Moving some util types into poly.

src/poly/arena.h

@@ -0,0 +1,55 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef POLY_ARENA_H_
+#define POLY_ARENA_H_
+
+#include <cstddef>
+#include <cstdint>
+
+namespace poly {
+
+class Arena {
+ public:
+  Arena(size_t chunk_size = 4 * 1024 * 1024);
+  ~Arena();
+
+  void Reset();
+  void DebugFill();
+
+  void* Alloc(size_t size);
+  template <typename T>
+  T* Alloc() {
+    return reinterpret_cast<T*>(Alloc(sizeof(T)));
+  }
+
+  void* CloneContents();
+
+ private:
+  class Chunk {
+   public:
+    Chunk(size_t chunk_size);
+    ~Chunk();
+
+    Chunk* next;
+
+    size_t capacity;
+    uint8_t* buffer;
+    size_t offset;
+  };
+
+ private:
+  size_t chunk_size_;
+  Chunk* head_chunk_;
+  Chunk* active_chunk_;
+};
+
+}  // namespace poly
+
+#endif  // POLY_ARENA_H_