Initial stuff

storage.hpp

@@ -0,0 +1,226 @@
+/*
+ * 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_STORAGE_HPP
+#define CORE_STORAGE_HPP
+
+#include <QStandardPaths>
+#include <QDir>
+
+#include "storage.h"
+#include <cstring>
+
+template <class K, class V>
+Core::Storage<K, V>::Storage(const QString& p_name):
+    name(p_name),
+    opened(false),
+    environment(),
+    base()
+{
+}
+
+template <class K, class V>
+Core::Storage<K, V>::~Storage()
+{
+    close();
+}
+
+template <class K, class V>
+void Core::Storage<K, V>::open()
+{
+    if (!opened) {
+        mdb_env_create(&environment);
+        QString path(QStandardPaths::writableLocation(QStandardPaths::CacheLocation));
+        path += "/" + name;
+        QDir cache(path);
+        
+        if (!cache.exists()) {
+            bool res = cache.mkpath(path);
+            if (!res) {
+                throw Directory(path.toStdString());
+            }
+        }
+        
+        mdb_env_set_maxdbs(environment, 1);
+        mdb_env_set_mapsize(environment, 10UL * 1024UL * 1024UL);
+        mdb_env_open(environment, path.toStdString().c_str(), 0, 0664);
+        
+        MDB_txn *txn;
+        mdb_txn_begin(environment, NULL, 0, &txn);
+        mdb_dbi_open(txn, "base", MDB_CREATE, &base);
+        mdb_txn_commit(txn);
+        opened = true;
+    }
+}
+
+template <class K, class V>
+void Core::Storage<K, V>::close()
+{
+    if (opened) {
+        mdb_dbi_close(environment, base);
+        mdb_env_close(environment);
+        opened = false;
+    }
+}
+
+template <class K, class V>
+void Core::Storage<K, V>::addRecord(const K& key, const V& value)
+{
+    if (!opened) {
+        throw Closed("addRecord", name.toStdString());
+    }
+    QByteArray ba;
+    QDataStream ds(&ba, QIODevice::WriteOnly);
+    ds << value;
+    
+    MDB_val lmdbKey, lmdbData;
+    lmdbKey << key;
+
+    lmdbData.mv_size = ba.size();
+    lmdbData.mv_data = (uint8_t*)ba.data();
+    MDB_txn *txn;
+    mdb_txn_begin(environment, NULL, 0, &txn);
+    int rc;
+    rc = mdb_put(txn, base, &lmdbKey, &lmdbData, MDB_NOOVERWRITE);
+    if (rc != 0) {
+        mdb_txn_abort(txn);
+        if (rc == MDB_KEYEXIST) {
+            throw Exist(name.toStdString(), std::to_string(key));
+        } else {
+            throw Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        mdb_txn_commit(txn);
+    }
+}
+
+template <class K, class V>
+void Core::Storage<K, V>::changeRecord(const K& key, const V& value)
+{
+    if (!opened) {
+        throw Closed("changeRecord", name.toStdString());
+    }
+
+    QByteArray ba;
+    QDataStream ds(&ba, QIODevice::WriteOnly);
+    ds << value;
+    
+    MDB_val lmdbKey, lmdbData;
+    lmdbKey << key;
+    lmdbData.mv_size = ba.size();
+    lmdbData.mv_data = (uint8_t*)ba.data();
+    MDB_txn *txn;
+    mdb_txn_begin(environment, NULL, 0, &txn);
+    int rc;
+    rc = mdb_put(txn, base, &lmdbKey, &lmdbData, 0);
+    if (rc != 0) {
+        mdb_txn_abort(txn);
+        if (rc) {
+            throw Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        mdb_txn_commit(txn);
+    }
+}
+
+template <class K, class V>
+V Core::Storage<K, V>::getRecord(const K& key) const
+{
+    if (!opened) {
+        throw Closed("addElement", name.toStdString());
+    }
+    
+    MDB_val lmdbKey, lmdbData;
+    lmdbKey << key;
+    
+    MDB_txn *txn;
+    int rc;
+    mdb_txn_begin(environment, NULL, MDB_RDONLY, &txn);
+    rc = mdb_get(txn, base, &lmdbKey, &lmdbData);
+    if (rc) {
+        mdb_txn_abort(txn);
+        if (rc == MDB_NOTFOUND) {
+            throw NotFound(std::to_string(key), name.toStdString());
+        } else {
+            throw Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        QByteArray ba((char*)lmdbData.mv_data, lmdbData.mv_size);
+        QDataStream ds(&ba, QIODevice::ReadOnly);
+        V value;
+        ds >> value;
+        mdb_txn_abort(txn);
+
+        return value;
+    }
+}
+
+template <class K, class V>
+void Core::Storage<K, V>::removeRecord(const K& key)
+{
+    if (!opened) {
+        throw Closed("addElement", name.toStdString());
+    }
+    
+    MDB_val lmdbKey;
+    lmdbKey << key;
+    
+    MDB_txn *txn;
+    int rc;
+    mdb_txn_begin(environment, NULL, 0, &txn);
+    rc = mdb_del(txn, base, &lmdbKey, NULL);
+    if (rc) {
+        mdb_txn_abort(txn);
+        if (rc == MDB_NOTFOUND) {
+            throw NotFound(std::to_string(key), name.toStdString());
+        } else {
+            throw Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        mdb_txn_commit(txn);
+    }
+}
+
+template <class K, class V>
+QString Core::Storage<K, V>::getName() const {
+    return name;}
+
+MDB_val& operator << (MDB_val& data, const QString& value) {
+    QByteArray ba = value.toUtf8();
+    data.mv_size = ba.size();
+    data.mv_data = ba.data();
+    return data;
+}
+MDB_val& operator >> (MDB_val& data, QString& value) {
+    value = QString::fromUtf8((const char*)data.mv_data, data.mv_size);
+    return data;
+}
+
+MDB_val& operator << (MDB_val& data, uint32_t& value) {
+    data.mv_size = 4;
+    data.mv_data = &value;
+    return data;
+}
+MDB_val& operator >> (MDB_val& data, uint32_t& value) {
+    std::memcpy(&value, data.mv_data, data.mv_size);
+    return data;
+}
+
+std::string std::to_string(const QString& str) {
+    return str.toStdString();
+}
+#endif //CORE_STORAGE_HPP