new class to store string key-values on disk, will use for downloaded file index

2019-09-11 18:03:52 +03:00 · 2019-09-11 18:03:52 +03:00 · 1df49583fb
commit 1df49583fb
parent 0574d6f72b
6 changed files with 257 additions and 2 deletions
--- a/core/storage.cpp
+++ b/core/storage.cpp
@ -0,0 +1,157 @@
+/*
+ * 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/>.
+ */
+
+#include <QStandardPaths>
+#include <QDir>
+
+#include "storage.h"
+
+Core::Storage::Storage(const QString& p_name):
+    name(p_name),
+    opened(false),
+    environment(),
+    base()
+{
+}
+
+Core::Storage::~Storage()
+{
+    close();
+}
+
+void Core::Storage::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 Archive::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;
+    }
+}
+
+void Core::Storage::close()
+{
+    if (opened) {
+        mdb_dbi_close(environment, base);
+        mdb_env_close(environment);
+        opened = false;
+    }
+}
+
+void Core::Storage::addRecord(const QString& key, const QString& value)
+{
+    if (!opened) {
+        throw Archive::Closed("addElement", name.toStdString());
+    }
+    const std::string& id = key.toStdString();
+    const std::string& val = value.toStdString();
+    
+    MDB_val lmdbKey, lmdbData;
+    lmdbKey.mv_size = id.size();
+    lmdbKey.mv_data = (char*)id.c_str();
+    lmdbData.mv_size = val.size();
+    lmdbData.mv_data = (char*)val.c_str();
+    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 Archive::Exist(name.toStdString(), id);
+        } else {
+            throw Archive::Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        mdb_txn_commit(txn);
+    }
+}
+
+QString Core::Storage::getRecord(const QString& key) const
+{
+    if (!opened) {
+        throw Archive::Closed("addElement", name.toStdString());
+    }
+    const std::string& id = key.toStdString();
+    
+    MDB_val lmdbKey, lmdbData;
+    lmdbKey.mv_size = id.size();
+    lmdbKey.mv_data = (char*)id.c_str();
+    
+    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 Archive::NotFound(id, name.toStdString());
+        } else {
+            throw Archive::Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        std::string sId((char*)lmdbData.mv_data, lmdbData.mv_size);
+        QString value(sId.c_str());
+        mdb_txn_abort(txn);
+        return value;
+    }
+}
+
+void Core::Storage::removeRecord(const QString& key)
+{
+    if (!opened) {
+        throw Archive::Closed("addElement", name.toStdString());
+    }
+    const std::string& id = key.toStdString();
+    
+    MDB_val lmdbKey;
+    lmdbKey.mv_size = id.size();
+    lmdbKey.mv_data = (char*)id.c_str();
+    
+    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 Archive::NotFound(id, name.toStdString());
+        } else {
+            throw Archive::Unknown(name.toStdString(), mdb_strerror(rc));
+        }
+    } else {
+        mdb_txn_commit(txn);
+    }
+}