sfree(msg);
}
-/* label_pair_create allocates and initializes a new label pair. */
-static Io__Prometheus__Client__LabelPair *label_pair_create(char const *name,
- char const *value) {
- Io__Prometheus__Client__LabelPair *msg = calloc(1, sizeof(*msg));
- if (msg == NULL)
+/* label_pair_clone allocates and initializes a new label pair. */
+static Io__Prometheus__Client__LabelPair *
+label_pair_clone(Io__Prometheus__Client__LabelPair const *orig) {
+ Io__Prometheus__Client__LabelPair *copy = calloc(1, sizeof(*copy));
+ if (copy == NULL)
return NULL;
- io__prometheus__client__label_pair__init(msg);
+ io__prometheus__client__label_pair__init(copy);
- msg->name = strdup(name);
- msg->value = strdup(value);
- if ((msg->name == NULL) || (msg->value == NULL)) {
- label_pair_destroy(msg);
+ copy->name = strdup(orig->name);
+ copy->value = strdup(orig->value);
+ if ((copy->name == NULL) || (copy->value == NULL)) {
+ label_pair_destroy(copy);
return NULL;
}
- return msg;
+ return copy;
}
/* metric_destroy frees the memory used by a metric. */
sfree(msg);
}
-/* metric_add_labels adds the labels that identify this metric to m.
- * The logic is copied from the "collectd_exporter". Essentially, the labels
- * contain the hostname, the plugin instance and the type instance of a
- * value_list_t. */
-static int metric_add_labels(Io__Prometheus__Client__Metric *m,
- value_list_t const *vl) {
- size_t n_label = 1;
- if (strlen(vl->plugin_instance) != 0)
- n_label++;
- if (strlen(vl->type_instance) != 0)
- n_label++;
-
- m->label = calloc(n_label, sizeof(*m->label));
- if (m->label == NULL)
- return ENOMEM;
-
- if (strlen(vl->plugin_instance) != 0) {
- m->label[m->n_label] = label_pair_create(vl->plugin, vl->plugin_instance);
- m->n_label++;
- }
-
- if (strlen(vl->type_instance) != 0) {
- char const *name = "type";
- if (strlen(vl->plugin_instance) == 0)
- name = vl->plugin;
-
- m->label[m->n_label] = label_pair_create(name, vl->type_instance);
- m->n_label++;
- }
-
- m->label[m->n_label] = label_pair_create("instance", vl->host);
- m->n_label++;
-
- for (size_t i = 0; i < m->n_label; i++) {
- if (m->label[i] == NULL)
- return ENOMEM;
- }
-
- return 0;
-}
-
/* metric_cmp compares two metrics. It's prototype makes it easy to use with
* qsort(3) and bsearch(3). */
static int metric_cmp(void const *a, void const *b) {
return 1;
/* Prometheus does not care about the order of labels. All labels in this
- * plugin are created by metric_add_labels(), though, and therefore always
+ * plugin are created by METRIC_ADD_LABELS(), though, and therefore always
* appear in the same order. We take advantage of this and simplify the check
- * by making sure all labels are the same in each position. */
+ * by making sure all labels are the same in each position.
+ *
+ * We also only need to check the label values, because the label names are
+ * the same for all metrics in a metric family.
