build_runner_core/lib/src/asset_graph/serialization.dart - third_party/dart-pkg - Git at Google

 // Copyright (c) 2017, 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.

 part of 'graph.dart';

 /// Part of the serialized graph, used to ensure versioning constraints.
 ///
 /// This should be incremented any time the serialize/deserialize formats
 /// change.
 const _version = 22;

 /// Deserializes an [AssetGraph] from a [Map].
 class _AssetGraphDeserializer {
   // Iteration order does not matter
   final _idToAssetId = HashMap<int, AssetId>();
   final Map _serializedGraph;

   _AssetGraphDeserializer._(this._serializedGraph);

   factory _AssetGraphDeserializer(List<int> bytes) {
     dynamic decoded;
     try {
       decoded = jsonDecode(utf8.decode(bytes));
     } on FormatException {
       throw AssetGraphCorruptedException();
     }
     if (decoded is! Map) throw AssetGraphCorruptedException();
     final serializedGraph = decoded as Map;
     if (serializedGraph['version'] != _version) {
       throw AssetGraphCorruptedException();
     }
     return _AssetGraphDeserializer._(serializedGraph);
   }

   /// Perform the deserialization, should only be called once.
   AssetGraph deserialize() {
     var graph = AssetGraph._(
         _deserializeDigest(_serializedGraph['buildActionsDigest'] as String),
         _serializedGraph['dart_version'] as String);

     var packageNames = _serializedGraph['packages'] as List;

     // Read in the id => AssetId map from the graph first.
     var assetPaths = _serializedGraph['assetPaths'] as List;
     for (var i = 0; i < assetPaths.length; i += 2) {
       var packageName = packageNames[assetPaths[i + 1] as int] as String;
       _idToAssetId[i ~/ 2] = AssetId(packageName, assetPaths[i] as String);
     }

     // Read in all the nodes and their outputs.
     //
     // Note that this does not read in the inputs of generated nodes.
     for (var serializedItem in _serializedGraph['nodes']) {
       graph._add(_deserializeAssetNode(serializedItem as List));
     }

     // Update the inputs of all generated nodes based on the outputs of the
     // current nodes.
     for (var node in graph.allNodes) {
       // These aren't explicitly added as inputs.
       if (node is BuilderOptionsAssetNode) continue;

       for (var output in node.outputs) {
         if (output == null) {
           log.severe('Found a null output from ${node.id} which is a '
               '${node.runtimeType}. If you encounter this error please copy '
               'the details from this message and add them to '
               'https://github.com/dart-lang/build/issues/1804.');
           throw AssetGraphCorruptedException();
         }
         var inputsNode = graph.get(output) as NodeWithInputs;
         if (inputsNode == null) {
           log.severe('Failed to locate $output referenced from ${node.id} '
               'which is a ${node.runtimeType}. If you encounter this error '
               'please copy the details from this message and add them to '
               'https://github.com/dart-lang/build/issues/1804.');
           throw AssetGraphCorruptedException();
         }
         inputsNode.inputs ??= HashSet<AssetId>();
         inputsNode.inputs.add(node.id);
       }

       if (node is PostProcessAnchorNode) {
         graph.get(node.primaryInput).anchorOutputs.add(node.id);
       }
     }

