Implement virGetVersion (#2)

Author: WenceyWang

src/libvirt/Connect.cs

@@ -19,13 +19,13 @@ public Connect(string uri)
 
         public string Uri { get; }
 
-        public bool IsOpen { get; set; }
+        public bool IsOpen { get; private set; }
 
         public void Open(bool readOnly = false)
         {
             if (IsDisposed)
             {
-                throw new ObjectDisposedException("Cannot open a disposed Connect");
+                throw new ObjectDisposedException(null, "Cannot open a disposed Connect.");
             }
 
             if (readOnly)
@@ -51,15 +51,15 @@ public void Close(bool ignoreErrors = false)
 
             int result = Libvirt.virConnectClose(_conn);
 
-            if (!ignoreErrors) 
+            if (!ignoreErrors)
             {
                 ThrowExceptionOnError(result);
             }
 
             IsOpen = false;
         }
 
-        public List<Domain> GetDomains(virConnectListAllDomainsFlags flags = default(virConnectListAllDomainsFlags))
+        public List<Domain> GetDomains(virConnectListAllDomainsFlags flags = default)
         {
             int result = Libvirt.virConnectListAllDomains(_conn, out IntPtr ptrDomains, flags);
 
@@ -95,7 +95,7 @@ public Domain CreateDomain(string xml)
 
         public string Type => GetString(() => Libvirt.virConnectGetType(_conn));
 
-        private new string GetString(Func<string> func)
+        protected override string GetString(Func<string> func)
         {
             if (!IsOpen)
             {

src/libvirt/Libvirt.cs

@@ -4,7 +4,7 @@
 
 namespace libvirt
 {
-    public class Libvirt
+    public static class Libvirt
     {
         public const string Name = "libvirt";
 
@@ -34,6 +34,25 @@ private static IntPtr ImportResolver(string libraryName, Assembly assembly, DllI
 
         public const int VIR_UUID_BUFLEN = 36;
 
+        public static Version GetVersion()
+        {
+            LibvirtHelper.ThrowExceptionOnError(virGetVersion(out ulong libVer, null, out _));
+
+            int release = (int) (libVer % 1000);
+            int minor = (int) ((libVer % 1000000) / 1000);
+            int major = (int) (libVer / 1000000);
+
+            return new Version(major, minor, release);
+
+        }
+
+        #region Library
+
+        [DllImport(Libvirt.Name, CallingConvention = CallingConvention.Cdecl, EntryPoint = "virGetVersion")]
+        public static extern int virGetVersion([Out] out ulong libVer, [In] string type, [Out] out ulong typeVer);
+
+        #endregion
+
         #region Connect
 
         [DllImport(Libvirt.Name, CallingConvention = CallingConvention.Cdecl, EntryPoint = "virConnectOpen")]

src/libvirt/LibvirtHelper.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace libvirt
+{
+    public static class LibvirtHelper
+    {
+        public static void ThrowExceptionOnError(int result) => ThrowExceptionOn(() => result == -1);
+
+        public static void ThrowExceptionOnError(IntPtr result) => ThrowExceptionOn(() => result == IntPtr.Zero);
+
+        public static void ThrowExceptionOnError(string result) => ThrowExceptionOn(() => result == null);
+
+        private static void ThrowExceptionOn(Func<bool> predicate)
+        {
+            if (predicate())
+            {
+                virError error = GetLastError();
+
+                if (error?.level == virErrorLevel.VIR_ERR_ERROR)
+                {
+                    throw new LibvirtException(error);
+                }
+            }
+        }
+
+        private static virError GetLastError()
+        {
+            IntPtr errPtr = Libvirt.virGetLastError();
+
+            return Marshal.PtrToStructure<virError>(errPtr);
+        }
+    }
+}

src/libvirt/LibvirtObject.cs

@@ -16,7 +16,7 @@ protected void EnsureObjectIsNotDisposed()
             }
         }
 
-        protected string GetString(Func<string> func)
+        protected virtual string GetString(Func<string> func)
         {
             EnsureObjectIsNotDisposed();
 
@@ -32,7 +32,7 @@ protected string GetUUID(Func<char[], int> func)
             EnsureObjectIsNotDisposed();
 
             char[] uuid = new char[Libvirt.VIR_UUID_BUFLEN];
-            
+
             var result = func(uuid);
 
             ThrowExceptionOnError(result);
@@ -51,35 +51,11 @@ protected int GetInt32(Func<int> func)
             return result;
         }
 
-        protected void ThrowExceptionOnError(int result) =>  ThrowExceptionOn(() => result == -1);
-
-        protected void ThrowExceptionOnError(IntPtr result) => ThrowExceptionOn(() => result == IntPtr.Zero);
+        protected void ThrowExceptionOnError(int result) => LibvirtHelper.ThrowExceptionOnError(result);
 
-        protected void ThrowExceptionOnError(string result) => ThrowExceptionOn(() => result == null);
+        protected void ThrowExceptionOnError(IntPtr result) => LibvirtHelper.ThrowExceptionOnError(result);
 
-        private void ThrowExceptionOn(Func<bool> predicate)
-        {
-            if (predicate())
-            {
-                var error = GetLastError();
-
-                if (error != null && error.level == virErrorLevel.VIR_ERR_ERROR)
-                {
-                    throw new LibvirtException(error);
-                }
-            }
-        }
+        protected void ThrowExceptionOnError(string result) => LibvirtHelper.ThrowExceptionOnError(result);
 
-        private virError GetLastError()
-        {
-            IntPtr errPtr = Libvirt.virGetLastError();
-
-            if (errPtr == IntPtr.Zero) 
-            {
-                return null;
-            }
-
-            return (virError) Marshal.PtrToStructure(errPtr, typeof(virError));
-        }
     }
 }

tests/libvirt.Tests/LibraryTests.cs

@@ -0,0 +1,13 @@
+using Xunit;
+
+namespace libvirt.Tests
+{
+    public class LibraryTests
+    {
+        [Fact]
+        public void GetVersion_ReturnVersion()
+        {
+            Libvirt.GetVersion();
+        }
+    }
+}