refactor: hide implementation details of zone loading processors

src/ZoneLoading/Loading/Processor/ProcessorIW4xDecryption.cpp

@@ -2,44 +2,62 @@
 
 #include <cassert>
 
-ProcessorIW4xDecryption::ProcessorIW4xDecryption()
-    : m_last_byte(0u)
+namespace
 {
-}
-
-uint8_t ProcessorIW4xDecryption::RotateLeft(const uint8_t value, const unsigned count)
-{
-    assert(count < sizeof(value) * 8);
-    return static_cast<uint8_t>(value << count | (value >> ((sizeof(value) * 8) - count)));
-}
-
-uint8_t ProcessorIW4xDecryption::RotateRight(uint8_t value, const unsigned count)
-{
-    assert(count < sizeof(value) * 8);
-    return static_cast<uint8_t>(value >> count | (value << ((sizeof(value) * 8) - count)));
-}
-
-size_t ProcessorIW4xDecryption::Load(void* buffer, const size_t length)
-{
-    const auto readLen = m_base_stream->Load(buffer, length);
-
-    auto* charBuffer = static_cast<uint8_t*>(buffer);
-    for (auto i = 0u; i < readLen; i++)
+    uint8_t RotateLeft(const uint8_t value, const unsigned count)
     {
-        auto value = charBuffer[i];
-        value ^= m_last_byte;
-        value = RotateLeft(value, 4);
-        value ^= -1;
-        value = RotateRight(value, 6);
-
-        charBuffer[i] = value;
-        m_last_byte = value;
+        assert(count < sizeof(value) * 8);
+        return static_cast<uint8_t>(value << count | (value >> ((sizeof(value) * 8) - count)));
     }
 
-    return readLen;
-}
+    uint8_t RotateRight(const uint8_t value, const unsigned count)
+    {
+        assert(count < sizeof(value) * 8);
+        return static_cast<uint8_t>(value >> count | (value << ((sizeof(value) * 8) - count)));
+    }
 
-int64_t ProcessorIW4xDecryption::Pos()
+    class ProcessorIW4xDecryption final : public StreamProcessor
+    {
+    public:
+        ProcessorIW4xDecryption()
+            : m_last_byte(0u)
+        {
+        }
+
+        size_t Load(void* buffer, const size_t length) override
+        {
+            const auto readLen = m_base_stream->Load(buffer, length);
+
+            auto* charBuffer = static_cast<uint8_t*>(buffer);
+            for (auto i = 0u; i < readLen; i++)
+            {
+                auto value = charBuffer[i];
+                value ^= m_last_byte;
+                value = RotateLeft(value, 4);
+                value ^= -1;
+                value = RotateRight(value, 6);
+
+                charBuffer[i] = value;
+                m_last_byte = value;
+            }
+
+            return readLen;
+        }
+
+        int64_t Pos() override
+        {
+            return m_base_stream->Pos();
+        }
+
+    private:
+        uint8_t m_last_byte;
+    };
+} // namespace
+
+namespace processor
 {
-    return m_base_stream->Pos();
-}
+    std::unique_ptr<StreamProcessor> CreateProcessorIW4xDecryption()
+    {
+        return std::make_unique<ProcessorIW4xDecryption>();
+    }
+} // namespace processor