Add a byte store that can be shared for use with Cider.

Change-Id: I492aebb476aa7e681eb4d7d5bff995d12917c9b4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/150684
Commit-Queue: Keerti Parthasarathy <keertip@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/lib/src/dart/micro/cider_byte_store.dart

@@ -0,0 +1,55 @@
+// Copyright (c) 2020, 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.
+
+import 'package:collection/collection.dart';
+
+/**
+ * Store of bytes associated with string keys and a hash.
+ *
+ * Each key must be not longer than 100 characters and consist of only `[a-z]`,
+ * `[0-9]`, `.` and `_` characters. The key cannot be an empty string, the
+ * literal `.`, or contain the sequence `..`.
+ *
+ * Note that associations are not guaranteed to be persistent. The value
+ * associated with a key can change or become `null` at any point in time.
+ */
+abstract class CiderByteStore {
+  /**
+   * Return the bytes associated with the errors for given [key] and [signature].
+   * Return `null` if the association does not exist.
+   */
+  List<int> get(String key, List<int> signature);
+
+  /**
+   * Associate the given [bytes] with the [key] and [digest].
+   */
+  void put(String key, List<int> signature, List<int> bytes);
+}
+
+class CiderMemoryByteStore implements CiderByteStore {
+  final Map<String, _CiderCacheEntry> _map = {};
+
+  @override
+  List<int> get(String key, List<int> signature) {
+    var entry = _map[key];
+
+    if (entry != null &&
+        const ListEquality().equals(entry.signature, signature)) {
+      return entry.bytes;
+    }
+    return null;
+  }
+
+  @override
+  void put(String key, List<int> signature, List<int> bytes) {
+    _map[key] = _CiderCacheEntry(signature, bytes);
+  }
+}
+
+class _CiderCacheEntry {
+  final List<int> signature;
+  final List<int> bytes;
+
+  _CiderCacheEntry(this.signature, this.bytes);
+}

pkg/analyzer/lib/src/dart/micro/library_graph.dart

@@ -11,10 +11,10 @@ import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/file_system/file_system.dart';
-import 'package:analyzer/src/dart/analysis/byte_store.dart';
 import 'package:analyzer/src/dart/analysis/feature_set_provider.dart';
 import 'package:analyzer/src/dart/analysis/performance_logger.dart';
 import 'package:analyzer/src/dart/analysis/unlinked_api_signature.dart';
+import 'package:analyzer/src/dart/micro/cider_byte_store.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ -27,7 +27,6 @@ import 'package:analyzer/src/summary/idl.dart';
 import 'package:analyzer/src/summary/link.dart' as graph
     show DependencyWalker, Node;
 import 'package:analyzer/src/summary2/informative_data.dart';
-import 'package:collection/collection.dart';
 import 'package:convert/convert.dart';
 
 /// Ensure that the [FileState.libraryCycle] for the [file] and anything it
@@ -168,16 +167,7 @@ class FileState {
     // Prepare bytes of the unlinked bundle - existing or new.
     List<int> bytes;
     {
-      bytes = _fsState._byteStore.get(unlinkedKey);
-      // unlinked summary should be updated if contents have changed, can be
-      // seen if file digest has changed.
-      if (bytes != null) {
-        var ciderUnlinkedUnit = CiderUnlinkedUnit.fromBuffer(bytes);
-        if (!const ListEquality()
-            .equals(ciderUnlinkedUnit.contentDigest, _digest)) {
-          bytes = null;
-        }
-      }
+      bytes = _fsState._byteStore.get(unlinkedKey, _digest);
 
       if (bytes == null || bytes.isEmpty) {
         var content = _fsState.timers.read.run(() {
@@ -189,7 +179,7 @@ class FileState {
         _fsState.timers.unlinked.run(() {
           var unlinkedBuilder = serializeAstCiderUnlinked(_digest, unit);
           bytes = unlinkedBuilder.toBuffer();
-          _fsState._byteStore.put(unlinkedKey, bytes);
+          _fsState._byteStore.put(unlinkedKey, _digest, bytes);
         });
 
