[or-cvs] Add a memdup function to util

[Nick Mathewson]

Update of /home/or/cvsroot/tor/src/common
In directory moria:/tmp/cvs-serv22234/src/common

Modified Files:
	util.c util.h 
Log Message:
Add a memdup function to util

Index: util.c
===================================================================
RCS file: /home/or/cvsroot/tor/src/common/util.c,v
retrieving revision 1.261
retrieving revision 1.262
diff -u -p -d -r1.261 -r1.262
--- util.c	9 Jun 2006 17:07:22 -0000	1.261
+++ util.c	18 Jun 2006 07:22:36 -0000	1.262
@@ -190,6 +190,22 @@ _tor_strndup(const char *s, size_t n DMA
   return dup;
 }
 
+/** Allocate a chunk of <b>len</b> bytes, with the same contents starting at
+ * <b>mem</b>. */
+void *
+_tor_memdup(const void *mem, size_t len DMALLOC_PARAMS)
+{
+  char *dup;
+  tor_assert(mem);
+  dup = _tor_malloc(len DMALLOC_FN_ARGS);
+  /* Performance note: Ordinarily we prefer strlcpy to strncpy.  But
+   * this function gets called a whole lot, and platform strncpy is
+   * much faster than strlcpy when strlen(s) is much longer than n.
+   */
+  memcpy(dup, mem, len);
+  return dup;
+}
+
 /* =====
  * String manipulation
  * ===== */

Index: util.h
===================================================================
RCS file: /home/or/cvsroot/tor/src/common/util.h,v
retrieving revision 1.158
retrieving revision 1.159
diff -u -p -d -r1.158 -r1.159
--- util.h	15 Mar 2006 23:35:55 -0000	1.158
+++ util.h	18 Jun 2006 07:22:36 -0000	1.159
@@ -67,6 +67,7 @@ void *_tor_malloc_zero(size_t size DMALL
 void *_tor_realloc(void *ptr, size_t size DMALLOC_PARAMS);
 char *_tor_strdup(const char *s DMALLOC_PARAMS);
 char *_tor_strndup(const char *s, size_t n DMALLOC_PARAMS);
+void *_tor_memdup(const void *mem, size_t len DMALLOC_PARAMS);
 #ifdef USE_DMALLOC
 extern int dmalloc_free(const char *file, const int line, void *pnt,
                         const int func_id);
@@ -85,6 +86,7 @@ extern int dmalloc_free(const char *file
 #define tor_realloc(ptr, size) _tor_realloc(ptr, size DMALLOC_ARGS)
 #define tor_strdup(s)          _tor_strdup(s DMALLOC_ARGS)
 #define tor_strndup(s, n)      _tor_strndup(s, n DMALLOC_ARGS)
+#define tor_memdup(s, n)      _tor_strndup(s, n DMALLOC_ARGS)
 
 /* String manipulation */
 #define HEX_CHARACTERS "0123456789ABCDEFabcdef"