Faster pagesize aligned fopen for netstat -s (Eric Dumazet)

lib/proc.c

 /* Tolerant /proc file parser. Copyright 1998 Andi Kleen */
-/* $Id: proc.c,v 1.4 1999/01/05 20:54:00 philip Exp $ */ 
+/* $Id: proc.c,v 1.5 2007/12/01 18:44:57 ecki Exp $ */ 
 /* Fixme: cannot currently cope with removed fields */ 
 
 #include <string.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <ctype.h>
+#include <unistd.h>
 
 /* Caller must free return string. */
 
@@ -72,3 +73,22 @@ int proc_guess_fmt(char *name, FILE *fh, ...)
     va_end(ap);
     return flag;
 }
+
+
+FILE *proc_fopen(const char *name)
+{
+    static char *buffer;
+    static size_t pagesz;
+    FILE *fd = fopen(name, "r");
+
+    if (fd == NULL)
+      return NULL;
+      
+    if (!buffer) {
+      pagesz = getpagesize();
+      buffer = malloc(pagesz);
+    }
+    
+    setvbuf(fd, buffer, _IOFBF, pagesz);
+    return fd;
+}

lib/proc.h

-
-
-/* Generate a suitable scanf format for a column title line */
+/* 
+ * prototypes for proc.c
+ */
 char *proc_gen_fmt(char *name, int more, FILE * fh,...);
 int   proc_guess_fmt(char *name, FILE* fh,...);
+FILE *proc_fopen(const char *name);
+

statistics.c

 /*
  * Copyright 1997,1999,2000 Andi Kleen. Subject to the GPL. 
- * $Id: statistics.c,v 1.19 2007/12/01 18:29:05 ecki Exp $
+ * $Id: statistics.c,v 1.20 2007/12/01 18:44:56 ecki Exp $
  * 19980630 - i18n - Arnaldo Carvalho de Melo <acme@conectiva.com.br> 
  * 19981113 - i18n fixes - Arnaldo Carvalho de Melo <acme@conectiva.com.br> 
  * 19990101 - added net/netstat, -t, -u, -w supprt - Bernd Eckenfels 
@@ -11,6 +11,7 @@
 #include <string.h>
 #include "config.h"
 #include "intl.h"
+#include "proc.h"
 
 /* #define WARN 1 */
 
@@ -387,7 +388,7 @@ void parsesnmp(int flag_raw, int flag_tcp, int flag_udp)
 
     f_raw = flag_raw; f_tcp = flag_tcp; f_udp = flag_udp;
     
-    f = fopen("/proc/net/snmp", "r");
+    f = proc_fopen("/proc/net/snmp");
     if (!f) {
 	perror(_("cannot open /proc/net/snmp"));
 	return;
@@ -401,7 +402,7 @@ void parsesnmp(int flag_raw, int flag_tcp, int flag_udp)
 
     fclose(f);
 
-    f = fopen("/proc/net/netstat", "r");
+    f = proc_fopen("/proc/net/netstat");
 
     if (f) {
     	if (process_fd(f) <0)