/DLR_Main/Languages/IronPython/IronPython/Runtime/Types/OldClass.cs

/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Apache License, Version 2.0. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Apache License, Version 2.0, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Apache License, Version 2.0.

 *

 * You must not remove this notice, or any other, from this software.

 *

 *

 * ***************************************************************************/



#if !CLR2

using System.Linq.Expressions;

#else

using Microsoft.Scripting.Ast;

#endif



using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Diagnostics;

using System.Dynamic;

using System.Runtime.Serialization;

using System.Threading;



using Microsoft.Scripting;

using Microsoft.Scripting.Runtime;

using Microsoft.Scripting.Utils;



using IronPython.Runtime.Operations;



using SpecialNameAttribute = System.Runtime.CompilerServices.SpecialNameAttribute;



namespace IronPython.Runtime.Types {



    // OldClass represents the type of old-style Python classes (which could not inherit from 

    // built-in Python types). 

    // 

    // Object instances of old-style Python classes are represented by OldInstance.

    // 

    // UserType is the equivalent of OldClass for new-style Python classes (which can inherit 

    // from built-in types).



    [Flags]

    enum OldClassAttributes {

        None = 0x00,

        HasFinalizer = 0x01,

        HasSetAttr = 0x02,

        HasDelAttr = 0x04,

    }



    [PythonType("classobj"), DontMapGetMemberNamesToDir]

    [Serializable]

    [DebuggerTypeProxy(typeof(OldClass.OldClassDebugView)), DebuggerDisplay("old-style class {Name}")]

    public sealed class OldClass :

#if !SILVERLIGHT // ICustomTypeDescriptor

 ICustomTypeDescriptor,

#endif

 ICodeFormattable,

        IMembersList,

        IDynamicMetaObjectProvider, 

        IPythonMembersList {



        [NonSerialized]

        private List<OldClass> _bases;

        private PythonType _type;



        internal PythonDictionary _dict;

        private int _attrs;  // actually OldClassAttributes - losing type safety for thread safety

        internal object _name;



        private int _optimizedInstanceNamesVersion;

        private string[] _optimizedInstanceNames;



        public static string __doc__ = "classobj(name, bases, dict)";



        public static object __new__(CodeContext/*!*/ context, [NotNull]PythonType cls, string name, PythonTuple bases, PythonDictionary/*!*/ dict) {

            if (dict == null) {

                throw PythonOps.TypeError("dict must be a dictionary");

            } else if (cls != TypeCache.OldClass) {

                throw PythonOps.TypeError("{0} is not a subtype of classobj", cls.Name);

            }



            if (!dict.ContainsKey("__module__")) {

                object moduleValue;

                if (context.TryGetGlobalVariable("__name__", out moduleValue)) {

                    dict["__module__"] = moduleValue;

                }

            }



            foreach (object o in bases) {

                if (o is PythonType) {

                    return PythonOps.MakeClass(context, name, bases._data, String.Empty, dict);

                }

            }



            return new OldClass(name, bases, dict, String.Empty);

        }



        internal OldClass(string name, PythonTuple bases, PythonDictionary/*!*/ dict, string instanceNames) {

            _bases = ValidateBases(bases);



            Init(name, dict, instanceNames);

        }



        private void Init(string name, PythonDictionary/*!*/ dict, string instanceNames) {

            _name = name;



            InitializeInstanceNames(instanceNames);



            _dict = dict;



            

            if (!_dict._storage.Contains("__doc__")) {

                _dict._storage.Add(ref _dict._storage, "__doc__", null);

            }



            CheckSpecialMethods(_dict);

        }



        private void CheckSpecialMethods(PythonDictionary dict) {

            if (dict._storage.Contains("__del__")) {

                HasFinalizer = true;

            }



            if (dict._storage.Contains("__setattr__")) {

                HasSetAttr = true;

            }



            if (dict._storage.Contains("__delattr__")) {

                HasDelAttr = true;

