From 6f1c39fd21f5a374a2a1c41b72c8da4e1a2701d4 Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <mail@smessmer.de>
Date: Mon, 27 Apr 2015 10:35:01 +0200
Subject: [PATCH] QueueMap: Added more test cases and improved interface

---
 implementations/caching/Cache.cpp             |   2 +-
 implementations/caching/QueueMap.h            |   5 +-
 test/implementations/caching/QueueMapTest.cpp | 500 +++++++++++++++---
 3 files changed, 429 insertions(+), 78 deletions(-)

diff --git a/implementations/caching/Cache.cpp b/implementations/caching/Cache.cpp
index 050dbc40..e4cbac53 100644
--- a/implementations/caching/Cache.cpp
+++ b/implementations/caching/Cache.cpp
@@ -47,7 +47,7 @@ void Cache::push(unique_ptr<Block> block) {
 
 void Cache::_popOldEntries() {
   lock_guard<mutex> lock(_mutex);
-  while(_cachedBlocks.size() > 0 && _cachedBlocks.peek().ageSeconds() > PURGE_LIFETIME_SEC) {
+  while(_cachedBlocks.size() > 0 && _cachedBlocks.peek()->ageSeconds() > PURGE_LIFETIME_SEC) {
 	_cachedBlocks.pop();
   }
 }
diff --git a/implementations/caching/QueueMap.h b/implementations/caching/QueueMap.h
index d21b31cf..c8814691 100644
--- a/implementations/caching/QueueMap.h
+++ b/implementations/caching/QueueMap.h
@@ -51,7 +51,10 @@ public:
     return pop(*_sentinel.next->key);
   }
 
-  const Value &peek() {
+  boost::optional<const Value &> peek() {
+    if(_sentinel.next == &_sentinel) {
+      return boost::none;
+    }
     return _sentinel.next->value();
   }
 
diff --git a/test/implementations/caching/QueueMapTest.cpp b/test/implementations/caching/QueueMapTest.cpp
index 37dc300a..851180e9 100644
--- a/test/implementations/caching/QueueMapTest.cpp
+++ b/test/implementations/caching/QueueMapTest.cpp
@@ -1,139 +1,487 @@
 #include <google/gtest/gtest.h>
 #include <messmer/cpp-utils/macros.h>
 #include "../../../implementations/caching/QueueMap.h"
+#include <memory>
+#include <boost/optional/optional_io.hpp>
 
 using ::testing::Test;
+using std::unique_ptr;
+using std::make_unique;
 
 using namespace blockstore::caching;
 
 // This is a not-default-constructible Key type
 class MinimalKeyType {
 public:
-  static MinimalKeyType create() {
-    return MinimalKeyType();
+  static int instances;
+  static MinimalKeyType create(int value) {
+    return MinimalKeyType(value);
   }
   bool operator==(const MinimalKeyType &rhs) const {
-    return true;
+    return _value == rhs._value;
+  }
+  int value() const {
+    return _value;
+  }
+  MinimalKeyType(const MinimalKeyType &rhs): MinimalKeyType(rhs.value()) {
+  }
+  ~MinimalKeyType() {
+    --instances;
   }
 private:
-  MinimalKeyType() {
+  MinimalKeyType(int value): _value(value) {
+    ++instances;
   }
+  int _value;
 };
+int MinimalKeyType::instances = 0;
 namespace std {
 template <> struct hash<MinimalKeyType> {
   size_t operator()(const MinimalKeyType &obj) const {
-    return 0;
+    return obj.value();
   }
 };
 }
 // This is a not-default-constructible non-copyable but moveable Value type
 class MinimalValueType {
 public:
-  static MinimalValueType create() {
-    return MinimalValueType();
+  static int instances;
+  static MinimalValueType create(int value) {
+    return MinimalValueType(value);
+  }
+  MinimalValueType(MinimalValueType &&rhs): MinimalValueType(rhs.value()) {
+    rhs._isMoved = true;
+  }
+  ~MinimalValueType() {
+    assert(!_isDestructed);
+    --instances;
+    _isDestructed = true;
+  }
+  int value() const {
+    assert(!_isMoved && !_isDestructed);
+    return _value;
   }
-  MinimalValueType(MinimalValueType &&rhs) = default;
 private:
-  MinimalValueType() {
+  MinimalValueType(int value): _value(value), _isMoved(false), _isDestructed(false) {
+    ++instances;
   }
+  int _value;
+  bool _isMoved;
+  bool _isDestructed;
   DISALLOW_COPY_AND_ASSIGN(MinimalValueType);
 };
+int MinimalValueType::instances = 0;
 
