From 1972a49b4159173d2d4e4dfc49864769f86d6200 Mon Sep 17 00:00:00 2001
From: Jim Borden <jim.borden@couchbase.com>
Date: Fri, 27 Jul 2018 07:07:16 +0900
Subject: [PATCH] [CBSE-5347] Fixes long document expiration

Closes #1029
---
 src/Couchbase.Lite.Shared/Database.cs         |  6 ++++-
 .../DocumentTest.cs                           | 27 +++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/Couchbase.Lite.Shared/Database.cs b/src/Couchbase.Lite.Shared/Database.cs
index 03856b37e..030d65476 100644
--- a/src/Couchbase.Lite.Shared/Database.cs
+++ b/src/Couchbase.Lite.Shared/Database.cs
@@ -2175,7 +2175,11 @@ internal void SchedulePurgeExpired(TimeSpan delay)
             if (nextExpiration.HasValue) {
                 var delta = (nextExpiration.Value - DateTime.UtcNow).Add(TimeSpan.FromSeconds(1));
                 var expirationTimeSpan = delta > delay ? delta : delay;
-                if (expirationTimeSpan.TotalSeconds <= Double.Epsilon) {
+                if (expirationTimeSpan.TotalMilliseconds >= UInt32.MaxValue) {
+                    _expirePurgeTimer.Change(TimeSpan.FromMilliseconds(UInt32.MaxValue - 1), TimeSpan.FromMilliseconds(-1));
+                    Log.To.Database.I(Tag, "{0:F3} seconds is too far in the future to schedule a document expiration," +
+                                           " will run again at the maximum value of {0:F3} seconds", expirationTimeSpan.TotalSeconds, (UInt32.MaxValue - 1) / 1000);
+                } else if (expirationTimeSpan.TotalSeconds <= Double.Epsilon) {
                     _expirePurgeTimer.Change(Timeout.Infinite, Timeout.Infinite);
                     PurgeExpired(null);
                 } else {
diff --git a/src/Couchbase.Lite.Tests.Shared/DocumentTest.cs b/src/Couchbase.Lite.Tests.Shared/DocumentTest.cs
index 957954ecb..56d3711c6 100644
--- a/src/Couchbase.Lite.Tests.Shared/DocumentTest.cs
+++ b/src/Couchbase.Lite.Tests.Shared/DocumentTest.cs
@@ -148,6 +148,33 @@ public void TestExpireDocument()
             Assert.IsTrue(Math.Abs((next.Value - future).TotalSeconds) < 1.0);
         }
 
+        [Category("issue/1029")]
+        [Test]
+        public void TestLongExpiration()
+        {
+            // Before the fix this would crash because timers cannot be scheduled so far
+            // in the future.  Now the timer will fire early, do nothing and reschedule
+            // itself
+            var now = DateTime.UtcNow;
+            Trace.WriteLine($"Now is {now}");
+            var doc = CreateDocumentWithProperties(database, new Dictionary<string, object> { { "foo", 17 } });
+            Assert.IsNull(doc.GetExpirationDate());
+            database.RunInTransaction(() =>
+            {
+                doc.ExpireAfter(TimeSpan.FromDays(60));
+                return true;
+            });
+            
+            var exp = doc.GetExpirationDate();
+            Trace.WriteLine($"Doc expiration is {exp}");
+            Assert.IsNotNull(exp);
+            Assert.IsTrue(Math.Abs((exp.Value - now).TotalDays - 60.0) < 1.0);
+
+            var next = database.Storage.NextDocumentExpiry();
+            Trace.WriteLine($"Next expiry at {next}");
+            Assert.IsTrue(Math.Abs((next.Value - now).TotalDays - 60.0) < 1.0);
+        }
+
         [Test] // #447
         public void TestDocumentArraysMaintainOrder()
         {