From f286886b4903df1a3d7c7923fc7395e9c22a9c8f Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <mail@smessmer.de>
Date: Mon, 27 Apr 2015 22:11:15 +0200
Subject: [PATCH] Handle QueueMap::push(existing_key) better and write more
 test cases for QueueMap

---
 implementations/caching/QueueMap.h            |  4 ++-
 test/implementations/caching/QueueMapTest.cpp | 30 +++++++++++++++++--
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/implementations/caching/QueueMap.h b/implementations/caching/QueueMap.h
index e3cbb0ec..f412432b 100644
--- a/implementations/caching/QueueMap.h
+++ b/implementations/caching/QueueMap.h
@@ -25,7 +25,9 @@ public:
 
   void push(const Key &key, Value value) {
     auto newEntry = _entries.emplace(std::piecewise_construct, std::forward_as_tuple(key), std::forward_as_tuple(_sentinel.prev, &_sentinel));
-    assert(newEntry.second == true);
+    if(newEntry.second != true) {
+      throw std::logic_error("There is already an element with this key");
+    }
     newEntry.first->second.init(&newEntry.first->first, std::move(value));
     //The following is ok, because std::unordered_map never invalidates pointers to its entries
     _sentinel.prev->next = &newEntry.first->second;
diff --git a/test/implementations/caching/QueueMapTest.cpp b/test/implementations/caching/QueueMapTest.cpp
index 851180e9..c49e6889 100644
--- a/test/implementations/caching/QueueMapTest.cpp
+++ b/test/implementations/caching/QueueMapTest.cpp
@@ -398,6 +398,34 @@ TEST_F(QueueMapValueTest, PushingSomePoppingLastPerKey) {
   EXPECT_EQ(boost::none, pop());
 }
 
+//This test forces the underlying datastructure (std::map or std::unordered_map) to grow and reallocate memory.
+//So it tests, that QueueMap still works after reallocating memory.
+TEST_F(QueueMapValueTest, ManyValues) {
+  //Push 1 million entries
+  for (int i = 0; i < 1000000; ++i) {
+    push(i, 2*i);
+  }
+  //pop every other one by key
+  for (int i = 0; i < 1000000; i += 2) {
+    EXPECT_EQ(2*i, pop(i).value());
+  }
+  //pop the rest in queue order
+  for (int i = 1; i < 1000000; i += 2) {
+    EXPECT_EQ(2*i, peek().value());
+    EXPECT_EQ(2*i, pop().value());
+  }
+  EXPECT_EQ(0, size());
+  EXPECT_EQ(boost::none, pop());
+  EXPECT_EQ(boost::none, peek());
+}
+
+TEST_F(QueueMapValueTest, PushAlreadyExistingValue) {
+  push(2, 3);
+  EXPECT_ANY_THROW(
+    push(2, 4);
+  );
+}
+
 class QueueMapPeekTest: public QueueMapTest {};
 
 TEST_F(QueueMapPeekTest, PoppingFromEmpty) {
@@ -483,5 +511,3 @@ TEST_F(QueueMapMoveConstructorTest, PushingAndPoppingPerKey_CopyIntoMap) {
   CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
   EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
 }
-
-//TODO Pushing the same key twice