+  _FileBasedSummaryResynthesizer _resynthesizer;
+  SummaryResultProvider _sdkProvider;
+
+  InputPackagesResultProvider(this._context, this._packageSummaryInputs) {
+    InternalAnalysisContext sdkContext = _context.sourceFactory.dartSdk.context;
+    _sdkProvider = sdkContext.resultProvider;
+    // Set the type provider to prevent the context from computing it.
+    _context.typeProvider = sdkContext.typeProvider;
+    // Create a chained resynthesizer.
+    _resynthesizer = new _FileBasedSummaryResynthesizer(
+        _sdkProvider.resynthesizer,
+        _context,
+        _context.typeProvider,
+        _context.sourceFactory,
+        _context.analysisOptions.strongMode,
+        _packageSummaryInputs.values.toList());
+  }
+
+  @override
+  bool compute(CacheEntry entry, ResultDescriptor result) {
+    if (_sdkProvider.compute(entry, result)) {
+      return true;
+    }
+    AnalysisTarget target = entry.target;
+    // Only library results are supported for now.
+    if (target is Source) {
+      Uri uri = target.uri;
+      // We know how to server results to input packages.
+      String sourcePackageName = _getPackageName(uri);
+      if (!_packageSummaryInputs.containsKey(sourcePackageName)) {
+        return false;
+      }
+      // Provide known results.
+      String uriString = uri.toString();
+      if (result == LIBRARY_ELEMENT1 ||
+          result == LIBRARY_ELEMENT2 ||
+          result == LIBRARY_ELEMENT3 ||
+          result == LIBRARY_ELEMENT4 ||
+          result == LIBRARY_ELEMENT5 ||
+          result == LIBRARY_ELEMENT6 ||
+          result == LIBRARY_ELEMENT7 ||
+          result == LIBRARY_ELEMENT8 ||
+          result == LIBRARY_ELEMENT ||
+          false) {
+        LibraryElement libraryElement =
+            _resynthesizer.getLibraryElement(uriString);
+        entry.setValue(result, libraryElement, TargetedResult.EMPTY_LIST);
+        return true;
+      } else if (result == READY_LIBRARY_ELEMENT2 ||
+          result == READY_LIBRARY_ELEMENT5 ||
+          result == READY_LIBRARY_ELEMENT6) {
+        entry.setValue(result, true, TargetedResult.EMPTY_LIST);
+        return true;
+      } else if (result == SOURCE_KIND) {
+        if (_resynthesizer.linkedMap.containsKey(uriString)) {
+          entry.setValue(result, SourceKind.LIBRARY, TargetedResult.EMPTY_LIST);
+          return true;
+        }
+        if (_resynthesizer.unlinkedMap.containsKey(uriString)) {
+          entry.setValue(result, SourceKind.PART, TargetedResult.EMPTY_LIST);
+          return true;
+        }
+        return false;
+      }
+    }
+    return false;
+  }
+}
+
+/**
+ * The [UriResolver] that knows about sources that are parts of packages which
+ * are served from their summaries.
+ */
+class InSummaryPackageUriResolver extends UriResolver {
+  final Map<String, String> _packageSummaryInputs;
+
+  InSummaryPackageUriResolver(this._packageSummaryInputs);
+
+  @override
+  Source resolveAbsolute(Uri uri, [Uri actualUri]) {
+    actualUri ??= uri;
+    String packageName = _getPackageName(actualUri);
+    if (_packageSummaryInputs.containsKey(packageName)) {
+      return new _InSummarySource(actualUri);
+    }
+    return null;
+  }
+}
+
+/**
+ * A concrete resynthesizer that serves summaries from given file paths.
+ */
+class _FileBasedSummaryResynthesizer extends SummaryResynthesizer {
+  final Map<String, UnlinkedUnit> unlinkedMap = <String, UnlinkedUnit>{};
+  final Map<String, LinkedLibrary> linkedMap = <String, LinkedLibrary>{};
+
+  _FileBasedSummaryResynthesizer(
+      SummaryResynthesizer parent,
+      AnalysisContext context,
+      TypeProvider typeProvider,
+      SourceFactory sourceFactory,
+      bool strongMode,
+      List<String> summaryPaths)
+      : super(parent, context, typeProvider, sourceFactory, strongMode) {
+    summaryPaths.forEach(_fillMaps);
+  }
+
+  @override
+  LinkedLibrary getLinkedSummary(String uri) {
+    return linkedMap[uri];
+  }
+
+  @override
+  UnlinkedUnit getUnlinkedSummary(String uri) {
+    return unlinkedMap[uri];
+  }
+
+  @override
+  bool hasLibrarySummary(String uri) {
+    return linkedMap.containsKey(uri);
+  }
+
+  void _fillMaps(String path) {
+    io.File file = new io.File(path);
+    List<int> buffer = file.readAsBytesSync();
+    PackageBundle bundle = new PackageBundle.fromBuffer(buffer);
+    for (int i = 0; i < bundle.unlinkedUnitUris.length; i++) {
+      unlinkedMap[bundle.unlinkedUnitUris[i]] = bundle.unlinkedUnits[i];
+    }
+    for (int i = 0; i < bundle.linkedLibraryUris.length; i++) {
+      linkedMap[bundle.linkedLibraryUris[i]] = bundle.linkedLibraries[i];
+    }
+  }
+}
+
+/**
+ * A placeholder of a source that is part of a package whose analysis results
+ * are served from its summary.  This source uses its URI as [fullName] and has
+ * empty contents.
+ */
+class _InSummarySource extends Source {
+  final Uri uri;
+
+  _InSummarySource(this.uri);
+
+  @override
+  TimestampedData<String> get contents => new TimestampedData<String>(0, '');
+
+  @override
+  String get encoding => uri.toString();
+
+  @override
+  String get fullName => encoding;
+
+  @override
+  int get hashCode => uri.hashCode;
+
+  @override
+  bool get isInSystemLibrary => false;
+
+  @override
+  int get modificationStamp => 0;
+
+  @override
+  String get shortName => pathos.basename(fullName);
+
+  @override
+  UriKind get uriKind => UriKind.PACKAGE_URI;
+
+  @override
+  bool operator ==(Object object) =>
+      object is _InSummarySource && object.uri == uri;
+
+  @override
+  bool exists() => true;
+
+  @override
+  Uri resolveRelativeUri(Uri relativeUri) {
+    Uri baseUri = uri;
+    return baseUri.resolveUri(relativeUri);
+  }
+
+  @override
+  String toString() => uri.toString();
+}