/Microsoft.Scripting/Actions/NamespaceTracker.cs

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

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Microsoft Public License. A 

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

 * you cannot locate the  Microsoft Public License, 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 Microsoft Public License.

 *

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

 *

 *

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



#if CODEPLEX_40

using System;

#else

using System; using Microsoft;

#endif

using System.Collections;

using System.Collections.Generic;

using System.Diagnostics;

#if CODEPLEX_40

using System.Linq.Expressions;

#else

using Microsoft.Linq.Expressions;

#endif

using System.Reflection;

using Microsoft.Scripting.Utils;

using System.Threading;

using Microsoft.Contracts;

using Microsoft.Scripting.Runtime;

using AstUtils = Microsoft.Scripting.Ast.Utils;



namespace Microsoft.Scripting.Actions {

    public class AssemblyLoadedEventArgs : EventArgs {

        private Assembly _assembly;



        public AssemblyLoadedEventArgs(Assembly assembly) {

            _assembly = assembly;

        }



        public Assembly Assembly {

            get {

                return _assembly;

            }

        }

    }



    /// <summary>

    /// NamespaceTracker represent a CLS namespace.

    /// </summary>

    public class NamespaceTracker : MemberTracker, IOldDynamicObject, IAttributesCollection, IMembersList {

        // _dict contains all the currently loaded entries. However, there may be pending types that have

        // not yet been loaded in _typeNames

        internal Dictionary<string, MemberTracker> _dict = new Dictionary<string, MemberTracker>();



        internal readonly List<Assembly> _packageAssemblies = new List<Assembly>();

        internal readonly Dictionary<Assembly, TypeNames> _typeNames = new Dictionary<Assembly, TypeNames>();



        private string _fullName; // null for the TopReflectedPackage

        private TopNamespaceTracker _topPackage;

        private int _id;



        private static int _masterId;



        #region Protected API Surface



        private NamespaceTracker() {

            UpdateId();

        }



        [Confined]

        public override string ToString() {

            return base.ToString() + ":" + _fullName;

        }



        protected NamespaceTracker(string name)

            : this() {

            _fullName = name;

        }



        #endregion



        #region Internal API Surface



        internal NamespaceTracker GetOrMakeChildPackage(string childName, Assembly assem) {

            // lock is held when this is called

            Assert.NotNull(childName, assem);

            Debug.Assert(childName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name

            Debug.Assert(_packageAssemblies.Contains(assem)); // Parent namespace must contain all the assemblies of the child



            MemberTracker ret;

            if (_dict.TryGetValue(childName, out ret)) {

                // If we have a module, then we add the assembly to the InnerModule

                // If it's not a module, we'll wipe it out below, eg "def System(): pass" then 

                // "import System" will result in the namespace being visible.

                NamespaceTracker package = ret as NamespaceTracker;

                if (package != null) {

                    if (!package._packageAssemblies.Contains(assem)) {

                        package._packageAssemblies.Add(assem);

                        package.UpdateId();

                    }

                    return package;

                }

            }



            return MakeChildPackage(childName, assem);

        }



        private NamespaceTracker MakeChildPackage(string childName, Assembly assem) {

            // lock is held when this is called

            Assert.NotNull(childName, assem);

            NamespaceTracker rp = new NamespaceTracker();

            rp.SetTopPackage(_topPackage);

            rp._packageAssemblies.Add(assem);



            rp._fullName = GetFullChildName(childName);

            _dict[childName] = rp;

            return rp;

        }



        private string GetFullChildName(string childName) {

            Assert.NotNull(childName);

            Debug.Assert(childName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name

            if (_fullName == null) {

                return childName;

            }



            return _fullName + Type.Delimiter + childName;

        }



        private static Type LoadType(Assembly assem, string fullTypeName) {

            Assert.NotNull(assem, fullTypeName);

            Type type = assem.GetType(fullTypeName);

            // We should ignore nested types. They will be loaded when the containing type is loaded

            Debug.Assert(!ReflectionUtils.IsNested(type));

            return type;

        }



        internal void AddTypeName(string typeName, Assembly assem) {

            // lock is held when this is called

            Assert.NotNull(typeName, assem);

            Debug.Assert(typeName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name



            if (!_typeNames.ContainsKey(assem)) {

                _typeNames[assem] = new TypeNames(assem, _fullName);

            }

            _typeNames[assem].AddTypeName(typeName);



            string normalizedTypeName = ReflectionUtils.GetNormalizedTypeName(typeName);

            if (_dict.ContainsKey(normalizedTypeName)) {

                // A similarly named type, namespace, or module already exists.

