private void BuildContent(TransformedFileInfo info, Int32 buildId)
{
info.WorkerSemaphore.Wait();
try
{
info.BuildId = buildId;
List <IStaticFileTransform> transforms;
// gather transformations and order them
if (info.MatchingTransforms == null)
{
transforms = _transformations.MatchingTransformations(info.Path);
info.MatchingTransforms = transforms;
}
else
{
transforms = info.MatchingTransforms;
}
// check if we have any transforms, if we dont we early exit
if (transforms.Count == 0)
{
if (info.Original.Exists == false || info.Original.IsDirectory)
{
info.Content = null;
info.Transformed = info.Original;
}
else
{
info.Content = ReadOriginalFileContent(info.Original);
info.Transformed = info.Original;
}
return; // early exit
}
// init or clear dependency list
if (info.Depdendencies == null)
{
info.Depdendencies = new List <TransformedFileInfo>();
}
else
{
info.Depdendencies.Clear();
}
// apply the transformations
var enumerator = transforms.GetEnumerator();
info.Content = RecursiveApplyTransform(enumerator, info);
info.Transformed = new FileWithMemoizedTransform(info.Original, info.Content);
enumerator.Dispose();
}
finally
{
info.WorkerSemaphore.Release();
}
}
private bool CheckIfNeedToBuild(TransformedFileInfo info)
{
// update file infos and recursively check for signature changed
info.Original = _baseProvider.GetFileInfo(info.Path);
if (info.Transformed != null && info.Original.LastModified == info.Transformed.LastModified)
{
if (info.Depdendencies != null)
{
foreach (var dependency in info.Depdendencies)
{
if (CheckIfNeedToBuild(dependency))
{
return(true);
}
}
}
return(false);
}
return(true);
}
private TransformedFileInfo GetTransformedFileInfo(String path, Int32 buildId = 0)
{
if (!_memoized.TryGetValue(path, out var info))
{
_sync.Wait();
try
{
info = new TransformedFileInfo()
{
Path = path
};
if (!_memoized.TryAdd(path, info))
{
throw new InvalidOperationException("Conflict!");
}
}
finally
{
_sync.Release();
}
}
if (CheckIfNeedToBuild(info))
{
// allocate build id to current run
if (buildId == 0)
{
buildId = Interlocked.Increment(ref _buildCounter);
}
// check build id of target, it should not equal current build
if (info.BuildId == buildId)
{
throw new InvalidOperationException($"Detected circular dependency {path}");
}
BuildContent(info, buildId);
}
return(info);
}
private String RecursiveApplyTransform(List <IStaticFileTransform> .Enumerator enumerator, TransformedFileInfo info)
{
if (enumerator.MoveNext())
{
var current = enumerator.Current;
var contentProvider = new ContentProvider(requested => {
if (requested == info.Path)
{
return(RecursiveApplyTransform(enumerator, info));
}
else
{
var dependency = GetTransformedFileInfo(requested, info.BuildId);
info.Depdendencies.Add(dependency);
return(dependency.Content);
}
});
return(current?.Apply(info.Path, contentProvider));
}
else
{
return(ReadOriginalFileContent(info.Original));
}
}
