Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/HttpCacheParams.cs

@@ -0,0 +1,202 @@
+//------------------------------------------------------------------------------
+// <copyright file="HttpCacheParams.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+/*
+ * Cache Vary class.  Wraps Vary header
+ * 
+ * Copyright (c) 1998 Microsoft Corporation
+ */
+
+namespace System.Web {
+    using System.Text;
+    using System.Runtime.InteropServices;
+    using System.Web.Util;
+    using System.Security.Permissions;
+
+
+    /// <devdoc>
+    ///    <para>Indicates that a cache should contain multiple 
+    ///       representations for a particular Uri. This class is an encapsulation that
+    ///       provides a rich, type-safe way to set the Vary header.</para>
+    /// </devdoc>
+    public sealed class HttpCacheVaryByParams {
+        HttpDictionary  _parameters;
+        int             _ignoreParams;
+        bool            _isModified;
+        bool            _paramsStar;
+
+        public HttpCacheVaryByParams() {
+            Reset();
+        }
+
+        internal void Reset() {
+            _isModified = false;
+            _paramsStar = false;
+            _parameters = null;
+            _ignoreParams = -1;
+        }
+
+        /*
+         * Reset based on the cached vary headers.
+         */
+        internal void ResetFromParams(String[] parameters) {
+            int i, n;
+
+            Reset();
+            if (parameters != null) {
+                _isModified = true;
+                if (parameters[0].Length == 0) {
+                    Debug.Assert(parameters.Length == 1, "parameters.Length == 1");
+
+                    IgnoreParams = true;
+                }
+                else if (parameters[0].Equals("*")) {
+                    Debug.Assert(parameters.Length == 1, "parameters.Length == 1");
+
+                    _paramsStar = true;
+                }
+                else {
+                    _parameters = new HttpDictionary();
+                    for (i = 0, n = parameters.Length; i < n; i++) {
+                        _parameters.SetValue(parameters[i], parameters[i]);
+                    }
+                }
+            }
+        }
+
+        internal bool IsModified() {
+            return _isModified;
+        }
+
+        internal bool AcceptsParams() {
+            return _ignoreParams == 1 || _paramsStar || _parameters != null;
+        }
+
+        internal String[] GetParams() {
+            String[]    s = null;
+            Object      item;
+            int         i, j, c, n;
+
+            if (_ignoreParams == 1) {
+                s =  new String[1] {String.Empty};
+            }
+            else if (_paramsStar) {
+                s =  new String[1] {"*"};
+            }
+            else if (_parameters != null) {
+                n = _parameters.Size;
+                c = 0;
+                for (i = 0; i < n; i++) {
+                    item = _parameters.GetValue(i);
+                    if (item != null) {
+                        c++;
+                    }
+                }
+
+                if (c > 0) {
+                    s = new string[c];
+                    j = 0;
+                    for (i = 0; i < n; i++) {
+                        item = _parameters.GetValue(i);
+                        if (item != null) {
+                            s[j] = (String) item;
+                            j++;
+                        }
+                    }
+
+                    Debug.Assert(j == c, "j == c");
+                }
+            }
+
+            return s;
+        }
+
+        //
+        // Public methods and properties
+        //
+
+
+        /// <devdoc>
+        ///    <para> Default property.
+        ///       Indexed property indicating that a cache should (or should not) vary according
+        ///       to a custom header.</para>
+        /// </devdoc>
+        public bool this[String header]
+        {
+            get {
+                if (header == null) {
+                    throw new ArgumentNullException("header");
+                }
+
+                if (header.Length == 0) {
+                    return _ignoreParams == 1;
+                }
+                else {
+                    return _paramsStar || 
+                           (_parameters != null && _parameters.GetValue(header) != null);
+                }
+            }
+
+            set {
+                if (header == null) {
+                    throw new ArgumentNullException("header");
+                }
+
+                if (header.Length == 0) {
+                    IgnoreParams = value;
+                }
+                /*
+                 * Since adding a Vary parameter is more restrictive, we don't
+                 * want components to be able to set a Vary parameter to false
+                 * if another component has set it to true.
+                 */
+                else if (value) {
+                    _isModified = true;
+                    _ignoreParams = 0;
+                    if (header.Equals("*")) {
+                        _paramsStar = true;
+                        _parameters = null;
+                    }
+                    else {
+                        // set value to header if true or null if false
+                        if (!_paramsStar) {
+                            if (_parameters == null) {
+                                _parameters = new HttpDictionary();
+                            }
+
+                            _parameters.SetValue(header, header);
+                        }
+                    }
+                }
+            }
+        }
+
+
+        public bool IgnoreParams {
+            get {
+                return _ignoreParams == 1;
+            }
+
+            set {
+                // Don't ignore if params have been added
+                if (_paramsStar || _parameters != null) {
+                    return;
+                }
+
+                if (_ignoreParams == -1 || _ignoreParams == 1) {
+                    _ignoreParams = value ? 1 : 0;
+                    _isModified = true;
+                }
+            }
+        }
+
+        internal bool IsVaryByStar { 
+            get { 
+                return _paramsStar; 
+            } 
+        }
+    }
+}