top(1): set max username length based on system constant

This changes previous behavior of calculating it at startup based on
the current max username length.

This is done because:
- it is in theory possible for the max length to change at run-time
  (e.g., a new user is added after top starts running)
- on machines with many users this delays startup significantly

PR:		20799
PR:		89762
Reported by:	ob@e-Gitt.NET
Reported by:	wkwu@Kavalan.csie.NCTU.edu.tw
Reported on:	2000-08-23 and 2005-11-30

usr.bin/top/machine.c

@@ -314,7 +314,7 @@ update_layout(void)
 }
 
 int
-machine_init(struct statics *statics, char do_unames)
+machine_init(struct statics *statics)
 {
 	int i, j, empty, pagesize;
 	uint64_t arc_size;
@@ -340,12 +340,7 @@ machine_init(struct statics *statics, char do_unames)
 	    NULL, 0) == 0 && carc_en == 1)
 		carc_enabled = 1;
 
-	if (do_unames) {
-	    while ((pw = getpwent()) != NULL) {
-		if (strlen(pw->pw_name) > namelength)
-			namelength = strlen(pw->pw_name);
-	    }
-	}
+	namelength = MAXLOGNAME;
 	if (smpmode && namelength > SMPUNAMELEN)
 		namelength = SMPUNAMELEN;
 	else if (namelength > UPUNAMELEN)

usr.bin/top/machine.h

@@ -85,7 +85,7 @@ char	*format_next_process(caddr_t handle, char *(*get_userid)(int),
 	    int flags);
 void	 toggle_pcpustats(void);
 void	 get_system_info(struct system_info *si);
-int	 machine_init(struct statics *statics, char do_unames);
+int	 machine_init(struct statics *statics);
 int	 proc_owner(int pid);
 
 /* non-int routines typically used by the machine dependent module */

usr.bin/top/top.c

@@ -548,7 +548,7 @@ char *argv[];
     }
 
     /* initialize the kernel memory interface */
-    if (machine_init(&statics, do_unames) == -1)
+    if (machine_init(&statics) == -1)
     {
 	exit(1);
     }
@@ -573,14 +573,6 @@ char *argv[];
 	}
     }
 
-#ifdef no_initialization_needed
-    /* initialize the hashing stuff */
-    if (do_unames)
-    {
-	init_hash();
-    }
-#endif
-
     /* initialize termcap */
     init_termcap(interactive);
 

usr.bin/top/username.c

@@ -60,17 +60,6 @@ struct hash_el {
 struct hash_el hash_table[Table_size];
 
 
-void
-init_hash()
-
-{
-    /*
-     *  There used to be some steps we had to take to initialize things.
-     *  We don't need to do that anymore, but we will leave this stub in
-     *  just in case future changes require initialization steps.
-     */
-}
-
 char *username(uid)
 
 int uid;