     return graph;
   }

   AssetNode _deserializeAssetNode(List serializedNode) {
     AssetNode node;
     var typeId =
         _NodeType.values[serializedNode[_AssetField.NodeType.index] as int];
     var id = _idToAssetId[serializedNode[_AssetField.Id.index] as int];
     var serializedDigest = serializedNode[_AssetField.Digest.index] as String;
     var digest = _deserializeDigest(serializedDigest);
     switch (typeId) {
       case _NodeType.Source:
         assert(serializedNode.length == _WrappedAssetNode._length);
         node = SourceAssetNode(id, lastKnownDigest: digest);
         break;
       case _NodeType.SyntheticSource:
         assert(serializedNode.length == _WrappedAssetNode._length);
         node = SyntheticSourceAssetNode(id);
         break;
       case _NodeType.Generated:
         assert(serializedNode.length == _WrappedGeneratedAssetNode._length);
         var offset = _AssetField.values.length;
         node = GeneratedAssetNode(
           id,
           phaseNumber:
               serializedNode[_GeneratedField.PhaseNumber.index + offset] as int,
           primaryInput: _idToAssetId[
               serializedNode[_GeneratedField.PrimaryInput.index + offset]
                   as int],
           state: NodeState.values[
               serializedNode[_GeneratedField.State.index + offset] as int],
           wasOutput: _deserializeBool(
               serializedNode[_GeneratedField.WasOutput.index + offset] as int),
           isFailure: _deserializeBool(
               serializedNode[_GeneratedField.IsFailure.index + offset] as int),
           builderOptionsId: _idToAssetId[
               serializedNode[_GeneratedField.BuilderOptions.index + offset]
                   as int],
           lastKnownDigest: digest,
           previousInputsDigest: _deserializeDigest(serializedNode[
               _GeneratedField.PreviousInputsDigest.index + offset] as String),
           isHidden: _deserializeBool(
               serializedNode[_GeneratedField.IsHidden.index + offset] as int),
         );
         break;
       case _NodeType.Glob:
         assert(serializedNode.length == _WrappedGlobAssetNode._length);
         var offset = _AssetField.values.length;
         node = GlobAssetNode(
           id,
           Glob(serializedNode[_GlobField.Glob.index + offset] as String),
           serializedNode[_GlobField.PhaseNumber.index + offset] as int,
           NodeState
               .values[serializedNode[_GlobField.State.index + offset] as int],
           lastKnownDigest: digest,
           results: _deserializeAssetIds(
                   serializedNode[_GlobField.Results.index + offset] as List)
               ?.toList(),
         );
         break;
       case _NodeType.Internal:
         assert(serializedNode.length == _WrappedAssetNode._length);
         node = InternalAssetNode(id, lastKnownDigest: digest);
         break;
       case _NodeType.BuilderOptions:
         assert(serializedNode.length == _WrappedAssetNode._length);
         node = BuilderOptionsAssetNode(id, digest);
         break;
       case _NodeType.Placeholder:
         assert(serializedNode.length == _WrappedAssetNode._length);
         node = PlaceHolderAssetNode(id);
         break;
       case _NodeType.PostProcessAnchor:
         assert(serializedNode.length == _WrappedPostProcessAnchorNode._length);
         var offset = _AssetField.values.length;
         node = PostProcessAnchorNode(
             id,
             _idToAssetId[
                 serializedNode[_PostAnchorField.PrimaryInput.index + offset]
                     as int],
             serializedNode[_PostAnchorField.ActionNumber.index + offset] as int,
             _idToAssetId[
                 serializedNode[_PostAnchorField.BuilderOptions.index + offset]
                     as int],
             previousInputsDigest: _deserializeDigest(serializedNode[
                     _PostAnchorField.PreviousInputsDigest.index + offset]
                 as String));
         break;
     }
     node.outputs.addAll(_deserializeAssetIds(
         serializedNode[_AssetField.Outputs.index] as List));
     node.primaryOutputs.addAll(_deserializeAssetIds(
         serializedNode[_AssetField.PrimaryOutputs.index] as List));
     node.deletedBy.addAll(_deserializeAssetIds(
         (serializedNode[_AssetField.DeletedBy.index] as List)?.cast<int>()));
     return node;
   }

   Iterable<AssetId> _deserializeAssetIds(List serializedIds) =>
       serializedIds.map((id) => _idToAssetId[id]);

   bool _deserializeBool(int value) => value != 0;
 }

 /// Serializes an [AssetGraph] into a [Map].
 class _AssetGraphSerializer {
   // Iteration order does not matter
   final _assetIdToId = HashMap<AssetId, int>();

   final AssetGraph _graph;

   _AssetGraphSerializer(this._graph);

   /// Perform the serialization, should only be called once.
   List<int> serialize() {
     var pathId = 0;
     // [path0, packageId0, path1, packageId1, ...]
     var assetPaths = <dynamic>[];
     var packages = _graph._nodesByPackage.keys.toList(growable: false);
     for (var node in _graph.allNodes) {
       _assetIdToId[node.id] = pathId;
       pathId++;
       assetPaths..add(node.id.path)..add(packages.indexOf(node.id.package));
     }

     var result = <String, dynamic>{
       'version': _version,
       'dart_version': _graph.dartVersion,
       'nodes': _graph.allNodes.map(_serializeNode).toList(growable: false),
       'buildActionsDigest': _serializeDigest(_graph.buildPhasesDigest),
       'packages': packages,
       'assetPaths': assetPaths,
     };
     return utf8.encode(json.encode(result));
   }

