UsbDkHelper: Introduce key iterator for RegAccess

Signed-off-by: Kirill Moizik <kirill@daynix.com>
Signed-off-by: Dmitry Fleytman <dfleytma@redhat.com>

UsbDkHelper/RegAccess.cpp

@@ -626,3 +626,15 @@ VOID UsbDkRegAccess::FormatFullRegPath(LPTSTR lpzFullPathBuff, DWORD_PTR dwNumbe
         }
     }
 }
+
+VOID UsbDkRegAccess::key_iterator::advance()
+{
+    assert(!m_End);
+
+    if (!m_Root->ReadKeyName(m_CurrentKeyName,
+                             TBUF_SIZEOF(m_CurrentKeyName),
+                             m_NextIndex++))
+    {
+        m_End = true;
+    }
+}

UsbDkHelper/RegAccess.h

@@ -44,6 +44,46 @@ public:
     UsbDkRegAccess(HKEY hNewPrKey, LPCTSTR lpzNewRegPath);
     virtual ~UsbDkRegAccess();
 
+    class key_iterator
+    {
+    public:
+        key_iterator(const UsbDkRegAccess &Root)
+            : m_Root(&Root)
+            , m_End(false)
+        {
+            advance();
+        }
+
+        key_iterator()
+        {}
+
+        const key_iterator& operator++()
+        {
+            advance();
+            return *this;
+        }
+
+        bool operator !=(const key_iterator& other) const
+        { return !m_End || !other.m_End; }
+
+        LPCTSTR operator *()
+        { return m_CurrentKeyName; }
+
+       private:
+        void advance();
+
+        const            UsbDkRegAccess* m_Root = nullptr;
+        TCHAR            m_CurrentKeyName[DEFAULT_REG_ENTRY_DATA_LEN] = {};
+        int              m_NextIndex = 0;
+        bool             m_End = true;
+    };
+
+    key_iterator begin() const
+    { return  key_iterator(*this); }
+
+    key_iterator end() const
+    { return  key_iterator(); }
+
     VOID  SetPrimaryKey(HKEY hNewPrKey);
     BOOL  SetRegPath(LPCTSTR lpzNewRegPath);
     HKEY  GetPrimaryKey(VOID);

UsbDkHelper/stdafx.h

@@ -50,6 +50,9 @@
 #include <vector>
 #include <winscard.h>
 
+//new behavior: elements of array 'array' will be default initialized
+#pragma warning(disable : 4351)
+
 #include "tstrings.h"
 #include "Exception.h"
 #include "Utils.h"