tests, set method, tests for set method

CHANGELOG.md

@@ -1,8 +1,12 @@
 # Changelog
 
-## LMDBAL 0.5.2 (October 21, 2023)
+## LMDBAL 0.5.2 (November 01, 2023)
 ### Improvements
 - RAII cursors
+- operation set for cursors
+
+### Bug fixes
+- error beginning transaction is now correctly handled and doesn't segfault
 
 ## LMDBAL 0.5.1 (October 21, 2023)
 ### Improvements

src/base.cpp

@@ -402,10 +402,9 @@ void LMDBAL::Base::commitTransaction(LMDBAL::TransactionID id, const std::string
 LMDBAL::TransactionID LMDBAL::Base::beginPrivateReadOnlyTransaction(const std::string& storageName) const {
     MDB_txn* txn;
     int rc = mdb_txn_begin(environment, NULL, MDB_RDONLY, &txn);
-    if (rc != MDB_SUCCESS) {
+    if (rc != MDB_SUCCESS)
-        mdb_txn_abort(txn);
         throw Unknown(name, mdb_strerror(rc), storageName);
-    }
+
     return txn;
 }
 

src/cursor.h

@@ -73,6 +73,7 @@ public:
 
 private:
     void dropped();
+    void freed();
     void terminated();
     void operateCursorRead(K& key, V& value, MDB_cursor_op operation, const std::string& methodName, const std::string& operationName) const;
 
@@ -91,6 +92,7 @@ private:
     inline static const std::string nextMethodName = "next";                    /**<\brief member function name, just for exceptions*/
     inline static const std::string prevMethodName = "prev";                    /**<\brief member function name, just for exceptions*/
     inline static const std::string currentMethodName = "current";              /**<\brief member function name, just for exceptions*/
+    inline static const std::string setMethodName = "set";                      /**<\brief member function name, just for exceptions*/
 
     inline static const std::string firstOperationName = "Cursor::first";       /**<\brief member function name, just for exceptions*/
     inline static const std::string lastOperationName = "Cursor::last";         /**<\brief member function name, just for exceptions*/

src/cursor.hpp

@@ -81,13 +81,11 @@ LMDBAL::Cursor<K, V>::Cursor(Cursor&& other):
     state(other.state),
     id(other.id)
 {
+    other.terminated();
     if (id != 0)
         storage->cursors[id] = this;
 
-    other.cursor = nullptr;
+    other.freed();
-    other.storage = nullptr;
-    other.id = 0;
-    other.state = closed;
 }
 
 /**
@@ -109,9 +107,7 @@ LMDBAL::Cursor<K, V>& LMDBAL::Cursor<K, V>::operator = (Cursor&& other) {
     id = other.id;
 
     if (id != 0) {
-        other.cursor = nullptr;
+        other.freed();
-        other.storage = nullptr;
-        other.id = 0;
         other.state = closed;
 
         storage->cursors[id] = this;
@@ -146,20 +142,29 @@ void LMDBAL::Cursor<K, V>::drop () {
     if (id != 0)
         storage->cursors.erase(id);
 
-    cursor = nullptr;
+    freed();
-    storage = nullptr;
-    id = 0;
 }
 
 /**
  * \brief A private method that turns cursor into an empty one
  *
- * This function is called from LMDBAL::Storage, when it gets destroyed, but still has some valid.
+ * This function is called from LMDBAL::Storage, when it gets destroyed, but still has some valid cursors.
  * Those cursors will become empty, and can't be used anymore
  */
 template<class K, class V>
 void LMDBAL::Cursor<K, V>::dropped () {
     terminated();
+    freed();
+}
+
+/**
+ * \brief A private method that turns cursor into an empty one (submethod)
+ *
+ * This function is called from LMDBAL::Storage, when the cursor is getting destoryed.
+ * Those cursors will become empty, and can't be used anymore
+ */
+template<class K, class V>
+void LMDBAL::Cursor<K, V>::freed () {
     cursor = nullptr;
     storage = nullptr;
     id = 0;
@@ -585,6 +590,34 @@ std::pair<K, V> LMDBAL::Cursor<K, V>::current () const {
     return result;
 }
 
