public ModuleController()
{
_app_domain_map = new Hashtable ();
_ref_counts = new Hashtable ();
_search_path = new ArrayList ();
_roles = new ArrayList ();
_resolver = new DepResolver (this, _search_path);
_loader = new ModuleLoader (_search_path, _resolver);
_info_map = new Hashtable ();
}
public AppDomain LoadModule(ArrayList _parents, string _name, out ModuleInfo _info, bool checking, bool depcheck)
{
// Okay, this is tricky. First, we have to load the module into a temp domain
// to retrieve its module info. Then, we have to attempt to resolve the dependencies.
// This is going to be fun. Heh.
if (_parents == null)
_parents = new ArrayList ();
// Try to find the module on the search path.
string _filename = SearchForModule (_name);
if (_filename == null)
throw new ModuleNotFoundException (string.Format ("The module {0} was not found along the module search path.", _name));
// Okay, well, now we know the module exists at least in the file (we hope its a proper dll, but we'll see :). Now we
// need to create the temporary AppDomain and load it to get the info from it.
AppDomainSetup _setup = new AppDomainSetup ();
_setup.ApplicationBase = Directory.GetCurrentDirectory ();
AppDomain _tempDomain = AppDomain.CreateDomain (_name, new Evidence (), _setup);
byte[] _raw_bytes = LoadRawFile (_filename);
// set up the search path
// Let's there this son of a bitch up.
_tempDomain.ClearPrivatePath ();
_tempDomain.AppendPrivatePath (Directory.GetCurrentDirectory ());
foreach (string s in _search_path) {
_tempDomain.AppendPrivatePath (s);
}
// The throw here is mostly used from dep resolver calls, although it should also be caught by the immediate caller
// (i.e. the application).
try {
_tempDomain.Load (_raw_bytes);
} catch (BadImageFormatException e) {
AppDomain.Unload (_tempDomain);
throw new ModuleImageException (e.Message);
}
// Okay, now lets grab the module info from the assembly attributes.
Assembly _asm = GetAssembly (_tempDomain, _name);
try {
_info = new ModuleInfo (_asm);
} catch (ModuleInfoException e) {
AppDomain.Unload (_tempDomain);
throw new InvalidModuleException (e.Message);
}
// okay, now we've got the info, let's do some magic with the dependencies.
// this will recursively load all of the appropriate assemblies as per the parsed
// depedency tree. It will take into account dependency operators, such as AND, OR
// OPT (optional). Very intelligent stuff. Of course, if there are no depends,
// this just simply returns. This will of course continue updating the parents as needed
// since each time a new module is loaded, the resolver is recursively called until
// a module with no dependencies is found. This is cool. What this will do is call this method with
// checking=true, which will cause it to just return if the module suceeds. This way
// we can ensure we don't load unneeded module Z that is a dependency of X which depends
// on Y, because if Z suceeds but Y fails, we don't want X, Y, or Z to fail. This way,
// we can ensure the entire tree can be loaded first (this does take into account already
// loaded assemblies).
if (depcheck)
{
DepResolver _resolver = new DepResolver (_controller, _search_path);
_parents.Add (_name);
try {
_resolver.Resolve (_parents, _info);
} catch (Exception e) {
AppDomain.Unload (_tempDomain);
throw e;
}
}
if (checking)
{
AppDomain.Unload (_tempDomain);
return null;
}
// okay, they're good, lets load the suckers.
// alright, we've got them all loaded, they exist in the assembly map.
// now we create the *real* app domain.
// We can't do any more with this.
return _tempDomain;
}
public ModuleLoader(ArrayList search_path, DepResolver resolver)
{
_search_path = search_path;
_resolver = resolver;
}
