RequestUriProcessor.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataWeb / Server / System / Data / Services / RequestUriProcessor.cs / 1625574 / RequestUriProcessor.cs

                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//  
//      Provides a class capable of processing Astoria request Uris.
//  
// 
// @owner  [....]
//--------------------------------------------------------------------- 

namespace System.Data.Services
{
    #region Namespaces. 

    using System; 
    using System.Collections; 
    using System.Collections.Generic;
    using System.Data.Services.Client; 
    using System.Data.Services.Parsing;
    using System.Data.Services.Providers;
    using System.Diagnostics;
    using System.Linq; 
    using System.Linq.Expressions;
    using System.Reflection; 
 
    #endregion Namespaces.
 
    // Syntax for Astoria segments:
    // segment          ::= identifier [ query ]
    // query            ::= "(" key ")"
    // key              ::= keyvalue *["," keyvalue] 
    // keyvalue         ::= *quotedvalue | *unquotedvalue
    // quotedvalue      ::= "'" *qvchar "'" 
    // qvchar           ::= char-except-quote | "''" 
    // unquotedvalue    ::= char
 
    /// 
    /// Use this class to process a web data service request Uri.
    /// 
    internal static class RequestUriProcessor 
    {
        /// MethodInfo for the RequestUriProcessor.InvokeWhere method. 
        private static readonly MethodInfo InvokeWhereMethodInfo = typeof(RequestUriProcessor).GetMethod("InvokeWhere", BindingFlags.NonPublic | BindingFlags.Static); 

        /// Recursion limit on segment length. 
        private const int RecursionLimit = 100;

        /// 
        /// Parses the request Uri that the host is exposing and returns 
        /// information about the intended results.
        ///  
        /// Request uri that needs to get processed. 
        /// Data service for which the request is being processed.
        ///  
        /// An initialized RequestDescription instance describing what the
        /// request is for.
        /// 
        ///  
        /// A  with status code 404 (Not Found) is returned if an identifier
        /// in a segment cannot be resolved; 400 (Bad Request) is returned if a syntax 
        /// error is found when processing a restriction (parenthesized text) or 
        /// in the query portion.
        ///  
        /// 
        /// Very important: no rights are checked on the last segment of the request.
        /// 
        internal static RequestDescription ProcessRequestUri(Uri absoluteRequestUri, IDataService service) 
        {
            Debug.Assert(service != null, "service != null"); 
            Debug.Assert(absoluteRequestUri != null, "absoluteRequestUri != null"); 
            Debug.Assert(absoluteRequestUri.IsAbsoluteUri, "absoluteRequestUri.IsAbsoluteUri(" + absoluteRequestUri + ")");
 
            string[] segments = EnumerateSegments(absoluteRequestUri, service.OperationContext.AbsoluteServiceUri);
            if (segments.Length > RecursionLimit)
            {
                throw DataServiceException.CreateBadRequestError(Strings.RequestUriProcessor_TooManySegments); 
            }
 
            SegmentInfo[] segmentInfos = CreateSegments(segments, service); 
            SegmentInfo lastSegment = (segmentInfos.Length == 0) ? null : segmentInfos[segmentInfos.Length - 1];
            RequestTargetKind targetKind = (lastSegment == null) ? RequestTargetKind.ServiceDirectory : lastSegment.TargetKind; 

            // Create a ResultDescription from the processed segments.
            RequestDescription resultDescription;
            Uri resultUri = GetResultUri(service.OperationContext); 
            if (targetKind == RequestTargetKind.Metadata ||
                targetKind == RequestTargetKind.Batch || 
                targetKind == RequestTargetKind.ServiceDirectory) 
            {
                resultDescription = new RequestDescription(targetKind, RequestTargetSource.None, resultUri); 
            }
            else if (targetKind == RequestTargetKind.VoidServiceOperation)
            {
                Debug.Assert(lastSegment != null, "lastSegment != null"); 
                Debug.Assert(lastSegment.TargetSource == RequestTargetSource.ServiceOperation, "targetSource == RequestTargetSource.ServiceOperation");
 
                service.Provider.InvokeServiceOperation(lastSegment.Operation, lastSegment.OperationParameters); 

                resultDescription = new RequestDescription( 
                    RequestTargetKind.VoidServiceOperation,     // targetKind
                    RequestTargetSource.ServiceOperation,       // targetSource
                    resultUri);                                 // resultUri
            } 
            else
            { 
                Debug.Assert(lastSegment != null, "lastSegment != null"); 
                Debug.Assert(
                    targetKind == RequestTargetKind.ComplexObject || 
                    targetKind == RequestTargetKind.OpenProperty ||
                    targetKind == RequestTargetKind.OpenPropertyValue ||
                    targetKind == RequestTargetKind.Primitive ||
                    targetKind == RequestTargetKind.PrimitiveValue || 
                    targetKind == RequestTargetKind.Resource ||
                    targetKind == RequestTargetKind.MediaResource, 
                    "Known targetKind " + targetKind); 
                RequestTargetSource targetSource = lastSegment.TargetSource;
                ResourceProperty projectedProperty = lastSegment.ProjectedProperty; 
                string containerName =
                    (lastSegment.TargetKind != RequestTargetKind.PrimitiveValue &&
                     lastSegment.TargetKind != RequestTargetKind.OpenPropertyValue &&
                     lastSegment.TargetKind != RequestTargetKind.MediaResource) ? 
                     lastSegment.Identifier :
                     segmentInfos[segmentInfos.Length - 2].Identifier; 
                bool usesContainerName = 
                    (targetSource == RequestTargetSource.Property &&
                     projectedProperty != null && 
                     projectedProperty.Kind != ResourcePropertyKind.ResourceSetReference) ||
                    (targetSource == RequestTargetSource.ServiceOperation &&
                     lastSegment.Operation.ResultKind == ServiceOperationResultKind.QueryWithSingleResult);
                string mimeType = 
                    (targetSource == RequestTargetSource.Property && projectedProperty != null) ? projectedProperty.MimeType :
                    (targetSource == RequestTargetSource.ServiceOperation) ? lastSegment.Operation.MimeType : 
                    null; 

                RequestQueryCountOption countOption = 
                    lastSegment.Identifier == XmlConstants.UriCountSegment ?
                        RequestQueryCountOption.ValueOnly :
                        RequestQueryCountOption.None;
 
                // Throw if $count and $inlinecount requests have been disabled by the user
                if (countOption != RequestQueryCountOption.None && !service.Configuration.DataServiceBehavior.AcceptCountRequests) 
                { 
                    throw DataServiceException.CreateBadRequestError(Strings.DataServiceConfiguration_CountNotSupportedInV1Server);
                } 

                resultDescription = new RequestDescription(
                    segmentInfos,
                    containerName, 
                    usesContainerName,
                    mimeType, 
                    resultUri) 
                    {
                        CountOption = lastSegment.Identifier == XmlConstants.UriCountSegment ? RequestQueryCountOption.ValueOnly : RequestQueryCountOption.None 
                    };

