net/djbdns/patches/110-dnscache-cachestats.patch

   1 #
   2 # This patch to djbdns 1.05 modifies the dnscache program to keep a
   3 # counter of cache hits and cache misses.
   4 #
   5 # Two new fields are added to the ``stats'' output line:
   6 #  . the fifth number is the number of cache hits
   7 #  . the sixth number is the number of cache misses
   8 # e.g.
   9 #  @400000003fa92ccc317d70f4 stats 3 1201 1 0 21 49
  10 # indicates 21 hits and 49 misses.
  11 #
  12 # James Raftery <james@now.ie>  6 Nov. 2003
  13 #
  14 --- a/cache.c
  15 +++ b/cache.c
  16 @@ -7,6 +7,11 @@
  17
  18  uint64 cache_motion = 0;
  19
  20 +/* record cache stats */
  21 +/* James Raftery <james@now.ie> 6 Nov. 2003 */
  22 +uint64 cache_hit = 0;
  23 +uint64 cache_miss = 0;
  24 +
  25  static char *x = 0;
  26  static uint32 size;
  27  static uint32 hsize;
  28 @@ -112,15 +117,20 @@ char *cache_get(const char *key,unsigned
  29          if (u > size - pos - 20 - keylen) cache_impossible();
  30          *datalen = u;
  31
  32 +        cache_hit++;
  33          return x + pos + 20 + keylen;
  34        }
  35      }
  36      nextpos = prevpos ^ get4(pos);
  37      prevpos = pos;
  38      pos = nextpos;
  39 -    if (++loop > 100) return 0; /* to protect against hash flooding */
  40 +    if (++loop > 100) { /* to protect against hash flooding */
  41 +      cache_miss++;
  42 +      return 0;
  43 +    }
  44    }
  45
  46 +  cache_miss++;
  47    return 0;
  48  }
  49
  50 --- a/cache.h
  51 +++ b/cache.h
  52 @@ -5,6 +5,12 @@
  53  #include "uint64.h"
  54
  55  extern uint64 cache_motion;
  56 +
  57 +/* record cache stats */
  58 +/* James Raftery <james@now.ie> 6 Nov. 2003 */
  59 +extern uint64 cache_hit;
  60 +extern uint64 cache_miss;
  61 +
  62  extern int cache_init(unsigned int);
  63  extern void cache_set(const char *,unsigned int,const char *,unsigned int,uint32);
  64  extern char *cache_get(const char *,unsigned int,unsigned int *,uint32 *);
  65 --- a/log.c
  66 +++ b/log.c
  67 @@ -279,6 +279,12 @@ void log_stats(void)
  68    time_t cur = time(NULL);
  69    extern uint64 numqueries;
  70    extern uint64 cache_motion;
  71 +
  72 +  /* record cache stats */
  73 +  /* James Raftery <james@now.ie> 6 Nov. 2003 */
  74 +  extern uint64 cache_hit;
  75 +  extern uint64 cache_miss;
  76 +
  77    extern int uactive;
  78    extern int tactive;
  79
  80 @@ -290,6 +296,8 @@ void log_stats(void)
  81    number(numqueries); space();
  82    number(cache_motion); space();
  83    number(uactive); space();
  84 -  number(tactive);
  85 +  number(tactive); space();
  86 +  number(cache_hit); space();
  87 +  number(cache_miss);
  88    line();
  89  }