#W# Initial Commit: Avatars Conquest

Scripts/Commands/Generic/Extensions/Compilers/SortCompiler.cs

@@ -0,0 +1,172 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Reflection.Emit;
+using System.Text;
+using Server;
+
+namespace Server.Commands.Generic
+{
+	public sealed class OrderInfo
+	{
+		private Property m_Property;
+		private int m_Order;
+
+		public Property Property
+		{
+			get { return m_Property; }
+			set { m_Property = value; }
+		}
+
+		public bool IsAscending
+		{
+			get { return ( m_Order > 0 ); }
+			set { m_Order = ( value ? +1 : -1 ); }
+		}
+
+		public bool IsDescending
+		{
+			get { return ( m_Order < 0 ); }
+			set { m_Order = ( value ? -1 : +1 ); }
+		}
+
+		public int Sign
+		{
+			get { return Math.Sign( m_Order ); }
+			set
+			{
+				m_Order = Math.Sign( value );
+
+				if ( m_Order == 0 )
+					throw new InvalidOperationException( "Sign cannot be zero." );
+			}
+		}
+
+		public OrderInfo( Property property, bool isAscending )
+		{
+			m_Property = property;
+
+			this.IsAscending = isAscending;
+		}
+	}
+
+	public static class SortCompiler
+	{
+		public static IComparer Compile( AssemblyEmitter assembly, Type objectType, OrderInfo[] orders )
+		{
+			TypeBuilder typeBuilder = assembly.DefineType(
+					"__sort",
+					TypeAttributes.Public,
+					typeof( object )
+				);
+
+			#region Constructor
+			{
+				ConstructorBuilder ctor = typeBuilder.DefineConstructor(
+						MethodAttributes.Public,
+						CallingConventions.Standard,
+						Type.EmptyTypes
+					);
+
+				ILGenerator il = ctor.GetILGenerator();
+
+				// : base()
+				il.Emit( OpCodes.Ldarg_0 );
+				il.Emit( OpCodes.Call, typeof( object ).GetConstructor( Type.EmptyTypes ) );
+
+				// return;
+				il.Emit( OpCodes.Ret );
+			}
+			#endregion
+
+			#region IComparer
+			typeBuilder.AddInterfaceImplementation( typeof( IComparer ) );
+
+			MethodBuilder compareMethod;
+
+			#region Compare
+			{
+				MethodEmitter emitter = new MethodEmitter( typeBuilder );
+
+				emitter.Define(
+					/*  name  */ "Compare",
+					/*  attr  */ MethodAttributes.Public | MethodAttributes.Virtual,
+					/* return */ typeof( int ),
+					/* params */ new Type[] { typeof( object ), typeof( object ) } );
+
+				LocalBuilder a = emitter.CreateLocal( objectType );
+				LocalBuilder b = emitter.CreateLocal( objectType );
+
+				LocalBuilder v = emitter.CreateLocal( typeof( int ) );
+
+				emitter.LoadArgument( 1 );
+				emitter.CastAs( objectType );
+				emitter.StoreLocal( a );
+
+				emitter.LoadArgument( 2 );
+				emitter.CastAs( objectType );
+				emitter.StoreLocal( b );
+
+				emitter.Load( 0 );
+				emitter.StoreLocal( v );
+
+				Label end = emitter.CreateLabel();
+
+				for ( int i = 0; i < orders.Length; ++i )
+				{
+					if ( i > 0 )
+					{
+						emitter.LoadLocal( v );
+						emitter.BranchIfTrue( end ); // if ( v != 0 ) return v;
+					}
+
+					OrderInfo orderInfo = orders[i];
+
+					Property prop = orderInfo.Property;
+					int sign = orderInfo.Sign;
+
+					emitter.LoadLocal( a );
+					emitter.Chain( prop );
+
+					bool couldCompare =
+					emitter.CompareTo( sign, delegate()
+					{
+						emitter.LoadLocal( b );
+						emitter.Chain( prop );
+					} );
+
+					if ( !couldCompare )
+						throw new InvalidOperationException( "Property is not comparable." );
+
+					emitter.StoreLocal( v );
+				}
+
+				emitter.MarkLabel( end );
+
+				emitter.LoadLocal( v );
+				emitter.Return();
+
+				typeBuilder.DefineMethodOverride(
+						emitter.Method,
+						typeof( IComparer ).GetMethod(
+							"Compare",
+							new Type[]
+								{
+									typeof( object ),
+									typeof( object )
+								}
+						)
+					);
+
+				compareMethod = emitter.Method;
+			}
+			#endregion
+			#endregion
+
+			Type comparerType = typeBuilder.CreateType();
+
+			return (IComparer) Activator.CreateInstance( comparerType );
+		}
+	}
+}