Improve performance of resolving of direct references

libgit2 · May 21, 2011 · 4b46919 · 4b46919
1 parent b283190
commit 4b46919
Show file tree

Hide file tree

Showing 3 changed files with 27 additions and 15 deletions.
diff --git a/LibGit2Sharp/DirectReference.cs b/LibGit2Sharp/DirectReference.cs
@@ -1,18 +1,37 @@
-namespace LibGit2Sharp
+using System;
+
+namespace LibGit2Sharp
 {
     /// <summary>
     ///   A DirectReference points directly to a <see cref = "GitObject" />
     /// </summary>
     public class DirectReference : Reference
     {
+        private readonly Func<GitObject> targetResolver;
+        private bool resolved;
+        private GitObject target;
+
+        internal DirectReference(Func<GitObject> targetResolver)
+        {
+            this.targetResolver = targetResolver;
+        }
+
         /// <summary>
         ///   Gets the target of this <see cref = "DirectReference" />
         /// </summary>
-        public GitObject Target { get; internal set; }
-
-        protected override object ProvideAdditionalEqualityComponent()
+        public GitObject Target
         {
-            return Target;
+            get
+            {
+                if (resolved)
+                {
+                    return target;
+                }
+
+                target = targetResolver();
+                resolved = true;
+                return target;
+            }
         }
 
         /// <summary>

diff --git a/LibGit2Sharp/Reference.cs b/LibGit2Sharp/Reference.cs
@@ -11,7 +11,7 @@ namespace LibGit2Sharp
     public abstract class Reference : IEquatable<Reference>
     {
         private static readonly LambdaEqualityHelper<Reference> equalityHelper =
-            new LambdaEqualityHelper<Reference>(new Func<Reference, object>[] { x => x.CanonicalName, x => x.ProvideAdditionalEqualityComponent() });
+            new LambdaEqualityHelper<Reference>(new Func<Reference, object>[] { x => x.CanonicalName, x => x.TargetIdentifier });
 
         /// <summary>
         ///   Gets the full name of this reference.
@@ -57,8 +57,8 @@ public abstract class Reference : IEquatable<Reference>
                     var targetId = new ObjectId(oid);
                     targetIdentifier = targetId.Sha;
 
-                    var target = repo.Lookup(targetId);
-                    reference = new DirectReference { CanonicalName = name, Target = target, TargetIdentifier = targetIdentifier};
+                    var targetResolver = new Func<GitObject>(() => repo.Lookup(targetId));
+                    reference = new DirectReference(targetResolver) { CanonicalName = name, TargetIdentifier = targetIdentifier};
                     break;
 
                 default:
@@ -88,8 +88,6 @@ public abstract class Reference : IEquatable<Reference>
                               Enum.GetName(typeof (GitReferenceType), type)));
         }
 
-        protected abstract object ProvideAdditionalEqualityComponent();
-
         /// <summary>
         ///   Recursively peels the target of the reference until a direct reference is encountered.
         /// </summary>

diff --git a/LibGit2Sharp/SymbolicReference.cs b/LibGit2Sharp/SymbolicReference.cs
@@ -10,11 +10,6 @@ public class SymbolicReference : Reference
         /// </summary>
         public Reference Target { get; internal set; }
 
-        protected override object ProvideAdditionalEqualityComponent()
-        {
-            return Target;
-        }
-
         /// <summary>
         ///   Recursively peels the target of the reference until a direct reference is encountered.
         /// </summary>