   List _serializeNode(AssetNode node) {
     if (node is GeneratedAssetNode) {
       return _WrappedGeneratedAssetNode(node, this);
     } else if (node is PostProcessAnchorNode) {
       return _WrappedPostProcessAnchorNode(node, this);
     } else if (node is GlobAssetNode) {
       return _WrappedGlobAssetNode(node, this);
     } else {
       return _WrappedAssetNode(node, this);
     }
   }

   int findAssetIndex(AssetId id,
       {@required AssetId from, @required String field}) {
     final index = _assetIdToId[id];
     if (index == null) {
       log.severe('The $field field in $from references a non-existent asset '
           '$id and will corrupt the asset graph. '
           'If you encounter this error please copy '
           'the details from this message and add them to '
           'https://github.com/dart-lang/build/issues/1804.');
     }
     return index;
   }
 }

 /// Used to serialize the type of a node using an int.
 enum _NodeType {
   Source,
   SyntheticSource,
   Generated,
   Internal,
   BuilderOptions,
   Placeholder,
   PostProcessAnchor,
   Glob,
 }

 /// Field indexes for all [AssetNode]s
 enum _AssetField {
   NodeType,
   Id,
   Outputs,
   PrimaryOutputs,
   Digest,
   DeletedBy,
 }

 /// Field indexes for [GeneratedAssetNode]s
 enum _GeneratedField {
   PrimaryInput,
   WasOutput,
   IsFailure,
   PhaseNumber,
   State,
   PreviousInputsDigest,
   BuilderOptions,
   IsHidden,
 }

 /// Field indexes for [GlobAssetNode]s
 enum _GlobField {
   PhaseNumber,
   State,
   Glob,
   Results,
 }

 /// Field indexes for [PostProcessAnchorNode]s.
 enum _PostAnchorField {
   ActionNumber,
   BuilderOptions,
   PreviousInputsDigest,
   PrimaryInput,
 }

 /// Wraps an [AssetNode] in a class that implements [List] instead of
 /// creating a new list for each one.
 class _WrappedAssetNode extends Object with ListMixin implements List {
   final AssetNode node;
   final _AssetGraphSerializer serializer;

   _WrappedAssetNode(this.node, this.serializer);

   static final int _length = _AssetField.values.length;

   @override
   int get length => _length;

   @override
   set length(_) => throw UnsupportedError(
       'length setter not unsupported for WrappedAssetNode');

   @override
   Object operator [](int index) {
     var fieldId = _AssetField.values[index];
     switch (fieldId) {
       case _AssetField.NodeType:
         if (node is SourceAssetNode) {
           return _NodeType.Source.index;
         } else if (node is GeneratedAssetNode) {
           return _NodeType.Generated.index;
         } else if (node is GlobAssetNode) {
           return _NodeType.Glob.index;
         } else if (node is SyntheticSourceAssetNode) {
           return _NodeType.SyntheticSource.index;
         } else if (node is InternalAssetNode) {
           return _NodeType.Internal.index;
         } else if (node is BuilderOptionsAssetNode) {
           return _NodeType.BuilderOptions.index;
         } else if (node is PlaceHolderAssetNode) {
           return _NodeType.Placeholder.index;
         } else if (node is PostProcessAnchorNode) {
           return _NodeType.PostProcessAnchor.index;
         } else {
           throw StateError('Unrecognized node type');
         }
         break;
       case _AssetField.Id:
         return serializer.findAssetIndex(node.id, from: node.id, field: 'id');
       case _AssetField.Outputs:
         return node.outputs
             .map((id) =>
                 serializer.findAssetIndex(id, from: node.id, field: 'outputs'))
             .toList(growable: false);
       case _AssetField.PrimaryOutputs:
         return node.primaryOutputs
             .map((id) => serializer.findAssetIndex(id,
                 from: node.id, field: 'primaryOutputs'))
             .toList(growable: false);
       case _AssetField.Digest:
         return _serializeDigest(node.lastKnownDigest);
       case _AssetField.DeletedBy:
         return node.deletedBy
             .map((id) => serializer.findAssetIndex(id,
                 from: node.id, field: 'deletedBy'))
             .toList(growable: false);
       default:
         throw RangeError.index(index, this);
     }
   }

   @override
   operator []=(_, __) =>
       throw UnsupportedError('[]= not supported for WrappedAssetNode');
 }

 /// Wraps a [GeneratedAssetNode] in a class that implements [List] instead of
 /// creating a new list for each one.
 class _WrappedGeneratedAssetNode extends _WrappedAssetNode {
   final GeneratedAssetNode generatedNode;

   /// Offset in the serialized format for additional fields in this class but
   /// not in [_WrappedAssetNode].
   ///
   /// Indexes below this number are forwarded to `super[index]`.
   static final int _serializedOffset = _AssetField.values.length;

   static final int _length = _serializedOffset + _GeneratedField.values.length;

