/// <see cref="StoreWriter.DoOptCommitAsync"/>
protected override async Task DoOptCommitAsync(Hash hash, Func <Task> optionalWrite, CancellationToken cancel)
{
var path = DiskStorePaths.PathOfHash(_path, hash);
if (!File.Exists(path))
{
if (optionalWrite != null)
{
await optionalWrite().ConfigureAwait(false);
}
// Close the file before the move, but only after the optional
// writes are finished.
_temp.Close();
// ReSharper disable AssignNullToNotNullAttribute
// ... we know there's a dirname in the path (it's, at the very least, _path itself)
Directory.CreateDirectory(Path.GetDirectoryName(path));
// ReSharper restore AssignNullToNotNullAttribute
try
{
File.Move(_tempPath, path);
}
catch (IOException) when(File.Exists(path))
{
// Another writer raced us to create the destination file.
// So, there's nothing left for us to do.
}
}
}
/// <summary> Delete the blob for the specified hash. </summary>
/// <remarks> Disks do not have infinite storage space, so deleting values is necessary. </remarks>
public void Delete(Hash hash)
{
var path = DiskStorePaths.PathOfHash(Path, hash);
if (!File.Exists(path))
{
return;
}
try
{
File.Delete(path);
}
catch (IOException) when(!File.Exists(path))
{
// Another writer raced us to delete the destination file.
// So, there's nothing left for us to do.
}
var directory = P.GetDirectoryName(path);
if (directory == null)
{
return;
}
try
{
Directory.Delete(path);
}
catch (IOException)
{
// There is no thread-safe way to check whether a directory is
// empty, and then delete it (there's always the possibility for
// another thread to create a file in that directory between the
// empty-check and the deletion), so all we can do is try to delete
// it (in non-recursive mode, so that it can only be dropped if it
// is empty) and ignore the exception thrown if it contains a file.
}
}
/// <summary> Determine whether the blob exists. </summary>
public bool BlobExists(Hash hash)
{
var blobPath = DiskStorePaths.PathOfHash(Path, hash);
return(File.Exists(blobPath));
}
/// <see cref="IReadOnlyStore{TBlobRef}.this"/>
public IReadBlobRef this[Hash hash] => new DiskBlobRef(hash, DiskStorePaths.PathOfHash(Path, hash));