            }



            foreach (OldClass oc in _bases) {

                if (oc.HasDelAttr) {

                    HasDelAttr = true;

                }

                if (oc.HasSetAttr) {

                    HasSetAttr = true;

                }

                if (oc.HasFinalizer) {

                    HasFinalizer = true;

                }

            }

        }



#if !SILVERLIGHT // SerializationInfo

        private OldClass(SerializationInfo info, StreamingContext context) {

            _bases = (List<OldClass>)info.GetValue("__class__", typeof(List<OldClass>));

            _name = info.GetValue("__name__", typeof(object));

            _dict = new PythonDictionary();



            InitializeInstanceNames(""); //TODO should we serialize the optimization data



            List<object> keys = (List<object>)info.GetValue("keys", typeof(List<object>));

            List<object> values = (List<object>)info.GetValue("values", typeof(List<object>));

            for (int i = 0; i < keys.Count; i++) {

                _dict[keys[i]] = values[i];

            }



            if (_dict.has_key("__del__")) HasFinalizer = true;

        }



#pragma warning disable 169 // unused method - called via reflection from serialization

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA1801:ReviewUnusedParameters", MessageId = "context")]

        private void GetObjectData(SerializationInfo info, StreamingContext context) {

            ContractUtils.RequiresNotNull(info, "info");



            info.AddValue("__bases__", _bases);

            info.AddValue("__name__", _name);



            List<object> keys = new List<object>();

            List<object> values = new List<object>();

            foreach (KeyValuePair<object, object> kvp in _dict._storage.GetItems()) {

                keys.Add(kvp.Key);

                values.Add(kvp.Value);

            }



            info.AddValue("keys", keys);

            info.AddValue("values", values);

        }

#pragma warning restore 169

#endif



        private void InitializeInstanceNames(string instanceNames) {

            if (instanceNames.Length == 0) {

                _optimizedInstanceNames = ArrayUtils.EmptyStrings;

                _optimizedInstanceNamesVersion = 0;

                return;

            }



            string[] names = instanceNames.Split(',');

            _optimizedInstanceNames = new string[names.Length];

            for (int i = 0; i < names.Length; i++) {

                _optimizedInstanceNames[i] = names[i];

            }

            _optimizedInstanceNamesVersion = CustomInstanceDictionaryStorage.AllocateVersion();

        }



        internal string[] OptimizedInstanceNames {

            get { return _optimizedInstanceNames; }

        }



        internal int OptimizedInstanceNamesVersion {

            get { return _optimizedInstanceNamesVersion; }

        }



        internal string Name {

            get { return _name.ToString(); }

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1007:UseGenericsWhereAppropriate")]

        internal bool TryLookupSlot(string name, out object ret) {

            if (_dict._storage.TryGetValue(name, out ret)) {

                return true;

            }



            // bases only ever contains OldClasses (tuples are immutable, and when assigned

            // to we verify the types in the Tuple)

            foreach (OldClass c in _bases) {

                if (c.TryLookupSlot(name, out ret)) return true;

            }



            ret = null;

            return false;

        }



        internal bool TryLookupOneSlot(PythonType lookingType, string name, out object ret) {

            if (_dict._storage.TryGetValue(name, out ret)) {

                ret = GetOldStyleDescriptor(TypeObject.Context.SharedContext, ret, null, lookingType);

                return true;

            }

            return false;

        }



        internal string FullName {

            get { return _dict["__module__"].ToString() + '.' + _name; }

        }





        internal List<OldClass> BaseClasses {

            get {

                return _bases;

            }

        }



        internal object GetOldStyleDescriptor(CodeContext context, object self, object instance, object type) {

            PythonTypeSlot dts = self as PythonTypeSlot;

            object callable;

            if (dts != null && dts.TryGetValue(context, instance, TypeObject, out callable)) {

                return callable;

            }



            return PythonOps.GetUserDescriptor(self, instance, type);