                // Update the feature version if the target set contains any type with FF KeepInContent=false.
                resultDescription.UpdateAndCheckEpmFeatureVersion(service); 

                // Update the response DSV for GET if the target set contains any type with FF KeepInContent=false. 
                // 
                // Note the response DSV is payload specific and since for GET we won't know if the instances to be
                // serialized will contain any properties with FF KeepInContent=false until serialization time which 
                // happens after the headers are written, the best we can do is to determin this at the set level.
                //
                // For CUD operations we'll raise the version based on the actual instances at deserialization time.
                if (service.OperationContext.Host.AstoriaHttpVerb == AstoriaVerbs.GET) 
                {
                    resultDescription.UpdateEpmResponseVersion(service.OperationContext.Host.RequestAccept, service.Provider); 
                } 
            }
 
            // Process query options ($filter, $orderby, $expand, etc.)
            resultDescription = RequestQueryProcessor.ProcessQuery(service, resultDescription);

            // $count, $inlinecount and $select are 2.0 features - raise the max version of used features accordingly 
            if (resultDescription.CountOption != RequestQueryCountOption.None ||
                (resultDescription.RootProjectionNode != null && resultDescription.RootProjectionNode.ProjectionsSpecified)) 
            { 
                resultDescription.RaiseFeatureVersion(2, 0, service.Configuration);
            } 

            return resultDescription;
        }
 
        /// Appends a segment with the specified escaped .
        /// URI to append to. 
        /// Segment text, already escaped. 
        /// A new URI with a new segment escaped.
        internal static Uri AppendEscapedSegment(Uri uri, string text) 
        {
            Debug.Assert(uri != null, "uri != null");
            Debug.Assert(text != null, "text != null");
 
            UriBuilder builder = new UriBuilder(uri);
            if (!builder.Path.EndsWith("/", StringComparison.Ordinal)) 
            { 
                builder.Path += "/";
            } 

            builder.Path += text;
            return builder.Uri;
        } 

        /// Appends a segment with the specified unescaped . 
        /// URI to append to. 
        /// Segment text, already escaped.
        /// A new URI with a new segment escaped. 
        internal static Uri AppendUnescapedSegment(Uri uri, string text)
        {
            Debug.Assert(uri != null, "uri != null");
            Debug.Assert(text != null, "text != null"); 
            return AppendEscapedSegment(uri, Uri.EscapeDataString(text));
        } 
 
        /// Gets the absolute URI that a reference (typically from a POST or PUT body) points to.
        /// Textual, URI-encoded reference. 
        /// Context for current operation.
        /// The absolute URI that  resolves to.
        internal static Uri GetAbsoluteUriFromReference(string reference, DataServiceOperationContext operationContext)
        { 
            return GetAbsoluteUriFromReference(reference, operationContext.AbsoluteServiceUri);
        } 
 
        /// Gets the absolute URI that a reference (typically from a POST or PUT body) points to.
        /// Textual, URI-encoded reference. 
        /// Absolure URI for service, used to validate that the URI points within.
        /// The absolute URI that  resolves to.
        internal static Uri GetAbsoluteUriFromReference(string reference, Uri absoluteServiceUri)
        { 
            Debug.Assert(!String.IsNullOrEmpty(reference), "!String.IsNullOrEmpty(reference) -- caller should check and throw appropriate message");
            Debug.Assert(absoluteServiceUri != null, "absoluteServiceUri != null"); 
            Debug.Assert(absoluteServiceUri.IsAbsoluteUri, "absoluteServiceUri.IsAbsoluteUri(" + absoluteServiceUri + ")"); 

            Uri referenceAsUri = new Uri(reference, UriKind.RelativeOrAbsolute); 
            if (!referenceAsUri.IsAbsoluteUri)
            {
                string slash = String.Empty;
                if (absoluteServiceUri.OriginalString.EndsWith("/", StringComparison.Ordinal)) 
                {
                    if (reference.StartsWith("/", StringComparison.Ordinal)) 
                    { 
                        reference = reference.Substring(1, reference.Length - 1);
                    } 
                }
                else if (!reference.StartsWith("/", StringComparison.Ordinal))
                {
                    slash = "/"; 
                }
 
                referenceAsUri = new Uri(absoluteServiceUri.OriginalString + slash + reference); 
            }
 
            if (!UriUtil.UriInvariantInsensitiveIsBaseOf(absoluteServiceUri, referenceAsUri))
            {
                string message = Strings.BadRequest_RequestUriDoesNotHaveTheRightBaseUri(referenceAsUri, absoluteServiceUri);
                throw DataServiceException.CreateBadRequestError(message); 
            }
 
            Debug.Assert( 
                referenceAsUri.IsAbsoluteUri,
                "referenceAsUri.IsAbsoluteUri(" + referenceAsUri + ") - otherwise composition from absolute yielded relative"); 

            return referenceAsUri;
        }
 
        /// Gets the specified  as a string suitable for an HTTP request.
        ///  to get string for. 
        /// A string suitable for an HTTP request. 
        internal static string GetHttpRequestUrl(Uri uri)
        { 
            Debug.Assert(uri != null, "uri != null");
            if (uri.IsAbsoluteUri)
            {
                return uri.GetComponents(UriComponents.HttpRequestUrl, UriFormat.UriEscaped); 
            }
            else 
            { 
                return uri.OriginalString;
            } 
        }

        /// Gets the URI to the results, without the query component.
        /// OperationContext with request information. 
        /// The URI to the results, without the query component.
        internal static Uri GetResultUri(DataServiceOperationContext operationContext) 
        { 
            Debug.Assert(operationContext != null, "operationContext != null");
            Uri requestUri = operationContext.AbsoluteRequestUri; 
            UriBuilder resultBuilder = new UriBuilder(requestUri);
            resultBuilder.Query = null;

            // This is fix for bug 565322. 
            // Since we don't allow uri to compose on collections, () must be present
            // as the last thing in the uri, if present. We need to remove the () from 
            // the uri, since its a optional thing and we want to return a canonical 
            // uri from the server.
            if (resultBuilder.Path.EndsWith("()", StringComparison.Ordinal)) 
            {
                resultBuilder.Path = resultBuilder.Path.Substring(0, resultBuilder.Path.Length - 2);
            }
 
            return resultBuilder.Uri;
        } 
 
        /// 
        /// Returns an object that can enumerate the segments in the specified path (eg: /foo/bar -> foo, bar). 
        /// 
        /// A valid path portion of an uri.
        /// baseUri for the request that is getting processed.
        /// An enumerable object of unescaped segments. 
        internal static string[] EnumerateSegments(Uri absoluteRequestUri, Uri baseUri)
        { 
            Debug.Assert(absoluteRequestUri != null, "absoluteRequestUri != null"); 
            Debug.Assert(absoluteRequestUri.IsAbsoluteUri, "absoluteRequestUri.IsAbsoluteUri(" + absoluteRequestUri.IsAbsoluteUri + ")");
            Debug.Assert(baseUri != null, "baseUri != null"); 
            Debug.Assert(baseUri.IsAbsoluteUri, "baseUri.IsAbsoluteUri(" + baseUri + ")");

            if (!UriUtil.UriInvariantInsensitiveIsBaseOf(baseUri, absoluteRequestUri))
            { 
                throw DataServiceException.CreateBadRequestError(Strings.BadRequest_RequestUriDoesNotHaveTheRightBaseUri(absoluteRequestUri, baseUri));
            } 
 
            try
            { 
                //
                Uri uri = absoluteRequestUri;
                int numberOfSegmentsToSkip = 0;
 
