Boost dbengine (#14832)

* configure extent cache size

* workers can now execute up to 10 jobs in a run, boosting query prep and extent reads

* fix dispatched and executing counters

* boost to the max

* increase libuv worker threads

* query prep always get more prio than extent reads; stop processing in batch when dbengine is queue is critical

* fix accounting of query prep

* inlining of time-grouping functions, to speed up queries with billions of points

* make switching based on a local const variable

* print one pending contexts loading message per iteration

* inlined store engine query API

* inlined storage engine data collection api

* inlined all storage engine query ops

* eliminate and inline data collection ops

* simplified query group-by

* more error handling

* optimized partial trimming of group-by queries

* preparative work to support multiple passes of group-by

* more preparative work to support multiple passes of group-by (accepts multiple group-by params)

* unified query timings

* unified query timings - weights endpoint

* query target is no longer a static thread variable - there is a list of cached query targets, each of which of freed every 1000 queries

* fix query memory accounting

* added summary.dimension[].pri and sorted summary.dimensions based on priority and then name

* limit max ACLK WEB response size to 30MB

* the response type should be text/plain

* more preparative work for multiple group-by passes

* create functions for generating group by keys, ids and names

* multiple group-by passes are now supported

* parse group-by options array also with an index

* implemented percentage-of-instance group by function

* family is now merged in multi-node contexts

* prevent uninitialized use

1 files changed, 49 insertions, 5 deletions

diff --git a/web/api/queries/max/max.h b/web/api/queries/max/max.h
index e2427d26d4..c26bb79ad5 100644
--- a/web/api/queries/max/max.h
+++ b/web/api/queries/max/max.h
@@ -6,10 +6,54 @@
 #include "../query.h"
 #include "../rrdr.h"
 
-void grouping_create_max(RRDR *r, const char *options __maybe_unused);
-void grouping_reset_max(RRDR *r);
-void grouping_free_max(RRDR *r);
-void grouping_add_max(RRDR *r, NETDATA_DOUBLE value);
-NETDATA_DOUBLE grouping_flush_max(RRDR *r, RRDR_VALUE_FLAGS *rrdr_value_options_ptr);
+struct tg_max {
+    NETDATA_DOUBLE max;
+    size_t count;
+};
+
+static inline void tg_max_create(RRDR *r, const char *options __maybe_unused) {
+    r->time_grouping.data = onewayalloc_callocz(r->internal.owa, 1, sizeof(struct tg_max));
+}
+
+// resets when switches dimensions
+// so, clear everything to restart
+static inline void tg_max_reset(RRDR *r) {
+    struct tg_max *g = (struct tg_max *)r->time_grouping.data;
+    g->max = 0;
+    g->count = 0;
+}
+
+static inline void tg_max_free(RRDR *r) {
+    onewayalloc_freez(r->internal.owa, r->time_grouping.data);
+    r->time_grouping.data = NULL;
+}
+
+static inline void tg_max_add(RRDR *r, NETDATA_DOUBLE value) {
+    struct tg_max *g = (struct tg_max *)r->time_grouping.data;
+
+    if(!g->count || fabsndd(value) > fabsndd(g->max)) {
+        g->max = value;
+        g->count++;
+    }
+}
+
+static inline NETDATA_DOUBLE tg_max_flush(RRDR *r, RRDR_VALUE_FLAGS *rrdr_value_options_ptr) {
+    struct tg_max *g = (struct tg_max *)r->time_grouping.data;
+
+    NETDATA_DOUBLE value;
+
+    if(unlikely(!g->count)) {
+        value = 0.0;
+        *rrdr_value_options_ptr |= RRDR_VALUE_EMPTY;
+    }
+    else {
+        value = g->max;
+    }
+
+    g->max = 0.0;
+    g->count = 0;
+
+    return value;
+}
 
 #endif //NETDATA_API_QUERY_MAX_H