Code

src/common.c: Reimplement format_name for performance.
[collectd.git] / src / common.c
index 406482ad6a84c5d13642d4a0f8b5bb5909b01434..5de7d97b9ef3e9dfb090816aa2c1418567e4f43a 100644 (file)
@@ -636,24 +636,23 @@ long long get_kstat_value (kstat_t *ksp, char *name)
        kstat_named_t *kn;
        long long retval = -1LL;
 
-#ifdef assert
-       assert (ksp != NULL);
-       assert (ksp->ks_type == KSTAT_TYPE_NAMED);
-#else
        if (ksp == NULL)
        {
-               ERROR ("ERROR: %s:%i: ksp == NULL\n", __FILE__, __LINE__);
+               ERROR ("get_kstat_value (\"%s\"): ksp is NULL.", name);
                return (-1LL);
        }
        else if (ksp->ks_type != KSTAT_TYPE_NAMED)
        {
-               ERROR ("ERROR: %s:%i: ksp->ks_type != KSTAT_TYPE_NAMED\n", __FILE__, __LINE__);
+               ERROR ("get_kstat_value (\"%s\"): ksp->ks_type (%#x) "
+                               "is not KSTAT_TYPE_NAMED (%#x).",
+                               name,
+                               (unsigned int) ksp->ks_type,
+                               (unsigned int) KSTAT_TYPE_NAMED);
                return (-1LL);
        }
-#endif
 
        if ((kn = (kstat_named_t *) kstat_data_lookup (ksp, name)) == NULL)
-               return (retval);
+               return (-1LL);
 
        if (kn->data_type == KSTAT_DATA_INT32)
                retval = (long long) kn->value.i32;
@@ -665,7 +664,7 @@ long long get_kstat_value (kstat_t *ksp, char *name)
                retval = (long long) kn->value.ui64; /* XXX: Might overflow! */
        else
                WARNING ("get_kstat_value: Not a numeric value: %s", name);
-                
+
        return (retval);
 }
 #endif /* HAVE_LIBKSTAT */
@@ -772,36 +771,43 @@ int format_name (char *ret, int ret_len,
                const char *plugin, const char *plugin_instance,
                const char *type, const char *type_instance)
 {
-       int  status;
+  char *buffer;
+  size_t buffer_size;
+
+  buffer = ret;
+  buffer_size = (size_t) ret_len;
+
+#define APPEND(str) do {                                               \
+  size_t l = strlen (str);                                             \
+  if (l >= buffer_size)                                                \
+    return (ENOBUFS);                                                  \
+  memcpy (buffer, (str), l);                                           \
+  buffer += l; buffer_size -= l;                                       \
+} while (0)
 
-       assert (plugin != NULL);
-       assert (type != NULL);
+  assert (plugin != NULL);
+  assert (type != NULL);
 
-       if ((plugin_instance == NULL) || (strlen (plugin_instance) == 0))
-       {
-               if ((type_instance == NULL) || (strlen (type_instance) == 0))
-                       status = ssnprintf (ret, ret_len, "%s/%s/%s",
-                                       hostname, plugin, type);
-               else
-                       status = ssnprintf (ret, ret_len, "%s/%s/%s-%s",
-                                       hostname, plugin, type,
-                                       type_instance);
-       }
-       else
-       {
-               if ((type_instance == NULL) || (strlen (type_instance) == 0))
-                       status = ssnprintf (ret, ret_len, "%s/%s-%s/%s",
-                                       hostname, plugin, plugin_instance,
-                                       type);
-               else
-                       status = ssnprintf (ret, ret_len, "%s/%s-%s/%s-%s",
-                                       hostname, plugin, plugin_instance,
-                                       type, type_instance);
-       }
+  APPEND (hostname);
+  APPEND ("/");
+  APPEND (plugin);
+  if ((plugin_instance != NULL) && (plugin_instance[0] != 0))
+  {
+    APPEND ("-");
+    APPEND (plugin_instance);
+  }
+  APPEND ("/");
+  APPEND (type);
+  if ((type_instance != NULL) && (type_instance[0] != 0))
+  {
+    APPEND ("-");
+    APPEND (type_instance);
+  }
+  assert (buffer_size > 0);
+  buffer[0] = 0;
 
