NadekoBot/NadekoBot.Core/Services/ServiceProvider.cs
2017-09-30 00:46:33 +02:00

143 lines
5.3 KiB
C#

using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Reflection;
using System.Linq;
using System.Diagnostics;
using NLog;
#if GLOBAL_NADEKO
using NadekoBot.Common;
#endif
namespace NadekoBot.Services
{
public interface INServiceProvider : IServiceProvider, IEnumerable<object>
{
T GetService<T>();
}
public class NServiceProvider : INServiceProvider
{
public class ServiceProviderBuilder
{
private ConcurrentDictionary<Type, object> _dict = new ConcurrentDictionary<Type, object>();
private readonly Logger _log;
public ServiceProviderBuilder()
{
_log = LogManager.GetCurrentClassLogger();
}
public ServiceProviderBuilder AddManual<T>(T obj)
{
_dict.TryAdd(typeof(T), obj);
return this;
}
public NServiceProvider Build()
{
return new NServiceProvider(_dict);
}
public ServiceProviderBuilder LoadFrom(Assembly assembly)
{
var allTypes = assembly.GetTypes();
var services = new Queue<Type>(allTypes
.Where(x => x.GetInterfaces().Contains(typeof(INService))
&& !x.GetTypeInfo().IsInterface && !x.GetTypeInfo().IsAbstract
#if GLOBAL_NADEKO
&& x.GetTypeInfo().GetCustomAttribute<NoPublicBot>() == null
#endif
)
.ToArray());
var interfaces = new HashSet<Type>(allTypes
.Where(x => x.GetInterfaces().Contains(typeof(INService))
&& x.GetTypeInfo().IsInterface));
var alreadyFailed = new Dictionary<Type, int>();
var sw = Stopwatch.StartNew();
var swInstance = new Stopwatch();
while (services.Count > 0)
{
var type = services.Dequeue(); //get a type i need to make an instance of
if (_dict.TryGetValue(type, out _)) // if that type is already instantiated, skip
continue;
var ctor = type.GetConstructors()[0];
var argTypes = ctor
.GetParameters()
.Select(x => x.ParameterType)
.ToArray(); // get constructor argument types i need to pass in
var args = new List<object>(argTypes.Length);
foreach (var arg in argTypes) //get constructor arguments from the dictionary of already instantiated types
{
if (_dict.TryGetValue(arg, out var argObj)) //if i got current one, add it to the list of instances and move on
args.Add(argObj);
else //if i failed getting it, add it to the end, and break
{
services.Enqueue(type);
if (alreadyFailed.ContainsKey(type))
{
alreadyFailed[type]++;
if (alreadyFailed[type] > 3)
_log.Warn(type.Name + " wasn't instantiated in the first 3 attempts. Missing " + arg.Name + " type");
}
else
alreadyFailed.Add(type, 1);
break;
}
}
if (args.Count != argTypes.Length)
continue;
// _log.Info("Loading " + type.Name);
swInstance.Restart();
var instance = ctor.Invoke(args.ToArray());
swInstance.Stop();
if (swInstance.Elapsed.TotalSeconds > 5)
_log.Info($"{type.Name} took {swInstance.Elapsed.TotalSeconds:F2}s to load.");
var interfaceType = interfaces.FirstOrDefault(x => instance.GetType().GetInterfaces().Contains(x));
if (interfaceType != null)
_dict.TryAdd(interfaceType, instance);
_dict.TryAdd(type, instance);
}
sw.Stop();
_log.Info($"All services loaded in {sw.Elapsed.TotalSeconds:F2}s");
return this;
}
}
private readonly ImmutableDictionary<Type, object> _services;
private NServiceProvider() { }
public NServiceProvider(IDictionary<Type, object> services)
{
this._services = services.ToImmutableDictionary();
}
public T GetService<T>()
{
return (T)((IServiceProvider)(this)).GetService(typeof(T));
}
object IServiceProvider.GetService(Type serviceType)
{
_services.TryGetValue(serviceType, out var toReturn);
return toReturn;
}
IEnumerator IEnumerable.GetEnumerator() => _services.Values.GetEnumerator();
public IEnumerator<object> GetEnumerator() => _services.Values.GetEnumerator();
}
}