        }



        internal static object GetOldStyleDescriptor(CodeContext context, object self, object instance, PythonType type) {

            PythonTypeSlot dts = self as PythonTypeSlot;

            object callable;

            if (dts != null && dts.TryGetValue(context, instance, type, out callable)) {

                return callable;

            }



            return PythonOps.GetUserDescriptor(self, instance, type);

        }



        internal bool HasFinalizer {

            get {

                return (_attrs & (int)OldClassAttributes.HasFinalizer) != 0;

            }

            set {

                int oldAttrs, newAttrs;

                do {

                    oldAttrs = _attrs;

                    newAttrs = value ? oldAttrs | ((int)OldClassAttributes.HasFinalizer) : oldAttrs & ((int)~OldClassAttributes.HasFinalizer);

                } while (Interlocked.CompareExchange(ref _attrs, newAttrs, oldAttrs) != oldAttrs);

            }

        }



        internal bool HasSetAttr {

            get {

                return (_attrs & (int)OldClassAttributes.HasSetAttr) != 0;

            }

            set {

                int oldAttrs, newAttrs;

                do {

                    oldAttrs = _attrs;

                    newAttrs = value ? oldAttrs | ((int)OldClassAttributes.HasSetAttr) : oldAttrs & ((int)~OldClassAttributes.HasSetAttr);

                } while (Interlocked.CompareExchange(ref _attrs, newAttrs, oldAttrs) != oldAttrs);

            }

        }



        internal bool HasDelAttr {

            get {

                return (_attrs & (int)OldClassAttributes.HasDelAttr) != 0;

            }

            set {

                int oldAttrs, newAttrs;

                do {

                    oldAttrs = _attrs;

                    newAttrs = value ? oldAttrs | ((int)OldClassAttributes.HasDelAttr) : oldAttrs & ((int)~OldClassAttributes.HasDelAttr);

                } while (Interlocked.CompareExchange(ref _attrs, newAttrs, oldAttrs) != oldAttrs);

            }

        }



        public override string ToString() {

            return FullName;

        }



        #region Calls



        // Calling an OldClass instance means instantiating that class and invoking the __init__() member if 

        // it's defined.



        // OldClass impls IDynamicMetaObjectProvider. But May wind up here still if IDynamicObj doesn't provide a rule (such as for list sigs).

        // If our IDynamicMetaObjectProvider implementation is complete, we can then remove these Call methods.

        [SpecialName]

        public object Call(CodeContext context, [NotNull]params object[] args\u00F8) {

            OldInstance inst = new OldInstance(context, this);

            object value;

            // lookup the slot directly - we don't go through __getattr__

            // until after the instance is created.

            if (TryLookupSlot("__init__", out value)) {

                PythonOps.CallWithContext(context, GetOldStyleDescriptor(context, value, inst, this), args\u00F8);

            } else if (args\u00F8.Length > 0) {

                MakeCallError();

            }

            return inst;

        }



        [SpecialName]

        public object Call(CodeContext context, [ParamDictionary]IDictionary<object, object> dict\u00F8, [NotNull]params object[] args\u00F8) {

            OldInstance inst = new OldInstance(context, this);

            object meth;

            if (PythonOps.TryGetBoundAttr(inst, "__init__", out meth)) {

                PythonCalls.CallWithKeywordArgs(context, meth, args\u00F8, dict\u00F8);

            } else if (dict\u00F8.Count > 0 || args\u00F8.Length > 0) {

                MakeCallError();

            }

            return inst;

        }



        #endregion // calls

        

        internal PythonType TypeObject {

            get {

                if (_type == null) {

                    Interlocked.CompareExchange(ref _type, new PythonType(this), null);

                }

                return _type;

            }

        }



        private List<OldClass> ValidateBases(object value) {

            PythonTuple t = value as PythonTuple;

            if (t == null) throw PythonOps.TypeError("__bases__ must be a tuple object");



