From cfd3c03cda7ec6a100e47cfbb1971f035fae5fd6 Mon Sep 17 00:00:00 2001
From: nulltoken <emeric.fermas@gmail.com>
Date: Sat, 7 Sep 2013 20:57:51 +0200
Subject: [PATCH] Small refactoring

---
 LibGit2Sharp/OdbBackend.cs       | 30 ++++++++++++++++++------------
 LibGit2Sharp/OdbBackendStream.cs | 14 +++++++-------
 2 files changed, 25 insertions(+), 19 deletions(-)

diff --git a/LibGit2Sharp/OdbBackend.cs b/LibGit2Sharp/OdbBackend.cs
index 76551cec0..35a4c6af3 100644
--- a/LibGit2Sharp/OdbBackend.cs
+++ b/LibGit2Sharp/OdbBackend.cs
@@ -393,10 +393,7 @@ private static OdbBackend MarshalOdbBackend(IntPtr backendPtr)
                 UIntPtr len,
                 GitObjectType type)
             {
-                if (len.ToUInt64() > long.MaxValue)
-                {
-                    return (int)GitErrorCode.Error;
-                }
+                long length = ConverToLong(len);
 
                 OdbBackend odbBackend = MarshalOdbBackend(backend);
                 if (odbBackend == null)
@@ -406,9 +403,9 @@ private static OdbBackend MarshalOdbBackend(IntPtr backendPtr)
 
                 try
                 {
-                    using (var stream = new UnmanagedMemoryStream((byte*)data, (long)len.ToUInt64()))
+                    using (var stream = new UnmanagedMemoryStream((byte*)data, length))
                     {
-                        return odbBackend.Write(new ObjectId(oid), stream, (long)len.ToUInt64(), type.ToObjectType());
+                        return odbBackend.Write(new ObjectId(oid), stream, length, type.ToObjectType());
                     }
                 }
                 catch (Exception ex)
@@ -421,15 +418,12 @@ private static OdbBackend MarshalOdbBackend(IntPtr backendPtr)
             private static int WriteStream(
                 out IntPtr stream_out,
                 IntPtr backend,
-                UIntPtr length,
+                UIntPtr len,
                 GitObjectType type)
             {
                 stream_out = IntPtr.Zero;
 
-                if (length.ToUInt64() > long.MaxValue)
-                {
-                    return (int)GitErrorCode.Error;
-                }
+                long length = ConverToLong(len);
 
                 OdbBackend odbBackend = MarshalOdbBackend(backend);
                 if (odbBackend == null)
@@ -442,7 +436,7 @@ private static OdbBackend MarshalOdbBackend(IntPtr backendPtr)
                 try
                 {
                     OdbBackendStream stream;
-                    int toReturn = odbBackend.WriteStream((long)length.ToUInt64(), objectType, out stream);
+                    int toReturn = odbBackend.WriteStream(length, objectType, out stream);
 
                     if (toReturn == 0)
                     {
@@ -578,6 +572,18 @@ private unsafe int CallbackMethod(ObjectId id)
             }
         }
 
+        internal static long ConverToLong(UIntPtr len)
+        {
+            if (len.ToUInt64() > long.MaxValue)
+            {
+                throw new InvalidOperationException(
+                    string.Format("Provided length ({0}) exceeds long.MaxValue ({1}).",
+                        len.ToUInt64(), long.MaxValue));
+            }
+
+            return (long)len.ToUInt64();
+        }
+
         /// <summary>
         /// Flags used by subclasses of OdbBackend to indicate which operations they support.
         /// </summary>
diff --git a/LibGit2Sharp/OdbBackendStream.cs b/LibGit2Sharp/OdbBackendStream.cs
index 570917ce9..6397b7bb3 100644
--- a/LibGit2Sharp/OdbBackendStream.cs
+++ b/LibGit2Sharp/OdbBackendStream.cs
@@ -145,14 +145,15 @@ private static class BackendStreamEntryPoints
             {
                 OdbBackendStream odbBackendStream = GCHandle.FromIntPtr(Marshal.ReadIntPtr(stream, GitOdbBackendStream.GCHandleOffset)).Target as OdbBackendStream;
 
-                if (odbBackendStream != null &&
-                    len.ToUInt64() < long.MaxValue)
+                if (odbBackendStream != null)
                 {
-                    using (UnmanagedMemoryStream memoryStream = new UnmanagedMemoryStream((byte*)buffer, 0, (long)len.ToUInt64(), FileAccess.ReadWrite))
+                    long length = OdbBackend.ConverToLong(len);
+
+                    using (UnmanagedMemoryStream memoryStream = new UnmanagedMemoryStream((byte*)buffer, 0, length, FileAccess.ReadWrite))
                     {
                         try
                         {
-                            return odbBackendStream.Read(memoryStream, (long)len.ToUInt64());
+                            return odbBackendStream.Read(memoryStream, length);
                         }
                         catch (Exception ex)
                         {
@@ -171,10 +172,9 @@ private static class BackendStreamEntryPoints
             {
                 OdbBackendStream odbBackendStream = GCHandle.FromIntPtr(Marshal.ReadIntPtr(stream, GitOdbBackendStream.GCHandleOffset)).Target as OdbBackendStream;
 
-                if (odbBackendStream != null &&
-                    len.ToUInt64() < long.MaxValue)
+                if (odbBackendStream != null)
                 {
-                    long length = (long)len.ToUInt64();
+                    long length = OdbBackend.ConverToLong(len);
 
                     using (UnmanagedMemoryStream dataStream = new UnmanagedMemoryStream((byte*)buffer, length))
                     {