Add a method to get databases by uuid.

Each database gets a random uuid on construction which is not saved by
KeePass2XmlWriter and only valid until the database object is deleted.

src/core/Database.cpp

@@ -25,19 +25,29 @@
 #include "crypto/Random.h"
 #include "format/KeePass2.h"
 
+QHash<Uuid, Database*> Database::m_uuidMap;
+
 Database::Database()
     : m_metadata(new Metadata(this))
     , m_cipher(KeePass2::CIPHER_AES)
     , m_compressionAlgo(CompressionGZip)
     , m_transformRounds(50000)
     , m_hasKey(false)
+    , m_uuid(Uuid::random())
 {
     setRootGroup(new Group());
     rootGroup()->setUuid(Uuid::random());
 
+    m_uuidMap.insert(m_uuid, this);
+
     connect(m_metadata, SIGNAL(modified()), this, SIGNAL(modified()));
 }
 
+Database::~Database()
+{
+    m_uuidMap.remove(m_uuid);
+}
+
 Group* Database::rootGroup()
 {
     return m_rootGroup;
@@ -240,3 +250,13 @@ void Database::recycleGroup(Group* group)
         delete group;
     }
 }
+
+Uuid Database::uuid()
+{
+    return m_uuid;
+}
+
+Database* Database::databaseByUuid(const Uuid& uuid)
+{
+    return m_uuidMap.value(uuid, 0);
+}

src/core/Database.h

@@ -49,6 +49,7 @@ public:
     static const quint32 CompressionAlgorithmMax = CompressionGZip;
 
     Database();
+    ~Database();
     Group* rootGroup();
     const Group* rootGroup() const;
 
@@ -89,6 +90,13 @@ public:
     void recycleEntry(Entry* entry);
     void recycleGroup(Group* group);
 
+    /**
+     * Returns a unique id that is only valid as long as the Database exists.
+     */
+    Uuid uuid();
+
+    static Database* databaseByUuid(const Uuid& uuid);
+
 Q_SIGNALS:
     void groupDataChanged(Group* group);
     void groupAboutToAdd(Group* group, int index);
@@ -117,6 +125,9 @@ private:
 
     CompositeKey m_key;
     bool m_hasKey;
+
+    Uuid m_uuid;
+    static QHash<Uuid, Database*> m_uuidMap;
 };
 
 #endif // KEEPASSX_DATABASE_H