UriTemplateHelpers.cs source code in C# .NET

                        Code:
                         / WCF / WCF / 3.5.30729.1 / untmp / Orcas / SP / ndp / cdf / src / NetFx35 / System.ServiceModel.Web / System / UriTemplateHelpers.cs / 3 / UriTemplateHelpers.cs
                        
                        
                            //---------------------------------------------------------------- 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//---------------------------------------------------------------

namespace System 
{
    using System.Collections.Generic; 
    using System.Collections.Specialized; 
    using System.Diagnostics;
    using System.ServiceModel; 
    using System.ServiceModel.Web;
    using System.Web;
    using System.Diagnostics.CodeAnalysis;
    using System.ServiceModel.Channels; 

    static class UriTemplateHelpers 
    { 
        static UriTemplateQueryComparer queryComparer = new UriTemplateQueryComparer();
        static UriTemplateQueryKeyComparer queryKeyComperar = new UriTemplateQueryKeyComparer(); 

        [Conditional("DEBUG")]
        public static void AssertCanonical(string s)
        { 
            Fx.Assert(s == s.ToUpperInvariant(), "non-canonicalized");
        } 
        public static bool CanMatchQueryInterestingly(UriTemplate ut, NameValueCollection query, bool mustBeEspeciallyInteresting) 
        {
            if (ut.queries.Count == 0) 
            {
                return false; // trivial, not interesting
            }
            string[] queryKeys = query.AllKeys; 
            foreach (KeyValuePair kvp in ut.queries)
            { 
                string queryKeyName = kvp.Key; 
                if (kvp.Value.Nature == UriTemplatePartType.Literal)
                { 
                    bool queryKeysContainsQueryVarName = false;
                    for (int i = 0; i < queryKeys.Length; ++i)
                    {
                        if (StringComparer.OrdinalIgnoreCase.Equals(queryKeys[i], queryKeyName)) 
                        {
                            queryKeysContainsQueryVarName = true; 
                            break; 
                        }
                    } 
                    if (!queryKeysContainsQueryVarName)
                    {
                        return false;
                    } 
                    if (kvp.Value == UriTemplateQueryValue.Empty)
                    { 
                        if (!string.IsNullOrEmpty(query[queryKeyName])) 
                        {
                            return false; 
                        }
                    }
                    else
                    { 
                        if (((UriTemplateLiteralQueryValue)(kvp.Value)).AsRawUnescapedString() != query[queryKeyName])
                        { 
                            return false; 
                        }
                    } 
                }
                else
                {
                    if (mustBeEspeciallyInteresting && Array.IndexOf(queryKeys, queryKeyName) == -1) 
                    {
                        return false; 
                    } 
                }
            } 
            return true;
        }

        public static bool CanMatchQueryTrivially(UriTemplate ut) 
        {
            return (ut.queries.Count == 0); 
        } 

        public static void DisambiguateSamePath(UriTemplate[] array, int a, int b, bool allowDuplicateEquivalentUriTemplates) 
        {
            // [a,b) all have same path
            // ensure queries make them unambiguous
            Fx.Assert(b > a, "array bug"); 
            // sort empty queries to front
            Array.Sort(array, a, b - a, queryComparer); 
            if (b - a == 1) 
            {
                return; // if only one, cannot be ambiguous 
            }
            if (!allowDuplicateEquivalentUriTemplates)
            {
                // ensure at most one empty query and ignore it 
                if (array[a].queries.Count == 0)
                { 
                    a++; 
                }
                if (array[a].queries.Count == 0) 
                {
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SR2.GetString(
                        SR2.UTTDuplicate, array[a].ToString(), array[a - 1].ToString())));
                } 
                if (b - a == 1)
                { 
                    return; // if only one, cannot be ambiguous 
                }
            } 
            else
            {
                while (a < b && array[a].queries.Count == 0)  // all equivalent
                { 
                    a++;
                } 
                if (b - a <= 1) 
                {
                    return; 
                }
            }
            Fx.Assert(b > a, "array bug");
            // now consider non-empty queries 
            // more than one, so enforce that
            // forall 
            //   exist set of querystringvars S where 
            //     every op has literal value foreach var in S, and
            //     those literal tuples are different 
            EnsureQueriesAreDistinct(array, a, b, allowDuplicateEquivalentUriTemplates);
        }

        public static IEqualityComparer GetQueryKeyComparer() 
        {
            return queryKeyComperar; 
        } 

