初始化

Common/SnowIdGenerate/TimeExtensions.cs

@@ -0,0 +1,40 @@
+using System;
+
+namespace Snowflake
+{
+    public static class System
+    {
+        public static Func<long> currentTimeFunc = InternalCurrentTimeMillis;
+ 
+        public static long CurrentTimeMillis()
+        {
+            return currentTimeFunc();
+        }
+
+        public static IDisposable StubCurrentTime(Func<long> func)
+        {
+            currentTimeFunc = func;
+            return new DisposableAction(() =>
+            {
+                currentTimeFunc = InternalCurrentTimeMillis;
+            });  
+        }
+
+        public static IDisposable StubCurrentTime(long millis)
+        {
+            currentTimeFunc = () => millis;
+            return new DisposableAction(() =>
+            {
+                currentTimeFunc = InternalCurrentTimeMillis;
+            });
+        }
+
+        private static readonly DateTime Jan1st1970 = new DateTime
+           (1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+
+        private static long InternalCurrentTimeMillis()
+        {
+            return (long)(DateTime.UtcNow - Jan1st1970).TotalMilliseconds;
+        }        
+    }
+}