checkpoint

2020-04-29 13:10:17 -04:00
parent c1618deb83
commit 64f7dd4b7d
54 changed files with 294 additions and 263 deletions
--- a/Alpm/SafeDatabaseHandle.cs
+++ b/Alpm/SafeDatabaseHandle.cs
@@ -0,0 +1,52 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.ConstrainedExecution;
+using System.Runtime.InteropServices;
+
+namespace Foodsoft.Alpm
+{
+    internal sealed class SafeDatabaseHandle : SafeHandle
+    {
+        internal SafeAlpmHandle SafeAlpmHandle
+        {
+            [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+            [PrePrepareMethod]
+            get;
+        } = null!; // we always throw in the constructor on failure
+
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [PrePrepareMethod]
+        internal SafeDatabaseHandle(IntPtr dbPtr, SafeAlpmHandle safeAlpmHandle)
+            : base(IntPtr.Zero, true)
+        {
+            var success = false;
+
+            RuntimeHelpers.PrepareConstrainedRegions();
+            try { }
+            finally
+            {
+                safeAlpmHandle.DangerousAddRef(ref success);
+                if (success)
+                {
+                    SafeAlpmHandle = safeAlpmHandle;
+                    handle = dbPtr;
+                }
+            }
+
+            if (!success) throw new ObjectDisposedException(GetType().FullName);
+        }
+
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail), PrePrepareMethod]
+        protected override bool ReleaseHandle()
+        {
+            SafeAlpmHandle.DangerousRelease();
+            return true;
+        }
+
+        public override bool IsInvalid
+        {
+            [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success), PrePrepareMethod]
+            get => handle == IntPtr.Zero;
+        }
+    }
+}