make GitObject not implement IDisposable

This requires that all GitObjects eager load their properties.
Handles to the C git objects are used and immediately closed now.

Author: tclem

LibGit2Sharp.Tests/RepositoryFixture.cs

@@ -44,17 +44,6 @@ public void CanCreateRepo()
             }
         }
 
-        [Test]
-        public void CanDisposeObjects()
-        {
-            using (var repo = new Repository(Constants.TestRepoPath))
-            {
-                using (var commit = repo.Lookup(commitSha))
-                {
-                }
-            }
-        }
-
         [Test]
         public void CanLookupByReference()
         {

LibGit2Sharp/Commit.cs

@@ -3,54 +3,74 @@
 
 namespace LibGit2Sharp
 {
+    /// <summary>
+    ///   A Commit
+    /// </summary>
     public class Commit : GitObject
     {
         //public Commit(Repository repo, Signature author, Signature committer, string message = null, Tree tree = null, IEnumerable<Commit> parents = null, string updateRefName = null)
         //{
         //}
 
-        private Signature author;
-        private Signature committer;
-        private string message;
-        private string messageShort;
+        private readonly Repository repo;
         private List<Commit> parents;
 
-        internal Commit(IntPtr obj, ObjectId id = null)
+        internal Commit(IntPtr obj, Repository repo, ObjectId id = null)
             : base(obj, id)
         {
+            this.repo = repo;
+            Message = NativeMethods.git_commit_message(obj);
+            MessageShort = NativeMethods.git_commit_message_short(obj);
+            Author = new Signature(NativeMethods.git_commit_author(obj));
+            Committer = new Signature(NativeMethods.git_commit_committer(obj));
         }
 
-        public string Message
-        {
-            get { return message ?? (message = NativeMethods.git_commit_message(Obj)); }
-        }
+        /// <summary>
+        ///   Gets the commit message.
+        /// </summary>
+        public string Message { get; private set; }
 
-        public string MessageShort
-        {
-            get { return messageShort ?? (messageShort = NativeMethods.git_commit_message_short(Obj)); }
-        }
+        /// <summary>
+        ///   Gets the short commit message which is usually the first line of the commit.
+        /// </summary>
+        public string MessageShort { get; private set; }
 
-        public Signature Author
-        {
-            get { return author ?? (author = new Signature(NativeMethods.git_commit_author(Obj))); }
-        }
+        /// <summary>
+        ///   Gets the author of this commit.
+        /// </summary>
+        public Signature Author { get; private set; }
 
-        public Signature Committer
-        {
-            get { return committer ?? (committer = new Signature(NativeMethods.git_commit_committer(Obj))); }
-        }
+        /// <summary>
+        ///   Gets the committer.
+        /// </summary>
+        public Signature Committer { get; private set; }
 
+        /// <summary>
+        ///   Gets the parents of this commit. This property is lazy loaded and can throw an exception if the commit no longer exists in the repo.
+        /// </summary>
         public List<Commit> Parents
         {
             get
             {
                 if (parents == null)
                 {
-                    IntPtr parentCommit;
-                    parents = new List<Commit>();
-                    for (uint i = 0; NativeMethods.git_commit_parent(out parentCommit, Obj, i) == (int) GitErrorCode.GIT_SUCCESS; i++)
+                    var oid = Id.Oid;
+                    IntPtr obj;
+                    var res = NativeMethods.git_object_lookup(out obj, repo.RepoPtr, ref oid, GitObjectType.Commit);
+                    Ensure.Success(res);
+
+                    try
+                    {
+                        IntPtr parentCommit;
+                        parents = new List<Commit>();
+                        for (uint i = 0; NativeMethods.git_commit_parent(out parentCommit, obj, i) == (int) GitErrorCode.GIT_SUCCESS; i++)
+                        {
+                            parents.Add(new Commit(parentCommit, repo));
+                        }
+                    }
+                    finally
                     {
-                        parents.Add(new Commit(parentCommit));
+                        NativeMethods.git_object_close(obj);
                     }
                 }
                 return parents;

