C# TokenBasedSet.GetItem方法代码示例

     private void AppendTokenBasedSets( TokenBasedSet thisSet, TokenBasedSet permSet, int type, bool unrestricted )
     {
         int thisMaxIndex = thisSet.GetMaxUsedIndex();
         int permMaxIndex = permSet == null ? 0 : permSet.GetMaxUsedIndex();
         int maxIndex = thisMaxIndex > permMaxIndex ? thisMaxIndex : permMaxIndex;
         
         // Loop over the relevant indexes...
         for (int i = 0; i <= maxIndex; i++)
         {
             PermissionList plist = (PermissionList)thisSet.GetItem(i);
             CodeAccessPermission cap = permSet == null ? null : (CodeAccessPermission)permSet.GetItem(i);
             
             if (plist == null)
             {
                 if (this.m_unrestricted)
                 {
                     switch (type)
                     {
                     case PermissionList.MatchChecked:
                     case PermissionList.MatchPermitOnly:
                         plist = new PermissionList();
                         plist.AppendPermission(cap, type);
                         thisSet.SetItem( i, plist );
                         break;
                     
                     case PermissionList.MatchDeny:
                     case PermissionList.MatchAssert:
                         if (cap != null)
                         {
                             plist = new PermissionList();
                             plist.AppendPermission(cap, type);
                             thisSet.SetItem( i, plist );
                         }
                         break;
                     
                     default:
                         throw new ArgumentException(Environment.GetResourceString( "Argument_InvalidPermissionListType" ));
                     }
                 }
             }
             else
             {                    
                 // A list already exists. All lists should have at least
                 // one element in them.
 
                 // Normally, only append if the permission is not null.
                 // However, if the type is Checked, then make sure the
                 // list is terminated with a permission, null or not.
                 switch (type)
                 {
                 case PermissionList.MatchChecked:
                 case PermissionList.MatchPermitOnly:
                     plist.AppendPermissionAndCompress(cap, type);
                     break;
                         
                 case PermissionList.MatchDeny:
                 case PermissionList.MatchAssert:
                     if (cap != null)
                         plist.AppendPermissionAndCompress(cap, type);
                     break;
                         
                 default:
                     throw new ArgumentException(Environment.GetResourceString( "Argument_InvalidPermissionListType" ));
                 }
             }
         }
     }

		private void AppendStackHelper( TokenBasedSet thisSet, TokenBasedSet permSet, bool unrestrictedThisSet, bool unrestrictedPermSet, bool unrestricted )
		{
            int maxThis = thisSet.GetMaxUsedIndex();
            int maxPerm = permSet.GetMaxUsedIndex();
            
            int maxIndex = maxThis > maxPerm ? maxThis : maxPerm;
            
            for (int i = 0; i <= maxIndex; i++)
            {
                PermissionList plist = (PermissionList)thisSet.GetItem(i);
                PermissionList appendList = (PermissionList)permSet.GetItem(i);
                if (plist != null)
                {
                    if (appendList != null)
                    {
                        // This call will not add the permission if the list is
                        // empty, or if the last element is a normal check with
                        // a null Permission. Let the method take care of it...
                        plist.AppendStack(appendList.Copy());
                    }
                    else
                    {
                        // Nothing on the compressed stack for this index,
                        // so terminate current list.
                        if (!unrestrictedPermSet)
                        {
                            thisSet.SetItem( i, plist.Copy() );
                        }
                    }
                }
                else if (unrestrictedThisSet && appendList != null)
                {
                    thisSet.SetItem(i, appendList.Copy());
                }
            }
		}

        private static bool CheckTokenBasedSets( TokenBasedSet thisSet, TokenBasedSet permSet, bool unrestricted, PermissionListSetState state, out Exception exception, bool bNeedAlteredSet, out TokenBasedSet alteredSet )
        {
            alteredSet = null;

            // If the set is empty, there is no reason to walk the
            // stack.