         _fsState.timers.prefetch.run(() {
@@ -377,7 +367,7 @@ class FileState {
 class FileSystemState {
   final PerformanceLog _logger;
   final ResourceProvider _resourceProvider;
-  final MemoryByteStore _byteStore;
+  final CiderByteStore _byteStore;
   final SourceFactory _sourceFactory;
   final AnalysisOptions _analysisOptions;
   final Uint32List _linkedSalt;

pkg/analyzer/lib/src/dart/micro/resolve_file.dart

@@ -19,6 +19,7 @@ import 'package:analyzer/src/dart/analysis/feature_set_provider.dart';
 import 'package:analyzer/src/dart/analysis/performance_logger.dart';
 import 'package:analyzer/src/dart/analysis/results.dart';
 import 'package:analyzer/src/dart/micro/analysis_context.dart';
+import 'package:analyzer/src/dart/micro/cider_byte_store.dart';
 import 'package:analyzer/src/dart/micro/library_analyzer.dart';
 import 'package:analyzer/src/dart/micro/library_graph.dart';
 import 'package:analyzer/src/generated/engine.dart'
@@ -33,7 +34,6 @@ import 'package:analyzer/src/summary2/linked_element_factory.dart';
 import 'package:analyzer/src/summary2/reference.dart';
 import 'package:analyzer/src/task/options.dart';
 import 'package:analyzer/src/workspace/workspace.dart';
-import 'package:collection/collection.dart';
 import 'package:meta/meta.dart';
 import 'package:yaml/yaml.dart';
 
@@ -47,7 +47,7 @@ class FileContext {
 class FileResolver {
   final PerformanceLog logger;
   final ResourceProvider resourceProvider;
-  final MemoryByteStore byteStore;
+  CiderByteStore byteStore;
   final SourceFactory sourceFactory;
 
   /*
@@ -76,22 +76,48 @@ class FileResolver {
 
   _LibraryContext libraryContext;
 
-  FileResolver(
-    this.logger,
-    this.resourceProvider,
-    this.byteStore,
-    this.sourceFactory,
-    this.getFileDigest,
-    this.prefetchFiles, {
+  FileResolver.from({
+    @required PerformanceLog logger,
+    @required ResourceProvider resourceProvider,
+    @required SourceFactory sourceFactory,
+    @required String Function(String path) getFileDigest,
+    @required void Function(List<String> paths) prefetchFiles,
     @required Workspace workspace,
+    CiderByteStore byteStore,
     Duration libraryContextResetTimeout = const Duration(seconds: 60),
-  }) : this.workspace = workspace {
+  })  : this.logger = logger,
+        this.sourceFactory = sourceFactory,
+        this.resourceProvider = resourceProvider,
+        this.getFileDigest = getFileDigest,
+        this.prefetchFiles = prefetchFiles,
+        this.workspace = workspace {
+    byteStore ??= CiderMemoryByteStore();
+    this.byteStore = byteStore;
     _libraryContextReset = _LibraryContextReset(
       fileResolver: this,
       resetTimeout: libraryContextResetTimeout,
     );
   }
 
+  FileResolver(
+    PerformanceLog logger,
+    ResourceProvider resourceProvider,
+    @deprecated ByteStore byteStore,
+    SourceFactory sourceFactory,
+    String Function(String path) getFileDigest,
+    void Function(List<String> paths) prefetchFiles, {
+    @required Workspace workspace,
+    Duration libraryContextResetTimeout = const Duration(seconds: 60),
+  }) : this.from(
+          logger: logger,
+          resourceProvider: resourceProvider,
+          sourceFactory: sourceFactory,
+          getFileDigest: getFileDigest,
+          prefetchFiles: prefetchFiles,
+          workspace: workspace,
+          libraryContextResetTimeout: libraryContextResetTimeout,
+        );
+
   FeatureSet get defaultFeatureSet => FeatureSet.fromEnableFlags([]);
 