LibGit2Sharp/GitObject.cs

@@ -3,7 +3,10 @@
 
 namespace LibGit2Sharp
 {
-    public class GitObject : IDisposable
+    /// <summary>
+    ///   A GitObject
+    /// </summary>
+    public class GitObject
     {
         public static GitObjectTypeMap TypeToTypeMap =
             new GitObjectTypeMap
@@ -15,82 +18,60 @@ public class GitObject : IDisposable
                     {typeof (GitObject), GitObjectType.Any},
                 };
 
-        protected IntPtr Obj = IntPtr.Zero;
-        private bool disposed;
-
         protected GitObject(IntPtr obj, ObjectId id = null)
         {
-            Obj = obj;
             if (id == null)
             {
-                var ptr = NativeMethods.git_object_id(Obj);
-                id = new ObjectId((GitOid)Marshal.PtrToStructure(ptr, typeof(GitOid)));
+                var ptr = NativeMethods.git_object_id(obj);
+                id = new ObjectId((GitOid) Marshal.PtrToStructure(ptr, typeof (GitOid)));
             }
             Id = id;
         }
 
+        /// <summary>
+        ///   Gets the id of this object
+        /// </summary>
         public ObjectId Id { get; private set; }
 
+        /// <summary>
+        ///   Gets the 40 character sha1 of this object.
+        /// </summary>
         public string Sha
         {
             get { return Id.Sha; }
         }
 
-        #region IDisposable Members
-
-        public void Dispose()
-        {
-            Dispose(true);
-            GC.SuppressFinalize(this);
-        }
-
-        #endregion
-
         internal static GitObject CreateFromPtr(IntPtr obj, ObjectId id, Repository repo)
         {
-            var type = NativeMethods.git_object_type(obj);
-            switch (type)
-            {
-                case GitObjectType.Commit:
-                    return new Commit(obj, id);
-                case GitObjectType.Tree:
-                    return new Tree(obj, id);
-                case GitObjectType.Tag:
-                    return new Tag(obj, id);
-                case GitObjectType.Blob:
-                    return new Blob(obj, id);
-                default:
-                    return new GitObject(obj, id);
-            }
-        }
-
-        private void Dispose(bool disposing)
-        {
-            // Check to see if Dispose has already been called.
-            if (!disposed)
+            try
             {
-                // If disposing equals true, dispose all managed
-                // and unmanaged resources.
-                if (disposing)
+                var type = NativeMethods.git_object_type(obj);
+                switch (type)
                 {
-                    // Dispose managed resources.
+                    case GitObjectType.Commit:
+                        return new Commit(obj, repo, id);
+                    case GitObjectType.Tree:
+                        return new Tree(obj, id);
+                    case GitObjectType.Tag:
+                        return new Tag(obj, id);
+                    case GitObjectType.Blob:
+                        return new Blob(obj, id);
+                    default:
+                        return new GitObject(obj, id);
                 }
-
-                // Call the appropriate methods to clean up
-                // unmanaged resources here.
-                NativeMethods.git_object_close(Obj);
-
-                // Note disposing has been done.
-                disposed = true;
+            }
+            finally
+            {
+                NativeMethods.git_object_close(obj);
             }
         }
 
         public override bool Equals(object obj)
         {
             if (ReferenceEquals(null, obj)) return false;
             if (ReferenceEquals(this, obj)) return true;
-            if (obj.GetType() != typeof(GitObject)) return false;
-            return Equals((GitObject)obj);
+            if (obj.GetType() != typeof (GitObject)) return false;
+            return Equals((GitObject) obj);
         }
 
         public bool Equals(GitObject other)
@@ -100,14 +81,6 @@ public bool Equals(GitObject other)
             return other.Id.Equals(Id);
         }
 
-        ~GitObject()
-        {
-            // Do not re-create Dispose clean-up code here.
-            // Calling Dispose(false) is optimal in terms of
-            // readability and maintainability.
-            Dispose(false);
-        }
-
         public override int GetHashCode()
         {
             return Id.GetHashCode();