   @override
   int get length => _length;

   _WrappedGeneratedAssetNode(
       this.generatedNode, _AssetGraphSerializer serializer)
       : super(generatedNode, serializer);

   @override
   Object operator [](int index) {
     if (index < _serializedOffset) return super[index];
     var fieldId = _GeneratedField.values[index - _serializedOffset];
     switch (fieldId) {
       case _GeneratedField.PrimaryInput:
         return generatedNode.primaryInput != null
             ? serializer.findAssetIndex(generatedNode.primaryInput,
                 from: generatedNode.id, field: 'primaryInput')
             : null;
       case _GeneratedField.WasOutput:
         return _serializeBool(generatedNode.wasOutput);
       case _GeneratedField.IsFailure:
         return _serializeBool(generatedNode.isFailure);
       case _GeneratedField.PhaseNumber:
         return generatedNode.phaseNumber;
       case _GeneratedField.State:
         return generatedNode.state.index;
       case _GeneratedField.PreviousInputsDigest:
         return _serializeDigest(generatedNode.previousInputsDigest);
       case _GeneratedField.BuilderOptions:
         return serializer.findAssetIndex(generatedNode.builderOptionsId,
             from: generatedNode.id, field: 'builderOptions');
       case _GeneratedField.IsHidden:
         return _serializeBool(generatedNode.isHidden);
       default:
         throw RangeError.index(index, this);
     }
   }
 }

 /// Wraps a [GlobAssetNode] in a class that implements [List] instead of
 /// creating a new list for each one.
 class _WrappedGlobAssetNode extends _WrappedAssetNode {
   final GlobAssetNode globNode;

   /// Offset in the serialized format for additional fields in this class but
   /// not in [_WrappedAssetNode].
   ///
   /// Indexes below this number are forwarded to `super[index]`.
   static final int _serializedOffset = _AssetField.values.length;

   static final int _length = _serializedOffset + _GlobField.values.length;

   @override
   int get length => _length;

   _WrappedGlobAssetNode(this.globNode, _AssetGraphSerializer serializer)
       : super(globNode, serializer);

   @override
   Object operator [](int index) {
     if (index < _serializedOffset) return super[index];
     var fieldId = _GlobField.values[index - _serializedOffset];
     switch (fieldId) {
       case _GlobField.PhaseNumber:
         return globNode.phaseNumber;
       case _GlobField.State:
         return globNode.state.index;
       case _GlobField.Glob:
         return globNode.glob.pattern;
       case _GlobField.Results:
         return globNode.results
             .map((id) => serializer.findAssetIndex(id,
                 from: globNode.id, field: 'results'))
             .toList(growable: false);
       default:
         throw RangeError.index(index, this);
     }
   }
 }

 /// Wraps a [PostProcessAnchorNode] in a class that implements [List] instead of
 /// creating a new list for each one.
 class _WrappedPostProcessAnchorNode extends _WrappedAssetNode {
   final PostProcessAnchorNode wrappedNode;

   /// Offset in the serialized format for additional fields in this class but
   /// not in [_WrappedAssetNode].
   ///
   /// Indexes below this number are forwarded to `super[index]`.
   static final int _serializedOffset = _AssetField.values.length;

   static final int _length = _serializedOffset + _PostAnchorField.values.length;

   @override
   int get length => _length;

   _WrappedPostProcessAnchorNode(
       this.wrappedNode, _AssetGraphSerializer serializer)
       : super(wrappedNode, serializer);

   @override
   Object operator [](int index) {
     if (index < _serializedOffset) return super[index];
     var fieldId = _PostAnchorField.values[index - _serializedOffset];
     switch (fieldId) {
       case _PostAnchorField.ActionNumber:
         return wrappedNode.actionNumber;
       case _PostAnchorField.BuilderOptions:
         return serializer.findAssetIndex(wrappedNode.builderOptionsId,
             from: wrappedNode.id, field: 'builderOptions');
       case _PostAnchorField.PreviousInputsDigest:
         return _serializeDigest(wrappedNode.previousInputsDigest);
       case _PostAnchorField.PrimaryInput:
         return wrappedNode.primaryInput != null
             ? serializer.findAssetIndex(wrappedNode.primaryInput,
                 from: wrappedNode.id, field: 'primaryInput')
             : null;
       default:
         throw RangeError.index(index, this);
     }
   }
 }

 Digest _deserializeDigest(String serializedDigest) =>
     serializedDigest == null ? null : Digest(base64.decode(serializedDigest));