+/**
+ * \brief Sets cursors to the defined position
+ *
+ * If exactly the same element wasn't found it sets the cursor to the first
+ * element greater then the key and returns false
+ *
+ * \param[in]   key     a key of the element you would like the cursor to be
+ * \returns     true if the exact value was found, false otherwise
+ *
+ * \exception LMDBAL::CursorNotReady   thrown if you try to call this method on a closed cursor
+ * \exception LMDBAL::Unknown          thrown if there was some unexpected problem
+ */
+template<class K, class V>
+bool LMDBAL::Cursor<K, V>::set (const K& key) {
+    if (state == closed)
+        storage->throwCursorNotReady(setMethodName);
+
+    MDB_val mdbKey = storage->keySerializer.setData(key);
+    int result = mdb_cursor_get(cursor, &mdbKey, nullptr, MDB_SET);
+    if (result == MDB_SUCCESS)
+        return true;
+    else if (result == MDB_NOTFOUND)
+        return false;
+
+    storage->throwUnknown(result);
+    return false;   //unreachable, just to suppress the warning
+}
+
 /**
  * \brief a private mothod that actually doing all the reading
  *

src/storage.hpp

@@ -1022,6 +1022,9 @@ void LMDBAL::Storage<K, V>::close() {
 /**
  * \brief Creates cursor
  *
+ * This is a legitimate way to aquire cursor to a storage.
+ * Aquired cursor is RAII safe, automatic destructor will free everything it occupied.
+ *
  * \returns LMDBAL::Cursor for this storage and returs you a pointer to a created cursor
  */
 template<class K, class V>
@@ -1029,6 +1032,29 @@ LMDBAL::Cursor<K, V> LMDBAL::Storage<K, V>::createCursor() {
     return Cursor<K, V>(this);
 }
 
+/**
+ * \brief Frees cursor
+ *
+ * This is a legitimate way to free cursor.
+ * You don't actually need to do it manually,
+ * you can just reassign cursor, let it be destroyed by leaving the scope
+ * or call LMDBAL::Cursor<K, V>::drop, but you may if you wish.
+ *
+ * \param[in]  cursor       cursor you wish to destroy
+ *
+ * \exception LMDBAL::Unknown  thrown if you try to destroy a cursor this storage didn't create
+ */
+template<class K, class V>
+void LMDBAL::Storage<K, V>::destroyCursor(LMDBAL::Cursor<K, V>& cursor) {
+    typename std::map<uint32_t, Cursor<K, V>*>::iterator itr = cursors.find(cursor.id);
+    if (itr == cursors.end())
+        throwUnknown("An attempt to destroy a cursor the storage doesn't own");
+
+    cursor.close();
+    cursors.erase(itr);
+    cursor.freed();
+}
+
 /**
  * \brief Reads current storage flags it was opened with
  *

test/cachecursor.cpp

@@ -23,7 +23,12 @@ protected:
         }
     }
 
+    int getCacheCursorsSize() const {
+        return cache->cursors.size();
+    }
+
     static void TearDownTestSuite() {
+        cursor.drop();
         transaction.terminate();
         db->close();
         db->removeDirectory();
@@ -62,7 +67,9 @@ TEST_F(CacheCursorTest, PopulatingTheTable) {
 }
 
 TEST_F(CacheCursorTest, Creation) {
+    EXPECT_EQ(getCacheCursorsSize(), 0);
     cursor = cache->createCursor();
+    EXPECT_EQ(getCacheCursorsSize(), 1);
 
     EXPECT_THROW(cursor.first(), LMDBAL::CursorNotReady);
     EXPECT_THROW(cursor.last(), LMDBAL::CursorNotReady);
@@ -74,6 +81,7 @@ TEST_F(CacheCursorTest, Creation) {
 }
 
 TEST_F(CacheCursorTest, FirstPrivate) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     EXPECT_EQ(cache->count(), data.size());
 
     std::pair<uint64_t, std::string> element = cursor.first();
@@ -85,6 +93,7 @@ TEST_F(CacheCursorTest, FirstPrivate) {
 }
 
