Add CKeyValues3Iterator

public/tier1/keyvalues3.h

@@ -46,6 +46,11 @@ struct KV3ToKV1Translation_t;
 	2. Directly through the constructor.
 */
 
+// Quick way to iterate across whole kv3, to access currently iterated kv3 use iter.Get()
+// Mostly useful to iterate unnamed data, like arrays of primitives
+#define FOR_EACH_KV3( kv, iter ) \
+	for ( CKeyValues3Iterator iter( kv ); iter.IsValid(); iter.Advance() )
+
 struct KV3ID_t
 {
 	const char* m_name;
@@ -606,6 +611,29 @@ private:
 };
 COMPILE_TIME_ASSERT(sizeof(KeyValues3) == 16);
 
+class CKeyValues3Iterator
+{
+public:
+	CKeyValues3Iterator() : m_Stack() {}
+	CKeyValues3Iterator( KeyValues3 *kv ) : CKeyValues3Iterator() { Init( kv ); }
+
+	void Init( KeyValues3 *kv );
+
+	void Advance();
+
+	KeyValues3 *Get() const { return IsValid() ? m_Stack[m_Stack.Count() - 1].m_pKV : nullptr; }
+	bool IsValid() const { return m_Stack.Count() > 0; }
+
+private:
+	struct StackEntry_t
+	{
+		KeyValues3 *m_pKV;
+		int m_nIndex;
+	};
+
+	CUtlVectorFixedGrowable<StackEntry_t, 4> m_Stack;
+};
+
 class CKeyValues3Array
 {
 public:

tier1/keyvalues3.cpp

@@ -1269,6 +1269,54 @@ KeyValues3& KeyValues3::operator=( const KeyValues3& src )
 	return *this;
 }
 
+void CKeyValues3Iterator::Init( KeyValues3 *kv )
+{
+	m_Stack.Purge();
+
+	if(kv)
+	{
+		auto entry = m_Stack.AddToTailGetPtr();
+		entry->m_nIndex = -1;
+		entry->m_pKV = kv;
+	}
+}
+
+void CKeyValues3Iterator::Advance()
+{
+	while(m_Stack.Count() > 0)
+	{
+		auto &entry = m_Stack[m_Stack.Count() - 1];
+		auto kv = entry.m_pKV;
+
+		if(kv->GetType() == KV3_TYPE_ARRAY)
+		{
+			entry.m_nIndex++;
+
+			if(entry.m_nIndex < kv->GetArrayElementCount())
+			{
+				auto new_entry = m_Stack.AddToTailGetPtr();
+				new_entry->m_nIndex = -1;
+				new_entry->m_pKV = kv->GetArrayElement( entry.m_nIndex );
+				return;
+			}
+		}
+		else if(kv->GetType() == KV3_TYPE_TABLE)
+		{
+			entry.m_nIndex++;
+
+			if(entry.m_nIndex < kv->GetMemberCount())
+			{
+				auto new_entry = m_Stack.AddToTailGetPtr();
+				new_entry->m_nIndex = -1;
+				new_entry->m_pKV = kv->GetMember( entry.m_nIndex );
+				return;
+			}
+		}
+
+		m_Stack.RemoveMultipleFromTail( 1 );
+	}
+}
+
 CKeyValues3Array::CKeyValues3Array( int cluster_elem, int alloc_size ) :
 	m_nClusterElement( cluster_elem ),
 	m_nAllocatedChunks( alloc_size ),