ofpbuf: New function ofpbuf_to_string().

Useful for debugging.

From Jean Tourrilhes <jt@hpl.hp.com>.

diff --git a/lib/ofpbuf.c b/lib/ofpbuf.c
index fd01ea8..9cb2ceb 100644 (file)
--- a/lib/ofpbuf.c
+++ b/lib/ofpbuf.c
@@ -19,6 +19,7 @@
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
+#include "dynamic-string.h"
 #include "util.h"
 
 /* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
@@ -286,3 +287,18 @@ ofpbuf_try_pull(struct ofpbuf *b, size_t size)
 {
     return b->size >= size ? ofpbuf_pull(b, size) : NULL;
 }
+
+/* Returns a string that describes some of 'b''s metadata plus a hex dump of up
+ * to 'maxbytes' from the start of the buffer. */
+char *
+ofpbuf_to_string(const struct ofpbuf *b, size_t maxbytes)
+{
+    struct ds s;
+
+    ds_init(&s);
+    ds_put_format(&s, "size=%zu, allocated=%zu, head=%zu, tail=%zu\n",
+                  b->size, b->allocated,
+                  ofpbuf_headroom(b), ofpbuf_tailroom(b));
+    ds_put_hex_dump(&s, b->data, MIN(b->size, maxbytes), 0, false);
+    return ds_cstr(&s);
+}

diff --git a/lib/ofpbuf.h b/lib/ofpbuf.h
index b65f79e..9072cc4 100644 (file)
--- a/lib/ofpbuf.h
+++ b/lib/ofpbuf.h
@@ -74,6 +74,8 @@ void ofpbuf_clear(struct ofpbuf *);
 void *ofpbuf_pull(struct ofpbuf *, size_t);
 void *ofpbuf_try_pull(struct ofpbuf *, size_t);
 
+char *ofpbuf_to_string(const struct ofpbuf *, size_t maxbytes);
+
 #ifdef  __cplusplus
 }
 #endif