X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=util.h;h=c2f10f83d33e0fa697f09d7a43353f77dfeec417;hb=927950400bd569326c3babf4e29038523fa464a6;hp=816c05621571262924460c46ed3358819ecd051e;hpb=8534d6023d74efac11d7e2b5d1903638f3c1eca3;p=secnet.git

diff --git a/util.h b/util.h
index 816c056..c2f10f8 100644
--- a/util.h
+++ b/util.h
@@ -29,6 +29,11 @@ extern void *buf_prepend(struct buffer_if *buf, int32_t amount);
 extern void *buf_unappend(struct buffer_if *buf, int32_t amount);
 extern void *buf_unprepend(struct buffer_if *buf, int32_t amount);
 
+static inline int32_t buf_remaining_space(const struct buffer_if *buf)
+{
+    return (buf->base + buf->len) - buf->start;
+}
+
 extern void buffer_readonly_view(struct buffer_if *n, const void*, int32_t len);
 extern void buffer_readonly_clone(struct buffer_if *n, const struct buffer_if*);
   /* Caller must only use unappend, unprepend et al. on n.
@@ -51,4 +56,12 @@ extern void send_nak(const struct comm_addr *dest, uint32_t our_index,
 
 extern int consttime_memeq(const void *s1, const void *s2, size_t n);
 
+#define MINMAX(ae,be,op) ({			\
+	typeof((ae)) a=(ae);			\
+	typeof((be)) b=(be);			\
+	a op b ? a : b;				\
+    })
+#define MAX(a,b) MINMAX((a),(b),>)
+#define MIN(a,b) MINMAX((a),(b),<)
+
 #endif /* util_h */