            if (permSet == null || permSet.IsEmpty())
            {
                if (bNeedAlteredSet)
                    alteredSet = new TokenBasedSet( 1, 4 );
                exception = null;
                return false;
            }

            int permMaxIndex = permSet.GetMaxUsedIndex();
            
            // Make a quick check to see if permSet definitely contains permissions that this set doesn't
            
            if (permMaxIndex > thisSet.GetMaxUsedIndex())
            {
                // The only way we don't want to throw an exception is
                // if we are unrestricted.  Then, if we don't want to throw
                // an exception we may want to terminate the stack walk
                // based on an unrestricted assert.

                if (unrestricted)
                {
                    if (((state & PermissionListSetState.UnrestrictedAssert) != 0))
                    {
                        if (bNeedAlteredSet)
                            alteredSet = new TokenBasedSet( 1, 4 );
                        exception = null;
                        return false;
                    }
                    else
                    {
                        exception = null;
                        return true;
                    }
                }
                else
                {
                    exception = new SecurityException(Environment.GetResourceString("Security_GenericNoType") );
                    return false;
                }
            }


            bool continueStackWalk = false;
            
            // We know that checking to <permMaxIndex> is sufficient because of above check
            for (int i = 0; i <= permMaxIndex; i++)
            {
                Object obj = permSet.GetItem(i);
                
                if (obj != null)
                {
                    CodeAccessPermission cap = (CodeAccessPermission)obj;

                    PermissionList permList = (PermissionList)thisSet.GetItem(i);
                    
                    if (permList != null)
                    {
                        bool tempContinue = permList.CheckDemandInternal(cap, out exception);

                        if (exception != null)
                            return false;

                        if (tempContinue)
                        {
                            // If we are supposed to continue the stack walk but there is an unrestricted
                            // deny, then we should fail.

                            if (((state & PermissionListSetState.UnrestrictedDeny) != 0) && (cap is IUnrestrictedPermission))
                            {
                                exception = new SecurityException(String.Format( Environment.GetResourceString("Security_Generic"), cap.GetType().AssemblyQualifiedName ) );
                                return false;
                            }

                            continueStackWalk = true;
                        }
                        else if (((state & PermissionListSetState.UnrestrictedAssert) == 0) && (cap is IUnrestrictedPermission))
                        {
                            // We only want to build the altered set if we don't have an
                            // unrestricted assert because we know if we have an unrestricted
                            // assert and we don't throw an exception that the stackwalk should
                            // include no unrestricted permissions.

                            if (bNeedAlteredSet)
                            {
                                if (alteredSet == null)
                                    alteredSet = CopyTokenBasedSet( permSet );

                                alteredSet.SetItem( i, null );
                            }
                        }
                    }
                    else
                    {
//.........这里部分代码省略.........

        public static TokenBasedSet CopyTokenBasedSet( TokenBasedSet set )
        {
            if (set == null || set.GetCount() == 0)
                return null;

            int maxIndex = set.GetMaxUsedIndex();

            TokenBasedSet copySet = new TokenBasedSet( maxIndex + 1, 4 );

            for (int i = 0; i <= maxIndex; ++i)
            {
                Object obj = set.GetItem( i );

                if (obj == null)
                    copySet.SetItem( i, null );
                else if (obj is IPermission)
                    copySet.SetItem( i, ((IPermission)obj).Copy() );
                else if (obj is PermissionList)
                    copySet.SetItem( i, ((PermissionList)obj).Copy() );
                else
                {
                    BCLDebug.Assert( false, "CopyTokenBasedSet can only be used for IPermission and PermissionList based TokenBasedSets" );
                    copySet.SetItem( i, obj );
                }
            }

            return copySet;
        }

        private static void CheckTokenBasedSetHelper( bool ignoreGrants,
                                                      TokenBasedSet grants,
                                                      TokenBasedSet denied,
                                                      TokenBasedSet demands )
        {
            if (demands == null)
                return;

            TokenBasedSetEnumerator enumerator = (TokenBasedSetEnumerator)demands.GetEnum();
            
            while (enumerator.MoveNext())
            {
                CodeAccessPermission demand = (CodeAccessPermission)enumerator.Current;
                int index = enumerator.GetCurrentIndex();

                if (demand != null)
                {
                    try
                    {
                        // Check to make sure the permission was granted, unless we are supposed
                        // to ignore grants.
                    