 String _serializeDigest(Digest digest) =>
     digest == null ? null : base64.encode(digest.bytes);

 int _serializeBool(bool value) => value ? 1 : 0;
	// Copyright (c) 2017, 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.

	part of 'graph.dart';

	/// Part of the serialized graph, used to ensure versioning constraints.
	///
	/// This should be incremented any time the serialize/deserialize formats
	/// change.
	const _version = 22;

	/// Deserializes an [AssetGraph] from a [Map].
	class _AssetGraphDeserializer {
	// Iteration order does not matter
	final _idToAssetId = HashMap<int, AssetId>();
	final Map _serializedGraph;

	_AssetGraphDeserializer._(this._serializedGraph);

	factory _AssetGraphDeserializer(List<int> bytes) {
	dynamic decoded;
	try {
	decoded = jsonDecode(utf8.decode(bytes));
	} on FormatException {
	throw AssetGraphCorruptedException();
	}
	if (decoded is! Map) throw AssetGraphCorruptedException();
	final serializedGraph = decoded as Map;
	if (serializedGraph['version'] != _version) {
	throw AssetGraphCorruptedException();
	}
	return _AssetGraphDeserializer._(serializedGraph);
	}

	/// Perform the deserialization, should only be called once.
	AssetGraph deserialize() {
	var graph = AssetGraph._(
	_deserializeDigest(_serializedGraph['buildActionsDigest'] as String),
	_serializedGraph['dart_version'] as String);

	var packageNames = _serializedGraph['packages'] as List;

	// Read in the id => AssetId map from the graph first.
	var assetPaths = _serializedGraph['assetPaths'] as List;
	for (var i = 0; i < assetPaths.length; i += 2) {
	var packageName = packageNames[assetPaths[i + 1] as int] as String;
	_idToAssetId[i ~/ 2] = AssetId(packageName, assetPaths[i] as String);
	}

	// Read in all the nodes and their outputs.
	//
	// Note that this does not read in the inputs of generated nodes.
	for (var serializedItem in _serializedGraph['nodes']) {
	graph._add(_deserializeAssetNode(serializedItem as List));
	}

	// Update the inputs of all generated nodes based on the outputs of the
	// current nodes.
	for (var node in graph.allNodes) {
	// These aren't explicitly added as inputs.
	if (node is BuilderOptionsAssetNode) continue;

	for (var output in node.outputs) {
	if (output == null) {
	log.severe('Found a null output from ${node.id} which is a '
	'${node.runtimeType}. If you encounter this error please copy '
	'the details from this message and add them to '
	'https://github.com/dart-lang/build/issues/1804.');
	throw AssetGraphCorruptedException();
	}
	var inputsNode = graph.get(output) as NodeWithInputs;
	if (inputsNode == null) {
	log.severe('Failed to locate $output referenced from ${node.id} '
	'which is a ${node.runtimeType}. If you encounter this error '
	'please copy the details from this message and add them to '
	'https://github.com/dart-lang/build/issues/1804.');
	throw AssetGraphCorruptedException();
	}
	inputsNode.inputs ??= HashSet<AssetId>();
	inputsNode.inputs.add(node.id);
	}

	if (node is PostProcessAnchorNode) {
	graph.get(node.primaryInput).anchorOutputs.add(node.id);
	}
	}

