Store time of last decrypted message for each olm session

Is required to correctly choose a session to use for sending messages

3 files changed, 19 insertions, 4 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index 11c81edf..506a2bc0 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -216,7 +216,7 @@ public:
             qCWarning(E2EE) << "Failed to pickle olm session. Error" << std::get<QOlmError>(pickleResult);
             return;
         }
-        q->database()->saveOlmSession(senderKey, session->sessionId(), std::get<QByteArray>(pickleResult));
+        q->database()->saveOlmSession(senderKey, session->sessionId(), std::get<QByteArray>(pickleResult), QDateTime::currentDateTime());
     }
     QString sessionDecryptPrekey(const QOlmMessage& message, const QString &senderKey, std::unique_ptr<QOlmAccount>& olmAccount)
     {
@@ -227,6 +227,7 @@ public:
                 qCDebug(E2EE) << "Found inbound session";
                 const auto result = session->decrypt(message);
                 if(std::holds_alternative<QString>(result)) {
+                    q->database()->setOlmSessionLastReceived(QString(session->sessionId()), QDateTime::currentDateTime());
                     return std::get<QString>(result);
                 } else {
                     qCDebug(E2EE) << "Failed to decrypt prekey message";
@@ -261,6 +262,7 @@ public:
         for(auto& session : olmSessions[senderKey]) {
             const auto result = session->decrypt(message);
             if(std::holds_alternative<QString>(result)) {
+                q->database()->setOlmSessionLastReceived(QString(session->sessionId()), QDateTime::currentDateTime());
                 return std::get<QString>(result);
             }
         }
diff --git a/lib/database.cpp b/lib/database.cpp
index d070e1de..21e79d58 100644
--- a/lib/database.cpp
+++ b/lib/database.cpp
@@ -100,6 +100,7 @@ void Database::migrateTo2()
     qCDebug(DATABASE) << "Migrating database to version 2";
     transaction();
     execute(QStringLiteral("ALTER TABLE inbound_megolm_sessions ADD ed25519Key TEXT"));
+    execute(QStringLiteral("ALTER TABLE olm_sessions ADD lastReceived TEXT"));
     execute(QStringLiteral("PRAGMA user_version = 2;"));
     commit();
 }
@@ -141,12 +142,13 @@ void Database::clear()
 
 }
 
-void Database::saveOlmSession(const QString& senderKey, const QString& sessionId, const QByteArray &pickle)
+void Database::saveOlmSession(const QString& senderKey, const QString& sessionId, const QByteArray &pickle, const QDateTime& timestamp)
 {
-    auto query = prepareQuery(QStringLiteral("INSERT INTO olm_sessions(senderKey, sessionId, pickle) VALUES(:senderKey, :sessionId, :pickle);"));
+    auto query = prepareQuery(QStringLiteral("INSERT INTO olm_sessions(senderKey, sessionId, pickle, lastReceived) VALUES(:senderKey, :sessionId, :pickle, :lastReceived);"));
     query.bindValue(":senderKey", senderKey);
     query.bindValue(":sessionId", sessionId);
     query.bindValue(":pickle", pickle);
+    query.bindValue(":lastReceived", timestamp);
     transaction();
     execute(query);
     commit();
@@ -253,3 +255,13 @@ void Database::clearRoomData(const QString& roomId)
     execute(query3);
     commit();
 }
+
+void Database::setOlmSessionLastReceived(const QString& sessionId, const QDateTime& timestamp)
+{
+    auto query = prepareQuery(QStringLiteral("UPDATE olm_sessions SET lastReceived=:lastReceived WHERE sessionId=:sessionId;"));
+    query.bindValue(":lastReceived", timestamp);
+    query.bindValue(":sessionId", sessionId);
+    transaction();
+    execute(query);
+    commit();
+}
diff --git a/lib/database.h b/lib/database.h
index f9a8df1a..cf241dbc 100644
--- a/lib/database.h
+++ b/lib/database.h
@@ -27,13 +27,14 @@ public:
     QByteArray accountPickle();
     void setAccountPickle(const QByteArray &pickle);
     void clear();
-    void saveOlmSession(const QString& senderKey, const QString& sessionId, const QByteArray &pickle);
+    void saveOlmSession(const QString& senderKey, const QString& sessionId, const QByteArray &pickle, const QDateTime& timestamp);
     UnorderedMap<QString, std::vector<QOlmSessionPtr>> loadOlmSessions(const PicklingMode& picklingMode);
     UnorderedMap<std::pair<QString, QString>, QOlmInboundGroupSessionPtr> loadMegolmSessions(const QString& roomId, const PicklingMode& picklingMode);
     void saveMegolmSession(const QString& roomId, const QString& senderKey, const QString& sessionKey, const QString& ed25519Key, const QByteArray& pickle);
     void addGroupSessionIndexRecord(const QString& roomId, const QString& sessionId, uint32_t index, const QString& eventId, qint64 ts);
     std::pair<QString, qint64> groupSessionIndexRecord(const QString& roomId, const QString& sessionId, qint64 index);
     void clearRoomData(const QString& roomId);
+    void setOlmSessionLastReceived(const QString& sessionId, const QDateTime& timestamp);
 
 private:
     void migrateTo1();