static void Main(string[] args)
{
// force reference for reflection.
var folderBlueprint = new FolderBlueprint();
var spec = new Specification("Folder", new object());
var allocator = new DefaultAllocator();
if (!allocator.CanLease(spec))
{
Console.WriteLine("Can't provide leased folder.");
}
var folderLease = allocator.Lease(spec).Result as FolderLease;
Debug.Assert(folderLease != null, "folderLease != null");
Console.WriteLine("Got folder lease at " + folderLease.Directory.FullName);
folderLease.Release();
}
public async Task<ILease> Lease(Specification spec)
{
// Check to see if any resources can give us a lease.
foreach (var resource in _activeResources.Where(resource => resource.CanLease(this, spec)))
return await resource.Lease(this, spec);
// Nope, see if any blueprints can allocate a resource that
// will give us a lease.
foreach (var blueprint in _blueprints.Where(blueprint => blueprint.CanAllocate(this, spec)))
{
var resource = await blueprint.Allocate(this, spec);
if (resource.CanLease(this, spec))
return await resource.Lease(this, spec);
resource.Deallocate();
throw new Exception("Blueprint stated that it could allocate a resource matching the spec, but the new resource could not lease.");
}
// Otherwise throw an exception.
throw new Exception("Lease can't be provided.");
}
public ILease WaitForLease(Specification spec)
{
return Lease(spec).Result;
}
public bool CanLease(Specification spec)
{
if (_activeResources.Any(resource => resource.CanLease(this, spec)))
return true;
return _blueprints.Any(blueprint => blueprint.CanAllocate(this, spec));
}
public async Task<ILease> Lease(IAllocator allocator, Specification spec)
{
LeasedOut = true;
_folderLease = new FolderLease(this, Directory);
return _folderLease;
}
public bool CanLease(IAllocator allocator, Specification spec)
{
return spec.ResourceType == "Folder" && !LeasedOut;
}
public async Task<IResource> Allocate(IAllocator allocator, Specification spec)
{
var directory = new DirectoryInfo("C:\\Workspace");
return new FolderResource(directory.CreateSubdirectory("FolderAllocation_" + RandomString()));
}
public bool CanAllocate(IAllocator allocator, Specification spec)
{
return spec.ResourceType == "Folder" &&
Directory.Exists("C:\\Workspace");
}