	return graph;
	}

	AssetNode _deserializeAssetNode(List serializedNode) {
	AssetNode node;
	var typeId =
	_NodeType.values[serializedNode[_AssetField.NodeType.index] as int];
	var id = _idToAssetId[serializedNode[_AssetField.Id.index] as int];
	var serializedDigest = serializedNode[_AssetField.Digest.index] as String;
	var digest = _deserializeDigest(serializedDigest);
	switch (typeId) {
	case _NodeType.Source:
	assert(serializedNode.length == _WrappedAssetNode._length);
	node = SourceAssetNode(id, lastKnownDigest: digest);
	break;
	case _NodeType.SyntheticSource:
	assert(serializedNode.length == _WrappedAssetNode._length);
	node = SyntheticSourceAssetNode(id);
	break;
	case _NodeType.Generated:
	assert(serializedNode.length == _WrappedGeneratedAssetNode._length);
	var offset = _AssetField.values.length;
	node = GeneratedAssetNode(
	id,
	phaseNumber:
	serializedNode[_GeneratedField.PhaseNumber.index + offset] as int,
	primaryInput: _idToAssetId[
	serializedNode[_GeneratedField.PrimaryInput.index + offset]
	as int],
	state: NodeState.values[
	serializedNode[_GeneratedField.State.index + offset] as int],
	wasOutput: _deserializeBool(
	serializedNode[_GeneratedField.WasOutput.index + offset] as int),
	isFailure: _deserializeBool(
	serializedNode[_GeneratedField.IsFailure.index + offset] as int),
	builderOptionsId: _idToAssetId[
	serializedNode[_GeneratedField.BuilderOptions.index + offset]
	as int],
	lastKnownDigest: digest,
	previousInputsDigest: _deserializeDigest(serializedNode[
	_GeneratedField.PreviousInputsDigest.index + offset] as String),
	isHidden: _deserializeBool(
	serializedNode[_GeneratedField.IsHidden.index + offset] as int),
	);
	break;
	case _NodeType.Glob:
	assert(serializedNode.length == _WrappedGlobAssetNode._length);
	var offset = _AssetField.values.length;
	node = GlobAssetNode(
	id,
	Glob(serializedNode[_GlobField.Glob.index + offset] as String),
	serializedNode[_GlobField.PhaseNumber.index + offset] as int,
	NodeState
	.values[serializedNode[_GlobField.State.index + offset] as int],
	lastKnownDigest: digest,
	results: _deserializeAssetIds(
	serializedNode[_GlobField.Results.index + offset] as List)
	?.toList(),
	);
	break;
	case _NodeType.Internal:
	assert(serializedNode.length == _WrappedAssetNode._length);
	node = InternalAssetNode(id, lastKnownDigest: digest);
	break;
	case _NodeType.BuilderOptions:
	assert(serializedNode.length == _WrappedAssetNode._length);
	node = BuilderOptionsAssetNode(id, digest);
	break;
	case _NodeType.Placeholder:
	assert(serializedNode.length == _WrappedAssetNode._length);
	node = PlaceHolderAssetNode(id);
	break;
	case _NodeType.PostProcessAnchor:
	assert(serializedNode.length == _WrappedPostProcessAnchorNode._length);
	var offset = _AssetField.values.length;
	node = PostProcessAnchorNode(
	id,
	_idToAssetId[
	serializedNode[_PostAnchorField.PrimaryInput.index + offset]
	as int],
	serializedNode[_PostAnchorField.ActionNumber.index + offset] as int,
	_idToAssetId[
	serializedNode[_PostAnchorField.BuilderOptions.index + offset]
	as int],
	previousInputsDigest: _deserializeDigest(serializedNode[
	_PostAnchorField.PreviousInputsDigest.index + offset]
	as String));
	break;
	}
	node.outputs.addAll(_deserializeAssetIds(
	serializedNode[_AssetField.Outputs.index] as List));
	node.primaryOutputs.addAll(_deserializeAssetIds(
	serializedNode[_AssetField.PrimaryOutputs.index] as List));
	node.deletedBy.addAll(_deserializeAssetIds(
	(serializedNode[_AssetField.DeletedBy.index] as List)?.cast<int>()));
	return node;
	}

	Iterable<AssetId> _deserializeAssetIds(List serializedIds) =>
	serializedIds.map((id) => _idToAssetId[id]);

	bool _deserializeBool(int value) => value != 0;
	}

	/// Serializes an [AssetGraph] into a [Map].
	class _AssetGraphSerializer {
	// Iteration order does not matter
	final _assetIdToId = HashMap<AssetId, int>();

	final AssetGraph _graph;

	_AssetGraphSerializer(this._graph);

	/// Perform the serialization, should only be called once.
	List<int> serialize() {
	var pathId = 0;
	// [path0, packageId0, path1, packageId1, ...]
	var assetPaths = <dynamic>[];
	var packages = _graph._nodesByPackage.keys.toList(growable: false);
	for (var node in _graph.allNodes) {
	_assetIdToId[node.id] = pathId;
	pathId++;
	assetPaths..add(node.id.path)..add(packages.indexOf(node.id.package));
	}

	var result = <String, dynamic>{
	'version': _version,
	'dart_version': _graph.dartVersion,
	'nodes': _graph.allNodes.map(_serializeNode).toList(growable: false),
	'buildActionsDigest': _serializeDigest(_graph.buildPhasesDigest),
	'packages': packages,
	'assetPaths': assetPaths,
	};
	return utf8.encode(json.encode(result));
	}