   /// Update the resolver to reflect the fact that the file with the given
@@ -134,16 +160,13 @@ class FileResolver {
         var errorsSignature = errorsSignatureBuilder.toByteList();
 
         var errorsKey = file.path + '.errors';
-        var bytes = byteStore.get(errorsKey);
-
+        var bytes = byteStore.get(errorsKey, errorsSignature);
         List<AnalysisError> errors;
         if (bytes != null) {
           var data = CiderUnitErrors.fromBuffer(bytes);
-          if (const ListEquality().equals(data.signature, errorsSignature)) {
-            errors = data.errors.map((error) {
-              return ErrorEncoding.decode(file.source, error);
-            }).toList();
-          }
+          errors = data.errors.map((error) {
+            return ErrorEncoding.decode(file.source, error);
+          }).toList();
         }
 
         if (errors == null) {
@@ -154,7 +177,7 @@ class FileResolver {
             signature: errorsSignature,
             errors: errors.map((ErrorEncoding.encode)).toList(),
           ).toBuffer();
-          byteStore.put(errorsKey, bytes);
+          byteStore.put(errorsKey, errorsSignature, bytes);
         }
 
         return ErrorsResultImpl(
@@ -412,7 +435,7 @@ class FileResolverTestView {
 class _LibraryContext {
   final PerformanceLog logger;
   final ResourceProvider resourceProvider;
-  final MemoryByteStore byteStore;
+  final CiderByteStore byteStore;
   final MicroContextObjects contextObjects;
 
   LinkedElementFactory elementFactory;
@@ -451,15 +474,7 @@ class _LibraryContext {
       cycle.directDependencies.forEach(loadBundle);
 
       var key = cycle.cyclePathsHash;
-      var bytes = byteStore.get(key);
-
-      // check to see if any of the sources have changed
-      if (bytes != null) {
-        var hash = CiderLinkedLibraryCycle.fromBuffer(bytes).signature;
-        if (!const ListEquality().equals(hash, cycle.signature)) {
-          bytes = null;
-        }
-      }
+      var bytes = byteStore.get(key, cycle.signature);
 
       if (bytes == null) {
         librariesLinkedTimer.start();
@@ -510,7 +525,7 @@ class _LibraryContext {
 
         bytes = serializeBundle(cycle.signature, linkResult).toBuffer();
 
-        byteStore.put(key, bytes);
+        byteStore.put(key, cycle.signature, bytes);
         bytesPut += bytes.length;
 
         librariesLinkedTimer.stop();

pkg/analyzer/test/src/dart/micro/file_resolution.dart

@@ -5,8 +5,8 @@
 import 'dart:convert';
 
 import 'package:analyzer/dart/analysis/results.dart';
-import 'package:analyzer/src/dart/analysis/byte_store.dart';
 import 'package:analyzer/src/dart/analysis/performance_logger.dart';
+import 'package:analyzer/src/dart/micro/cider_byte_store.dart';
 import 'package:analyzer/src/dart/micro/resolve_file.dart';
 import 'package:analyzer/src/test_utilities/find_element.dart';
 import 'package:analyzer/src/test_utilities/find_node.dart';
@@ -22,7 +22,7 @@ import '../resolution/resolution.dart';
 class FileResolutionTest with ResourceProviderMixin, ResolutionTest {
   static final String _testFile = '/workspace/dart/test/lib/test.dart';
 
-  final ByteStore byteStore = MemoryByteStore();
+  final CiderByteStore byteStore = CiderMemoryByteStore();
 
   final StringBuffer logBuffer = StringBuffer();
   PerformanceLog logger;
@@ -44,15 +44,14 @@ class FileResolutionTest with ResourceProviderMixin, ResolutionTest {
       convertPath(_testFile),
     );
 
-    fileResolver = FileResolver(
-      logger,
-      resourceProvider,
-      byteStore,
-      workspace.createSourceFactory(sdk, null),
-      (String path) => _getDigest(path),
-      null,
+    fileResolver = FileResolver.from(
+      logger: logger,
+      resourceProvider: resourceProvider,
+      byteStore: byteStore,
+      sourceFactory: workspace.createSourceFactory(sdk, null),
+      getFileDigest: (String path) => _getDigest(path),
       workspace: workspace,
-      libraryContextResetTimeout: null,
+      prefetchFiles: null,
     );
     fileResolver.testView = FileResolverTestView();
   }