                // Since there is a svc part in the segment, we will need to skip 2 segments
                numberOfSegmentsToSkip = baseUri.Segments.Length; 
 
                string[] uriSegments = uri.Segments;
                int populatedSegmentCount = 0; 
                for (int i = numberOfSegmentsToSkip; i < uriSegments.Length; i++)
                {
                    string segment = uriSegments[i];
                    if (segment.Length != 0 && segment != "/") 
                    {
                        populatedSegmentCount++; 
                    } 
                }
 
                string[] segments = new string[populatedSegmentCount];
                int segmentIndex = 0;
                for (int i = numberOfSegmentsToSkip; i < uriSegments.Length; i++)
                { 
                    string segment = uriSegments[i];
                    if (segment.Length != 0 && segment != "/") 
                    { 
                        if (segment[segment.Length - 1] == '/')
                        { 
                            segment = segment.Substring(0, segment.Length - 1);
                        }

                        segments[segmentIndex++] = Uri.UnescapeDataString(segment); 
                    }
                } 
 
                Debug.Assert(segmentIndex == segments.Length, "segmentIndex == segments.Length -- otherwise we mis-counted populated/skipped segments.");
                return segments; 
            }
            catch (UriFormatException)
            {
                throw DataServiceException.CreateSyntaxError(); 
            }
        } 
 
        /// 
        /// Given the uri, extract the key values from the uri 
        /// 
        /// uri from which the key values needs to be extracted
        /// Data context for which the request is being processed.
        /// returns the name of the source resource set name 
        /// key values as specified in the uri
        internal static KeyInstance ExtractKeyValuesFromUri(Uri absoluteRequestUri, IDataService service, out string containerName) 
        { 
            Debug.Assert(absoluteRequestUri != null, "absoluteRequestUri != null");
            Debug.Assert(absoluteRequestUri.IsAbsoluteUri, "absoluteRequestUri.IsAbsoluteUri(" + absoluteRequestUri + ")"); 
            Debug.Assert(service != null, "service != null");

            RequestDescription description = RequestUriProcessor.ProcessRequestUri(absoluteRequestUri, service);
 
            //
 
 
            if (description.TargetKind != RequestTargetKind.Resource || !description.IsSingleResult || description.TargetSource != RequestTargetSource.EntitySet)
            { 
                throw DataServiceException.CreateBadRequestError(Strings.BadRequestStream_MustSpecifyCanonicalUriInPayload(absoluteRequestUri));
            }

            // Dereferencing an object by specifying its key values implied the right to read it. 
            Debug.Assert(description.LastSegmentInfo.SingleResult, "description.LastSegmentInfo.SingleResult");
            DataServiceConfiguration.CheckResourceRightsForRead(description.LastSegmentInfo.TargetContainer, true /* singleResult */); 
 
            containerName = description.ContainerName;
 
            Debug.Assert(description.LastSegmentInfo.Key != null && !description.LastSegmentInfo.Key.IsEmpty, "Key Must be specified");
            return description.LastSegmentInfo.Key;
        }
 
        /// Invokes Queryable.Select for the specified query and selector.
        /// Query to invoke .Select method on. 
        /// Type that will be projected out. 
        /// Selector lambda expression.
        /// The resulting query. 
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)]
        internal static IQueryable InvokeSelectForTypes(IQueryable query, Type projectedType, LambdaExpression selector)
        {
            Debug.Assert(query != null, "query != null"); 
            Debug.Assert(projectedType != null, "projectedType != null");
            Debug.Assert(selector != null, "selector != null"); 
            MethodInfo method = typeof(RequestUriProcessor).GetMethod("InvokeSelect", BindingFlags.Static | BindingFlags.NonPublic); 
            method = method.MakeGenericMethod(query.ElementType, projectedType);
            return (IQueryable)method.Invoke(null, new object[] { query, selector }); 
        }

        /// Invokes Queryable.Where for the specified query and predicate.
        /// Query to invoke .Where method on. 
        /// Predicate to pass as argument.
        /// The resulting query. 
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)] 
        internal static IQueryable InvokeWhereForType(IQueryable query, LambdaExpression predicate)
        { 
            Debug.Assert(query != null, "query != null");
            Debug.Assert(predicate != null, "predicate != null");
            MethodInfo whereMethod = InvokeWhereMethodInfo.MakeGenericMethod(query.ElementType);
            return (IQueryable)whereMethod.Invoke(null, new object[] { query, predicate }); 
        }
 
        /// Composes the filter portion of a segment onto the specifies query. 
        /// Filter portion of segment, possibly null.
        /// Segment on which to compose. 
        private static void ComposeQuery(string filter, SegmentInfo segment)
        {
            Debug.Assert(filter != null, "filter != null");
            Debug.Assert(segment != null, "segment!= null"); 
            Debug.Assert(segment.SingleResult == false, "segment.SingleResult == false");
 
            ResourceType resourceType = segment.TargetResourceType; 
            segment.Key = ExtractKeyValues(resourceType, filter);
            segment.SingleResult = !segment.Key.IsEmpty; 
            if (segment.SingleResult)
            {
                if (!segment.Key.AreValuesNamed && segment.Key.ValueCount > 1)
                { 
                    throw DataServiceException.CreateBadRequestError(Strings.RequestUriProcessor_KeysMustBeNamed);
                } 
 
                segment.RequestQueryable = SelectResourceByKey(segment.RequestQueryable, resourceType, segment.Key);
                segment.SingleResult = true; 
            }
        }

        /// Creates the first  for a request. 
        /// Service for which the request is being processed.
        /// Identifier portion of segment. 
        /// Whether rights should be checked on this segment. 
        /// Query portion with key; possibly null.
        /// True if the first segment is also the last segment. 
        /// whether this segment references some other segment.
        /// A description of the information on the segment.
        private static SegmentInfo CreateFirstSegment(IDataService service, string identifier, bool checkRights, string queryPortion, bool isLastSegment, out bool crossReferencingUrl)
        { 
            Debug.Assert(service != null, "service != null");
            Debug.Assert(identifier != null, "identifier != null"); 
 
            crossReferencingUrl = false;
            SegmentInfo segment = new SegmentInfo(); 
            segment.Identifier = identifier;

            // Look for well-known system entry points.
            if (segment.Identifier == XmlConstants.UriMetadataSegment) 
            {
                WebUtil.CheckSyntaxValid(queryPortion == null); 
                segment.TargetKind = RequestTargetKind.Metadata; 
                return segment;
            } 

            if (segment.Identifier == XmlConstants.UriBatchSegment)
            {
                WebUtil.CheckSyntaxValid(queryPortion == null); 
                segment.TargetKind = RequestTargetKind.Batch;
                return segment; 
            } 

            if (segment.Identifier == XmlConstants.UriCountSegment) 
            {
                // $count on root: throw
                throw DataServiceException.CreateResourceNotFound(Strings.RequestUriProcessor_CountOnRoot);
            } 