            List<OldClass> res = new List<OldClass>(t.__len__());

            foreach (object o in t) {

                OldClass oc = o as OldClass;

                if (oc == null) throw PythonOps.TypeError("__bases__ items must be classes (got {0})", PythonTypeOps.GetName(o));



                if (oc.IsSubclassOf(this)) {

                    throw PythonOps.TypeError("a __bases__ item causes an inheritance cycle");

                }



                res.Add(oc);

            }

            return res;

        }



        internal object GetMember(CodeContext context, string name) {

            object value;



            if (!TryGetBoundCustomMember(context, name, out value)) {

                throw PythonOps.AttributeError("type object '{0}' has no attribute '{1}'", Name, name);

            }



            return value;

        }



        internal bool TryGetBoundCustomMember(CodeContext context, string name, out object value) {

            if (name == "__bases__") { value = PythonTuple.Make(_bases); return true; }

            if (name == "__name__") { value = _name; return true; }

            if (name == "__dict__") {

                //!!! user code can modify __del__ property of __dict__ behind our back

                HasDelAttr = HasSetAttr = true;  // pessimisticlly assume the user is setting __setattr__ in the dict

                value = _dict; return true;

            }



            if (TryLookupSlot(name, out value)) {

                value = GetOldStyleDescriptor(context, value, null, this);

                return true;

            }

            return false;

        }



        internal bool DeleteCustomMember(CodeContext context, string name) {

            if (!_dict._storage.Remove(ref _dict._storage, name)) {

                throw PythonOps.AttributeError("{0} is not a valid attribute", name);

            }



            if (name == "__del__") {

                HasFinalizer = false;

            }

            if (name == "__setattr__") {

                HasSetAttr = false;

            }

            if (name == "__delattr__") {

                HasDelAttr = false;

            }



            return true;

        }



        internal static void RecurseAttrHierarchy(OldClass oc, IDictionary<object, object> attrs) {

            foreach (KeyValuePair<object, object> kvp in oc._dict._storage.GetItems()) {

                if (!attrs.ContainsKey(kvp.Key)) {

                    attrs.Add(kvp.Key, kvp.Key);

                }

            }



            //  recursively get attrs in parent hierarchy

            if (oc._bases.Count != 0) {

                foreach (OldClass parent in oc._bases) {

                    RecurseAttrHierarchy(parent, attrs);

                }

            }

        }



        #region IMembersList Members



        IList<string> IMembersList.GetMemberNames() {

            return PythonOps.GetStringMemberList(this);

        }



        IList<object> IPythonMembersList.GetMemberNames(CodeContext/*!*/ context) {

            PythonDictionary attrs = new PythonDictionary(_dict);

            RecurseAttrHierarchy(this, attrs);

            return PythonOps.MakeListFromSequence(attrs);

        }



        #endregion



        internal bool IsSubclassOf(object other) {

            if (this == other) return true;



            OldClass dt = other as OldClass;

            if (dt == null) return false;



            List<OldClass> bases = _bases;

            foreach (OldClass bc in bases) {

                if (bc.IsSubclassOf(other)) {

                    return true;

                }

            }

            return false;

        }



        #region ICustomTypeDescriptor Members

#if !SILVERLIGHT // ICustomTypeDescriptor



        AttributeCollection ICustomTypeDescriptor.GetAttributes() {

            return CustomTypeDescHelpers.GetAttributes(this);

        }



        string ICustomTypeDescriptor.GetClassName() {

            return CustomTypeDescHelpers.GetClassName(this);

        }



        string ICustomTypeDescriptor.GetComponentName() {

            return CustomTypeDescHelpers.GetComponentName(this);

        }



        TypeConverter ICustomTypeDescriptor.GetConverter() {

            return CustomTypeDescHelpers.GetConverter(this);

        }



        EventDescriptor ICustomTypeDescriptor.GetDefaultEvent() {

            return CustomTypeDescHelpers.GetDefaultEvent(this);

        }



        PropertyDescriptor ICustomTypeDescriptor.GetDefaultProperty() {

            return CustomTypeDescHelpers.GetDefaultProperty(this);

