From 8d9fef80156c4b4cf16232ce588915e191f928c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9mi=20Audebert?= <halfr@lse.epita.fr>
Date: Wed, 4 Nov 2015 14:59:06 +0100
Subject: [PATCH] journal: implement GetUsage() (sd_journal_get_usage())

---
 sdjournal/journal.go      | 14 ++++++++++++++
 sdjournal/journal_test.go | 20 ++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/sdjournal/journal.go b/sdjournal/journal.go
index f4e6346f..71337b6c 100644
--- a/sdjournal/journal.go
+++ b/sdjournal/journal.go
@@ -237,3 +237,17 @@ func (j *Journal) Wait(timeout time.Duration) int {
 
 	return int(r)
 }
+
+// GetUsage returns the journal disk space usage, in bytes.
+func (j *Journal) GetUsage() (uint64, error) {
+	var out C.uint64_t
+	j.mu.Lock()
+	err := C.sd_journal_get_usage(j.cjournal, &out)
+	j.mu.Unlock()
+
+	if err != 0 {
+		return 0, fmt.Errorf("failed to get journal disk space usage: %d", err)
+	}
+
+	return uint64(out), nil
+}
diff --git a/sdjournal/journal_test.go b/sdjournal/journal_test.go
index ad6cd0ed..2861b31f 100644
--- a/sdjournal/journal_test.go
+++ b/sdjournal/journal_test.go
@@ -68,3 +68,23 @@ func TestJournalFollow(t *testing.T) {
 		t.Fatalf("Error during follow: %s", err)
 	}
 }
+
+func TestJournalGetUsage(t *testing.T) {
+	j, err := NewJournal()
+
+	if err != nil {
+		t.Fatalf("Error opening journal: %s", err)
+	}
+
+	if j == nil {
+		t.Fatal("Got a nil journal")
+	}
+
+	defer j.Close()
+
+	_, err = j.GetUsage()
+
+	if err != nil {
+		t.Fatalf("Error getting journal size: %s", err)
+	}
+}