unit: rework resource management API

This introduces a new static list of known attributes and their special
semantics. This means that cgroup attribute values can now be
automatically translated from user to kernel notation for command line
set settings, too.

This also adds proper support for multi-line attributes.

1 files changed, 43 insertions, 0 deletions

diff --git a/src/core/cgroup-semantics.h b/src/core/cgroup-semantics.h
new file mode 100644
index 0000000000..4f848f4bb7
--- /dev/null
+++ b/src/core/cgroup-semantics.h
@@ -0,0 +1,43 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+typedef struct CGroupSemantics CGroupSemantics;
+
+struct CGroupSemantics {
+        const char *controller;
+        const char *name;
+        const char *pretty;
+
+        bool multiple;
+
+        /* This call is used for parsing the pretty value to the actual attribute value */
+        int (*map_pretty)(const CGroupSemantics *semantics, const char *value, char **ret);
+
+        /* Right before writing this attribute the attribute value is converted to a low-level value */
+        int (*map_write)(const CGroupSemantics *semantics, const char *value, char **ret);
+
+        /* If this attribute takes a list, this call can be used to reset the list to empty */
+        int (*reset)(const CGroupSemantics *semantics, const char *group);
+};
+
+int cgroup_semantics_find(const char *controller, const char *name, const char *value, char **ret, const CGroupSemantics **semantics);