                        if (!ignoreGrants)
                        {
                            CodeAccessPermission grant
                                = grants != null ? (CodeAccessPermission)grants.GetItem(index) : null;
                            if (grant != null)
                            {
                                grant.CheckDemand(demand);
                            }
                            else
                            {
                                if (!demand.IsSubsetOf( null ))
                                    throw new SecurityException(String.Format(Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), demand.GetType(), demand.ToXml().ToString());
                            }
                        }
                    
                        // Check to make sure our permission was not denied.
                
                        if (denied != null)
                        {
                            CodeAccessPermission deny
                                = (CodeAccessPermission)denied.GetItem(index);
                            if (deny != null && deny.Intersect(demand) != null)
                                throw new SecurityException(String.Format(Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), demand.GetType(), demand.ToXml().ToString());
                        }
                    }
                    catch (Exception e)
                    {
                        // Any exception besides a security exception in this code means that
                        // a permission was unable to properly handle what we asked of it.
                        // We will define this to mean that the demand failed.
                        
                        if (e is SecurityException)
                            throw e;
                        else
                            throw new SecurityException(String.Format(Environment.GetResourceString("Security_Generic"), demand.GetType().AssemblyQualifiedName), demand.GetType(), demand.ToXml().ToString());
                    }                                
                }
            }
        }

     public PermissionListSet(PermissionListSet permListSet)
     {
         if (permListSet == null)
         {
             Reset();
             return;
         }
         
         m_unrestrictedPermSet = new TokenBasedSet(permListSet.m_unrestrictedPermSet);
 
         // Now deep copy all permission lists in set.
         // Note that this DOES deep copy permissions in the list.
         for (int i = 0; i <= m_unrestrictedPermSet.GetMaxUsedIndex(); i++)
         {
             PermissionList plist = (PermissionList)m_unrestrictedPermSet.GetItem(i);
             if (plist != null)
             {
                 m_unrestrictedPermSet.SetItem(i, plist.Copy());
             }
         }
         
         m_normalPermSet = new TokenBasedSet(permListSet.m_normalPermSet);
         
         // Now deep copy all permission lists in set.
         // Note that this DOES deep copy permissions in the list.
         for (int i = 0; i <= m_normalPermSet.GetMaxUsedIndex(); i++)
         {
             PermissionList plist = (PermissionList)m_normalPermSet.GetItem(i);
             if (plist != null)
             {
                 m_normalPermSet.SetItem(i, plist.Copy());
             }
         }        
         
         m_unrestricted = permListSet.m_unrestricted;
         m_state = permListSet.m_state;
     }

        public PermissionSet(PermissionSet permSet)
            : this()
        {
            if (permSet == null)
            {
                Reset();
                return;
            }

            m_Unrestricted = permSet.m_Unrestricted;
            m_CheckedForNonCas = permSet.m_CheckedForNonCas;
            m_ContainsCas = permSet.m_ContainsCas;
            m_ContainsNonCas = permSet.m_ContainsNonCas;
            m_ignoreTypeLoadFailures = permSet.m_ignoreTypeLoadFailures;

            if (permSet.m_permSet != null)
            {
                m_permSet = new TokenBasedSet(permSet.m_permSet);
                