 TEST_F(CacheCursorTest, NextPrivate) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
     reference++;
@@ -107,6 +116,7 @@ TEST_F(CacheCursorTest, NextPrivate) {
 }
 
 TEST_F(CacheCursorTest, LastPrivate) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     EXPECT_EQ(cache->count(), data.size());
 
     std::pair<uint64_t, std::string> element = cursor.last();
@@ -118,6 +128,7 @@ TEST_F(CacheCursorTest, LastPrivate) {
 }
 
 TEST_F(CacheCursorTest, PrevPrivate) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
     reference++;
@@ -140,6 +151,7 @@ TEST_F(CacheCursorTest, PrevPrivate) {
 }
 
 TEST_F(CacheCursorTest, CurrentPrivate) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.first();
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
@@ -172,8 +184,42 @@ TEST_F(CacheCursorTest, CurrentPrivate) {
     EXPECT_EQ(cache->count(), data.size());
 }
 
+TEST_F(CacheCursorTest, SettingPrivate) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
+
+    EXPECT_FALSE(cursor.set(6684));
+    EXPECT_EQ(cursor.current().second, "tanned inmate");
+
+    std::map<uint64_t, std::string>::const_iterator reference = data.begin();
+    std::advance(reference, 5);
+    EXPECT_TRUE(cursor.set(reference->first));
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+}
+
 TEST_F(CacheCursorTest, Destruction) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     cursor.close();
+    EXPECT_EQ(getCacheCursorsSize(), 1);
 
     EXPECT_THROW(cursor.first(), LMDBAL::CursorNotReady);
     EXPECT_THROW(cursor.last(), LMDBAL::CursorNotReady);
@@ -182,11 +228,14 @@ TEST_F(CacheCursorTest, Destruction) {
     EXPECT_THROW(cursor.current(), LMDBAL::CursorNotReady);
 
     cursor = LMDBAL::Cursor<uint64_t, std::string>();
+    EXPECT_EQ(getCacheCursorsSize(), 0);
 
     cursor = cache->createCursor();
+    EXPECT_EQ(getCacheCursorsSize(), 1);
 }
 
 TEST_F(CacheCursorTest, FirstPublic) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     transaction = db->beginTransaction();
 
     cursor.open(transaction);
@@ -199,6 +248,7 @@ TEST_F(CacheCursorTest, FirstPublic) {
 }
 
 TEST_F(CacheCursorTest, NextPublic) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
     reference++;
@@ -220,6 +270,7 @@ TEST_F(CacheCursorTest, NextPublic) {
 }
 
 TEST_F(CacheCursorTest, LastPublic) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.last();
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
@@ -229,6 +280,7 @@ TEST_F(CacheCursorTest, LastPublic) {
 }
 
 TEST_F(CacheCursorTest, PrevPublic) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
     reference++;
@@ -250,6 +302,7 @@ TEST_F(CacheCursorTest, PrevPublic) {
 }
 
 TEST_F(CacheCursorTest, CurrentPublic) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.first();
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
@@ -282,6 +335,71 @@ TEST_F(CacheCursorTest, CurrentPublic) {
     EXPECT_EQ(cache->count(), data.size());
 }
 