            // Look for a service operation. 
            segment.Operation = service.Provider.TryResolveServiceOperation(segment.Identifier); 
            if (segment.Operation != null)
            { 
                WebUtil.DebugEnumIsDefined(segment.Operation.ResultKind);
                segment.TargetSource = RequestTargetSource.ServiceOperation;
                if (service.OperationContext.RequestMethod != segment.Operation.Method)
                { 
                    throw DataServiceException.CreateMethodNotAllowed(Strings.RequestUriProcessor_MethodNotAllowed, segment.Operation.Method);
                } 
 
                segment.TargetContainer = segment.Operation.ResourceSet;
 
                if (segment.Operation.ResultKind != ServiceOperationResultKind.Void)
                {
                    segment.TargetResourceType = segment.Operation.ResultType;
                } 
                else
                { 
                    segment.TargetResourceType = null; 
                }
 
                segment.OperationParameters = ReadOperationParameters(service.OperationContext.Host, segment.Operation);
                switch (segment.Operation.ResultKind)
                {
                    case ServiceOperationResultKind.QueryWithMultipleResults: 
                    case ServiceOperationResultKind.QueryWithSingleResult:
                        try 
                        { 
                            segment.RequestQueryable = (IQueryable)service.Provider.InvokeServiceOperation(segment.Operation, segment.OperationParameters);
                        } 
                        catch (TargetInvocationException exception)
                        {
                            ErrorHandler.HandleTargetInvocationException(exception);
                            throw; 
                        }
 
                        WebUtil.CheckResourceExists(segment.RequestQueryable != null, segment.Identifier); 
                        segment.SingleResult = (segment.Operation.ResultKind == ServiceOperationResultKind.QueryWithSingleResult);
                        break; 

                    case ServiceOperationResultKind.DirectValue:
                    case ServiceOperationResultKind.Enumeration:
                        object methodResult; 
                        try
                        { 
                            methodResult = service.Provider.InvokeServiceOperation(segment.Operation, segment.OperationParameters); 
                        }
                        catch (TargetInvocationException exception) 
                        {
                            ErrorHandler.HandleTargetInvocationException(exception);
                            throw;
                        } 

                        segment.SingleResult = (segment.Operation.ResultKind == ServiceOperationResultKind.DirectValue); 
                        WebUtil.CheckResourceExists(segment.SingleResult || methodResult != null, segment.Identifier);   // Enumerations shouldn't be null. 
                        segment.RequestEnumerable = segment.SingleResult ? new object[1] { methodResult } : (IEnumerable)methodResult;
                        segment.TargetResourceType = segment.Operation.ResultType; 
                        segment.TargetKind = TargetKindFromType(segment.TargetResourceType);
                        WebUtil.CheckSyntaxValid(queryPortion == null);
                        RequestQueryProcessor.CheckEmptyQueryArguments(service, false /*checkForOnlyV2QueryParameters*/);
                        break; 

                    default: 
                        Debug.Assert(segment.Operation.ResultKind == ServiceOperationResultKind.Void, "segment.Operation.ResultKind == ServiceOperationResultKind.Nothing"); 
                        segment.TargetKind = RequestTargetKind.VoidServiceOperation;
                        break; 
                }

                if (segment.RequestQueryable != null)
                { 
                    segment.TargetKind = TargetKindFromType(segment.TargetResourceType);
                    if (queryPortion != null) 
                    { 
                        WebUtil.CheckSyntaxValid(!segment.SingleResult);
                        ComposeQuery(queryPortion, segment); 
                    }
                }

                if (checkRights) 
                {
                    DataServiceConfiguration.CheckServiceRights(segment.Operation, segment.SingleResult); 
                } 

                return segment; 
            }

            SegmentInfo newSegmentInfo = service.GetSegmentForContentId(segment.Identifier);
            if (newSegmentInfo != null) 
            {
                newSegmentInfo.Identifier = segment.Identifier; 
                crossReferencingUrl = true; 
                return newSegmentInfo;
            } 

            // Look for an entity set.
            ResourceSetWrapper container = service.Provider.TryResolveResourceSet(segment.Identifier);
            WebUtil.CheckResourceExists(container != null, segment.Identifier); 

            if (ShouldRequestQuery(service, isLastSegment, false, queryPortion)) 
            { 
#if DEBUG
                segment.RequestQueryable = service.Provider.GetQueryRootForResourceSet(container, service); 
#else
                segment.RequestQueryable = service.Provider.GetQueryRootForResourceSet(container);
#endif
                WebUtil.CheckResourceExists(segment.RequestQueryable != null, segment.Identifier); 
            }
 
            segment.TargetContainer = container; 
            segment.TargetResourceType = container.ResourceType;
            segment.TargetSource = RequestTargetSource.EntitySet; 
            segment.TargetKind = RequestTargetKind.Resource;
            segment.SingleResult = false;
            if (queryPortion != null)
            { 
                ComposeQuery(queryPortion, segment);
            } 
 
            if (checkRights)
            { 
                DataServiceConfiguration.CheckResourceRightsForRead(container, segment.SingleResult);
            }

            if (segment.RequestQueryable != null) 
            {
                // We only need to invoke the query interceptor if we called get query root. 
                segment.RequestQueryable = DataServiceConfiguration.ComposeResourceContainer(service, container, segment.RequestQueryable); 
            }
 
            return segment;
        }

        /// Whether a query should be requested and composed with interceptors for a segment. 
        /// Service under which request is being analyzed.
        /// Whether this is the last segment of the URI. 
        /// Is the current segment being checked after a $links segment. 
        /// Query portion of the segment.
        /// true if the segments should be read and composed with interceptors; false otherwise. 
        /// 
        /// For V1 providers we always get the query root or else we introduce a breaking change.
        /// If this is an insert operation and the current segment is the first and last segment,
        /// we don't need to get the query root as we won't even invoke the query. 
        /// Note that we need to make sure we only skip the query root if the query portion is null, this
        /// is because in the deep insert case, we can be doing a binding to a single entity and we would 
        /// need the query root for that entity. 
        /// We shall also skip requesting the query if the request is for an update on $links for non-V1 providers.
        ///  
        private static bool ShouldRequestQuery(IDataService service, bool isLastSegment, bool isAfterLink, string queryPortion)
        {
            Debug.Assert(service != null, "service != null");
 
            if (service.Provider.IsV1Provider)
            { 
                return true; 
            }
 
