[Glacier] Add buffer types for holding bytes and capabilities.

lib/glacier/buffer/cap_buffer.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stdint.h>
+
+namespace glcr {
+
+// TODO: Hold cap type instead of uint64_t
+class CapBuffer {
+ public:
+  CapBuffer(uint64_t size) : buffer_(new uint64_t[size]) {}
+  CapBuffer(const CapBuffer&) = delete;
+  CapBuffer(CapBuffer&&) = delete;
+
+  ~CapBuffer() { delete[] buffer_; }
+
+  uint64_t At(uint64_t offset) const { return buffer_[offset]; }
+
+  void WriteAt(uint64_t offset, uint64_t cap) { buffer_[offset] = cap; }
+
+ private:
+  uint64_t* buffer_;
+};
+
+}  // namespace glcr