                // now deep copy all permissions in set
                for (int i = m_permSet.GetStartingIndex(); i <= m_permSet.GetMaxUsedIndex(); i++)
                {
                    Object obj = m_permSet.GetItem(i);
                    IPermission perm = obj as IPermission;
#if FEATURE_CAS_POLICY
                    ISecurityElementFactory elem = obj as ISecurityElementFactory;
#endif // FEATURE_CAS_POLICY
                    if (perm != null)
                    {
                        m_permSet.SetItem(i, perm.Copy());
                    }
#if FEATURE_CAS_POLICY
                    else if (elem != null)
                    {
                        m_permSet.SetItem(i, elem.Copy());
                    }
#endif // FEATURE_CAS_POLICY
                }
            }
        }

        // Used to merge two distinct TokenBasedSets (used currently only in PermissionSet Deserialization)
        internal TokenBasedSet SpecialUnion(TokenBasedSet other)
        {
            // This gets called from PermissionSet.OnDeserialized and it's possible that the TokenBasedSets have 
            // not been subjected to VTS callbacks yet
            OnDeserializedInternal();
            TokenBasedSet unionSet = new TokenBasedSet();
            int maxMax;
            if (other != null)
            {
                other.OnDeserializedInternal();
                maxMax = this.GetMaxUsedIndex() > other.GetMaxUsedIndex() ? this.GetMaxUsedIndex() : other.GetMaxUsedIndex();
            }
            else
                maxMax = this.GetMaxUsedIndex();
        
            for (int i = 0; i <= maxMax; ++i)
            {
                Object thisObj = this.GetItem( i );
                IPermission thisPerm = thisObj as IPermission;
#if FEATURE_CAS_POLICY
                ISecurityElementFactory thisElem = thisObj as ISecurityElementFactory;
#endif // FEATURE_CAS_POLICY

                Object otherObj = (other != null)?other.GetItem( i ):null;
                IPermission otherPerm = otherObj as IPermission;
#if FEATURE_CAS_POLICY
                ISecurityElementFactory otherElem = otherObj as ISecurityElementFactory;
#endif // FEATURE_CAS_POLICY

                if (thisObj == null && otherObj == null)
                    continue;
        
             
                if (thisObj == null)
                {
#if FEATURE_CAS_POLICY
                    if (otherElem != null)
                    {
                        otherPerm = PermissionSet.CreatePerm(otherElem, false);
                    }
#endif // FEATURE_CAS_POLICY

                    PermissionToken token = PermissionToken.GetToken(otherPerm);
                    
                    if (token == null)
                    {
                        throw new SerializationException(Environment.GetResourceString("Serialization_InsufficientState"));
                    }
                    
                    unionSet.SetItem(token.m_index, otherPerm);
                }
                else if (otherObj == null)
                {
#if FEATURE_CAS_POLICY
                    if (thisElem != null)
                    {
                        thisPerm = PermissionSet.CreatePerm(thisElem, false);
                    }
#endif // FEATURE_CAS_POLICY

                    PermissionToken token = PermissionToken.GetToken(thisPerm);
                    if (token == null)
                    {
                        throw new SerializationException(Environment.GetResourceString("Serialization_InsufficientState"));
                    }
                    unionSet.SetItem( token.m_index, thisPerm);
                }
                else
                {
                    Contract.Assert( (thisObj == null || otherObj == null), "Permission cannot be in both TokenBasedSets" );
                }
            }
            return unionSet;
        }

        /// <include file='doc\PermissionSet.uex' path='docs/doc[@for="PermissionSet.PermissionSet1"]/*' />
        public PermissionSet(PermissionSet permSet)
            : this()
        {
            if (permSet == null)
            {
                Reset();
                return;
            }
    
            m_Unrestricted = permSet.m_Unrestricted;
            m_CheckedForNonCas = permSet.m_CheckedForNonCas;
            m_ContainsCas = permSet.m_ContainsCas;
            m_ContainsNonCas = permSet.m_ContainsNonCas;
            
            if (permSet.m_normalPermSet != null)
            {
                m_normalPermSet = new TokenBasedSet(permSet.m_normalPermSet);
                