            AstoriaVerbs verbUsed = service.OperationContext.Host.AstoriaHttpVerb;
            bool isPostQueryForSet = isLastSegment && verbUsed == AstoriaVerbs.POST && string.IsNullOrEmpty(queryPortion);
            bool isUpdateQueryForLinks = isAfterLink && (verbUsed == AstoriaVerbs.PUT || verbUsed == AstoriaVerbs.MERGE);
 
            return !(isPostQueryForSet || isUpdateQueryForLinks);
        } 
 
        /// Creates a  array for the given .
        /// Segments to process. 
        /// Service for which segments are being processed.
        /// Segment information describing the given .
        private static SegmentInfo[] CreateSegments(string[] segments, IDataService service)
        { 
            Debug.Assert(segments != null, "segments != null");
            Debug.Assert(service != null, "service != null"); 
            SegmentInfo previous = null; 
            SegmentInfo[] segmentInfos = new SegmentInfo[segments.Length];
            bool crossReferencingUri = false; 
            bool postLinkSegment = false;
            for (int i = 0; i < segments.Length; i++)
            {
                string segmentText = segments[i]; 
                bool checkRights = (i != segments.Length - 1);  // Whether rights should be checked on this segment.
                string identifier; 
                bool hasQuery = ExtractSegmentIdentifier(segmentText, out identifier); 
                string queryPortion = hasQuery ? segmentText.Substring(identifier.Length) : null;
                SegmentInfo segment; 

                // We allow a single trailing '/', which results in an empty segment.
                // However System.Uri removes it, so any empty segment we see is a 404 error.
                if (identifier.Length == 0) 
                {
                    throw DataServiceException.ResourceNotFoundError(Strings.RequestUriProcessor_EmptySegmentInRequestUrl); 
                } 

                if (previous == null) 
                {
                    segment = CreateFirstSegment(service, identifier, checkRights, queryPortion, segments.Length == 1, out crossReferencingUri);
                }
                else if (previous.TargetKind == RequestTargetKind.Batch || 
                         previous.TargetKind == RequestTargetKind.Metadata ||
                         previous.TargetKind == RequestTargetKind.PrimitiveValue || 
                         previous.TargetKind == RequestTargetKind.VoidServiceOperation || 
                         previous.TargetKind == RequestTargetKind.OpenPropertyValue ||
                         previous.TargetKind == RequestTargetKind.MediaResource) 
                {
                    // Nothing can come after a $metadata, $value or $batch segment.
                    // Nothing can come after a service operation with void return type.
                    throw DataServiceException.ResourceNotFoundError(Strings.RequestUriProcessor_MustBeLeafSegment(previous.Identifier)); 
                }
                else if (postLinkSegment && identifier != XmlConstants.UriCountSegment) 
                { 
                    // DEVNOTE([....]): [Resources]/$links/[Property]/$count is valid
                    throw DataServiceException.ResourceNotFoundError(Strings.RequestUriProcessor_CannotSpecifyAfterPostLinkSegment(identifier, XmlConstants.UriLinkSegment)); 
                }
                else if (previous.TargetKind == RequestTargetKind.Primitive)
                {
                    // $value is the well-known identifier to return a primitive property 
                    // in its natural MIME format.
                    if (identifier != XmlConstants.UriValueSegment) 
                    { 
                        throw DataServiceException.ResourceNotFoundError(Strings.RequestUriProcessor_ValueSegmentAfterScalarPropertySegment(previous.Identifier, identifier));
                    } 

                    WebUtil.CheckSyntaxValid(!hasQuery);
                    segment = new SegmentInfo(previous);
                    segment.Identifier = identifier; 
                    segment.SingleResult = true;
                    segment.TargetKind = RequestTargetKind.PrimitiveValue; 
                } 
                else if (previous.TargetKind == RequestTargetKind.Resource &&
                          previous.SingleResult && 
                          identifier == XmlConstants.UriLinkSegment)
                {
                    segment = new SegmentInfo(previous);
                    segment.Identifier = identifier; 
                    segment.TargetKind = RequestTargetKind.Link;
                } 
                else 
                {
                    Debug.Assert( 
                        previous.TargetKind == RequestTargetKind.ComplexObject ||
                        previous.TargetKind == RequestTargetKind.Resource ||
                        previous.TargetKind == RequestTargetKind.OpenProperty ||
                        previous.TargetKind == RequestTargetKind.Link, 
                        "previous.TargetKind(" + previous.TargetKind + ") can have properties");
 
                    postLinkSegment = (previous.TargetKind == RequestTargetKind.Link); 

                    // Enumerable and DirectValue results cannot be composed at all. 
                    if (previous.Operation != null && (previous.Operation.ResultKind == ServiceOperationResultKind.Enumeration || previous.Operation.ResultKind == ServiceOperationResultKind.DirectValue))
                    {
                        throw DataServiceException.ResourceNotFoundError(
                            Strings.RequestUriProcessor_IEnumerableServiceOperationsCannotBeFurtherComposed(previous.Identifier)); 
                    }
 
                    if (!previous.SingleResult && identifier != XmlConstants.UriCountSegment) 
                    {
                        // $count can be applied to a collection 
                        throw DataServiceException.CreateBadRequestError(
                            Strings.RequestUriProcessor_CannotQueryCollections(previous.Identifier));
                    }
 
                    segment = new SegmentInfo();
                    segment.Identifier = identifier; 
                    segment.TargetSource = RequestTargetSource.Property; 

                    // A segment will correspond to a property in the object model; 
                    // if we are processing an open type, anything further in the
                    // URI also represents an open type property.
                    if (previous.TargetResourceType == null)
                    { 
                        Debug.Assert(previous.TargetKind == RequestTargetKind.OpenProperty, "For open properties, the target resource type must be null");
                        segment.ProjectedProperty = null; 
                    } 
                    else
                    { 
                        Debug.Assert(previous.TargetKind != RequestTargetKind.OpenProperty, "Since the query element type is known, this can't be open property");
                        Debug.Assert(previous.TargetResourceType != null, "Previous wasn't open, so it should have a resource type");
                        segment.ProjectedProperty = previous.TargetResourceType.TryResolvePropertyName(identifier);
                    } 

                    if (identifier == XmlConstants.UriCountSegment) 
                    { 
                        if (previous.TargetKind != RequestTargetKind.Resource)
                        { 
                            throw DataServiceException.CreateResourceNotFound(Strings.RequestUriProcessor_CountNotSupported(previous.Identifier));
                        }

                        if (previous.SingleResult) 
                        {
                            throw DataServiceException.CreateResourceNotFound(Strings.RequestUriProcessor_CannotQuerySingletons(previous.Identifier, identifier)); 
                        } 

                        if (service.OperationContext.Host.AstoriaHttpVerb != AstoriaVerbs.GET) 
                        {
                            throw DataServiceException.CreateBadRequestError(Strings.RequestQueryProcessor_RequestVerbCannotCountError);
                        }
 
                        segment.RequestEnumerable = previous.RequestEnumerable;
                        segment.SingleResult = true; 
                        segment.TargetKind = RequestTargetKind.PrimitiveValue; 
                        segment.TargetResourceType = previous.TargetResourceType;
                        segment.TargetContainer = previous.TargetContainer; 
                    }
                    else if (identifier == XmlConstants.UriValueSegment &&
                        (previous.TargetKind == RequestTargetKind.OpenProperty || (previous.TargetKind == RequestTargetKind.Resource)))
                    { 
                        segment.RequestEnumerable = previous.RequestEnumerable;
                        segment.SingleResult = true; 
                        segment.TargetResourceType = previous.TargetResourceType; 

