posix: add flock wrapper

CMakeLists.txt

@@ -93,6 +93,8 @@ list (
     posix/except.hpp
     posix/fd.cpp
     posix/fd.hpp
+    posix/flock.cpp
+    posix/flock.hpp
     posix/ostream.cpp
     posix/ostream.hpp
     posix/util.cpp

posix/flock.cpp

@@ -0,0 +1,55 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright 2021-2022, Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "./flock.hpp"
+#include "./except.hpp"
+
+#include <sys/file.h>
+
+using flock_  = cruft::posix::flock;
+
+
+
+///////////////////////////////////////////////////////////////////////////////
+flock_::flock (
+    cruft::posix::fd &&_fd,
+    int operation
+)
+    : m_fd (std::move (_fd))
+{
+    cruft::posix::error::try_code (
+        ::flock (m_fd.native (), operation)
+    );
+}
+
+
+//-----------------------------------------------------------------------------
+flock_::flock (flock_ &&rhs) noexcept
+    : m_fd (std::move (rhs.m_fd))
+{ ; }
+
+
+//-----------------------------------------------------------------------------
+flock_::~flock ()
+{
+    if (m_fd.native () < 0)
+        return;
+
+    cruft::posix::error::try_code (
+        ::flock (m_fd.native (), LOCK_UN)
+    );
+}
+
+
+//-----------------------------------------------------------------------------
+cruft::posix::fd const&
+flock_::native (void) const
+{
+    return m_fd;
+}
+

posix/flock.hpp

@@ -0,0 +1,32 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Copyright 2021-2022, Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "./fd.hpp"
+
+
+///////////////////////////////////////////////////////////////////////////////
+namespace cruft::posix {
+    class flock {
+    public:
+        flock (cruft::posix::fd const&, int operation);
+        flock (cruft::posix::fd &&, int operation);
+        flock (int fd, int operation);
+
+        ~flock ();
+
+        flock (flock&&) noexcept;
+        flock& operator= (flock&&) noexcept;
+        flock (flock const&) = delete;
+        flock& operator= (flock const&) = delete;
+
+        cruft::posix::fd const& native (void) const;
+
+    private:
+        cruft::posix::fd m_fd;
+    };
+}