 class QueueMapTest: public Test {
 public:
-  QueueMap<int, int> map;
+  QueueMapTest() {
+    MinimalKeyType::instances = 0;
+    MinimalValueType::instances = 0;
+    _map = make_unique<QueueMap<MinimalKeyType, MinimalValueType>>();
+  }
+  ~QueueMapTest() {
+    _map.reset();
+    EXPECT_EQ(0, MinimalKeyType::instances);
+    EXPECT_EQ(0, MinimalValueType::instances);
+  }
+  void push(int key, int value) {
+    _map->push(MinimalKeyType::create(key), MinimalValueType::create(value));
+  }
+  boost::optional<int> pop() {
+    auto elem = _map->pop();
+    if (!elem) {
+      return boost::none;
+    }
+    return elem.value().value();
+  }
+  boost::optional<int> pop(int key) {
+    auto elem = _map->pop(MinimalKeyType::create(key));
+    if (!elem) {
+      return boost::none;
+    }
+    return elem.value().value();
+  }
+  boost::optional<int> peek() {
+    auto elem = _map->peek();
+    if (!elem) {
+      return boost::none;
+    }
+    return elem.value().value();
+  }
+  int size() {
+    return _map->size();
+  }
+private:
+  unique_ptr<QueueMap<MinimalKeyType, MinimalValueType>> _map;
 };
 
-TEST_F(QueueMapTest, TypeConstraints) {
-  QueueMap<MinimalKeyType, MinimalValueType> obj;
-  //Call all functions to ensure they still work
-  obj.push(MinimalKeyType::create(), MinimalValueType::create());
-  obj.peek();
-  obj.pop(MinimalKeyType::create());
-  obj.push(MinimalKeyType::create(), MinimalValueType::create());
-  obj.pop();
-  obj.size();
+class QueueMapSizeTest: public QueueMapTest {};
+
+TEST_F(QueueMapSizeTest, Empty) {
+  EXPECT_EQ(0, size());
 }
 
-TEST_F(QueueMapTest, Size_Empty) {
-  EXPECT_EQ(0, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOne) {
+  push(2, 3);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOne) {
-  map.push(2, 3);
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_EQ(2, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingTwo) {
-  map.push(2, 3);
-  map.push(3, 4);
-  EXPECT_EQ(2, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingTwoAndPoppingOldest) {
+  push(2, 3);
+  push(3, 4);
+  pop();
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingTwoAndPoppingOldest) {
-  map.push(2, 3);
-  map.push(3, 4);
-  map.pop();
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingTwoAndPoppingFirst) {
-  map.push(2, 3);
-  map.push(3, 4);
-  map.pop(2);
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingTwoAndPoppingLast) {
+  push(2, 3);
+  push(3, 4);
+  pop(3);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingTwoAndPoppingLast) {
-  map.push(2, 3);
-  map.push(3, 4);
-  map.pop(3);
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOne) {
+  push(2, 3);
+  pop();
+  EXPECT_EQ(0, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOnePoppingOne) {
-  map.push(2, 3);
-  map.pop();
-  EXPECT_EQ(0, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePerKey) {
+  push(2, 3);
+  pop(2);
+  EXPECT_EQ(0, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOnePoppingOnePerKey) {
-  map.push(2, 3);
-  map.pop(2);
-  EXPECT_EQ(0, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePushingOne) {
+  push(2, 3);
+  pop();
+  push(3, 4);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOnePoppingOnePushingOne) {
-  map.push(2, 3);
-  map.pop();
-  map.push(3, 4);
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePerKeyPushingOne) {
+  push(2, 3);
+  pop(2);
+  push(3, 4);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOnePoppingOnePerKeyPushingOne) {
-  map.push(2, 3);
-  map.pop(2);
-  map.push(3, 4);
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePushingSame) {
+  push(2, 3);
+  pop();
+  push(2, 3);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOnePoppingOnePushingSame) {
-  map.push(2, 3);
-  map.pop();
-  map.push(2, 3);
-  EXPECT_EQ(1, map.size());
+TEST_F(QueueMapSizeTest, AfterPushingOnePoppingOnePerKeyPushingSame) {
+  push(2, 3);
+  pop(2);
+  push(2, 3);
+  EXPECT_EQ(1, size());
 }
 