                        if (previous.TargetKind == RequestTargetKind.OpenProperty) 
                        {
                            segment.TargetKind = RequestTargetKind.OpenPropertyValue;
                        }
                        else 
                        {
                            // If the previous segment is an entity, we expect it to be an MLE. We cannot validate our assumption 
                            // until later when we get the actual instance of the entity because the type hierarchy can contain 
                            // a mix of MLE and non-MLE types.
                            segment.TargetKind = RequestTargetKind.MediaResource; 

                            // There is no valid query option for Media Resource.
                            RequestQueryProcessor.CheckEmptyQueryArguments(service, false /*checkForOnlyV2QueryParameters*/);
                        } 
                    }
                    else if (segment.ProjectedProperty == null) 
                    { 
                        // Handle an open type property. If the current leaf isn't an
                        // object (which implies it's already an open type), then 
                        // it should be marked as an open type.
                        if (previous.TargetResourceType != null)
                        {
                            WebUtil.CheckResourceExists(previous.TargetResourceType.IsOpenType, segment.Identifier); 
                        }
 
                        // Open navigation properties are not supported on OpenTypes.  We should throw on the following cases: 
                        // 1. the segment after $links is always a navigation property pointing to a resource
                        // 2. if the segment hasQuery, it is pointing to a resource 
                        // 3. if this is a POST operation, the target has to be either a set of links or an entity set
                        if (previous.TargetKind == RequestTargetKind.Link || hasQuery || service.OperationContext.Host.AstoriaHttpVerb == AstoriaVerbs.POST)
                        {
                            throw DataServiceException.CreateBadRequestError(Strings.OpenNavigationPropertiesNotSupportedOnOpenTypes(segment.Identifier)); 
                        }
 
                        segment.TargetResourceType = null; 
                        segment.TargetKind = RequestTargetKind.OpenProperty;
                        segment.SingleResult = true; 

                        if (!crossReferencingUri)
                        {
                            segment.RequestQueryable = SelectOpenProperty(previous.RequestQueryable, identifier); 
                        }
                    } 
                    else 
                    {
                        // Handle a strongly-typed property. 
                        segment.TargetResourceType = segment.ProjectedProperty.ResourceType;
                        ResourcePropertyKind propertyKind = segment.ProjectedProperty.Kind;
                        segment.SingleResult = (propertyKind != ResourcePropertyKind.ResourceSetReference);
                        if (!crossReferencingUri) 
                        {
                            if (segment.ProjectedProperty.CanReflectOnInstanceTypeProperty) 
                            { 
                                segment.RequestQueryable = segment.SingleResult ?
                                    SelectElement(previous.RequestQueryable, segment.ProjectedProperty) : 
                                    SelectMultiple(previous.RequestQueryable, segment.ProjectedProperty);
                            }
                            else
                            { 
                                segment.RequestQueryable = segment.SingleResult ?
                                    SelectLateBoundProperty( 
                                        previous.RequestQueryable, 
                                        segment.ProjectedProperty) :
                                    SelectLateBoundPropertyMultiple( 
                                        previous.RequestQueryable,
                                        segment.ProjectedProperty);
                            }
                        } 

                        if (previous.TargetKind == RequestTargetKind.Link && 
                            segment.ProjectedProperty.TypeKind != ResourceTypeKind.EntityType) 
                        {
                            throw DataServiceException.CreateBadRequestError(Strings.RequestUriProcessor_LinkSegmentMustBeFollowedByEntitySegment(identifier, XmlConstants.UriLinkSegment)); 
                        }

                        switch (propertyKind)
                        { 
                            case ResourcePropertyKind.ComplexType:
                                segment.TargetKind = RequestTargetKind.ComplexObject; 
                                break; 
                            case ResourcePropertyKind.ResourceReference:
                            case ResourcePropertyKind.ResourceSetReference: 
                                segment.TargetKind = RequestTargetKind.Resource;
                                segment.TargetContainer = service.Provider.GetContainer(previous.TargetContainer, previous.TargetResourceType, segment.ProjectedProperty);
                                if (segment.TargetContainer == null)
                                { 
                                    throw DataServiceException.CreateResourceNotFound(segment.ProjectedProperty.Name);
                                } 
 
                                break;
                            default: 
                                Debug.Assert(segment.ProjectedProperty.IsOfKind(ResourcePropertyKind.Primitive), "must be primitive type property");
                                segment.TargetKind = RequestTargetKind.Primitive;
                                break;
                        } 

                        if (hasQuery) 
                        { 
                            WebUtil.CheckSyntaxValid(!segment.SingleResult);
                            if (!crossReferencingUri) 
                            {
                                ComposeQuery(queryPortion, segment);
                            }
                            else 
                            {
                                throw DataServiceException.CreateBadRequestError(Strings.BadRequest_ResourceCanBeCrossReferencedOnlyForBindOperation); 
                            } 
                        }
 
                        // Do security checks and authorization query composition.
                        if (segment.TargetContainer != null)
                        {
                            if (checkRights) 
                            {
                                DataServiceConfiguration.CheckResourceRightsForRead(segment.TargetContainer, segment.SingleResult); 
                            } 

                            if (!crossReferencingUri && ShouldRequestQuery(service, i == segments.Length - 1, postLinkSegment, queryPortion)) 
                            {
                                segment.RequestQueryable = DataServiceConfiguration.ComposeResourceContainer(service, segment.TargetContainer, segment.RequestQueryable);
                            }
                        } 
                    }
                } 
 
#if DEBUG
                segment.AssertValid(); 
#endif
                segmentInfos[i] = segment;
                previous = segment;
            } 

            if (segments.Length != 0 && previous.TargetKind == RequestTargetKind.Link) 
            { 
                throw DataServiceException.CreateBadRequestError(Strings.RequestUriProcessor_MissingSegmentAfterLink(XmlConstants.UriLinkSegment));
            } 

            return segmentInfos;
        }
 
        /// Returns an object that can enumerate key values.
        /// resource type whose keys need to be extracted 
        /// Key (query) part of an Astoria segment. 
        /// An object that can enumerate key values.
        private static KeyInstance ExtractKeyValues(ResourceType resourceType, string filter) 
        {
            KeyInstance key;
            filter = RemoveFilterParens(filter);
            WebUtil.CheckSyntaxValid(KeyInstance.TryParseKeysFromUri(filter, out key)); 

            if (!key.IsEmpty) 
            { 
                // Make sure the keys specified in the uri matches with the number of keys in the metadata
                if (resourceType.KeyProperties.Count != key.ValueCount) 
                {
                    throw DataServiceException.CreateBadRequestError(Strings.BadRequest_KeyCountMismatch(resourceType.FullName));
                }
 