+TEST_F(CacheCursorTest, SettingPublic) {
+    EXPECT_EQ(getCacheCursorsSize(), 1);
+
+    EXPECT_FALSE(cursor.set(557));
+    EXPECT_EQ(cursor.current().second, "resilent pick forefront");
+
+    std::map<uint64_t, std::string>::const_iterator reference = data.begin();
+    std::advance(reference, 3);
+    EXPECT_TRUE(cursor.set(reference->first));
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+}
+
+TEST_F(CacheCursorTest, CursorRAIIBehaviour) {
+    int initialiCursorsAmount = getCacheCursorsSize();
+    {
+        LMDBAL::Cursor<uint64_t, std::string> cur = cache->createCursor();
+        EXPECT_EQ(initialiCursorsAmount + 1, getCacheCursorsSize());
+        cur.open(transaction);
+        EXPECT_NO_THROW(cur.first());
+    }
+
+    EXPECT_EQ(initialiCursorsAmount, getCacheCursorsSize());
+    LMDBAL::Cursor<uint64_t, std::string> cur;
+    EXPECT_EQ(initialiCursorsAmount, getCacheCursorsSize());
+    EXPECT_EQ(cur.empty(), true);
+    cur = cache->createCursor();
+    EXPECT_EQ(cur.empty(), false);
+    EXPECT_EQ(initialiCursorsAmount + 1, getCacheCursorsSize());
+    EXPECT_THROW(emptyCache->destroyCursor(cur), LMDBAL::Unknown);
+    cache->destroyCursor(cur);
+    EXPECT_EQ(cur.empty(), true);
+    EXPECT_EQ(initialiCursorsAmount, getCacheCursorsSize());
+
+    cur = cache->createCursor();
+    EXPECT_EQ(initialiCursorsAmount + 1, getCacheCursorsSize());
+    EXPECT_EQ(cur.empty(), false);
+
+    cur.drop();
+    EXPECT_EQ(cur.empty(), true);
+    EXPECT_EQ(initialiCursorsAmount, getCacheCursorsSize());
+
+    EXPECT_NO_THROW(cur.drop());
+    EXPECT_THROW(cache->destroyCursor(cur), LMDBAL::Unknown);
+}
+
 TEST_F(CacheCursorTest, CornerCases) {
     transaction.terminate();
     EXPECT_THROW(cursor.current(), LMDBAL::Unknown);

test/storagecursor.cpp

@@ -22,7 +22,12 @@ protected:
         }
     }
 
+    int getTableCursorsSize() const {
+        return table->cursors.size();
+    }
+
     static void TearDownTestSuite() {
+        cursor.drop();
         transaction.terminate();
         db->close();
         db->removeDirectory();
@@ -61,7 +66,9 @@ TEST_F(StorageCursorTest, PopulatingTheTable) {
 }
 
 TEST_F(StorageCursorTest, Creation) {
+    EXPECT_EQ(getTableCursorsSize(), 0);
     cursor = table->createCursor();
+    EXPECT_EQ(getTableCursorsSize(), 1);
 
     EXPECT_THROW(cursor.first(), LMDBAL::CursorNotReady);
     EXPECT_THROW(cursor.last(), LMDBAL::CursorNotReady);
@@ -73,6 +80,7 @@ TEST_F(StorageCursorTest, Creation) {
 }
 
 TEST_F(StorageCursorTest, FirstPrivate) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.first();
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
@@ -81,6 +89,7 @@ TEST_F(StorageCursorTest, FirstPrivate) {
 }
 
 TEST_F(StorageCursorTest, NextPrivate) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
     reference++;
@@ -100,6 +109,7 @@ TEST_F(StorageCursorTest, NextPrivate) {
 }
 
 TEST_F(StorageCursorTest, LastPrivate) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.last();
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
@@ -108,6 +118,7 @@ TEST_F(StorageCursorTest, LastPrivate) {
 }
 
 TEST_F(StorageCursorTest, PrevPrivate) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
     reference++;
@@ -127,6 +138,7 @@ TEST_F(StorageCursorTest, PrevPrivate) {
 }
 
 TEST_F(StorageCursorTest, CurrentPrivate) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.first();
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
@@ -157,8 +169,42 @@ TEST_F(StorageCursorTest, CurrentPrivate) {
     EXPECT_EQ(element.second, reference->second);
 }
 
+TEST_F(StorageCursorTest, SettingPrivate) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
+
+    EXPECT_FALSE(cursor.set(6684));
+    EXPECT_EQ(cursor.current().second, "tanned inmate");
+
+    std::map<uint64_t, std::string>::const_iterator reference = data.begin();
+    std::advance(reference, 5);
+    EXPECT_TRUE(cursor.set(reference->first));
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+}
+
 TEST_F(StorageCursorTest, Destruction) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     cursor.close();
+    EXPECT_EQ(getTableCursorsSize(), 1);
 
