HttpServerVarsCollection.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ FXUpdate3074 / FXUpdate3074 / 1.1 / untmp / whidbey / QFE / ndp / fx / src / xsp / System / Web / HttpServerVarsCollection.cs / 3 / HttpServerVarsCollection.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 * Collection of server variables with callback to HttpRequest for 'dynamic' ones 
 *
 * Copyright (c) 2000 Microsoft Corporation 
 */

namespace System.Web {
    using System.Runtime.Serialization; 
    using System.Runtime.Serialization.Formatters;
    using System.Text; 
 
    using System.Collections;
    using System.Collections.Specialized; 
    using System.Web.Util;
    using System.Globalization;
    using System.Security.Permissions;
    using System.Web.Hosting; 

    internal class HttpServerVarsCollection : HttpValueCollection { 
        private bool _populated; 
        private HttpRequest _request;
        private IIS7WorkerRequest _iis7workerRequest; 

        // We preallocate the base collection with a size that should be sufficient
        // to store all server variables w/o having to expand
        internal HttpServerVarsCollection(HttpWorkerRequest wr, HttpRequest request) : base(59) { 
            // if this is an IIS7WorkerRequest, then the collection will be writeable and we will
            // call into IIS7 to update the server var block when changes are made. 
            _iis7workerRequest = wr as IIS7WorkerRequest; 
            _request = request;
            _populated = false; 

            Debug.Assert( _request != null );
        }
 
        public override void GetObjectData(SerializationInfo info, StreamingContext context) {
            // this class, while derived from class implementing ISerializable, is not serializable 
            throw new SerializationException(); 
        }
 
        internal void Dispose() {
            _request = null;
        }
 
        internal void AddStatic(String name, String value) {
            if (value == null) 
                value = String.Empty; 

            InvalidateCachedArrays(); 
            BaseAdd(name, new HttpServerVarsCollectionEntry(name, value));
        }

        internal void AddDynamic(String name, DynamicServerVariable var) { 
            InvalidateCachedArrays();
            BaseAdd(name, new HttpServerVarsCollectionEntry(name, var)); 
        } 

        private String GetServerVar(Object e) { 
            HttpServerVarsCollectionEntry entry = (HttpServerVarsCollectionEntry)e;
            return (entry != null) ? entry.GetValue(_request) : null;
        }
 
        //
        //  Support for deferred population of the collection 
        // 

        private void Populate() { 
            if (!_populated) {
                if (_request != null) {
                    MakeReadWrite();
                    _request.FillInServerVariablesCollection(); 

                    if (_iis7workerRequest == null) { 
                        MakeReadOnly(); 
                    }
                } 
                _populated = true;
            }
        }
 
        private String GetSimpleServerVar(String name) {
            // get server var without population of the collection 
            // only most popular are included 

            if (name != null && name.Length > 1 && _request != null) { 
                switch (name[0]) {
                    case 'A':
                    case 'a':
                        if (StringUtil.EqualsIgnoreCase(name, "AUTH_TYPE")) 
                            return _request.CalcDynamicServerVariable(DynamicServerVariable.AUTH_TYPE);
                        else if (StringUtil.EqualsIgnoreCase(name, "AUTH_USER")) 
                            return _request.CalcDynamicServerVariable(DynamicServerVariable.AUTH_USER); 
                        break;
                    case 'H': 
                    case 'h':
                        if (StringUtil.EqualsIgnoreCase(name, "HTTP_USER_AGENT"))
                            return _request.UserAgent;
                        break; 
                    case 'Q':
                    case 'q': 
                        if (StringUtil.EqualsIgnoreCase(name, "QUERY_STRING")) 
                            return _request.QueryStringText;
                        break; 
                    case 'P':
                    case 'p':
                        if (StringUtil.EqualsIgnoreCase(name, "PATH_INFO"))
                            return _request.Path; 
                        else if (StringUtil.EqualsIgnoreCase(name, "PATH_TRANSLATED"))
                            return _request.PhysicalPath; 
                        break; 
                    case 'R':
                    case 'r': 
                        if (StringUtil.EqualsIgnoreCase(name, "REQUEST_METHOD"))
                            return _request.HttpMethod;
                        else if (StringUtil.EqualsIgnoreCase(name, "REMOTE_USER"))
                            return _request.CalcDynamicServerVariable(DynamicServerVariable.AUTH_USER); 
                        else if (StringUtil.EqualsIgnoreCase(name, "REMOTE_HOST"))
                            return _request.UserHostName; 
                        else if (StringUtil.EqualsIgnoreCase(name, "REMOTE_ADDRESS")) 
                            return _request.UserHostAddress;
                        break; 
                    case 'S':
                    case 's':
                        if (StringUtil.EqualsIgnoreCase(name, "SCRIPT_NAME"))
                            return _request.FilePath; 
                        break;
                } 
            } 

            // do the default processing (populate the collection) 
            return null;
        }

        // 
        //  Enumerator must pre-populate the collection
        // 
 
        public override IEnumerator GetEnumerator() {
            Populate(); 
            return base.GetEnumerator();
        }

        // 
        //  NameValueCollection overrides
        // 
 
        public override int Count {
            get { 
                Populate();
                return base.Count;
            }
        } 

        public override void Add(String name, String value) { 
            // not supported because it appends the value to a comma separated list 
            throw new NotSupportedException();
        } 

        public override void Clear() {
            throw new NotSupportedException();
        } 

        public override String Get(String name) { 
            if (!_populated) { 
                String value = GetSimpleServerVar(name);
 
                if (value != null)
                    return value;

