/// <summary>
/// this is for a metadata reference in a solution
/// </summary>
private static async Task <SymbolTreeInfo> LoadOrCreateAsync(Solution solution, IAssemblySymbol assembly, string filePath, CancellationToken cancellationToken)
{
// if assembly is not from a file, just create one on the fly
if (filePath == null || !File.Exists(filePath) || !FilePathUtilities.PartOfFrameworkOrReferencePaths(filePath))
{
return(Create(VersionStamp.Default, assembly, cancellationToken));
}
// if solution is not from a disk, just create one.
if (solution.FilePath == null || !File.Exists(solution.FilePath))
{
return(Create(VersionStamp.Default, assembly, cancellationToken));
}
// okay, see whether we can get one from persistence service.
var relativePath = FilePathUtilities.GetRelativePath(solution.FilePath, filePath);
var version = VersionStamp.Create(File.GetLastWriteTimeUtc(filePath));
var persistentStorageService = solution.Workspace.Services.GetService <IPersistentStorageService>();
// attempt to load from persisted state. metadata reference is solution wise information
SymbolTreeInfo info;
using (var storage = persistentStorageService.GetStorage(solution))
{
var key = PrefixMetadataSymbolTreeInfo + relativePath;
using (var stream = await storage.ReadStreamAsync(key, cancellationToken).ConfigureAwait(false))
{
if (stream != null)
{
using (var reader = new ObjectReader(stream))
{
info = ReadFrom(reader);
if (info != null && VersionStamp.CanReusePersistedVersion(version, info.version))
{
return(info);
}
}
}
}
cancellationToken.ThrowIfCancellationRequested();
// compute it if we couldn't load it from cache
info = Create(version, assembly, cancellationToken);
if (info != null)
{
using (var stream = SerializableBytes.CreateWritableStream())
using (var writer = new ObjectWriter(stream, cancellationToken: cancellationToken))
{
info.WriteTo(writer);
stream.Position = 0;
await storage.WriteStreamAsync(key, stream, cancellationToken).ConfigureAwait(false);
}
}
}
return(info);
}