                WebUtil.CheckSyntaxValid(key.TryConvertValues(resourceType));
            } 
 
            return key;
        } 

        /// Extracts the identifier part of the unescaped Astoria segment.
        /// Unescaped Astoria segment.
        /// On returning, the identifier in the segment. 
        /// true if keys follow the identifier.
        private static bool ExtractSegmentIdentifier(string segment, out string identifier) 
        { 
            Debug.Assert(segment != null, "segment != null");
 
            int filterStart = 0;
            while (filterStart < segment.Length && segment[filterStart] != '(')
            {
                filterStart++; 
            }
 
            identifier = segment.Substring(0, filterStart); 
            return filterStart < segment.Length;
        } 

        /// Generic method to invoke a Select method on an IQueryable source.
        /// Element type of the source.
        /// Result type of the projection. 
        /// Source query.
        /// Lambda expression that turns TSource into TResult. 
        /// A new query that projects TSource into TResult. 
        private static IQueryable InvokeSelect(IQueryable source, LambdaExpression selector)
        { 
            Debug.Assert(source != null, "source != null");
            Debug.Assert(selector != null, "selector != null");

            IQueryable typedSource = (IQueryable)source; 
            Expression> typedSelector = (Expression>)selector;
            return Queryable.Select(typedSource, typedSelector); 
        } 

        /// Generic method to invoke a SelectMany method on an IQueryable source. 
        /// Element type of the source.
        /// Result type of the projection.
        /// Source query.
        /// Lambda expression that turns TSource into IEnumerable<TResult>. 
        /// A new query that projects TSource into IEnumerable<TResult>.
        private static IQueryable InvokeSelectMany(IQueryable source, LambdaExpression selector) 
        { 
            Debug.Assert(source != null, "source != null");
            Debug.Assert(selector != null, "selector != null"); 

            IQueryable typedSource = (IQueryable)source;
            Expression>> typedSelector = (Expression>>)selector;
            return Queryable.SelectMany(typedSource, typedSelector); 
        }
 
        /// Generic method to invoke a Where method on an IQueryable source. 
        /// Element type of the source.
        /// Source query. 
        /// Lambda expression that filters the result of the query.
        /// A new query that filters the query.
        private static IQueryable InvokeWhere(IQueryable query, LambdaExpression predicate)
        { 
            Debug.Assert(query != null, "query != null");
            Debug.Assert(predicate != null, "predicate != null"); 
 
            IQueryable typedQueryable = (IQueryable)query;
 
            // If the type of predicate is not TSource, we need to replace the parameter with
            // a downcasted parameter type if predicate's input is a base class of TSource.
            if (predicate.Parameters[0].Type != typeof(TSource) &&
                predicate.Parameters[0].Type.IsAssignableFrom(typeof(TSource))) 
            {
                predicate = RequestUriProcessor.ReplaceParameterTypeForLambda(predicate, typeof(TSource)); 
            } 

            Expression> typedPredicate = (Expression>)predicate; 
            return Queryable.Where(typedQueryable, typedPredicate);
        }

        /// Replaced the type of input parameter with the given  
        /// Input lambda expression.
        /// Type of the new parameter that will be replaced. 
        /// New lambda expression with parameter of new type. 
        private static LambdaExpression ReplaceParameterTypeForLambda(LambdaExpression input, Type targetType)
        { 
            Debug.Assert(input.Parameters.Count == 1, "Assuming a single parameter for input lambda expression in this function.");

            ParameterExpression p = Expression.Parameter(targetType, input.Parameters[0].Name);
 
            return Expression.Lambda(
                    ParameterReplacerVisitor.Replace(input.Body, input.Parameters[0], p), 
                    p); 
        }
 
        /// 
        /// Reads the parameters for the specified  from the
        /// .
        ///  
        /// Host with request information.
        /// Operation with parameters to be read. 
        /// A new object[] with parameter values. 
        private static object[] ReadOperationParameters(DataServiceHostWrapper host, ServiceOperationWrapper operation)
        { 
            Debug.Assert(host != null, "host != null");

            object[] operationParameters = new object[operation.Parameters.Count];
            for (int i = 0; i < operation.Parameters.Count; i++) 
            {
                Type parameterType = operation.Parameters[i].ParameterType.InstanceType; 
                string queryStringValue = host.GetQueryStringItem(operation.Parameters[i].Name); 
                Type underlyingType = Nullable.GetUnderlyingType(parameterType);
                if (String.IsNullOrEmpty(queryStringValue)) 
                {
                    WebUtil.CheckSyntaxValid(parameterType.IsClass || underlyingType != null);
                    operationParameters[i] = null;
                } 
                else
                { 
                    // We choose to be a little more flexible than with keys and 
                    // allow surrounding whitespace (which is never significant).
                    // See SQLBUDT #555944. 
                    queryStringValue = queryStringValue.Trim();
                    Type targetType = underlyingType ?? parameterType;
                    if (WebConvert.IsKeyTypeQuoted(targetType))
                    { 
                        WebUtil.CheckSyntaxValid(WebConvert.IsKeyValueQuoted(queryStringValue));
                    } 
 
                    WebUtil.CheckSyntaxValid(WebConvert.TryKeyStringToPrimitive(queryStringValue, targetType, out operationParameters[i]));
                } 
            }

            return operationParameters;
        } 

        /// Removes the parens around the filter part of a query. 
        /// Filter with parens included. 
        /// Filter without parens.
        private static string RemoveFilterParens(string filter) 
        {
            Debug.Assert(filter != null, "filter != null");
            WebUtil.CheckSyntaxValid(filter.Length > 0 && filter[0] == '(' && filter[filter.Length - 1] == ')');
            return filter.Substring(1, filter.Length - 2); 
        }
 
        /// Project a property with a single element out of the specified query. 
        /// Base query to project from.
        /// Property to project. 
        /// A query with a composed primitive property projection.
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)]
        private static IQueryable SelectElement(IQueryable query, ResourceProperty property)
        { 
            Debug.Assert(query != null, "query != null");
            Debug.Assert(property.Kind != ResourcePropertyKind.ResourceSetReference, "property != ResourcePropertyKind.ResourceSetReference"); 
 
            ParameterExpression parameter = Expression.Parameter(query.ElementType, "element");
            MemberExpression body = Expression.Property(parameter, property.Name); 
            LambdaExpression selector = Expression.Lambda(body, parameter);

            MethodInfo method = typeof(RequestUriProcessor).GetMethod("InvokeSelect", BindingFlags.Static | BindingFlags.NonPublic);
            method = method.MakeGenericMethod(query.ElementType, property.Type); 
            return (IQueryable)method.Invoke(null, new object[] { query, selector });
        } 
 
        /// Project a property with multiple elements out of the specified query.
        /// Base query to project from. 
        /// Property to project.
        /// A query with a composed primitive property projection.
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)]
        private static IQueryable SelectMultiple(IQueryable query, ResourceProperty property) 
        {
            Debug.Assert(query != null, "query != null"); 
            Debug.Assert(property.Kind == ResourcePropertyKind.ResourceSetReference, "property == ResourcePropertyKind.ResourceSetReference"); 

            Type enumerableElement = BaseServiceProvider.GetIEnumerableElement(property.Type); 
            Debug.Assert(enumerableElement != null, "Providers should never expose a property as a resource-set if it doesn't implement IEnumerable`1.");

