static void CheckMarkedAsOwned( Owns o, FieldInfo field )
{
Debug.Assert
( o != null
, "Field "+field+" of "+field.DeclaringType+" is not marked with Industry.Owns(true|false)"
, "The field is of a static type of *, IEnumerable<*>, or IDictionary<*>"
+ " (where * implements IDisposable) but is not marked with the attribute Industry.Owns."
);
}
void EmitDisposeFor_Failed( FieldInfo field, Owns owns )
{
throw new InvalidOperationException( "Member "+field.Name+" is not an IDisposable, IDictionary, or IEnumerable but is marked with [Owns]" );
}
void EmitDisposeForIEnumerable( FieldInfo field, Owns owns )
{
Type value = null;
foreach ( var iface in field.FieldType.GetInterfaces() )
if ( iface.IsGenericType && iface.GetGenericTypeDefinition() == typeof(IEnumerable<>) )
{
var args = iface.GetGenericArguments();
value = args[0];
break;
}
if ( value != null ) {
// We were able to infer generic interface parameters
var valueIsDisposable = value.GetInterface(typeof(IDisposable).FullName) != null;
//var valueIsDisposable = value.IsSubclassOf(typeof(IDisposable));
if ( !valueIsDisposable ) return; // skip emitting anything for this member
CheckMarkedAsOwned( owns, field );
if ( owns.Key == false ) return; // skip emitting anything for this member
} else if ( owns == null || !owns.Key ) {
return; // We weren't able to infer generic interface parameters AND the member isn't marked as Owned. Skip it.
}
il.Emit( OpCodes.Ldarg_0 );
il.Emit( OpCodes.Ldfld, field );
il.Emit( OpCodes.Ldnull );
il.Emit( OpCodes.Ceq );
Label islistnull = il.DefineLabel();
il.Emit( OpCodes.Brtrue, islistnull );
il.Emit( OpCodes.Ldarg_0 );
il.Emit( OpCodes.Ldfld, field );
il.EmitCall( OpCodes.Call, typeof(Internal.RAIIMethods).GetMethod("DisposeOfEnumerable", BindingFlags.Public | BindingFlags.Static), null );
il.MarkLabel( islistnull );
}
void EmitDisposeForIDisposable( FieldInfo field, Owns owns )
{
CheckMarkedAsOwned( owns, field );
if ( owns.Key == false ) return; // skip emitting anything for this member
il.Emit( OpCodes.Ldarg_0 );
il.Emit( OpCodes.Ldfld, field );
il.Emit( OpCodes.Ldnull );
il.Emit( OpCodes.Ceq );
Label isnull = il.DefineLabel();
il.Emit( OpCodes.Brtrue, isnull );
var dispose = typeof(IDisposable).GetMethod( "Dispose" );
il.Emit( OpCodes.Ldarg_0 );
il.Emit( OpCodes.Ldfld, field );
il.EmitCall( OpCodes.Call, dispose, null );
il.MarkLabel( isnull );
}
void EmitDisposeForIDictionary( FieldInfo field, Owns owns )
{
Type key = null;
Type value = null;
foreach ( var iface in field.FieldType.GetInterfaces() )
if ( iface.IsGenericType && iface.GetGenericTypeDefinition() == typeof(Dictionary<,>) )
{
var args = iface.GetGenericArguments();
key = args[0];
value = args[1];
break;
}
if ( key != null || value != null ) {
// We were able to infer generic interface parameters
var keyIsDisposable = key .GetInterface(typeof(IDisposable).FullName) != null;
var valueIsDisposable = value.GetInterface(typeof(IDisposable).FullName) != null;
if ( !keyIsDisposable && !valueIsDisposable ) return; // skip emitting anything for this member
CheckMarkedAsOwned( owns, field );
if ( owns.Key == false && owns.Value == false ) return; // skip emitting anything for this member
} else if ( owns == null || (!owns.Key && !owns.Value) ) {
return; // We weren't able to infer generic interface parameters AND the member isn't marked as Owned. Skip it.
}
il.Emit( OpCodes.Ldarg_0 );
il.Emit( OpCodes.Ldfld, field );
il.Emit( OpCodes.Ldnull );
il.Emit( OpCodes.Ceq );
Label isdictnull = il.DefineLabel();
il.Emit( OpCodes.Brtrue, isdictnull );
il.Emit( OpCodes.Ldarg_0 );
il.Emit( OpCodes.Ldfld, field );
il.Emit( owns.Key ? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0 );
il.Emit( owns.Value? OpCodes.Ldc_I4_1 : OpCodes.Ldc_I4_0 );
il.EmitCall( OpCodes.Call, typeof(Internal.RAIIMethods).GetMethod("DisposeOfDictionary", BindingFlags.Public | BindingFlags.Static), null );
il.MarkLabel( isdictnull );
}
public Disposer Create()
{
foreach ( var field in type.GetFields(flags) ) {
var attribs = field.GetCustomAttributes( typeof(Owns), false );
Debug.Assert( attribs.Length <= 1 );
var FieldType = field.FieldType;
Owns owns = null;
if ( attribs.Length != 0 ) owns = attribs[0] as Owns;
else if ( type.IsSubclassOf( field.DeclaringType ) ) owns = new Owns(false);
if ( field.FieldType.GetInterface(typeof(IDisposable).FullName) != null ) EmitDisposeForIDisposable( field, owns );
else if ( field.FieldType.GetInterface(typeof(IDictionary).FullName) != null ) EmitDisposeForIDictionary( field, owns );
else if ( field.FieldType.GetInterface(typeof(IEnumerable).FullName) != null ) EmitDisposeForIEnumerable( field, owns );
else if ( owns != null && ( owns.Key || owns.Value ) ) EmitDisposeFor_Failed ( field, owns );
}
il.Emit( OpCodes.Ret );
return method.CreateDelegate(typeof(Disposer)) as Disposer;
}