                 // now deep copy all permissions in set
                for (int i = 0; i <= m_normalPermSet.GetMaxUsedIndex(); i++)
                {
                    IPermission perm = (IPermission)m_normalPermSet.GetItem(i);
                    if (perm != null)
                    {
                        m_normalPermSet.SetItem(i, perm.Copy());
                    }
                }
            }
               
            if (permSet.m_unrestrictedPermSet != null)
            {
                m_unrestrictedPermSet = new TokenBasedSet(permSet.m_unrestrictedPermSet);
                
                 // now deep copy all permissions in set
                for (int i = 0; i <= m_unrestrictedPermSet.GetMaxUsedIndex(); i++)
                {
                    IPermission perm = (IPermission)m_unrestrictedPermSet.GetItem(i);
                    if (perm != null)
                    {
                        m_unrestrictedPermSet.SetItem(i, perm.Copy());
                    }
                }
            }

            if (permSet.m_toBeLoaded != null)
            {
                this.m_toBeLoaded = new SecurityElement();

                IEnumerator enumerator = permSet.m_toBeLoaded.m_lChildren.GetEnumerator();

                while (enumerator.MoveNext())
                {
                    this.m_toBeLoaded.AddChild( (SecurityElement)enumerator.Current );
                }
            }

        }

        public PermissionSet(PermissionSet permSet)
            : this()
        {
            if (permSet == null)
            {
                Reset();
                return;
            }

            m_Unrestricted = permSet.m_Unrestricted;
            m_CheckedForNonCas = permSet.m_CheckedForNonCas;
            m_ContainsCas = permSet.m_ContainsCas;
            m_ContainsNonCas = permSet.m_ContainsNonCas;
            m_ignoreTypeLoadFailures = permSet.m_ignoreTypeLoadFailures;

            if (permSet.m_permSet != null)
            {
                m_permSet = new TokenBasedSet(permSet.m_permSet);
                
                // now deep copy all permissions in set
                for (int i = m_permSet.GetStartingIndex(); i <= m_permSet.GetMaxUsedIndex(); i++)
                {
                    Object obj = m_permSet.GetItem(i);
                    IPermission perm = obj as IPermission;

                    if (perm != null)
                    {
                        m_permSet.SetItem(i, perm.Copy());
                    }
                }
            }
        }

 internal TokenBasedSet SpecialUnion(TokenBasedSet other)
 {
     int maxUsedIndex;
     this.OnDeserializedInternal();
     TokenBasedSet set = new TokenBasedSet();
     if (other != null)
     {
         other.OnDeserializedInternal();
         maxUsedIndex = (this.GetMaxUsedIndex() > other.GetMaxUsedIndex()) ? this.GetMaxUsedIndex() : other.GetMaxUsedIndex();
     }
     else
     {
         maxUsedIndex = this.GetMaxUsedIndex();
     }
     for (int i = 0; i <= maxUsedIndex; i++)
     {
         object item = this.GetItem(i);
         IPermission perm = item as IPermission;
         ISecurityElementFactory factory = item as ISecurityElementFactory;
         object obj3 = (other != null) ? other.GetItem(i) : null;
         IPermission permission2 = obj3 as IPermission;
         ISecurityElementFactory factory2 = obj3 as ISecurityElementFactory;
         if ((item != null) || (obj3 != null))
         {
             if (item == null)
             {
                 if (factory2 != null)
                 {
                     permission2 = PermissionSet.CreatePerm(factory2, false);
                 }
                 PermissionToken token = PermissionToken.GetToken(permission2);
                 if (token == null)
                 {
                     throw new SerializationException(Environment.GetResourceString("Serialization_InsufficientState"));
                 }
                 set.SetItem(token.m_index, permission2);
             }
             else if (obj3 == null)
             {
                 if (factory != null)
                 {
                     perm = PermissionSet.CreatePerm(factory, false);
                 }
                 PermissionToken token2 = PermissionToken.GetToken(perm);
                 if (token2 == null)
                 {
                     throw new SerializationException(Environment.GetResourceString("Serialization_InsufficientState"));
                 }
                 set.SetItem(token2.m_index, perm);
             }
         }
     }
     return set;
 }