     EXPECT_THROW(cursor.first(), LMDBAL::CursorNotReady);
     EXPECT_THROW(cursor.last(), LMDBAL::CursorNotReady);
@@ -167,11 +213,14 @@ TEST_F(StorageCursorTest, Destruction) {
     EXPECT_THROW(cursor.current(), LMDBAL::CursorNotReady);
 
     cursor = LMDBAL::Cursor<uint64_t, std::string>();
+    EXPECT_EQ(getTableCursorsSize(), 0);
 
     cursor = table->createCursor();
+    EXPECT_EQ(getTableCursorsSize(), 1);
 }
 
 TEST_F(StorageCursorTest, FirstPublic) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     transaction = db->beginReadOnlyTransaction();
 
     cursor.open(transaction);
@@ -183,6 +232,7 @@ TEST_F(StorageCursorTest, FirstPublic) {
 }
 
 TEST_F(StorageCursorTest, NextPublic) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
     reference++;
@@ -202,6 +252,7 @@ TEST_F(StorageCursorTest, NextPublic) {
 }
 
 TEST_F(StorageCursorTest, LastPublic) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.last();
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
@@ -210,6 +261,7 @@ TEST_F(StorageCursorTest, LastPublic) {
 }
 
 TEST_F(StorageCursorTest, PrevPublic) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::map<uint64_t, std::string>::const_reverse_iterator reference = data.rbegin();
 
     reference++;
@@ -229,6 +281,7 @@ TEST_F(StorageCursorTest, PrevPublic) {
 }
 
 TEST_F(StorageCursorTest, CurrentPublic) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     std::pair<uint64_t, std::string> element = cursor.first();
     std::map<uint64_t, std::string>::const_iterator reference = data.begin();
 
@@ -259,7 +312,73 @@ TEST_F(StorageCursorTest, CurrentPublic) {
     EXPECT_EQ(element.second, reference->second);
 }
 
+TEST_F(StorageCursorTest, SettingPublic) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
+
+    EXPECT_FALSE(cursor.set(557));
+    EXPECT_EQ(cursor.current().second, "resilent pick forefront");
+
+    std::map<uint64_t, std::string>::const_iterator reference = data.begin();
+    std::advance(reference, 3);
+    EXPECT_TRUE(cursor.set(reference->first));
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    ++reference;
+    cursor.next();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+
+    --reference;
+    cursor.prev();
+    EXPECT_EQ(cursor.current().second, reference->second);
+}
+
+TEST_F(StorageCursorTest, CursorRAIIBehaviour) {
+    int initialiCursorsAmount = getTableCursorsSize();
+    {
+        LMDBAL::Cursor<uint64_t, std::string> cur = table->createCursor();
+        EXPECT_EQ(initialiCursorsAmount + 1, getTableCursorsSize());
+        cur.open(transaction);
+        EXPECT_NO_THROW(cur.first());
+    }
+
+    EXPECT_EQ(initialiCursorsAmount, getTableCursorsSize());
+    LMDBAL::Cursor<uint64_t, std::string> cur;
+    EXPECT_EQ(initialiCursorsAmount, getTableCursorsSize());
+    EXPECT_EQ(cur.empty(), true);
+    cur = table->createCursor();
+    EXPECT_EQ(cur.empty(), false);
+    EXPECT_EQ(initialiCursorsAmount + 1, getTableCursorsSize());
+    EXPECT_THROW(emptyTable->destroyCursor(cur), LMDBAL::Unknown);
+    table->destroyCursor(cur);
+    EXPECT_EQ(cur.empty(), true);
+    EXPECT_EQ(initialiCursorsAmount, getTableCursorsSize());
+
+    cur = table->createCursor();
+    EXPECT_EQ(initialiCursorsAmount + 1, getTableCursorsSize());
+    EXPECT_EQ(cur.empty(), false);
+
+    cur.drop();
+    EXPECT_EQ(cur.empty(), true);
+    EXPECT_EQ(initialiCursorsAmount, getTableCursorsSize());
+
+    EXPECT_NO_THROW(cur.drop());
+    EXPECT_THROW(table->destroyCursor(cur), LMDBAL::Unknown);
+}
+
 TEST_F(StorageCursorTest, CornerCases) {
+    EXPECT_EQ(getTableCursorsSize(), 1);
     transaction.terminate();
     EXPECT_THROW(cursor.current(), LMDBAL::Unknown);
     cursor.close();