            ParameterExpression parameter = Expression.Parameter(query.ElementType, "element");
            UnaryExpression body = 
                Expression.ConvertChecked(
                    Expression.Property(parameter, property.Name), 
                    typeof(IEnumerable<>).MakeGenericType(enumerableElement)); 
            LambdaExpression selector = Expression.Lambda(body, parameter);
 
            MethodInfo method = typeof(RequestUriProcessor).GetMethod("InvokeSelectMany", BindingFlags.Static | BindingFlags.NonPublic);
            method = method.MakeGenericMethod(query.ElementType, enumerableElement);
            return (IQueryable)method.Invoke(null, new object[] { query, selector });
        } 

        /// Project a property with a single element out of the specified query over an late bound (possibily open) property. 
        /// Base query to project from. 
        /// Name of property to project.
        /// A query with a composed property projection. 
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)]
        private static IQueryable SelectOpenProperty(IQueryable query, string propertyName)
        {
            Debug.Assert(query != null, "query != null"); 
            Debug.Assert(propertyName != null, "propertyName != null");
 
            ParameterExpression parameter = Expression.Parameter(query.ElementType, "element"); 
            Expression body = Expression.Call(null /* instance */, OpenTypeMethods.GetValueOpenPropertyMethodInfo, parameter, Expression.Constant(propertyName));
 
            LambdaExpression selector = Expression.Lambda(body, parameter);
            MethodInfo method = typeof(RequestUriProcessor).GetMethod("InvokeSelect", BindingFlags.Static | BindingFlags.NonPublic);
            method = method.MakeGenericMethod(query.ElementType, typeof(object));
            return (IQueryable)method.Invoke(null, new object[] { query, selector }); 
        }
 
        /// Project a property with a single element out of the specified query over an late bound (possibily open) property. 
        /// Base query to project from.
        /// Resource property containing the metadata for the late bound property. 
        /// A query with a composed property projection.
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)]
        private static IQueryable SelectLateBoundProperty(IQueryable query, ResourceProperty property)
        { 
            Debug.Assert(query != null, "query != null");
            Debug.Assert(property != null && !property.CanReflectOnInstanceTypeProperty, "property != null && !property.CanReflectOnInstanceTypeProperty"); 
 
            ParameterExpression parameter = Expression.Parameter(query.ElementType, "element");
            Expression body = Expression.Call(null /*instance*/, DataServiceProviderMethods.GetValueMethodInfo, parameter, Expression.Constant(property)); 
            body = Expression.Convert(body, property.Type);

            LambdaExpression selector = Expression.Lambda(body, parameter);
            MethodInfo method = typeof(RequestUriProcessor).GetMethod("InvokeSelect", BindingFlags.Static | BindingFlags.NonPublic); 
            method = method.MakeGenericMethod(query.ElementType, property.Type);
            return (IQueryable)method.Invoke(null, new object[] { query, selector }); 
        } 

        /// Project a property with a single element out of the specified query over an late bound (possibily open) property. 
        /// Base query to project from.
        /// Resource property containing the metadata for the late bound property.
        /// A query with a composed property projection.
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining | System.Runtime.CompilerServices.MethodImplOptions.NoOptimization)] 
        private static IQueryable SelectLateBoundPropertyMultiple(IQueryable query, ResourceProperty property)
        { 
            Debug.Assert(query != null, "query != null"); 
            Debug.Assert(property != null && property.Kind == ResourcePropertyKind.ResourceSetReference && !property.CanReflectOnInstanceTypeProperty, "property != null && property.Kind == ResourcePropertyKind.ResourceSetReference && !property.CanReflectOnInstanceTypeProperty");
 
            Type enumerableElement = BaseServiceProvider.GetIEnumerableElement(property.Type);
            ParameterExpression parameter = Expression.Parameter(query.ElementType, "element");
            MethodInfo getter = DataServiceProviderMethods.GetSequenceValueMethodInfo.MakeGenericMethod(enumerableElement);
            Expression body = Expression.Call(null /*instance*/, getter, parameter, Expression.Constant(property)); 
            LambdaExpression selector = Expression.Lambda(body, parameter);
 
            MethodInfo method = typeof(RequestUriProcessor).GetMethod("InvokeSelectMany", BindingFlags.Static | BindingFlags.NonPublic); 
            method = method.MakeGenericMethod(query.ElementType, enumerableElement);
            return (IQueryable)method.Invoke(null, new object[] { query, selector }); 
        }

        /// Selects a single resource by key values.
        /// Base query for resources 
        /// resource type whose keys are specified
        /// Key values for the given resource type. 
        /// A new query that selects the single resource that matches the specified key values. 
        private static IQueryable SelectResourceByKey(IQueryable query, ResourceType resourceType, KeyInstance key)
        { 
            Debug.Assert(query != null, "query != null");
            Debug.Assert(key != null && key.ValueCount != 0, "key != null && key.ValueCount != 0");
            Debug.Assert(resourceType.KeyProperties.Count == key.ValueCount, "resourceType.KeyProperties.Count == key.ValueCount");
 
            for (int i = 0; i < resourceType.KeyProperties.Count; i++)
            { 
                ResourceProperty keyProperty = resourceType.KeyProperties[i]; 
                Debug.Assert(keyProperty.IsOfKind(ResourcePropertyKind.Key), "keyProperty.IsOfKind(ResourcePropertyKind.Key)");
 
                object keyValue;
                if (key.AreValuesNamed)
                {
                    keyValue = key.NamedValues[keyProperty.Name]; 
                }
                else 
                { 
                    keyValue = key.PositionalValues[i];
                } 

                ParameterExpression parameter = Expression.Parameter(query.ElementType, "element");
                Expression e;
                if (keyProperty.CanReflectOnInstanceTypeProperty) 
                {
                    e = Expression.Property(parameter, keyProperty.Name); 
                } 
                else
                { 
                    e = Expression.Call(null /*instance*/, DataServiceProviderMethods.GetValueMethodInfo, parameter, Expression.Constant(keyProperty));
                    e = Expression.Convert(e, keyProperty.Type);
                }
 
                BinaryExpression body = Expression.Equal((Expression)e, Expression.Constant(keyValue));
                LambdaExpression predicate = Expression.Lambda(body, parameter); 
                query = InvokeWhereForType(query, predicate); 
            }
 
            return query;
        }

        /// Determines a matching target kind from the specified type. 
        /// ResourceType of element to get kind for.
        /// An appropriate  for the specified . 
        private static RequestTargetKind TargetKindFromType(ResourceType type) 
        {
            Debug.Assert(type != null, "type != null"); 

            switch (type.ResourceTypeKind)
            {
                case ResourceTypeKind.ComplexType: 
                    return RequestTargetKind.ComplexObject;
                case ResourceTypeKind.EntityType: 
                    return RequestTargetKind.Resource; 
                default:
                    Debug.Assert(type.ResourceTypeKind == ResourceTypeKind.Primitive, "typeKind == ResourceTypeKind.Primitive"); 
                    return RequestTargetKind.Primitive;
            }
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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