Merge pull request #2845 from FirelyTeam/feature/scopednode-cache-dic…

…tionaries

Scoped node cache overhaul

src/Hl7.Fhir.Base/ElementModel/ReferencedResourceCache.cs

@@ -0,0 +1,33 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Hl7.Fhir.ElementModel;
+
+#nullable enable
+
+internal class ReferencedResourceCache : IEnumerable<ScopedNode.BundledResource>
+{
+    private Dictionary<string, ScopedNode?> _items;
+
+    public ReferencedResourceCache(IEnumerable<KeyValuePair<string, ScopedNode?>> items)
+    {
+        _items = new Dictionary<string, ScopedNode?>();
+        foreach (var item in items)
+        {
+            _items.Add(item.Key, item.Value);
+        }
+    }
+
+    internal IEnumerable<ScopedNode> Resources => _items.Values.OfType<ScopedNode>();
+
+    internal ScopedNode? ResolveReference(string reference)
+    {
+        return _items.TryGetValue(reference, out var node) ? node : null;
+    }
+
+    public IEnumerator<ScopedNode.BundledResource> GetEnumerator() => _items.Select(i => new ScopedNode.BundledResource(i.Key, i.Value)).GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
+}
+
+#nullable restore

src/Hl7.Fhir.Base/ElementModel/ScopedNode.cs

@@ -9,6 +9,7 @@
 using Hl7.Fhir.Specification;
 using Hl7.Fhir.Utility;
 using System;
+using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -23,8 +24,8 @@ private class Cache
             public readonly object _lock = new();
 
             public string? Id;
-            public IEnumerable<ScopedNode>? ContainedResources;
-            public IEnumerable<BundledResource>? BundledResources;
+            public ReferencedResourceCache? ContainedResources;
+            public ReferencedResourceCache? BundledResources;
 
             public string? InstanceUri;
         }
@@ -166,20 +167,51 @@ public IEnumerable<ScopedNode> ParentResources()
         /// </summary>
         public IEnumerable<ScopedNode> ContainedResources()
         {
-            if (_cache.ContainedResources == null)
+            if (_cache.ContainedResources != null) return _cache.ContainedResources.Resources;
+
+            if (AtResource)
             {
-                _cache.ContainedResources = AtResource ?
-                    this.Children("contained").Cast<ScopedNode>() :
-                    Enumerable.Empty<ScopedNode>();
+                var referenceEntryPairs = from contained in this.Children("contained")
+                    let id = contained.Children("id").FirstOrDefault()?.Value as string
+                    let resource = contained as ScopedNode
+                    select new KeyValuePair<string, ScopedNode?>(id, resource);
+                _cache.ContainedResources = new ReferencedResourceCache(referenceEntryPairs);
             }
+            else
+                _cache.ContainedResources = new ReferencedResourceCache([]);
+
+            return _cache.ContainedResources.Resources;
+        }
+
+        internal ReferencedResourceCache ContainedResourcesWithId()
+        {
+            if (_cache.ContainedResources != null) return _cache.ContainedResources;
+
+            if (AtResource)
+            {
+                var referenceEntryPairs = from contained in this.Children("contained")
+                    let id = $"#{contained.Children("id").FirstOrDefault()?.Value as string}"
+                    let resource = contained as ScopedNode
+                    select new KeyValuePair<string, ScopedNode?>(id, resource);
+                _cache.ContainedResources = new ReferencedResourceCache(referenceEntryPairs);
+            }
+            else
+                _cache.ContainedResources = new ReferencedResourceCache([]);
+
             return _cache.ContainedResources;
         }
 
         /// <summary>
         /// A tuple of a bundled resource plus its Bundle.entry.fullUrl property.
         /// </summary>
-        public class BundledResource
+        public class BundledResource()
         {
+            public BundledResource(string? fullUrl, ScopedNode? resource) : this()
+            {
+                FullUrl = fullUrl;
+                Resource = resource;
+            }
+
             public string? FullUrl;
             public ScopedNode? Resource;
         }
@@ -189,21 +221,23 @@ public class BundledResource
         /// </summary>
         public IEnumerable<BundledResource> BundledResources()
         {
-            if (_cache.BundledResources == null)
+            if (_cache.BundledResources != null) return _cache.BundledResources;
+
+            if (InstanceType == "Bundle")
             {
-                if (InstanceType == "Bundle")
-                    _cache.BundledResources = from e in this.Children("entry")
-                                              let fullUrl = e.Children("fullUrl").FirstOrDefault()?.Value as string
-                                              let resource = e.Children("resource").FirstOrDefault() as ScopedNode
-                                              select new BundledResource { FullUrl = fullUrl, Resource = resource };
-                else
-                    _cache.BundledResources = Enumerable.Empty<BundledResource>();
+                var referenceEntryPairs = from e in this.Children("entry")
+                    let fullUrl = e.Children("fullUrl").FirstOrDefault()?.Value as string
+                    let resource = e.Children("resource").FirstOrDefault() as ScopedNode
+                    select new KeyValuePair<string, ScopedNode>(fullUrl, resource);
+                _cache.BundledResources = new ReferencedResourceCache(referenceEntryPairs);
             }
+
+            else
+                _cache.BundledResources = new ReferencedResourceCache([]);
 
             return _cache.BundledResources;
         }
 
-
         private readonly string? _fullUrl = null;
 
         /// <summary>

src/Hl7.Fhir.Base/ElementModel/ScopedNodeExtensions.cs

@@ -8,6 +8,7 @@
 
 using Hl7.Fhir.Rest;
 using Hl7.Fhir.Support.Poco;
+using Hl7.FhirPath.Sprache;
 using System;
 using System.Linq;
 
@@ -110,15 +111,13 @@ public static string MakeAbsolute(this ScopedNode node, string reference) =>
                 {
                     if (parent.InstanceType == FhirTypeConstants.BUNDLE)
                     {
-                        var result = parent.BundledResources().FirstOrDefault(br => br.FullUrl == url)?.Resource;
-                        if (result != null) return result;
-                    }
-                    else
-                    {
-                        if (parent.Id() == url) return parent;
-                        var result = parent.ContainedResources().FirstOrDefault(cr => cr.Id() == url);
-                        if (result != null) return result;
+                        return ((ReferencedResourceCache)parent.BundledResources()).ResolveReference(url); // safe cast but we cannot change the signature
                     }
+
+                    if (parent.Id() == url)
+                        return parent;
+                    if (parent.ContainedResourcesWithId().ResolveReference(url) is { } resource) // safe cast but we cannot change the signature
+                        return resource;
                 }
 
                 return null;