                Type newType = LoadType(assem, GetFullChildName(typeName));



                object existingValue = _dict[normalizedTypeName];

                TypeTracker existingTypeEntity = existingValue as TypeTracker;

                if (existingTypeEntity == null) {

                    // Replace the existing namespace or module with the new type

                    Debug.Assert(existingValue is NamespaceTracker);

                    _dict[normalizedTypeName] = MemberTracker.FromMemberInfo(newType);

                } else {

                    // Unify the new type with the existing type

                    _dict[normalizedTypeName] = TypeGroup.UpdateTypeEntity(existingTypeEntity, ReflectionCache.GetTypeTracker(newType));

                }

                return;

            }

        }



        /// <summary>

        /// Loads all the types from all assemblies that contribute to the current namespace (but not child namespaces)

        /// </summary>

        private void LoadAllTypes() {

            foreach (TypeNames typeNameList in _typeNames.Values) {

                foreach (string typeName in typeNameList.GetNormalizedTypeNames()) {

                    object value;

                    if (!TryGetValue(SymbolTable.StringToId(typeName), out value)) {

                        Debug.Assert(false, "We should never get here as TryGetMember should raise a TypeLoadException");

                        throw new TypeLoadException(typeName);

                    }

                }

            }

        }



        #endregion



        public override string Name {

            get {

                return _fullName;

            }

        }



        protected void DiscoverAllTypes(Assembly assem) {

            // lock is held when this is called

            Assert.NotNull(assem);



            NamespaceTracker previousPackage = null;

            string previousFullNamespace = String.Empty; // Note that String.Empty is not a valid namespace



            foreach (TypeName typeName in AssemblyTypeNames.GetTypeNames(assem, _topPackage.DomainManager.Configuration.PrivateBinding)) {

                NamespaceTracker package;

                Debug.Assert(typeName.Namespace != String.Empty);

                if (typeName.Namespace == previousFullNamespace) {

                    // We have a cache hit. We dont need to call GetOrMakePackageHierarchy (which generates

                    // a fair amount of temporary substrings)

                    package = previousPackage;

                } else {

                    package = GetOrMakePackageHierarchy(assem, typeName.Namespace);

                    previousFullNamespace = typeName.Namespace;

                    previousPackage = package;

                }



                package.AddTypeName(typeName.Name, assem);

            }

        }



        /// <summary>

        /// Populates the tree with nodes for each part of the namespace

        /// </summary>

        /// <param name="assem"></param>

        /// <param name="fullNamespace">Full namespace name. It can be null (for top-level types)</param>

        /// <returns></returns>

        private NamespaceTracker GetOrMakePackageHierarchy(Assembly assem, string fullNamespace) {

            // lock is held when this is called

            Assert.NotNull(assem);



            if (fullNamespace == null) {

                // null is the top-level namespace

                return this;

            }



            NamespaceTracker ret = this;

            string[] pieces = fullNamespace.Split(Type.Delimiter);

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

                ret = ret.GetOrMakeChildPackage(pieces[i], assem);

            }



            return ret;

        }

        /// <summary>

        /// As a fallback, so if the type does exist in any assembly. This would happen if a new type was added

        /// that was not in the hardcoded list of types. 

        /// This code is not accurate because:

        /// 1. We dont deal with generic types (TypeCollision). 

        /// 2. Previous calls to GetCustomMemberNames (eg. "from foo import *" in Python) would not have included this type.

        /// 3. This does not deal with new namespaces added to the assembly

        /// </summary>

        private MemberTracker CheckForUnlistedType(string nameString) {

            Assert.NotNull(nameString);



            string fullTypeName = GetFullChildName(nameString);

            foreach (Assembly assem in _packageAssemblies) {

                Type type = assem.GetType(fullTypeName, false);

                if (type == null || ReflectionUtils.IsNested(type)) {

                    continue;

                }



                bool publishType = type.IsPublic || _topPackage.DomainManager.Configuration.PrivateBinding;

                if (!publishType) {

                    continue;

                }



                // We dont use TypeCollision.UpdateTypeEntity here because we do not handle generic type names                    

                return ReflectionCache.GetTypeTracker(type);

            }



            return null;

        }



        #region IAttributesCollection Members



        public void Add(SymbolId name, object value) {

            throw new InvalidOperationException();

        }



        public bool TryGetValue(SymbolId name, out object value) {

            MemberTracker tmp;

            bool res = TryGetValue(name, out tmp);

            value = tmp;

            return res;

        }



        public bool TryGetValue(SymbolId name, out MemberTracker value) {

            lock (this) {

                LoadNamespaces();



                if (_dict.TryGetValue(SymbolTable.IdToString(name), out value)) {

                    return true;

                }



                MemberTracker existingTypeEntity = null;

                string nameString = SymbolTable.IdToString(name);



                if (nameString.IndexOf(Type.Delimiter) != -1) {

                    value = null;

                    return false;

