From ae1c922def53d9d6fea5143fa1a427eeeab07526 Mon Sep 17 00:00:00 2001
From: Olga Li <olga_li1@epam.com>
Date: Wed, 26 Jul 2017 17:28:16 +0300
Subject: [PATCH] Part2 (Olga Li)

---
 .../part2/cache/CachingDataStorageImpl.java   | 26 ++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/main/java/part2/cache/CachingDataStorageImpl.java b/src/main/java/part2/cache/CachingDataStorageImpl.java
index a2ae460..8a93abf 100755
--- a/src/main/java/part2/cache/CachingDataStorageImpl.java
+++ b/src/main/java/part2/cache/CachingDataStorageImpl.java
@@ -38,6 +38,30 @@ public OutdatableResult<T> getOutdatable(String key) {
         // TODO don't use obtrudeException on result - just don't
         // TODO use remove(Object key, Object value) to remove target value
         // TODO Start timeout after receiving result in CompletableFuture, not after receiving CompletableFuture itself
-        throw new UnsupportedOperationException();
+
+        CompletableFuture<T> result = new CompletableFuture<>();
+        CompletableFuture<Void> outdated = new CompletableFuture<>();
+
+        OutdatableResult<T> newResult = new OutdatableResult<>(result, outdated);
+        OutdatableResult<T> cacheResult = cache.putIfAbsent(key, newResult);
+
+        if (cacheResult != null) {
+            return cacheResult;
+        }
+
+        db.get(key).whenComplete((e, t) -> {
+            if (t != null) {
+                result.completeExceptionally(t);
+            } else {
+                result.complete(e);
+            }
+            scheduledExecutorService.schedule(() -> {
+                        cache.remove(key, newResult);
+                        outdated.complete(null);
+                    },
+                    timeout,
+                    timeoutUnits);
+        });
+        return newResult;
     }
 }