- Initial commit

Runtime/Shared/Database/Metadata.cs

@@ -0,0 +1,42 @@
+using System;
+using System.IO;
+
+using Best.HTTP.Shared.Databases.Utils;
+
+namespace Best.HTTP.Shared.Databases
+{
+    public abstract class Metadata
+    {
+        public int Index;
+        public int FilePosition;
+        public int Length;
+
+        public bool IsDeleted => this.FilePosition == -1 && this.Length == -1;
+
+        public void MarkForDelete()
+        {
+            this.FilePosition = -1;
+            this.Length = -1;
+        }
+
+        public virtual void SaveTo(Stream stream)
+        {
+            if (this.IsDeleted)
+                throw new Exception($"Trying to save a deleted metadata({this.ToString()})!");
+
+            stream.EncodeUnsignedVariableByteInteger((uint)this.FilePosition);
+            stream.EncodeUnsignedVariableByteInteger((uint)this.Length);
+        }
+
+        public virtual void LoadFrom(Stream stream)
+        {
+            this.FilePosition = (int)stream.DecodeUnsignedVariableByteInteger();
+            this.Length = (int)stream.DecodeUnsignedVariableByteInteger();
+        }
+
+        public override string ToString()
+        {
+            return $"[Metadata Idx: {Index}, Pos: {FilePosition}, Length: {Length}, IsDeleted: {IsDeleted}]";
+        }
+    }
+}