                }



                // Look up the type names and load the type if its name exists



                foreach (KeyValuePair<Assembly, TypeNames> kvp in _typeNames) {

                    if (!kvp.Value.Contains(nameString)) {

                        continue;

                    }



                    existingTypeEntity = kvp.Value.UpdateTypeEntity((TypeTracker)existingTypeEntity, nameString);

                }



                if (existingTypeEntity == null) {

                    existingTypeEntity = CheckForUnlistedType(nameString);

                }



                if (existingTypeEntity != null) {

                    _dict[SymbolTable.IdToString(name)] = existingTypeEntity;

                    value = existingTypeEntity;

                    return true;

                }



                return false;

            }

        }



        public bool Remove(SymbolId name) {

            throw new InvalidOperationException();

        }



        public bool ContainsKey(SymbolId name) {

            object dummy;

            return TryGetValue(name, out dummy);

        }



        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1065:DoNotRaiseExceptionsInUnexpectedLocations")]

        public object this[SymbolId name] {

            get {

                object res;

                if (TryGetValue(name, out res)) {

                    return res;

                }

                throw new KeyNotFoundException();

            }

            set {

                throw new InvalidOperationException();

            }

        }



        public IDictionary<SymbolId, object> SymbolAttributes {

            get {

                LoadNamespaces();



                Dictionary<SymbolId, object> res = new Dictionary<SymbolId, object>();

                foreach (KeyValuePair<object, object> kvp in this) {

                    string strkey = kvp.Key as string;

                    if (strkey != null) {

                        res[SymbolTable.StringToId(strkey)] = kvp.Value;

                    }

                }



                return res;

            }

        }



        public void AddObjectKey(object name, object value) {

            throw new InvalidOperationException();

        }



        public bool TryGetObjectValue(object name, out object value) {

            string str = name as string;

            if (str != null) {

                return TryGetValue(SymbolTable.StringToId(str), out value);

            }



            value = null;

            return false;

        }



        public bool RemoveObjectKey(object name) {

            throw new InvalidOperationException();

        }



        public bool ContainsObjectKey(object name) {

            object dummy;

            return TryGetObjectValue(name, out dummy);

        }



        public IDictionary<object, object> AsObjectKeyedDictionary() {

            LoadNamespaces();



            lock (this) {

                Dictionary<object, object> res = new Dictionary<object, object>();

                foreach (KeyValuePair<string, MemberTracker> kvp in _dict) {

                    res[kvp.Key] = kvp.Value;

                }

                return res;

            }

        }



        public int Count {

            get { return _dict.Count; }

        }



        public ICollection<object> Keys {

            get {

                LoadNamespaces();



                lock (this) {

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

                    foreach (string s in _dict.Keys) res.Add(s);



                    foreach (KeyValuePair<Assembly, TypeNames> kvp in _typeNames) {

                        foreach (string typeName in kvp.Value.GetNormalizedTypeNames()) {

                            if (!res.Contains(typeName)) {

                                res.Add(typeName);

                            }

                        }

                    }



                    res.Sort();

                    return res;

                }

            }

        }



        #endregion



        #region IEnumerable<KeyValuePair<object,object>> Members



        [Pure]

        public IEnumerator<KeyValuePair<object, object>> GetEnumerator() {

            foreach (object key in Keys) {

                yield return new KeyValuePair<object, object>(key, this[SymbolTable.StringToId((string)key)]);

            }

        }



        #endregion



        #region IEnumerable Members



        [Pure]

        IEnumerator IEnumerable.GetEnumerator() {

            foreach (object key in Keys) {

                yield return new KeyValuePair<object, object>(key, this[SymbolTable.StringToId((string)key)]);

            }

        }



        #endregion



        public IList<Assembly> PackageAssemblies {

            get {

                LoadNamespaces();



                return _packageAssemblies;

            }

        }



        protected virtual void LoadNamespaces() {

            if (_topPackage != null) {

                _topPackage.LoadNamespaces();

            }

        }



        protected void SetTopPackage(TopNamespaceTracker pkg) {

            Assert.NotNull(pkg);

            _topPackage = pkg;

        }



        /// <summary>

        /// This stores all the public non-nested type names in a single namespace and from a single assembly.

        /// This allows inspection of the namespace without eagerly loading all the types. Eagerly loading

        /// types slows down startup, increases working set, and is semantically incorrect as it can trigger

        /// TypeLoadExceptions sooner than required.

