[gnome-system-monitor] Move all code related to systemd in systemd.{cpp, h} to have a clean interface instead of #ifdef all

[Robert Roth <robertroth src gnome org>]

commit 2a7f1be18435e0d6541db46a0e05f909884254bd
Author: Benoit Dejean <bdejean gmail com>
Date:   Sat Feb 28 06:03:19 2015 +0100

    Move all code related to systemd in systemd.{cpp,h} to have a clean interface instead of #ifdef all over 
the place.
    
    Signed-off-by: Robert Roth <robert roth off gmail com>

 src/Makefile.am     |    1 +
 src/prefsdialog.cpp |    7 ++---
 src/proctable.cpp   |   40 ++------------------------------
 src/systemd.cpp     |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/systemd.h       |   12 ++++++++++
 src/util.h          |    3 --
 6 files changed, 81 insertions(+), 44 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index e4206e2..122316c 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -26,6 +26,7 @@ gnome_system_monitor_cpp_files = \
        smooth_refresh.cpp \
        disks.cpp \
        selinux.cpp \
+       systemd.cpp \
        cgroups.cpp \
        gsm_gnomesu.cpp \
        gsm_gksu.cpp \
diff --git a/src/prefsdialog.cpp b/src/prefsdialog.cpp
index 0c14682..0484253 100644
--- a/src/prefsdialog.cpp
+++ b/src/prefsdialog.cpp
@@ -11,6 +11,7 @@
 #include "proctable.h"
 #include "selinux.h"
 #include "settings-keys.h"
+#include "systemd.h"
 #include "util.h"
 
 static GtkWidget *prefs_dialog = NULL;
@@ -179,10 +180,8 @@ create_field_page(GtkBuilder* builder, GtkWidget *tree, const gchar *widgetname)
              column_id == COL_SESSION ||
              column_id == COL_SEAT ||
              column_id == COL_OWNER)
-#ifdef HAVE_SYSTEMD
-            && !LOGIND_RUNNING()
-#endif
-                )
+            && !procman::systemd_logind_running()
+            )
             continue;
 
         visible = gtk_tree_view_column_get_visible (column);
diff --git a/src/proctable.cpp b/src/proctable.cpp
index 370d8be..0549ef2 100644
--- a/src/proctable.cpp
+++ b/src/proctable.cpp
@@ -43,10 +43,6 @@
 #include <set>
 #include <list>
 
-#ifdef HAVE_SYSTEMD
-#include <systemd/sd-login.h>
-#endif
-
 #ifdef HAVE_WNCK
 #define WNCK_I_KNOW_THIS_IS_UNSTABLE
 #include <libwnck/libwnck.h>
@@ -61,6 +57,7 @@
 #include "settings-keys.h"
 #include "cgroups.h"
 #include "treeview.h"
+#include "systemd.h"
 
 ProcInfo::UserMap ProcInfo::users;
 ProcInfo::List ProcInfo::all;
@@ -554,9 +551,7 @@ proctable_new (GsmApplication * const app)
     if (!cgroups_enabled ())
         gsm_tree_view_add_excluded_column (GSM_TREE_VIEW (proctree), COL_CGROUP);
 
-#ifdef HAVE_SYSTEMD
-    if (!LOGIND_RUNNING ())
-#endif
+    if (!procman::systemd_logind_running())
     {
         gsm_tree_view_add_excluded_column (GSM_TREE_VIEW (proctree), COL_UNIT);
         gsm_tree_view_add_excluded_column (GSM_TREE_VIEW (proctree), COL_SESSION);
@@ -853,35 +848,6 @@ remove_info_from_tree (GsmApplication *app, GtkTreeModel *model,
     procman::poison(current->node, 0x69);
 }
 
-static void
-get_process_systemd_info(ProcInfo *info)
-{
-#ifdef HAVE_SYSTEMD
-    uid_t uid;
-
-    if (!LOGIND_RUNNING())
-        return;
-
-    free(info->unit);
-    info->unit = NULL;
-    sd_pid_get_unit(info->pid, &info->unit);
-
-    free(info->session);
-    info->session = NULL;
-    sd_pid_get_session(info->pid, &info->session);
-
-    free(info->seat);
-    info->seat = NULL;
-
-    if (info->session != NULL)
-        sd_session_get_seat(info->session, &info->seat);
-
-    if (sd_pid_get_owner_uid(info->pid, &uid) >= 0)
-        info->owner = info->lookup_user(uid);
-    else
-        info->owner = "";
-#endif
-}
 
 static void
 update_info (GsmApplication *app, ProcInfo *info)
@@ -930,7 +896,7 @@ update_info (GsmApplication *app, ProcInfo *info)
     /* get cgroup data */
     get_process_cgroup_info(info);
 
-    get_process_systemd_info(info);
+    procman::get_process_systemd_info(info);
 }
 
 ProcInfo::ProcInfo(pid_t pid)
diff --git a/src/systemd.cpp b/src/systemd.cpp
new file mode 100644
index 0000000..2c3c1a2
--- /dev/null
+++ b/src/systemd.cpp
@@ -0,0 +1,62 @@
+#include <config.h>
+#include <stdlib.h>
+
+#ifdef HAVE_SYSTEMD
+#include <systemd/sd-login.h>
+#endif
+
+#include "application.h"
+#include "systemd.h"
+
+
+bool
+procman::systemd_logind_running()
+{
+#ifdef HAVE_SYSTEMD
+  static bool init;
+  static bool is_running;
+
+  if (!init) {
+    /* check if logind is running */
+    if (access("/run/systemd/seats/", F_OK) >= 0) {
+      is_running = true;
+    }
+    init = true;
+  }
+
+  return is_running;
+
+#else
+  return false;
+#endif
+}
+
+void
+procman::get_process_systemd_info(ProcInfo *info)
+{
+#ifdef HAVE_SYSTEMD
+    uid_t uid;
+
+    if (!systemd_logind_running())
+        return;
+
+    free(info->unit);
+    info->unit = NULL;
+    sd_pid_get_unit(info->pid, &info->unit);
+
+    free(info->session);
+    info->session = NULL;
+    sd_pid_get_session(info->pid, &info->session);
+
+    free(info->seat);
+    info->seat = NULL;
+
+    if (info->session != NULL)
+        sd_session_get_seat(info->session, &info->seat);
+
+    if (sd_pid_get_owner_uid(info->pid, &uid) >= 0)
+        info->owner = info->lookup_user(uid);
+    else
+        info->owner = "";
+#endif
+}
diff --git a/src/systemd.h b/src/systemd.h
new file mode 100644
index 0000000..6604877
--- /dev/null
+++ b/src/systemd.h
@@ -0,0 +1,12 @@
+#ifndef PROCMAN_SYSTEMD_H_144CA8D6_BF03_11E4_B291_000C298F6617
+#define PROCMAN_SYSTEMD_H_144CA8D6_BF03_11E4_B291_000C298F6617
+
+#include "application.h"
+
+namespace procman
+{
+  bool systemd_logind_running();
+  void get_process_systemd_info(ProcInfo *info);
+}
+
+#endif
diff --git a/src/util.h b/src/util.h
index 0118df4..5a5ac84 100644
--- a/src/util.h
+++ b/src/util.h
@@ -8,9 +8,6 @@
 
 using std::string;
 
-/* check if logind is running */
-#define LOGIND_RUNNING() (access("/run/systemd/seats/", F_OK) >= 0)
-
 GtkWidget*
 procman_make_label_for_mmaps_or_ofiles(const char *format,
                                        const char *process_name,