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//------------------------------------------------------------------------------
// <copyright file="HttpServerVarsCollection.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
/*
* Collection of server variables with callback to HttpRequest for 'dynamic' ones
*
* Copyright (c) 2000 Microsoft Corporation
*/
namespace System.Web {
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.Serialization;
using System.Security.Permissions;
using System.Text;
using System.Web.Hosting;
using System.Web.Util;
internal class HttpServerVarsCollection : HttpValueCollection {
private bool _populated;
private HttpRequest _request;
private IIS7WorkerRequest _iis7workerRequest;
private List<HttpServerVarsCollectionEntry> _unsyncedEntries;
// 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 );
}
[SuppressMessage("Microsoft.Usage", "CA2236:CallBaseClassMethodsOnISerializableTypes",
Justification = "this class, while derived from class implementing ISerializable, is not serializable")]
public override void GetObjectData(SerializationInfo info, StreamingContext context) {
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();
// Add all unsynchronized entries, if any
if (_unsyncedEntries != null) {
foreach (var entry in _unsyncedEntries) {
var existingEntry = (HttpServerVarsCollectionEntry)BaseGet(entry.Name);
if (existingEntry != null && existingEntry.IsDynamic) {
// Exisiting dynamic server variables cannot be modified - ignore the new value
continue;
}
InvalidateCachedArrays();
BaseSet(entry.Name, entry); // Update an existing entry, or create one if it's new
}
_unsyncedEntries.Clear();
}
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, bool ensurePopulated = true) {
if (name == null) {
throw new ArgumentNullException("name");
}
if (value != null) {
if (this._populated || ensurePopulated) {
SetServerVariableManagedOnly(name, value);
}
else {
// Lazy synchronization - when populate is indeed required
if (_unsyncedEntries == null) {
_unsyncedEntries = new List<HttpServerVarsCollectionEntry>();
}
_unsyncedEntries.Add(new HttpServerVarsCollectionEntry(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 = UrlEncodeForToString(key);
s.Append(key);
s.Append('=');
value = Get(i);
if (urlencoded)
value = UrlEncodeForToString(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;
}
}
}
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