From: Samuel Just <sjust@redhat.com>
Date: Fri, 22 Nov 2019 01:52:00 +0000 (+0000)
Subject: crimson/common/errorator.h: add finally method for resource release
X-Git-Tag: v15.1.0~687^2~7
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=260f23b7598597ca90e7f436a52d09b23709a8b0;p=ceph-ci.git

crimson/common/errorator.h: add finally method for resource release

This way we can add things like resource handlers which are otherwise
transparent to passing values and errors.

Signed-off-by: Samuel Just <sjust@redhat.com>
---

diff --git a/src/crimson/common/errorator.h b/src/crimson/common/errorator.h
index 28aa729fe88..dc0ec2e61c8 100644
--- a/src/crimson/common/errorator.h
+++ b/src/crimson/common/errorator.h
@@ -518,6 +518,24 @@ private:
         });
     }
 
+    template <class FuncT>
+    auto finally(FuncT &&func) {
+      using func_result_t = std::invoke_result_t<FuncT>;
+      using func_errorator_t = get_errorator_t<func_result_t>;
+      using return_errorator_t = func_errorator_t;
+      using futurator_t =
+        typename return_errorator_t::template futurize<func_result_t>;
+
+      return this->then_wrapped(
+	[ func = std::forward<FuncT>(func)
+	] (auto&& future) mutable [[gnu::always_inline]] noexcept {
+	  return futurator_t::apply(std::forward<FuncT>(func)).safe_then(
+	    [future = std::forward<decltype(future)>(future)]() mutable {
+	      return std::move(future);
+	    });
+	});
+    }
+
     // taking ErrorFuncOne and ErrorFuncTwo separately from ErrorFuncTail
     // to avoid SFINAE
     template <class ValueFunc,