        public static string GetUriPath(Uri uri) 
        {
            return uri.GetComponents(UriComponents.Path | UriComponents.KeepDelimiter, UriFormat.Unescaped);
        }
        public static bool HasQueryLiteralRequirements(UriTemplate ut) 
        {
            foreach (UriTemplateQueryValue utqv in ut.queries.Values) 
            { 
                if (utqv.Nature == UriTemplatePartType.Literal)
                { 
                    return true;
                }
            }
            return false; 
        }
 
        public static UriTemplatePartType IdentifyPartType(string part) 
        {
            // Identifying the nature of a string - Literal|Compound|Variable 
            // Algorithem is based on the following steps:
            // - Finding the position of the first open curlly brace ('{') and close curlly brace ('}')
            //    in the string
            // - If we don't find any this is a Literal 
            // - otherwise, we validate that position of the close brace is at least two characters from
            //    the position of the open brace 
            // - Then we identify if we are dealing with a compound string or a single variable string 
            //    + var name is not at the string start --> Compound
            //    + var name is shorter then the entire string (End < Length-2 or End==Length-2 
            //       and string ends with '/') --> Compound
            //    + otherwise --> Variable
            int varStartIndex = part.IndexOf("{", StringComparison.Ordinal);
            int varEndIndex = part.IndexOf("}", StringComparison.Ordinal); 
            if (varStartIndex == -1)
            { 
                if (varEndIndex != -1) 
                {
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new FormatException( 
                        SR2.GetString(SR2.UTInvalidFormatSegmentOrQueryPart, part)));
                }
                return UriTemplatePartType.Literal;
            } 
            else
            { 
                if (varEndIndex < varStartIndex + 2) 
                {
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new FormatException( 
                        SR2.GetString(SR2.UTInvalidFormatSegmentOrQueryPart, part)));
                }
                if (varStartIndex > 0)
                { 
                    return UriTemplatePartType.Compound;
                } 
                else if ((varEndIndex < part.Length - 2) || 
                    ((varEndIndex == part.Length - 2) && !part.EndsWith("/", StringComparison.Ordinal)))
                { 
                    return UriTemplatePartType.Compound;
                }
                else
                { 
                    return UriTemplatePartType.Variable;
                } 
            } 
        }
        public static bool IsWildcardPath(string path) 
        {
            if (path.IndexOf('/') != -1)
            {
                return false; 
            }
            UriTemplatePartType partType; 
            return IsWildcardSegment(path, out partType); 
        }
 
        [SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters", Justification = "This is internal method that needs to return multiple things")]
        public static bool IsWildcardSegment(string segment, out UriTemplatePartType type)
        {
            type = IdentifyPartType(segment); 
            switch (type)
            { 
                case UriTemplatePartType.Literal: 
                    return (string.Compare(segment, UriTemplate.WildcardPath, StringComparison.Ordinal) == 0);
 
                case UriTemplatePartType.Compound:
                    return false;

                case UriTemplatePartType.Variable: 
                    return ((segment.IndexOf(UriTemplate.WildcardPath, StringComparison.Ordinal) == 1) &&
                        !segment.EndsWith("/", StringComparison.Ordinal) && 
                        (segment.Length > UriTemplate.WildcardPath.Length + 2)); 

                default: 
                    Fx.Assert("Bad part type identification !");
                    return false;
            }
        } 
        public static NameValueCollection ParseQueryString(string query)
        { 
            // We are adjusting the parsing of UrlUtility.ParseQueryString, which identify 
            //  ?wsdl as a null key with wsdl as a value
            NameValueCollection result = UrlUtility.ParseQueryString(query); 
            string nullKeyValuesString = result[(string) null];
            if (!string.IsNullOrEmpty(nullKeyValuesString))
            {
                result.Remove(null); 
                string[] nullKeyValues = nullKeyValuesString.Split(',');
                for (int i = 0; i < nullKeyValues.Length; i++) 
                { 
                    result.Add(nullKeyValues[i], null);
                } 
            }
            return result;
        }
        static bool AllTemplatesAreEquivalent(IList array, int a, int b) 
        {
            for (int i = a; i < b - 1; ++i) 
            { 
                if (!array[i].IsEquivalentTo(array[i + 1]))
                { 
                    return false;
                }
            }
            return true; 
        }
 
