src/daemon/common.[ch]: Improve signature of value_to_rate().

Passing in "value" as a derive_t and returning the rate as a value_t is
just inconvenient and wrong. Instead, pass "value" as a value_t and return
the rate in a gauge_t. While at it, move the state pointer to the end of
the argument list.

diff --git a/src/cpu.c b/src/cpu.c
index 2a2a4a9..bcaea38 100644 (file)
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -526,11 +526,12 @@ static void cpu_commit (void) /* {{{ */
 /* Adds a derive value to the internal state. This should be used by each read
  * function for each state. At the end of the iteration, the read function
  * should call cpu_commit(). */
-static int cpu_stage (size_t cpu_num, size_t state, derive_t value, cdtime_t now) /* {{{ */
+static int cpu_stage (size_t cpu_num, size_t state, derive_t d, cdtime_t now) /* {{{ */
 {
        int status;
        cpu_state_t *s;
-       value_t v;
+       gauge_t rate = NAN;
+       value_t val = {.derive = d};
 
        if (state >= COLLECTD_CPU_STATE_ACTIVE)
                return (EINVAL);
@@ -544,12 +545,11 @@ static int cpu_stage (size_t cpu_num, size_t state, derive_t value, cdtime_t now
 
        s = get_cpu_state (cpu_num, state);
 
-       v.gauge = NAN;
-       status = value_to_rate (&v, value, &s->conv, DS_TYPE_DERIVE, now);
+       status = value_to_rate (&rate, val, DS_TYPE_DERIVE, now, &s->conv);
        if (status != 0)
                return (status);
 
-       s->rate = v.gauge;
+       s->rate = rate;
        s->has_value = 1;
        return (0);
 } /* }}} int cpu_stage */

diff --git a/src/daemon/common.c b/src/daemon/common.c
index 73dd277..92950de 100644 (file)
--- a/src/daemon/common.c
+++ b/src/daemon/common.c
@@ -1469,11 +1469,10 @@ int rate_to_value (value_t *ret_value, gauge_t rate, /* {{{ */
        return (0);
 } /* }}} value_t rate_to_value */
 
-int value_to_rate (value_t *ret_rate, derive_t value, /* {{{ */
-               value_to_rate_state_t *state,
-               int ds_type, cdtime_t t)
+int value_to_rate (gauge_t *ret_rate, /* {{{ */
+               value_t value, int ds_type, cdtime_t t, value_to_rate_state_t *state)
 {
-       double interval;
+       gauge_t interval;
 
        /* Another invalid state: The time is not increasing. */
        if (t <= state->last_time)
@@ -1485,51 +1484,39 @@ int value_to_rate (value_t *ret_rate, derive_t value, /* {{{ */
        interval = CDTIME_T_TO_DOUBLE(t - state->last_time);
 
        /* Previous value is invalid. */
-       if (state->last_time == 0) /* {{{ */
+       if (state->last_time == 0)
        {
-               if (ds_type == DS_TYPE_DERIVE)
-               {
-                       state->last_value.derive = value;
-               }
-               else if (ds_type == DS_TYPE_COUNTER)
-               {
-                       state->last_value.counter = (counter_t) value;
-               }
-               else if (ds_type == DS_TYPE_ABSOLUTE)
-               {
-                       state->last_value.absolute = (absolute_t) value;
-               }
-               else
-               {
-                       assert (23 == 42);
-               }
-
+               state->last_value = value;
                state->last_time = t;
                return (EAGAIN);
-       } /* }}} */
+       }
 
-       if (ds_type == DS_TYPE_DERIVE)
-       {
-               ret_rate->gauge = (value - state->last_value.derive) / interval;
-               state->last_value.derive = value;
+       switch (ds_type) {
+       case DS_TYPE_DERIVE: {
+               derive_t diff = value.derive - state->last_value.derive;
+               *ret_rate = ((gauge_t) diff) / ((gauge_t) interval);
+               break;
        }
-       else if (ds_type == DS_TYPE_COUNTER)
-       {
-               counter_t diff = counter_diff (state->last_value.counter, (counter_t) value);
-               ret_rate->gauge = ((gauge_t) diff) / ((gauge_t) interval);
-               state->last_value.counter = (counter_t) value;
+       case DS_TYPE_GAUGE: {
+               *ret_rate = value.gauge;
+               break;
        }
-       else if (ds_type == DS_TYPE_ABSOLUTE)
-       {
-               ret_rate->gauge = (((absolute_t)value) - state->last_value.absolute) / interval;
-               state->last_value.absolute = (absolute_t) value;
+       case DS_TYPE_COUNTER: {
+               counter_t diff = counter_diff (state->last_value.counter, value.counter);
+               *ret_rate = ((gauge_t) diff) / ((gauge_t) interval);
+               break;
        }
-       else
-       {
-               assert (23 == 42);
+       case DS_TYPE_ABSOLUTE: {
+               absolute_t diff = value.absolute;
+               *ret_rate = ((gauge_t) diff) / ((gauge_t) interval);
+               break;
+       }
+       default:
+               return EINVAL;
        }
 
-        state->last_time = t;
+       state->last_value = value;
+       state->last_time = t;
        return (0);
 } /* }}} value_t rate_to_value */
 

diff --git a/src/daemon/common.h b/src/daemon/common.h
index da21cad..c3f7f54 100644 (file)
--- a/src/daemon/common.h
+++ b/src/daemon/common.h
@@ -357,8 +357,8 @@ counter_t counter_diff (counter_t old_value, counter_t new_value);
 int rate_to_value (value_t *ret_value, gauge_t rate,
                rate_to_value_state_t *state, int ds_type, cdtime_t t);
 
-int value_to_rate (value_t *ret_rate, derive_t value,
-               value_to_rate_state_t *state, int ds_type, cdtime_t t);
+int value_to_rate (gauge_t *ret_rate, value_t value, int ds_type, cdtime_t t,
+               value_to_rate_state_t *state);
 
 /* Converts a service name (a string) to a port number
  * (in the range [1-65535]). Returns less than zero on error. */

diff --git a/src/daemon/common_test.c b/src/daemon/common_test.c
index d34e411..21602d5 100644 (file)
--- a/src/daemon/common_test.c
+++ b/src/daemon/common_test.c
@@ -362,15 +362,15 @@ DEF_TEST(value_to_rate)
 
   for (i = 0; i < STATIC_ARRAY_SIZE (cases); i++) {
     value_to_rate_state_t state = { cases[i].v0, TIME_T_TO_CDTIME_T (cases[i].t0) };
-    value_t got;
+    gauge_t got;
 
     if (cases[i].t0 == 0) {
-      OK(value_to_rate (&got, cases[i].v1.derive, &state, cases[i].ds_type, TIME_T_TO_CDTIME_T (cases[i].t1)) == EAGAIN);
+      OK(value_to_rate (&got, cases[i].v1, cases[i].ds_type, TIME_T_TO_CDTIME_T(cases[i].t1), &state) == EAGAIN);
       continue;
     }
 
-    OK(value_to_rate (&got, cases[i].v1.derive, &state, cases[i].ds_type, TIME_T_TO_CDTIME_T (cases[i].t1)) == 0);
-    DBLEQ(cases[i].want, got.gauge);
+    OK(value_to_rate (&got, cases[i].v1, cases[i].ds_type, TIME_T_TO_CDTIME_T(cases[i].t1), &state) == 0);
+    DBLEQ(cases[i].want, got);
   }
 
   return 0;