serializer for QByteArray, method to read all records

CMakeLists.txt

@@ -55,6 +55,7 @@ set(HEADERS
   serializer_double.hpp
   serializer_stdstring.hpp
   serializer_qstring.hpp
+  serializer_qbytearray.hpp
 )
 
 if (BUILD_STATIC)

cache.h

@@ -44,6 +44,7 @@ public:
     virtual V getRecord(const K& key) const override;
     virtual uint32_t count() const override;
     virtual int drop(MDB_txn * transaction) override;
+    virtual std::map<K, V> readAll() const override;
 
 protected:
     Mode* mode;

cache.hpp

@@ -115,6 +115,22 @@ V DataBase::Cache<K, V>::getRecord(const K& key) const {
     }
 }
 
+template<class K, class V>
+std::map<K, V> DataBase::Cache<K, V>::readAll() const {
+    if (!DataBase::Table<K, V>::db->opened) {
+        throw Closed("readAll", DataBase::Table<K, V>::db->name, DataBase::Table<K, V>::name);
+    }
+
+    if (*mode != Mode::full) {                      //there is a room for optimization
+        *mode = Mode::full;                         //I can read and deserialize only those values
+        *cache = DataBase::Table<K, V>::readAll();  //that are missing in the cache
+        abscent->clear();
+        *sizeDifference = 0;
+    }
+
+    return *cache;
+}
+
 template<class K, class V>
 void DataBase::Cache<K, V>::removeRecord(const K& key) {
     if (!DataBase::Table<K, V>::db->opened) {

serializer.h

@@ -61,5 +61,6 @@ private:
 #include "serializer_double.hpp"
 #include "serializer_stdstring.hpp"
 #include "serializer_qstring.hpp"
+#include "serializer_qbytearray.hpp"
 
 #endif // CORE_DATABASE_SERIALIZER_H

serializer_qbytearray.hpp

@@ -0,0 +1,58 @@
+// Squawk messenger.
+// Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+#ifndef CORE_DATABASE_SERIALIZER_QBYTEARRAY_HPP
+#define CORE_DATABASE_SERIALIZER_QBYTEARRAY_HPP
+
+#include <QByteArray>
+
+template<>
+class DataBase::Serializer<QByteArray>
+{
+public:
+    Serializer():value() {};
+    Serializer(const QByteArray& p_value):value(p_value) {};
+    ~Serializer() {};
+
+    QByteArray deserialize(const MDB_val& data) {
+        value.setRawData((char*)data.mv_data, data.mv_size);
+        return value;
+    };
+    MDB_val setData(const QByteArray& data) {
+        value = data;
+        return getData();
+    };
+    MDB_val getData() {
+        MDB_val result;
+        result.mv_data = value.data();
+        result.mv_size = value.size();
+        return result;
+    };
+    void clear() {
+        value.clear();
+    };
+
+private:
+    QByteArray value;
+};
+
+
+#endif //CORE_DATABASE_SERIALIZER_QBYTEARRAY_HPP
+
+
+
+

table.h

@@ -58,6 +58,7 @@ public:
     virtual void changeRecord(const K& key, const V& value);
     virtual void removeRecord(const K& key);
     virtual V getRecord(const K& key) const;
+    virtual std::map<K, V> readAll() const;
 
 protected:
     Serializer<K>* keySerializer;

table.hpp

@@ -110,6 +110,39 @@ V DataBase::Table<K, V>::getRecord(const K& key) const {
     }
 }
 
+template<class K, class V>
+std::map<K, V> DataBase::Table<K, V>::readAll() const {
+    if (!db->opened) {
+        throw Closed("readAll", db->name, name);
+    }
+
+    std::map<K, V> result;
+    MDB_txn *txn;
+    MDB_cursor* cursor;
+    MDB_val lmdbKey, lmdbData;
+    int rc = mdb_txn_begin(db->environment, NULL, MDB_RDONLY, &txn);
+    if (rc != MDB_SUCCESS) {
+        throw Unknown(db->name, mdb_strerror(rc), name);
+    }
+    rc = mdb_cursor_open(txn, dbi, &cursor);
+    if (rc != MDB_SUCCESS) {
+        throw Unknown(db->name, mdb_strerror(rc), name);
+    }
+    rc = mdb_cursor_get(cursor, &lmdbKey, &lmdbData, MDB_FIRST);
+    while (rc == MDB_SUCCESS) {
+        K key = keySerializer->deserialize(lmdbKey);
+        V value = valueSerializer->deserialize(lmdbData);
+        result.insert(std::make_pair(key, value));
+        rc = mdb_cursor_get(cursor, &lmdbKey, &lmdbData, MDB_NEXT);
+    }
+
+    if (rc != MDB_NOTFOUND) {
+        throw Unknown(db->name, mdb_strerror(rc), name);
+    }
+
+    return result;
+}
+
 template<class K, class V>
 void DataBase::Table<K, V>::removeRecord(const K& key) {
     if (!db->opened) {