[Mammoth] Move request/response context to ipc/ folder.

lib/mammoth/ipc/request_context.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <glacier/status/error.h>
+#include <stdint.h>
+
+class RequestContext {
+ public:
+  RequestContext(void* buffer, uint64_t buffer_length)
+      : buffer_(buffer), buffer_length_(buffer_length) {
+    if (buffer_length_ < sizeof(uint64_t)) {
+      request_id_ = -1;
+    } else {
+      request_id_ = *reinterpret_cast<uint64_t*>(buffer);
+    }
+  }
+
+  uint64_t request_id() { return request_id_; }
+
+  template <typename T>
+  glcr::ErrorCode As(T** arg) {
+    if (buffer_length_ < sizeof(T)) {
+      return glcr::INVALID_ARGUMENT;
+    }
+    *arg = reinterpret_cast<T*>(buffer_);
+    return glcr::OK;
+  }
+
+ private:
+  uint64_t request_id_;
+  void* buffer_;
+  uint64_t buffer_length_;
+};