        }



        object ICustomTypeDescriptor.GetEditor(Type editorBaseType) {

            return CustomTypeDescHelpers.GetEditor(this, editorBaseType);

        }



        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[] attributes) {

            return CustomTypeDescHelpers.GetEvents(attributes);

        }



        EventDescriptorCollection ICustomTypeDescriptor.GetEvents() {

            return CustomTypeDescHelpers.GetEvents(this);

        }



        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[] attributes) {

            return CustomTypeDescHelpers.GetProperties(attributes);

        }



        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties() {

            return CustomTypeDescHelpers.GetProperties(this);

        }



        object ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor pd) {

            return CustomTypeDescHelpers.GetPropertyOwner(this, pd);

        }

#endif

        #endregion



        #region ICodeFormattable Members



        public string/*!*/ __repr__(CodeContext/*!*/ context) {

            return string.Format("<class {0} at {1}>", FullName, PythonOps.HexId(this));

        }



        #endregion



        #region Internal Member Accessors



        internal bool TryLookupInit(object inst, out object ret) {

            if (TryLookupSlot("__init__", out ret)) {

                ret = GetOldStyleDescriptor(DefaultContext.Default, ret, inst, this);

                return true;

            }



            return false;

        }



        internal static object MakeCallError() {

            // Normally, if we have an __init__ method, the method binder detects signature mismatches.

            // This can happen when a class does not define __init__ and therefore does not take any arguments.

            // Beware that calls like F(*(), **{}) have 2 arguments but they're empty and so it should still

            // match against def F(). 

            throw PythonOps.TypeError("this constructor takes no arguments");

        }



        internal void SetBases(object value) {

            _bases = ValidateBases(value);

        }



        internal void SetName(object value) {

            string n = value as string;

            if (n == null) throw PythonOps.TypeError("TypeError: __name__ must be a string object");

            _name = n;

        }



        internal void SetDictionary(object value) {

            PythonDictionary d = value as PythonDictionary;

            if (d == null) throw PythonOps.TypeError("__dict__ must be set to dictionary");

            _dict = d;

        }



        internal void SetNameHelper(string name, object value) {

            _dict._storage.Add(ref _dict._storage, name, value);



            if (name == "__del__") {

                HasFinalizer = true;

            } else if (name == "__setattr__") {

                HasSetAttr = true;

            } else if (name == "__delattr__") {

                HasDelAttr = true;

            }

        }



        internal object LookupValue(CodeContext context, string name) {

            object value;

            if (TryLookupValue(context, name, out value)) {

                return value;

            }



            throw PythonOps.AttributeErrorForMissingAttribute(this, name);

        }



        internal bool TryLookupValue(CodeContext context, string name, out object value) {

            if (TryLookupSlot(name, out value)) {

                value = GetOldStyleDescriptor(context, value, null, this);

                return true;

            }



            return false;

        }



        internal void DictionaryIsPublic() {

            HasDelAttr = true;

            HasSetAttr = true;

        }



        #endregion



        #region IDynamicMetaObjectProvider Members



        DynamicMetaObject/*!*/ IDynamicMetaObjectProvider.GetMetaObject(Expression/*!*/ parameter) {

            return new Binding.MetaOldClass(parameter, BindingRestrictions.Empty, this);

        }



        #endregion



        internal class OldClassDebugView {

            private readonly OldClass _class;



            public OldClassDebugView(OldClass klass) {

                _class = klass;

            }



            public List<OldClass> __bases__ {

                get {

                    return _class.BaseClasses;

                }

            }



            [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]

            internal List<ObjectDebugView> Members {

                get {

                    var res = new List<ObjectDebugView>();

                    if (_class._dict != null) {

                        foreach (var v in _class._dict) {

                            res.Add(new ObjectDebugView(v.Key, v.Value));

                        }

                    }



                    return res;

                }

            }

        }

    }

}