-       if ((status < 1) || (status >= ret_len))
-               return (-1);
-       return (0);
+#undef APPEND
+  return (0);
 } /* int format_name */
 
 int format_values (char *ret, size_t ret_len, /* {{{ */
@@ -1230,7 +1236,102 @@ counter_t counter_diff (counter_t old_value, counter_t new_value)
        }
 
        return (diff);
-} /* counter_t counter_to_gauge */
+} /* counter_t counter_diff */
+
+int rate_to_value (value_t *ret_value, gauge_t rate, /* {{{ */
+               rate_to_value_state_t *state,
+               int ds_type, cdtime_t t)
+{
+       gauge_t delta_gauge;
+       cdtime_t delta_t;
+
+       if (ds_type == DS_TYPE_GAUGE)
+       {
+               state->last_value.gauge = rate;
+               state->last_time = t;
+
+               *ret_value = state->last_value;
+               return (0);
+       }
+
+       /* Counter and absolute can't handle negative rates. Reset "last time"
+        * to zero, so that the next valid rate will re-initialize the
+        * structure. */
+       if ((rate < 0.0)
+                       && ((ds_type == DS_TYPE_COUNTER)
+                               || (ds_type == DS_TYPE_ABSOLUTE)))
+       {
+               memset (state, 0, sizeof (*state));
+               return (EINVAL);
+       }
+
+       /* Another invalid state: The time is not increasing. */
+       if (t <= state->last_time)
+       {
+               memset (state, 0, sizeof (*state));
+               return (EINVAL);
+       }
+
+       delta_t = t - state->last_time;
+       delta_gauge = (rate * CDTIME_T_TO_DOUBLE (delta_t)) + state->residual;
+
+       /* Previous value is invalid. */
+       if (state->last_time == 0) /* {{{ */
+       {
+               if (ds_type == DS_TYPE_DERIVE)
+               {
+                       state->last_value.derive = (derive_t) rate;
+                       state->residual = rate - ((gauge_t) state->last_value.derive);
+               }
+               else if (ds_type == DS_TYPE_COUNTER)
+               {
+                       state->last_value.counter = (counter_t) rate;
+                       state->residual = rate - ((gauge_t) state->last_value.counter);
+               }
+               else if (ds_type == DS_TYPE_ABSOLUTE)
+               {
+                       state->last_value.absolute = (absolute_t) rate;
+                       state->residual = rate - ((gauge_t) state->last_value.absolute);
+               }
+               else
+               {
+                       assert (23 == 42);
+               }
+
+               state->last_time = t;
+               return (EAGAIN);
+       } /* }}} */
+
+       if (ds_type == DS_TYPE_DERIVE)
+       {
+               derive_t delta_derive = (derive_t) delta_gauge;
+
+               state->last_value.derive += delta_derive;
+               state->residual = delta_gauge - ((gauge_t) delta_derive);
+       }
+       else if (ds_type == DS_TYPE_COUNTER)
+       {
+               counter_t delta_counter = (counter_t) delta_gauge;
+
+               state->last_value.counter += delta_counter;
+               state->residual = delta_gauge - ((gauge_t) delta_counter);
+       }
+       else if (ds_type == DS_TYPE_ABSOLUTE)
+       {
+               absolute_t delta_absolute = (absolute_t) delta_gauge;
+
+               state->last_value.absolute = delta_absolute;
+               state->residual = delta_gauge - ((gauge_t) delta_absolute);
+       }
+       else
+       {
+               assert (23 == 42);
+       }
+
+        state->last_time = t;
+       *ret_value = state->last_value;
+       return (0);
+} /* }}} value_t rate_to_value */
 
 int service_name_to_port_number (const char *service_name)
 {