	List _serializeNode(AssetNode node) {
	if (node is GeneratedAssetNode) {
	return _WrappedGeneratedAssetNode(node, this);
	} else if (node is PostProcessAnchorNode) {
	return _WrappedPostProcessAnchorNode(node, this);
	} else if (node is GlobAssetNode) {
	return _WrappedGlobAssetNode(node, this);
	} else {
	return _WrappedAssetNode(node, this);
	}
	}

	int findAssetIndex(AssetId id,
	{@required AssetId from, @required String field}) {
	final index = _assetIdToId[id];
	if (index == null) {
	log.severe('The $field field in $from references a non-existent asset '
	'$id and will corrupt the asset graph. '
	'If you encounter this error please copy '
	'the details from this message and add them to '
	'https://github.com/dart-lang/build/issues/1804.');
	}
	return index;
	}
	}

	/// Used to serialize the type of a node using an int.
	enum _NodeType {
	Source,
	SyntheticSource,
	Generated,
	Internal,
	BuilderOptions,
	Placeholder,
	PostProcessAnchor,
	Glob,
	}

	/// Field indexes for all [AssetNode]s
	enum _AssetField {
	NodeType,
	Id,
	Outputs,
	PrimaryOutputs,
	Digest,
	DeletedBy,
	}

	/// Field indexes for [GeneratedAssetNode]s
	enum _GeneratedField {
	PrimaryInput,
	WasOutput,
	IsFailure,
	PhaseNumber,
	State,
	PreviousInputsDigest,
	BuilderOptions,
	IsHidden,
	}

	/// Field indexes for [GlobAssetNode]s
	enum _GlobField {
	PhaseNumber,
	State,
	Glob,
	Results,
	}

	/// Field indexes for [PostProcessAnchorNode]s.
	enum _PostAnchorField {
	ActionNumber,
	BuilderOptions,
	PreviousInputsDigest,
	PrimaryInput,
	}

	/// Wraps an [AssetNode] in a class that implements [List] instead of
	/// creating a new list for each one.
	class _WrappedAssetNode extends Object with ListMixin implements List {
	final AssetNode node;
	final _AssetGraphSerializer serializer;

	_WrappedAssetNode(this.node, this.serializer);

	static final int _length = _AssetField.values.length;

	@override
	int get length => _length;

	@override
	set length(_) => throw UnsupportedError(
	'length setter not unsupported for WrappedAssetNode');

	@override
	Object operator [](int index) {
	var fieldId = _AssetField.values[index];
	switch (fieldId) {
	case _AssetField.NodeType:
	if (node is SourceAssetNode) {
	return _NodeType.Source.index;
	} else if (node is GeneratedAssetNode) {
	return _NodeType.Generated.index;
	} else if (node is GlobAssetNode) {
	return _NodeType.Glob.index;
	} else if (node is SyntheticSourceAssetNode) {
	return _NodeType.SyntheticSource.index;
	} else if (node is InternalAssetNode) {
	return _NodeType.Internal.index;
	} else if (node is BuilderOptionsAssetNode) {
	return _NodeType.BuilderOptions.index;
	} else if (node is PlaceHolderAssetNode) {
	return _NodeType.Placeholder.index;
	} else if (node is PostProcessAnchorNode) {
	return _NodeType.PostProcessAnchor.index;
	} else {
	throw StateError('Unrecognized node type');
	}
	break;
	case _AssetField.Id:
	return serializer.findAssetIndex(node.id, from: node.id, field: 'id');
	case _AssetField.Outputs:
	return node.outputs
	.map((id) =>
	serializer.findAssetIndex(id, from: node.id, field: 'outputs'))
	.toList(growable: false);
	case _AssetField.PrimaryOutputs:
	return node.primaryOutputs
	.map((id) => serializer.findAssetIndex(id,
	from: node.id, field: 'primaryOutputs'))
	.toList(growable: false);
	case _AssetField.Digest:
	return _serializeDigest(node.lastKnownDigest);
	case _AssetField.DeletedBy:
	return node.deletedBy
	.map((id) => serializer.findAssetIndex(id,
	from: node.id, field: 'deletedBy'))
	.toList(growable: false);
	default:
	throw RangeError.index(index, this);
	}
	}

	@override
	operator []=(_, __) =>
	throw UnsupportedError('[]= not supported for WrappedAssetNode');
	}

	/// Wraps a [GeneratedAssetNode] in a class that implements [List] instead of
	/// creating a new list for each one.
	class _WrappedGeneratedAssetNode extends _WrappedAssetNode {
	final GeneratedAssetNode generatedNode;

	/// Offset in the serialized format for additional fields in this class but
	/// not in [_WrappedAssetNode].
	///
	/// Indexes below this number are forwarded to `super[index]`.
	static final int _serializedOffset = _AssetField.values.length;

	static final int _length = _serializedOffset + _GeneratedField.values.length;

	@override
	int get length => _length;