        // Used to merge two distinct TokenBasedSets (used currently only in PermissionSet Deserialization)
        internal TokenBasedSet SpecialUnion(TokenBasedSet other, ref bool canUnrestrictedOverride)
        {
            // This gets called from PermissionSet.OnDeserialized and it's possible that the TokenBasedSets have 
            // not been subjected to VTS callbacks yet
            OnDeserializedInternal();
            TokenBasedSet unionSet = new TokenBasedSet();
            int maxMax;
            if (other != null)
            {
                other.OnDeserializedInternal();
                maxMax = this.GetMaxUsedIndex() > other.GetMaxUsedIndex() ? this.GetMaxUsedIndex() : other.GetMaxUsedIndex();
            }
            else
                maxMax = this.GetMaxUsedIndex();
        
            for (int i = 0; i <= maxMax; ++i)
            {
                Object thisObj = this.GetItem( i );
                IPermission thisPerm = thisObj as IPermission;
                ISecurityElementFactory thisElem = thisObj as ISecurityElementFactory;
                
                Object otherObj = (other != null)?other.GetItem( i ):null;
                IPermission otherPerm = otherObj as IPermission;
                ISecurityElementFactory otherElem = otherObj as ISecurityElementFactory;
        
                if (thisObj == null && otherObj == null)
                    continue;
        
             
                if (thisObj == null)
                {
                    if (otherElem != null)
                    {
                        otherPerm = PermissionSet.CreatePerm(otherElem, false);
                    }
                    
                    
                    

                    PermissionToken token = PermissionToken.GetToken(otherPerm);
                    
                    if (token == null)
                    {
                        throw new SerializationException(Environment.GetResourceString("Serialization_InsufficientState"));
                    }
                    
                    unionSet.SetItem(token.m_index, otherPerm);
                    if (!CodeAccessPermission.CanUnrestrictedOverride(otherPerm))
                        canUnrestrictedOverride = false;
                }
                else if (otherObj == null)
                {
                    if (thisElem != null)
                    {
                        thisPerm = PermissionSet.CreatePerm(thisElem, false);
                    }
                    PermissionToken token = PermissionToken.GetToken(thisPerm);
                    if (token == null)
                    {
                        throw new SerializationException(Environment.GetResourceString("Serialization_InsufficientState"));
                    }
                    unionSet.SetItem( token.m_index, thisPerm);
                    if (!CodeAccessPermission.CanUnrestrictedOverride(thisPerm))
                        canUnrestrictedOverride = false;

                }
                else
                {
                    BCLDebug.Assert( (thisObj == null || otherObj == null), "Permission cannot be in both TokenBasedSets" );
                }
            }
            return unionSet;
        }

        internal virtual void MergeDeniedSet( TokenBasedSet denied )
        {
            if (denied == null)
                return;

            int minMaxIndex;
            if (this.m_maxIndex < denied.m_maxIndex)
            {
                minMaxIndex = this.m_maxIndex;
                for (int i = this.m_maxIndex + 1; i <= denied.m_maxIndex; ++i)
                {
                    denied.RemoveItem(i);
                }
            }
            else
            {  
                minMaxIndex = denied.m_maxIndex;
            }
        
            IPermission p1;
            IPermission p2;
    
            for (int i = 0; i<=minMaxIndex ; i++)
            {
                p1 = (IPermission)this.GetItem(i);
                p2 = (IPermission)denied.GetItem(i);
                
                if (p1 != null)
                {
                    if (p2 != null && p1.IsSubsetOf(p2))
                    {
                        // If the permission appears in both sets, we can remove it from both
                        // (i.e. now it's not granted instead of being denied)
                        this.RemoveItem(i);
                        denied.RemoveItem(i);
                    }
                }
                else if (p2 != null)
                {
                    // If we tried to deny it and it wasn't granted, just remove it from the denied set.
                    denied.RemoveItem(i); 
                }
            }
    
        }