[lcd4linux @ 2004-05-29 00:27:14 by reinelt]

added plugin_diskstats.c

git-svn-id: https://ssl.bulix.org/svn/lcd4linux/trunk@443 3ae390bd-cb1e-0410-b409-cd5a39f66f1f

plugin_diskstats.c

@@ -0,0 +1,161 @@
+/* $Id: plugin_diskstats.c,v 1.1 2004/05/29 00:27:23 reinelt Exp $
+ *
+ * plugin for /proc/diskstats parsing
+ *
+ * Copyright 2003 Michael Reinelt <reinelt@eunet.at>
+ * Copyright 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
+ *
+ * This file is part of LCD4Linux.
+ *
+ * LCD4Linux is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * LCD4Linux is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * $Log: plugin_diskstats.c,v $
+ * Revision 1.1  2004/05/29 00:27:23  reinelt
+ *
+ * added plugin_diskstats.c
+ *
+ */
+
+/* 
+ * exported functions:
+ *
+ * int plugin_init_diskstats (void)
+ *  adds functions to access /proc/stat
+ *
+ */
+
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+
+#include "debug.h"
+#include "plugin.h"
+#include "qprintf.h"
+#include "hash.h"
+
+
+static HASH DISKSTATS = { 0, };
+static FILE *stream = NULL;
+
+
+static void hash_set2 (char *key1, char *key2, char *val) 
+{
+  char key[32];
+  
+  qprintf(key, sizeof(key), "%s.%s", key1, key2);
+  hash_set_delta (&DISKSTATS, key, val);
+}
+
+
+static int parse_diskstats (void)
+{
+  int age;
+  
+  // reread every 10 msec only
+  age = hash_age(&DISKSTATS, NULL, NULL);
+  if (age > 0 && age <= 10) return 0;
+  
+  if (stream == NULL) stream = fopen("/proc/diskstats", "r");
+  if (stream == NULL) {
+    error ("fopen(/proc/diskstats) failed: %s", strerror(errno));
+    return -1;
+  }
+  
+  rewind(stream);
+  
+  while (!feof(stream)) {
+    char buffer[1024];
+    char *beg, *end;
+    char *major = NULL;
+    char *minor = NULL;
+    char *name  = NULL; 
+    char *key[]  = { "reads",  "read_merges",  "read_sectors",  "read_ticks",
+		     "writes", "write_merges", "write_sectors", "write_ticks",
+		     "in_flight", "io_ticks", "time_in_queue" 
+    };
+    
+    int i;
+    
+    if (fgets (buffer, sizeof(buffer), stream) == NULL) break;
+    
+    beg = buffer;
+    i = 0;
+    while (beg != NULL) {
+      while (*beg == ' ') beg++; 
+      if ((end = strchr(beg, ' '))) *end = '\0'; 
+      switch (i++) {
+      case 0:
+	major = beg;
+	break;
+      case 1:
+	minor = beg;
+	break;
+      case 2:
+	name = beg;
+	hash_set2 ("major", name, major); 
+	hash_set2 ("minor", name, minor); 
+	break;
+      default:
+	hash_set2 (key[i-3], name, beg); 
+      }
+      beg = end ? end+1 : NULL;
+    }
+  }
+  return 0;
+}
+
+
+static void my_diskstats (RESULT *result, RESULT *arg1, RESULT *arg2, RESULT *arg3)
+{
+  char *dev, *key, buffer[32];
+  int delay;
+  double value;
+  
+  if (parse_diskstats() < 0) {
+    SetResult(&result, R_STRING, ""); 
+    return;
+  }
+  
+  dev   = R2S(arg1);
+  key   = R2S(arg2);
+  delay = R2N(arg3);
+  
+  qprintf(buffer, sizeof(buffer), "%s\\.%s", dev, key);
+  value  = hash_get_regex(&DISKSTATS, buffer, delay);
+  
+  SetResult(&result, R_NUMBER, &value); 
+}
+
+
+int plugin_init_diskstats (void)
+{
+  AddFunction ("diskstats", 3, my_diskstats);
+  return 0;
+}
+
+void plugin_exit_diskstats(void) 
+{
+  if (stream != NULL) {
+    fclose (stream);
+    stream = NULL;
+  }
+  hash_destroy(&DISKSTATS);
+}