        /// </summary>

        internal class TypeNames {

            List<string> _simpleTypeNames = new List<string>();

            Dictionary<string, List<string>> _genericTypeNames = new Dictionary<string, List<string>>();



            Assembly _assembly;

            string _fullNamespace;



            internal TypeNames(Assembly assembly, string fullNamespace) {

                _assembly = assembly;

                _fullNamespace = fullNamespace;

            }



            internal bool Contains(string normalizedTypeName) {

                Debug.Assert(normalizedTypeName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name

                Debug.Assert(ReflectionUtils.GetNormalizedTypeName(normalizedTypeName) == normalizedTypeName);



                return _simpleTypeNames.Contains(normalizedTypeName) || _genericTypeNames.ContainsKey(normalizedTypeName);

            }



            internal MemberTracker UpdateTypeEntity(TypeTracker existingTypeEntity, string normalizedTypeName) {

                Debug.Assert(normalizedTypeName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name

                Debug.Assert(ReflectionUtils.GetNormalizedTypeName(normalizedTypeName) == normalizedTypeName);



                // Look for a non-generic type

                if (_simpleTypeNames.Contains(normalizedTypeName)) {

                    Type newType = LoadType(_assembly, GetFullChildName(normalizedTypeName));

                    existingTypeEntity = TypeGroup.UpdateTypeEntity(existingTypeEntity, ReflectionCache.GetTypeTracker(newType));

                }



                // Look for generic types

                if (_genericTypeNames.ContainsKey(normalizedTypeName)) {

                    List<string> actualNames = _genericTypeNames[normalizedTypeName];

                    foreach (string actualName in actualNames) {

                        Type newType = LoadType(_assembly, GetFullChildName(actualName));

                        existingTypeEntity = TypeGroup.UpdateTypeEntity(existingTypeEntity, ReflectionCache.GetTypeTracker(newType));

                    }

                }



                return existingTypeEntity;

            }



            internal void AddTypeName(string typeName) {

                Debug.Assert(typeName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name



                string normalizedName = ReflectionUtils.GetNormalizedTypeName(typeName);

                if (normalizedName == typeName) {

                    _simpleTypeNames.Add(typeName);

                } else {

                    List<string> actualNames;

                    if (_genericTypeNames.ContainsKey(normalizedName)) {

                        actualNames = _genericTypeNames[normalizedName];

                    } else {

                        actualNames = new List<string>();

                        _genericTypeNames[normalizedName] = actualNames;

                    }

                    actualNames.Add(typeName);

                }

            }



            string GetFullChildName(string childName) {

                Debug.Assert(childName.IndexOf(Type.Delimiter) == -1); // This is the simple name, not the full name

                if (_fullNamespace == null) {

                    return childName;

                }



                return _fullNamespace + Type.Delimiter + childName;

            }



            internal ICollection<string> GetNormalizedTypeNames() {

                List<string> normalizedTypeNames = new List<string>();



                normalizedTypeNames.AddRange(_simpleTypeNames);

                normalizedTypeNames.AddRange(_genericTypeNames.Keys);



                return normalizedTypeNames;

            }

        }



        #region IOldDynamicObject Members



        public bool GetRule(OldDynamicAction action, CodeContext context, object[] args, RuleBuilder rule) {

            if (action.Kind == DynamicActionKind.GetMember) {

                return MakeGetMemberRule((OldGetMemberAction)action, context, rule);                

            }

            return false;

        }



        private bool MakeGetMemberRule(OldGetMemberAction action, CodeContext context, RuleBuilder rule) {

            object value;

            if (TryGetValue(action.Name, out value)) {

                Debug.Assert(value is MemberTracker);

                MemberTracker memValue = (MemberTracker)value;



                rule.MakeTest(typeof(NamespaceTracker));

                rule.AddTest(

                    Expression.Equal(

                        Expression.Property(

                            Expression.Convert(rule.Parameters[0], typeof(NamespaceTracker)),

                            typeof(NamespaceTracker).GetProperty("Id")

                        ),

                        AstUtils.Constant(Id)

                    )

                );





                Expression target = context.LanguageContext.Binder.ReturnMemberTracker(memValue.DeclaringType, memValue);



                rule.Target = rule.MakeReturn(context.LanguageContext.Binder, target);

                return true;

            }

            return false;

        }



        #endregion



        public int Id {

            get {

                return _id;

            }

        }



        #region IMembersList Members



        public IList<object> GetMemberNames(CodeContext context) {

            return (IList<object>)Keys;

        }



        #endregion



        public override TrackerTypes MemberType {

            get { return TrackerTypes.Namespace; }

        }



        public override Type DeclaringType {

            get { return null; }

        }



        protected void UpdateId() {

            _id = Interlocked.Increment(ref _masterId);

            foreach (KeyValuePair<string, MemberTracker> kvp in _dict) {

                NamespaceTracker ns = kvp.Value as NamespaceTracker;

                if (ns == null) continue;



                lock (ns) {

                    // namespace trackers are trees so we always take this

                    // in order

                    ns.UpdateId();

                }

            }

        }

    }

}