        static void EnsureQueriesAreDistinct(UriTemplate[] array, int a, int b, bool allowDuplicateEquivalentUriTemplates) 
        {
            Dictionary queryVarNamesWithLiteralVals = new Dictionary(StringComparer.OrdinalIgnoreCase); 
            for (int i = a; i < b; ++i)
            {
                foreach (KeyValuePair kvp in array[i].queries)
                { 
                    if (kvp.Value.Nature == UriTemplatePartType.Literal)
                    { 
                        if (!queryVarNamesWithLiteralVals.ContainsKey(kvp.Key)) 
                        {
                            queryVarNamesWithLiteralVals.Add(kvp.Key, 0); 
                        }
                    }
                }
            } 
            // now we have set of possibilities:
            // further refine to only those for whom all templates have literals 
            Dictionary queryVarNamesAllLiterals = new Dictionary(queryVarNamesWithLiteralVals); 
            for (int i = a; i < b; ++i)
            { 
                foreach (string s in queryVarNamesWithLiteralVals.Keys)
                {
                    if (!array[i].queries.ContainsKey(s) || (array[i].queries[s].Nature != UriTemplatePartType.Literal))
                    { 
                        queryVarNamesAllLiterals.Remove(s);
                    } 
                } 
            }
            queryVarNamesWithLiteralVals = null; // ensure we don't reference this variable any more 
            // now we have the set of names that every operation has as a literal
            if (queryVarNamesAllLiterals.Count == 0)
            {
                if (allowDuplicateEquivalentUriTemplates && AllTemplatesAreEquivalent(array, a, b)) 
                {
                    // we're ok, do nothing 
                } 
                else
                { 
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SR2.GetString(
                        SR2.UTTOtherAmbiguousQueries, array[a].ToString())));
                }
            } 
            // now just ensure that each template has a unique tuple of values for the names
            string[][] upsLits = new string[b - a][]; 
            for (int i = 0; i < b - a; ++i) 
            {
                upsLits[i] = GetQueryLiterals(array[i + a], queryVarNamesAllLiterals); 
            }
            for (int i = 0; i < b - a; ++i)
            {
                for (int j = i + 1; j < b - a; ++j) 
                {
                    if (Same(upsLits[i], upsLits[j])) 
                    { 
                        if (!array[i + a].IsEquivalentTo(array[j + a]))
                        { 
                            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SR2.GetString(
                                SR2.UTTAmbiguousQueries, array[a + i].ToString(), array[j + a].ToString())));
                        }
                        Fx.Assert(array[i + a].IsEquivalentTo(array[j + a]), "bad equiv logic"); 
                        if (!allowDuplicateEquivalentUriTemplates)
                        { 
                            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new InvalidOperationException(SR2.GetString( 
                                SR2.UTTDuplicate, array[a + i].ToString(), array[j + a].ToString())));
                        } 
                    }
                }
            }
            // we're good.  whew! 
        }
        static string[] GetQueryLiterals(UriTemplate up, Dictionary queryVarNames) 
        { 
            string[] queryLitVals = new string[queryVarNames.Count];
            int i = 0; 
            foreach (string queryVarName in queryVarNames.Keys)
            {
                Fx.Assert(up.queries.ContainsKey(queryVarName), "query doesn't have name");
                UriTemplateQueryValue utqv = up.queries[queryVarName]; 
                Fx.Assert(utqv.Nature == UriTemplatePartType.Literal, "query for name is not literal");
                if (utqv == UriTemplateQueryValue.Empty) 
                { 
                    queryLitVals[i] = null;
                } 
                else
                {
                    queryLitVals[i] = ((UriTemplateLiteralQueryValue)(utqv)).AsRawUnescapedString();
                } 
                ++i;
            } 
            return queryLitVals; 
        }
        static bool Same(string[] a, string[] b) 
        {
            Fx.Assert(a.Length == b.Length, "arrays not same length");
            for (int i = 0; i < a.Length; ++i)
            { 
                if (a[i] != b[i])
                { 
                    return false; 
                }
            } 
            return true;
        }

        class UriTemplateQueryComparer : IComparer 
        {
            public int Compare(UriTemplate x, UriTemplate y) 
            { 
                // sort the empty queries to the front
                return Comparer.Default.Compare(x.queries.Count, y.queries.Count); 
            }
        }
        class UriTemplateQueryKeyComparer : IEqualityComparer
        { 
            public bool Equals(string x, string y)
            { 
                return (string.Compare(x, y, StringComparison.OrdinalIgnoreCase) == 0); 
            }
            public int GetHashCode(string obj) 
            {
                if (obj == null)
                {
                    throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("obj"); 
                }
                return obj.ToUpperInvariant().GetHashCode(); 
            } 
        }
    } 
}

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