	_WrappedGeneratedAssetNode(
	this.generatedNode, _AssetGraphSerializer serializer)
	: super(generatedNode, serializer);

	@override
	Object operator [](int index) {
	if (index < _serializedOffset) return super[index];
	var fieldId = _GeneratedField.values[index - _serializedOffset];
	switch (fieldId) {
	case _GeneratedField.PrimaryInput:
	return generatedNode.primaryInput != null
	? serializer.findAssetIndex(generatedNode.primaryInput,
	from: generatedNode.id, field: 'primaryInput')
	: null;
	case _GeneratedField.WasOutput:
	return _serializeBool(generatedNode.wasOutput);
	case _GeneratedField.IsFailure:
	return _serializeBool(generatedNode.isFailure);
	case _GeneratedField.PhaseNumber:
	return generatedNode.phaseNumber;
	case _GeneratedField.State:
	return generatedNode.state.index;
	case _GeneratedField.PreviousInputsDigest:
	return _serializeDigest(generatedNode.previousInputsDigest);
	case _GeneratedField.BuilderOptions:
	return serializer.findAssetIndex(generatedNode.builderOptionsId,
	from: generatedNode.id, field: 'builderOptions');
	case _GeneratedField.IsHidden:
	return _serializeBool(generatedNode.isHidden);
	default:
	throw RangeError.index(index, this);
	}
	}
	}

	/// Wraps a [GlobAssetNode] in a class that implements [List] instead of
	/// creating a new list for each one.
	class _WrappedGlobAssetNode extends _WrappedAssetNode {
	final GlobAssetNode globNode;

	/// Offset in the serialized format for additional fields in this class but
	/// not in [_WrappedAssetNode].
	///
	/// Indexes below this number are forwarded to `super[index]`.
	static final int _serializedOffset = _AssetField.values.length;

	static final int _length = _serializedOffset + _GlobField.values.length;

	@override
	int get length => _length;

	_WrappedGlobAssetNode(this.globNode, _AssetGraphSerializer serializer)
	: super(globNode, serializer);

	@override
	Object operator [](int index) {
	if (index < _serializedOffset) return super[index];
	var fieldId = _GlobField.values[index - _serializedOffset];
	switch (fieldId) {
	case _GlobField.PhaseNumber:
	return globNode.phaseNumber;
	case _GlobField.State:
	return globNode.state.index;
	case _GlobField.Glob:
	return globNode.glob.pattern;
	case _GlobField.Results:
	return globNode.results
	.map((id) => serializer.findAssetIndex(id,
	from: globNode.id, field: 'results'))
	.toList(growable: false);
	default:
	throw RangeError.index(index, this);
	}
	}
	}

	/// Wraps a [PostProcessAnchorNode] in a class that implements [List] instead of
	/// creating a new list for each one.
	class _WrappedPostProcessAnchorNode extends _WrappedAssetNode {
	final PostProcessAnchorNode wrappedNode;

	/// Offset in the serialized format for additional fields in this class but
	/// not in [_WrappedAssetNode].
	///
	/// Indexes below this number are forwarded to `super[index]`.
	static final int _serializedOffset = _AssetField.values.length;

	static final int _length = _serializedOffset + _PostAnchorField.values.length;

	@override
	int get length => _length;

	_WrappedPostProcessAnchorNode(
	this.wrappedNode, _AssetGraphSerializer serializer)
	: super(wrappedNode, serializer);

	@override
	Object operator [](int index) {
	if (index < _serializedOffset) return super[index];
	var fieldId = _PostAnchorField.values[index - _serializedOffset];
	switch (fieldId) {
	case _PostAnchorField.ActionNumber:
	return wrappedNode.actionNumber;
	case _PostAnchorField.BuilderOptions:
	return serializer.findAssetIndex(wrappedNode.builderOptionsId,
	from: wrappedNode.id, field: 'builderOptions');
	case _PostAnchorField.PreviousInputsDigest:
	return _serializeDigest(wrappedNode.previousInputsDigest);
	case _PostAnchorField.PrimaryInput:
	return wrappedNode.primaryInput != null
	? serializer.findAssetIndex(wrappedNode.primaryInput,
	from: wrappedNode.id, field: 'primaryInput')
	: null;
	default:
	throw RangeError.index(index, this);
	}
	}
	}

	Digest _deserializeDigest(String serializedDigest) =>
	serializedDigest == null ? null : Digest(base64.decode(serializedDigest));

	String _serializeDigest(Digest digest) =>
	digest == null ? null : base64.encode(digest.bytes);

	int _serializeBool(bool value) => value ? 1 : 0;