                Populate(); 
            }
 
            if (_iis7workerRequest != null) { 
                string var = GetServerVar(BaseGet(name));
 
                if (String.IsNullOrEmpty(var)) {
                    var = _request.FetchServerVariable(name);
                }
 
                return var;
            } 
            else { 
                return GetServerVar(BaseGet(name));
            } 
        }

        public override String[] GetValues(String name) {
            String s = Get(name); 
            return(s != null) ? new String[1] { s} : null;
        } 
 
        [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.High)]
        public override void Set(String name, String value) { 
            if (_iis7workerRequest == null) {
                throw new PlatformNotSupportedException();
            }
 
            if (name == null) {
                throw new ArgumentNullException("name"); 
            } 

            SetNoDemand(name, value); 
        }

        internal void SetNoDemand(String name, String value) {
            if (value == null) { 
                value = String.Empty;
            } 
 
            _iis7workerRequest.SetServerVariable(name, value);
            SetServerVariableManagedOnly(name, value); 
            SynchronizeHeader(name, value);
            _request.InvalidateParams();
        }
 
        private void SynchronizeHeader(String name, String value) {
            if (StringUtil.StringStartsWith(name, "HTTP_")) 
            { 
                // update managed copy of header
                string headerName = name.Substring("HTTP_".Length); 
                headerName = headerName.Replace('_', '-');
                int knownIndex = HttpWorkerRequest.GetKnownRequestHeaderIndex(headerName);
                if (knownIndex > -1) {
                    headerName = HttpWorkerRequest.GetKnownRequestHeaderName(knownIndex); 
                }
 
                HttpHeaderCollection headers = _request.Headers as HttpHeaderCollection; 
                if (headers != null) {
                    headers.SynchronizeHeader(headerName, value); 
                }
            }
        }
 
        // updates managed copy of server variable with current value from native header block
        internal void SynchronizeServerVariable(String name, String value) { 
            if (name == null) { 
                throw new ArgumentNullException("name");
            } 

            if (value != null) {
                SetServerVariableManagedOnly(name, value);
            } 
            else {
                base.Remove(name); 
            } 

            _request.InvalidateParams(); 
        }

        // updates managed copy of server variable with current value from native header block
        private void SetServerVariableManagedOnly(String name, String value) { 
            Debug.Assert(name != null);
            Debug.Assert(value != null); 
 
            // populate in order to identify dynamic variables
            Populate(); 

            // dynamic server variables cannot be modified
            HttpServerVarsCollectionEntry entry = (HttpServerVarsCollectionEntry) BaseGet(name);
            if (entry != null && entry.IsDynamic) { 
                throw new HttpException(SR.GetString(SR.Server_variable_cannot_be_modified));
            } 
 
            InvalidateCachedArrays();
            // this will update an existing entry, or create one if it's new 
            BaseSet(name, new HttpServerVarsCollectionEntry(name, value));
        }

        [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.High)] 
        public override void Remove(String name) {
            if (_iis7workerRequest == null) { 
                throw new PlatformNotSupportedException(); 
            }
 
            if (name == null) {
                throw new ArgumentNullException("name");
            }
 
            RemoveNoDemand(name);
        } 
 
        internal void RemoveNoDemand(String name) {
            // delete by sending null value 
            _iis7workerRequest.SetServerVariable(name, null /*value*/);

            base.Remove(name);
            SynchronizeHeader(name, null); 
            _request.InvalidateParams();
        } 
 
        public override String Get(int index)  {
            Populate(); 
            return GetServerVar(BaseGet(index));
        }

        public override String[] GetValues(int index) { 
            String s = Get(index);
            return(s != null) ? new String[1] { s} : null; 
        } 

        public override String GetKey(int index) { 
            Populate();
            return base.GetKey(index);
        }
 
        public override string[] AllKeys {
            get { 
                Populate(); 
                return base.AllKeys;
            } 
        }

        //
        //  HttpValueCollection overrides 
        //
 
        internal override string ToString(bool urlencoded) { 
            Populate();
 
            StringBuilder s = new StringBuilder();
            int n = Count;
            String key, value;
 
            for (int i = 0; i < n; i++) {
                if (i > 0) 
                    s.Append('&'); 

                key = GetKey(i); 
                if (urlencoded)
                    key = HttpUtility.UrlEncodeUnicode(key);
                s.Append(key);
 
                s.Append('=');
 
                value = Get(i); 
                if (urlencoded)
                    value = HttpUtility.UrlEncodeUnicode(value); 
                s.Append(value);
            }

            return s.ToString(); 
        }
    } 
 
/*
 *  Entry in a server vars colleciton 
 */
    internal class HttpServerVarsCollectionEntry {
        internal readonly String Name;
        internal readonly bool   IsDynamic; 
        internal readonly String Value;
        internal readonly DynamicServerVariable Var; 
 
        internal HttpServerVarsCollectionEntry(String name, String value) {
            Name = name; 
            Value = value;
            IsDynamic = false;
        }
 
        internal HttpServerVarsCollectionEntry(String name, DynamicServerVariable var) {
            Name = name; 
            Var = var; 
            IsDynamic = true;
        } 

        internal String GetValue(HttpRequest request) {
            String v = null;
 
            if (IsDynamic) {
                if (request != null) 
                    v = request.CalcDynamicServerVariable(Var); 
            }
            else { 
                v = Value;
            }

            return v; 
        }
    } 
 

} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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