-TEST_F(QueueMapTest, Size_AfterPushingOnePoppingOnePerKeyPushingSame) {
-  map.push(2, 3);
-  map.pop(2);
-  map.push(2, 3);
-  EXPECT_EQ(1, map.size());
+class QueueMapMemoryLeakTest: public QueueMapTest {
+public:
+  void EXPECT_NUM_INSTANCES(int num) {
+    EXPECT_EQ(num, MinimalKeyType::instances);
+    EXPECT_EQ(num, MinimalValueType::instances);
+  }
+};
+
+TEST_F(QueueMapMemoryLeakTest, Empty) {
+  EXPECT_NUM_INSTANCES(0);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOne) {
+  push(2, 3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_NUM_INSTANCES(2);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingTwoAndPoppingOldest) {
+  push(2, 3);
+  push(3, 4);
+  pop();
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingTwoAndPoppingLast) {
+  push(2, 3);
+  push(3, 4);
+  pop(3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOne) {
+  push(2, 3);
+  pop();
+  EXPECT_NUM_INSTANCES(0);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePerKey) {
+  push(2, 3);
+  pop(2);
+  EXPECT_NUM_INSTANCES(0);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePushingOne) {
+  push(2, 3);
+  pop();
+  push(3, 4);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePerKeyPushingOne) {
+  push(2, 3);
+  pop(2);
+  push(3, 4);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePushingSame) {
+  push(2, 3);
+  pop();
+  push(2, 3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+TEST_F(QueueMapMemoryLeakTest, AfterPushingOnePoppingOnePerKeyPushingSame) {
+  push(2, 3);
+  pop(2);
+  push(2, 3);
+  EXPECT_NUM_INSTANCES(1);
+}
+
+class QueueMapValueTest: public QueueMapTest {};
+
+TEST_F(QueueMapValueTest, PoppingFromEmpty) {
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, PoppingFromEmptyPerKey) {
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapValueTest, PoppingNonexistingPerKey) {
+  push(3, 2);
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapValueTest, PushingOne) {
+  push(3, 2);
+  EXPECT_EQ(2, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, PushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_EQ(3, pop().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, AfterPushingTwoAndPoppingLast) {
+  push(2, 3);
+  push(3, 4);
+  pop(3);
+  EXPECT_EQ(boost::none, pop(3));
+  EXPECT_EQ(3, pop(2).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, AfterPushingOnePoppingOne) {
+  push(2, 3);
+  pop();
+  EXPECT_EQ(boost::none, pop());
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapValueTest, AfterPushingOnePoppingOnePerKey) {
+  push(2, 3);
+  pop(2);
+  EXPECT_EQ(boost::none, pop());
+  EXPECT_EQ(boost::none, pop(2));
+}
+
+TEST_F(QueueMapValueTest, AfterPushingOnePoppingOnePushingOne) {
+  push(2, 3);
+  pop();
+  push(3, 4);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, AfterPushingOnePoppingOnePerKeyPushingOne) {
+  push(2, 3);
+  pop(2);
+  push(3, 4);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, pop(3).value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, PushingSomePoppingMiddlePerKey) {
+  push(1, 2);
+  push(2, 3);
+  push(3, 4);
+  push(4, 5);
+  push(5, 6);
+  EXPECT_EQ(3, pop(2).value());
+  EXPECT_EQ(5, pop(4).value());
+  EXPECT_EQ(2, pop().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(6, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, PushingSomePoppingFirstPerKey) {
+  push(1, 2);
+  push(2, 3);
+  push(3, 4);
+  push(4, 5);
+  push(5, 6);
+  EXPECT_EQ(2, pop(1).value());
+  EXPECT_EQ(3, pop(2).value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(5, pop().value());
