public IAssembly TryLoad(string dll, string pdb, string version = null)
{
if (string.IsNullOrWhiteSpace(dll))
{
throw new ArgumentException(nameof(dll));
}
if (string.IsNullOrWhiteSpace(pdb))
{
throw new ArgumentException(nameof(pdb));
}
// Find version if it wasn't provided
if (string.IsNullOrWhiteSpace(version))
{
var assemblyName = _AssemblyNameReader.GetAssemblyName(dll);
if (assemblyName != null)
{
version = assemblyName.Version.ToString();
}
}
// Used cached assembly if it is already loaded and cached
IAssembly assembly = _AssemblyCache.FindAlreadyLoadedAssembly(dll, version);
if (assembly != null)
{
return(assembly);
}
// Load the assembly
assembly = _AppDomain.TryLoad(dll, pdb);
if (assembly == null)
{
return(null);
}
var assemblyVersion = assembly.GetName()?.Version?.ToString();
// Cache the loaded assembly (even if it is the wrong version)
// Also, for threadsafety, get the cached assembly back, in case two threads loaded at the same time
assembly = _AssemblyCache.Add(dll, assemblyVersion, assembly);
// Make sure the version matches the requested version
if (assemblyVersion != version)
{
return(null);
}
// If configured to do so, load all dependent assemblies immediately,
if (_Settings.LoadDependenciesProactively)
{
var dir = Path.GetDirectoryName(dll);
if (!dir.EndsWith("bin"))
{
ProactivelyLoadDependencies(Path.Combine(dir, "bin"));
}
}
return(assembly);
}
public IAssembly FindAlreadyLoadedAssembly(string dll, string version = null)
{
version = (string.IsNullOrWhiteSpace(version))
? _AssemblyNameReader.GetAssemblyName(dll)?.Version?.ToString()
: version;
var key = GetKey(dll, version);
// Find and return already loaded assembly
if (Assemblies.TryGetValue(key, out IAssembly cachedAssembly))
{
_Logger?.WriteLine(PluginLoaderLogLevel.Debug, $"Found already loaded plugin assembly: {key}");
return(cachedAssembly);
}
// See if the Assembly was loaded into the AppDomain already
// This could happen if it was loaded by some other system or reference
var alreadyLoddedassemblies = _AppDomain.GetAssemblies();
if (alreadyLoddedassemblies != null && alreadyLoddedassemblies.Any())
{
var dllAssemblyName = _AssemblyNameReader.GetAssemblyName(dll);
if (dllAssemblyName == null)
{
return(null);
}
foreach (var alreadyLoddedassembly in alreadyLoddedassemblies)
{
var loadedAssemblyName = alreadyLoddedassembly.GetName();
if (loadedAssemblyName.FullName == dllAssemblyName.FullName && loadedAssemblyName.Version.ToString() == version)
{
key = GetKey(dll, alreadyLoddedassembly.GetName().Version.ToString());
_Logger?.WriteLine(PluginLoaderLogLevel.Debug, $"Loading plugin assembly from dll: {key}");
Assemblies.TryAdd(key, alreadyLoddedassembly);
return(alreadyLoddedassembly);
}
}
}
// No assembly found, return null
return(null);
}
