1 files changed, 158 insertions, 0 deletions
diff --git a/SQLiteStudio3/coreSQLiteStudio/common/expiringcache.h b/SQLiteStudio3/coreSQLiteStudio/common/expiringcache.h
new file mode 100644
index 0000000..d9bd483
--- /dev/null
+++ b/SQLiteStudio3/coreSQLiteStudio/common/expiringcache.h
@@ -0,0 +1,158 @@
+#ifndef EXPIRINGCACHE_H
+#define EXPIRINGCACHE_H
+
+#include <QCache>
+#include <QDateTime>
+#include <QTimer>
+#include <QDebug>
+
+template <class K, class V>
+class ExpiringCache : public QCache<K, V>
+{
+    public:
+        ExpiringCache(int maxCost = 100, int expireMs = 1000);
+        ~ExpiringCache();
+
+        bool insert(const K& key, V* object, int cost = 1);
+        bool contains(const K& key) const;
+        V*	object(const K& key, bool noExpireCheck = false) const;
+        V*	operator[](const K& key) const;
+        V*	take(const K& key);
+        QList<K> keys() const;
+        bool remove(const K& key);
+        int	count() const;
+        void clear();
+        bool isEmpty() const;
+        void setExpireTime(int ms);
+
+    private:
+        bool expired(const K& key) const;
+
+        mutable QHash<K, qint64> expires;
+        int expireMs;
+};
+
+template <class K, class V>
+ExpiringCache<K, V>::ExpiringCache(int maxCost, int expireMs) :
+    QCache<K, V>(maxCost), expireMs(expireMs)
+{
+}
+
+template <class K, class V>
+ExpiringCache<K, V>::~ExpiringCache()
+{
+}
+
+template <class K, class V>
+bool ExpiringCache<K, V>::insert(const K& key, V* object, int cost)
+{
+    QList<K> keysBefore = QCache<K, V>::keys();
+    bool result = QCache<K, V>::insert(key, object, cost);
+    if (!result)
+        return false;
+
+    QList<K> keysAfter = QCache<K, V>::keys();
+
+    for (const K& keyBefore : keysBefore)
+    {
+        if (!keysAfter.contains(keyBefore))
+            expires.remove(keyBefore);
+    }
+
+    expires[key] = QDateTime::currentMSecsSinceEpoch() + expireMs;
+    return true;
+}
+
+template <class K, class V>
+bool ExpiringCache<K, V>::contains(const K& key) const
+{
+    if (expired(key))
+        return false;
+
+    return QCache<K, V>::contains(key);
+}
+
+template <class K, class V>
+V* ExpiringCache<K, V>::object(const K& key, bool noExpireCheck) const
+{
+    if (!noExpireCheck && expired(key))
+        return nullptr;
+
+    return QCache<K, V>::object(key);
+}
+
+template <class K, class V>
+V* ExpiringCache<K, V>::operator[](const K& key) const
+{
+    if (expired(key))
+        return nullptr;
+
+    return QCache<K, V>::operator[](key);
+}
+
+template <class K, class V>
+V* ExpiringCache<K, V>::take(const K& key)
+{
+    if (expired(key))
+        return nullptr;
+
+    expires.remove(key);
+    return QCache<K, V>::take(key);
+}
+
+template <class K, class V>
+QList<K> ExpiringCache<K, V>::keys() const
+{
+    QList<K> keyList;
+    for (const K& key : QCache<K, V>::keys())
+    {
+        if (!expired(key))
+            keyList << key;
+    }
+    return keyList;
+}
+
+template <class K, class V>
+bool ExpiringCache<K, V>::remove(const K& key)
+{
+    expires.remove(key);
+    return QCache<K, V>::remove(key);
+}
+
+template <class K, class V>
+int ExpiringCache<K, V>::count() const
+{
+    return keys().count();
+}
+
+template <class K, class V>
+void ExpiringCache<K, V>::clear()
+{
+    expires.clear();
+    QCache<K, V>::clear();
+}
+
+template <class K, class V>
+bool ExpiringCache<K, V>::isEmpty() const
+{
+    return keys().isEmpty();
+}
+
+template <class K, class V>
+void ExpiringCache<K, V>::setExpireTime(int ms)
+{
+    expireMs = ms;
+}
+
+template <class K, class V>
+bool ExpiringCache<K, V>::expired(const K& key) const
+{
+    if (expires.contains(key) && QDateTime::currentMSecsSinceEpoch() > expires[key])
+    {
+        expires.remove(key);
+        return true;
+    }
+    return false;
+}
+
+#endif // EXPIRINGCACHE_H