+ *
+ * 3 labels:
+ * [0] $plugin="$plugin_instance" => $plugin is the same within a family
+ * [1] type="$type_instance" => "type" is a static string
+ * [2] instance="$host" => "instance" is a static string
+ *
+ * 2 labels, variant 1:
+ * [0] $plugin="$plugin_instance" => $plugin is the same within a family
+ * [1] instance="$host" => "instance" is a static string
+ *
+ * 2 labels, variant 2:
+ * [0] $plugin="$type_instance" => $plugin is the same within a family
+ * [1] instance="$host" => "instance" is a static string
+ *
+ * 1 label:
+ * [1] instance="$host" => "instance" is a static string
+ */
for (size_t i = 0; i < m_a->n_label; i++) {
- int status = strcmp(m_a->label[i]->name, m_b->label[i]->name);
+ int status = strcmp(m_a->label[i]->value, m_b->label[i]->value);
if (status != 0)
return status;
- status = strcmp(m_a->label[i]->value, m_b->label[i]->value);
- if (status != 0)
- return status;
+#if COLLECT_DEBUG
+ assert(strcmp(m_a->label[i]->name, m_b->label[i]->name) == 0);
+#endif
}
return 0;
}
-/* metric_create allocates and initializes a new metric. */
-static Io__Prometheus__Client__Metric *metric_create(value_list_t const *vl) {
- Io__Prometheus__Client__Metric *msg = calloc(1, sizeof(*msg));
- if (msg == NULL)
+#define METRIC_INIT \
+ &(Io__Prometheus__Client__Metric) { \
+ .label = \
+ (Io__Prometheus__Client__LabelPair *[]){ \
+ &(Io__Prometheus__Client__LabelPair){ \
+ .name = NULL, \
+ }, \
+ &(Io__Prometheus__Client__LabelPair){ \
+ .name = NULL, \
+ }, \
+ &(Io__Prometheus__Client__LabelPair){ \
+ .name = NULL, \
+ }, \
+ }, \
+ .n_label = 0, \
+ }
+
+#define METRIC_ADD_LABELS(m, vl) \
+ do { \
+ if (strlen((vl)->plugin_instance) != 0) { \
+ (m)->label[(m)->n_label]->name = (char *)(vl)->plugin; \
+ (m)->label[(m)->n_label]->value = (char *)(vl)->plugin_instance; \
+ (m)->n_label++; \
+ } \
+ \
+ if (strlen((vl)->type_instance) != 0) { \
+ (m)->label[(m)->n_label]->name = "type"; \
+ if (strlen((vl)->plugin_instance) == 0) \
+ (m)->label[(m)->n_label]->name = (char *)(vl)->plugin; \
+ (m)->label[(m)->n_label]->value = (char *)(vl)->type_instance; \
+ (m)->n_label++; \
+ } \
+ \
+ (m)->label[(m)->n_label]->name = "instance"; \
+ (m)->label[(m)->n_label]->value = (char *)(vl)->host; \
+ (m)->n_label++; \
+ } while (0)
+
+/* metric_clone allocates and initializes a new metric based on orig. */
+static Io__Prometheus__Client__Metric *
+metric_clone(Io__Prometheus__Client__Metric const *orig) {
+ Io__Prometheus__Client__Metric *copy = calloc(1, sizeof(*copy));
+ if (copy == NULL)
return NULL;
- io__prometheus__client__metric__init(msg);
+ io__prometheus__client__metric__init(copy);
- if (metric_add_labels(msg, vl) != 0) {
- metric_destroy(msg);
+ copy->n_label = orig->n_label;
+ copy->label = calloc(copy->n_label, sizeof(*copy->label));
+ if (copy->label == NULL) {
+ sfree(copy);
return NULL;
}
- return msg;
+ for (size_t i = 0; i < copy->n_label; i++) {
+ copy->label[i] = label_pair_clone(orig->label[i]);
+ if (copy->label[i] == NULL) {
+ metric_destroy(copy);
+ return NULL;
+ }
+ }
+
+ return copy;
}
/* metric_update stores the new value and timestamp in m. */
static int
metric_family_delete_metric(Io__Prometheus__Client__MetricFamily *fam,
value_list_t const *vl) {
- Io__Prometheus__Client__Metric *key = metric_create(vl);
- if (key == NULL)
- return ENOMEM;
+ Io__Prometheus__Client__Metric *key = METRIC_INIT;
+ METRIC_ADD_LABELS(key, vl);
size_t i;
for (i = 0; i < fam->n_metric; i++) {
static Io__Prometheus__Client__Metric *
metric_family_get_metric(Io__Prometheus__Client__MetricFamily *fam,
value_list_t const *vl) {
- Io__Prometheus__Client__Metric *key = metric_create(vl);
- if (key == NULL)
- return NULL;
+ Io__Prometheus__Client__Metric *key = METRIC_INIT;
+ METRIC_ADD_LABELS(key, vl);
/* Metrics are sorted in metric_family_add_metric() so that we can do a binary
* search here. */
&key, fam->metric, fam->n_metric, sizeof(*fam->metric), metric_cmp);
if (m != NULL) {
- metric_destroy(key);
return *m;
}
+ Io__Prometheus__Client__Metric *new_metric = metric_clone(key);
+ if (new_metric == NULL)
+ return NULL;
+
DEBUG("write_prometheus plugin: created new metric in family");
- int status = metric_family_add_metric(fam, key);
+ int status = metric_family_add_metric(fam, new_metric);
if (status != 0) {
- metric_destroy(key);
+ metric_destroy(new_metric);
return NULL;
}
- return key;
+ return new_metric;
}
/* metric_family_update looks up the matching metric in a metric family,
projects / collectd.git / blobdiff