private static TreeAndVersion MakeNewTreeAndVersion(SyntaxTree oldTree, SourceText oldText, VersionStamp oldVersion, SyntaxTree newTree, SourceText newText, VersionStamp newVersion)
{
var topLevelChanged = TopLevelChanged(oldTree, oldText, newTree, newText);
var version = topLevelChanged ? newVersion : oldVersion;
return(TreeAndVersion.Create(newTree, version));
}
private static TreeAndVersion CreateTreeAndVersion(
ValueSource <TextAndVersion> newTextSource,
ProjectId cacheKey, string filePath,
ParseOptions options, HostLanguageServices languageServices,
PreservationMode mode, TextAndVersion textAndVersion,
CancellationToken cancellationToken)
{
var text = textAndVersion.Text;
var treeFactory = languageServices.GetService <ISyntaxTreeFactoryService>();
var tree = treeFactory.ParseSyntaxTree(filePath, options, text, cancellationToken);
var root = tree.GetRoot(cancellationToken);
if (mode == PreservationMode.PreserveValue && treeFactory.CanCreateRecoverableTree(root))
{
tree = treeFactory.CreateRecoverableTree(cacheKey, tree.FilePath, tree.Options, newTextSource, text.Encoding, root);
}
Contract.ThrowIfNull(tree);
// text version for this document should be unique. use it as a starting point.
return(TreeAndVersion.Create(tree, textAndVersion.Version));
}
private static TreeAndVersion IncrementallyParse(
TextAndVersion newTextAndVersion,
TreeAndVersion oldTreeAndVersion,
CancellationToken cancellationToken)
{
var newText = newTextAndVersion.Text;
var oldTree = oldTreeAndVersion.Tree;
var oldText = oldTree.GetText(cancellationToken);
var newTree = oldTree.WithChangedText(newText);
Contract.ThrowIfNull(newTree);
return(MakeNewTreeAndVersion(oldTree, oldText, oldTreeAndVersion.Version, newTree, newText, newTextAndVersion.Version));
}
// use static method so we don't capture references to this
private static Tuple <ValueSource <TextAndVersion>, TreeAndVersion> CreateRecoverableTextAndTree(
SyntaxNode newRoot, VersionStamp textVersion, VersionStamp treeVersion, Encoding encoding,
DocumentInfo.DocumentAttributes attributes, ParseOptions options, ISyntaxTreeFactoryService factory, PreservationMode mode, SolutionServices solutionServices)
{
string filePath = attributes.FilePath;
SyntaxTree tree = null;
ValueSource <TextAndVersion> lazyTextAndVersion = null;
if ((mode == PreservationMode.PreserveIdentity) || !factory.CanCreateRecoverableTree(newRoot))
{
// its okay to use a strong cached AsyncLazy here because the compiler layer SyntaxTree will also keep the text alive once its built.
lazyTextAndVersion = new TreeTextSource(
new AsyncLazy <SourceText>(
c => tree.GetTextAsync(c),
c => tree.GetText(c),
cacheResult: true),
textVersion,
filePath);
tree = factory.CreateSyntaxTree(GetSyntaxTreeFilePath(attributes), options, encoding, newRoot);
}
else
{
// uses CachedWeakValueSource so the document and tree will return the same SourceText instance across multiple accesses as long
// as the text is referenced elsewhere.
lazyTextAndVersion = new TreeTextSource(
new CachedWeakValueSource <SourceText>(
new AsyncLazy <SourceText>(
c => BuildRecoverableTreeTextAsync(tree, encoding, c),
c => BuildRecoverableTreeText(tree, encoding, c),
cacheResult: false)),
textVersion,
filePath);
tree = factory.CreateRecoverableTree(attributes.Id.ProjectId, GetSyntaxTreeFilePath(attributes), options, lazyTextAndVersion, encoding, newRoot);
}
return(Tuple.Create(lazyTextAndVersion, TreeAndVersion.Create(tree, treeVersion)));
}