+  EXPECT_EQ(6, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapValueTest, PushingSomePoppingLastPerKey) {
+  push(1, 2);
+  push(2, 3);
+  push(3, 4);
+  push(4, 5);
+  push(5, 6);
+  EXPECT_EQ(6, pop(5).value());
+  EXPECT_EQ(5, pop(4).value());
+  EXPECT_EQ(2, pop().value());
+  EXPECT_EQ(3, pop().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(boost::none, pop());
+}
+
+class QueueMapPeekTest: public QueueMapTest {};
+
+TEST_F(QueueMapPeekTest, PoppingFromEmpty) {
+  EXPECT_EQ(boost::none, peek());
+}
+
+TEST_F(QueueMapPeekTest, PushingOne) {
+  push(3, 2);
+  EXPECT_EQ(2, peek().value());
+}
+
+TEST_F(QueueMapPeekTest, PushingTwo) {
+  push(2, 3);
+  push(3, 4);
+  EXPECT_EQ(3, peek().value());
+  EXPECT_EQ(3, peek().value());
+  EXPECT_EQ(3, pop().value());
+  EXPECT_EQ(4, peek().value());
+  EXPECT_EQ(4, peek().value());
+  EXPECT_EQ(4, pop().value());
+  EXPECT_EQ(boost::none, peek());
+  EXPECT_EQ(boost::none, pop());
+}
+
+TEST_F(QueueMapPeekTest, AfterPushingTwoAndPoppingFirst) {
+  push(2, 3);
+  push(3, 4);
+  pop(2);
+  EXPECT_EQ(boost::none, pop(2));
+  EXPECT_EQ(4, peek().value());
+}
+
+class CopyableValueType {
+public:
+  static int numCopyConstructorCalled;
+  CopyableValueType(int value): _value(value) {}
+  CopyableValueType(const CopyableValueType &rhs): CopyableValueType(rhs._value) {
+    ++numCopyConstructorCalled;
+  }
+  CopyableValueType(CopyableValueType &&rhs): CopyableValueType(rhs._value) {
+    //Don't increase numCopyConstructorCalled
+  }
+  int value() const {
+    return _value;
+  }
+private:
+  int _value;
+};
+int CopyableValueType::numCopyConstructorCalled = 0;
+
+//Test that QueueMap uses a move constructor for Value if possible
+class QueueMapMoveConstructorTest: public Test {
+public:
+  QueueMapMoveConstructorTest() {
+    CopyableValueType::numCopyConstructorCalled = 0;
+    map = make_unique<QueueMap<MinimalKeyType, CopyableValueType>>();
+  }
+  unique_ptr<QueueMap<MinimalKeyType, CopyableValueType>> map;
+};
+
+TEST_F(QueueMapMoveConstructorTest, PushingAndPopping_MoveIntoMap) {
+  map->push(MinimalKeyType::create(0), CopyableValueType(2));
+  CopyableValueType val = map->pop().value();
+  EXPECT_EQ(0, CopyableValueType::numCopyConstructorCalled);
+}
+
+TEST_F(QueueMapMoveConstructorTest, PushingAndPoppingPerKey_MoveIntoMap) {
+  map->push(MinimalKeyType::create(0), CopyableValueType(2));
+  CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
+  EXPECT_EQ(0, CopyableValueType::numCopyConstructorCalled);
+}
+
+TEST_F(QueueMapMoveConstructorTest, PushingAndPopping_CopyIntoMap) {
+  CopyableValueType value(2);
+  map->push(MinimalKeyType::create(0), value);
+  CopyableValueType val = map->pop().value();
+  EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
+}
+
+TEST_F(QueueMapMoveConstructorTest, PushingAndPoppingPerKey_CopyIntoMap) {
+  CopyableValueType value(2);
+  map->push(MinimalKeyType::create(0), value);
+  CopyableValueType val = map->pop(MinimalKeyType::create(0)).value();
+  EXPECT_EQ(1, CopyableValueType::numCopyConstructorCalled);
 }
 
 //TODO Pushing the same key twice
-//TODO Popping from empty
-//TODO Popping invalid key
-//TODO Test that in all cases, destructors of Value are called correctly in QueueMap when [a] pop() [b] pop(key) [c] ~QueueMap()
-//TODO Test that pushing and popping a copy-and-move-constructible object only called 1 copy constructor
-//TODO Test that pushing and popping doesn't invalidate objects (e.g, calls too many destructors)