/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#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
* commonly, the data in a ofpbuf is at its beginning, and thus the ofpbuf's
* headroom is 0.) */
size_t
-ofpbuf_headroom(struct ofpbuf *b)
+ofpbuf_headroom(const struct ofpbuf *b)
{
return (char*)b->data - (char*)b->base;
}
/* Returns the number of bytes that may be appended to the tail end of ofpbuf
* 'b' before the ofpbuf must be reallocated. */
size_t
-ofpbuf_tailroom(struct ofpbuf *b)
+ofpbuf_tailroom(const struct ofpbuf *b)
{
return (char*)ofpbuf_end(b) - (char*)ofpbuf_tail(b);
}
return b->data;
}
+/* Prefixes 'size' zeroed bytes to the head end of 'b'. 'b' must have at least
+ * 'size' bytes of headroom. Returns a pointer to the first byte of the data's
+ * location in the ofpbuf. */
+void *
+ofpbuf_push_zeros(struct ofpbuf *b, size_t size)
+{
+ void *dst = ofpbuf_push_uninit(b, size);
+ memset(dst, 0, size);
+ return dst;
+}
+
void *
ofpbuf_push(struct ofpbuf *b, const void *p, 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);
+}