From: Florian Forster <octo@collectd.org>
Date: Mon, 29 Jun 2015 10:50:51 +0000 (+0200)
Subject: src/daemon/common.[ch]: Improve signature of value_to_rate().
X-Git-Tag: collectd-5.6.0~662
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=e41add16b3f19e89cd746a76c66cd28670037d7d;p=collectd.git

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 2a2a4a97..bcaea38c 100644
--- 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 73dd277f..92950ded 100644
--- 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 da21cad9..c3f7f548 100644
--- 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 d34e4112..21602d55 100644
--- 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;