X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fdaemon.h;h=b4f99a81a1d8a4a94cca1b778aa1d7465d61e55f;hp=77ee6281a13418e3b9e4d6a85ed301e7d9222727;hb=ffc01285ee4289da90983a3320873f27b3d31c4d;hpb=4b91462bad010a0b214e808f94a916002be65b91

diff --git a/daemon/daemon.h b/daemon/daemon.h
index 77ee628..b4f99a8 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -191,6 +191,24 @@ extern void pulse_mode_start (void);
 extern void pulse_mode_end (void);
 extern void pulse_mode_cancel (void);
 
+/* Return true iff the buffer is all zero bytes.
+ *
+ * Note that gcc is smart enough to optimize this properly:
+ * http://stackoverflow.com/questions/1493936/faster-means-of-checking-for-an-empty-buffer-in-c/1493989#1493989
+ */
+static inline int
+is_zero (const char *buffer, size_t size)
+{
+  size_t i;
+
+  for (i = 0; i < size; ++i) {
+    if (buffer[i] != 0)
+      return 0;
+  }
+
+  return 1;
+}
+
 /* Helper for functions that need a root filesystem mounted.
  * NB. Cannot be used for FileIn functions.
  */