public Task <Errorable <TagID> > ResolvePartialID(TagID.Partial id)
{
FileInfo[] fis = system.getPathsByPartialID(id);
if (fis.Length == 1)
{
return(Task.FromResult(TagID.TryParse(id.ToString().Substring(0, 2) + fis[0].Name)));
}
if (fis.Length == 0)
{
return(Task.FromResult((Errorable <TagID>) new TagIDPartialNoResolutionError(id)));
}
return(Task.FromResult((Errorable <TagID>) new TagIDPartialAmbiguousResolutionError(id, fis.SelectAsArray(f => TagID.TryParse(id.ToString().Substring(0, 2) + f.Name).Value))));
}
private async Task <Errorable <TagID> > getTagIDByName(TagName tagName)
{
FileInfo fiTracker = system.getTagPathByTagName(tagName);
Debug.Assert(fiTracker != null);
if (!fiTracker.Exists)
{
return(new TagNameDoesNotExistError(tagName));
}
byte[] buf;
int nr = 0;
using (var fs = new FileStream(fiTracker.FullName, FileMode.Open, FileAccess.Read, FileShare.Read, 16384, true))
{
// TODO: implement an async buffered Stream:
buf = new byte[16384];
nr = await fs.ReadAsync(buf, 0, 16384).ConfigureAwait(continueOnCapturedContext: false);
if (nr >= 16384)
{
// My, what a large tag you have!
throw new NotSupportedException();
}
}
// Parse the TagID:
using (var ms = new MemoryStream(buf, 0, nr, false))
using (var sr = new StreamReader(ms, Encoding.UTF8))
{
string line = sr.ReadLine();
if (line == null)
{
return(new TagNameDoesNotExistError(tagName));
}
return(TagID.TryParse(line));
}
}