One way allocator to double the speed of parallel context queries (#12787)

* one way allocator to speed up context queries

* fixed a bug while expanding memory pages

* reworked for clarity and finally fixed the bug of allocating memory beyond the page size

* further optimize allocation step to minimize the number of allocations made

* implement strdup with memcpy instead of strcpy

* added documentation

* prevent an uninitialized use of owa

* added callocz() interface

* integrate onewayalloc everywhere - apart sql queries

* one way allocator is now used in context queries using archived charts in sql

* align on the size of pointers

* forgotten freez()

* removed not needed memcpys

* give unique names to global variables to avoid conflicts with system definitions

6 files changed, 85 insertions, 71 deletions

diff --git a/web/api/formatters/rrd2json.c b/web/api/formatters/rrd2json.c
index 1a8b07c7c8..9ac54f7589 100644
--- a/web/api/formatters/rrd2json.c
+++ b/web/api/formatters/rrd2json.c
@@ -2,27 +2,27 @@
 
 #include "web/api/web_api_v1.h"
 
-static inline void free_single_rrdrim(RRDDIM *temp_rd, int archive_mode)
+static inline void free_single_rrdrim(ONEWAYALLOC *owa, RRDDIM *temp_rd, int archive_mode)
 {
     if (unlikely(!temp_rd))
         return;
 
-    freez((char *)temp_rd->id);
-    freez((char *)temp_rd->name);
+    onewayalloc_freez(owa, (char *)temp_rd->id);
 
     if (unlikely(archive_mode)) {
         temp_rd->rrdset->counter--;
         if (!temp_rd->rrdset->counter) {
-            freez((char *)temp_rd->rrdset->name);
-            freez(temp_rd->rrdset->context);
-            freez(temp_rd->rrdset);
+            onewayalloc_freez(owa, (char *)temp_rd->rrdset->name);
+            onewayalloc_freez(owa, temp_rd->rrdset->context);
+            onewayalloc_freez(owa, temp_rd->rrdset);
         }
     }
-    freez(temp_rd->state);
-    freez(temp_rd);
+
+    onewayalloc_freez(owa, temp_rd->state);
+    onewayalloc_freez(owa, temp_rd);
 }
 
-static inline void free_rrddim_list(RRDDIM *temp_rd, int archive_mode)
+static inline void free_rrddim_list(ONEWAYALLOC *owa, RRDDIM *temp_rd, int archive_mode)
 {
     if (unlikely(!temp_rd))
         return;
@@ -30,22 +30,22 @@ static inline void free_rrddim_list(RRDDIM *temp_rd, int archive_mode)
     RRDDIM *t;
     while (temp_rd) {
         t = temp_rd->next;
-        free_single_rrdrim(temp_rd, archive_mode);
+        free_single_rrdrim(owa, temp_rd, archive_mode);
         temp_rd = t;
     }
 }
 
-void free_context_param_list(struct context_param **param_list)
+void free_context_param_list(ONEWAYALLOC *owa, struct context_param **param_list)
 {
     if (unlikely(!param_list || !*param_list))
         return;
 
-    free_rrddim_list(((*param_list)->rd), (*param_list)->flags & CONTEXT_FLAGS_ARCHIVE);
-    freez((*param_list));
+    free_rrddim_list(owa, ((*param_list)->rd), (*param_list)->flags & CONTEXT_FLAGS_ARCHIVE);
+    onewayalloc_freez(owa, (*param_list));
     *param_list = NULL;
 }
 
-void rebuild_context_param_list(struct context_param *context_param_list, time_t after_requested)
+void rebuild_context_param_list(ONEWAYALLOC *owa, struct context_param *context_param_list, time_t after_requested)
 {
     RRDDIM *temp_rd = context_param_list->rd;
     RRDDIM *new_rd_list = NULL, *t;
@@ -59,19 +59,19 @@ void rebuild_context_param_list(struct context_param *context_param_list, time_t
             temp_rd->next = new_rd_list;
             new_rd_list = temp_rd;
         } else
-            free_single_rrdrim(temp_rd, is_archived);
+            free_single_rrdrim(owa, temp_rd, is_archived);
         temp_rd = t;
     }
     context_param_list->rd = new_rd_list;
 };
 
-void build_context_param_list(struct context_param **param_list, RRDSET *st)
+void build_context_param_list(ONEWAYALLOC *owa, struct context_param **param_list, RRDSET *st)
 {
     if (unlikely(!param_list || !st))
         return;
 
     if (unlikely(!(*param_list))) {
-        *param_list = mallocz(sizeof(struct context_param));
+        *param_list = onewayalloc_mallocz(owa, sizeof(struct context_param));
         (*param_list)->first_entry_t = LONG_MAX;
         (*param_list)->last_entry_t = 0;
         (*param_list)->flags = CONTEXT_FLAGS_CONTEXT;
@@ -86,14 +86,10 @@ void build_context_param_list(struct context_param **param_list, RRDSET *st)
     (*param_list)->last_entry_t  = MAX((*param_list)->last_entry_t, rrdset_last_entry_t_nolock(st));
 
     rrddim_foreach_read(rd1, st) {
-        RRDDIM *rd = mallocz(rd1->memsize);
-        memcpy(rd, rd1, rd1->memsize);
-        rd->id = strdupz(rd1->id);
-        rd->name = strdupz(rd1->name);
-        rd->state = mallocz(sizeof(*rd->state));
-        memcpy(rd->state, rd1->state, sizeof(*rd->state));
-        memcpy(&rd->state->collect_ops, &rd1->state->collect_ops, sizeof(struct rrddim_collect_ops));
-        memcpy(&rd->state->query_ops, &rd1->state->query_ops, sizeof(struct rrddim_query_ops));
+        RRDDIM *rd = onewayalloc_memdupz(owa, rd1, rd1->memsize);
+        rd->id = onewayalloc_strdupz(owa, rd1->id);
+        rd->name = onewayalloc_strdupz(owa, rd1->name);
+        rd->state = onewayalloc_memdupz(owa, rd1->state, sizeof(*rd->state));
         rd->next = (*param_list)->rd;
         (*param_list)->rd = rd;
     }
@@ -169,22 +165,27 @@ int rrdset2value_api_v1(
         , int *value_is_null
         , int timeout
 ) {
+    int ret = HTTP_RESP_INTERNAL_SERVER_ERROR;
+
+    ONEWAYALLOC *owa = onewayalloc_create(0);
 
-    RRDR *r = rrd2rrdr(st, points, after, before, group_method, group_time, options, dimensions, NULL, timeout);
+    RRDR *r = rrd2rrdr(owa, st, points, after, before, group_method, group_time, options, dimensions, NULL, timeout);
 
     if(!r) {
         if(value_is_null) *value_is_null = 1;
-        return HTTP_RESP_INTERNAL_SERVER_ERROR;
+        ret = HTTP_RESP_INTERNAL_SERVER_ERROR;
+        goto cleanup;
     }
 
     if(rrdr_rows(r) == 0) {
-        rrdr_free(r);
+        rrdr_free(owa, r);
 
         if(db_after)  *db_after  = 0;
         if(db_before) *db_before = 0;
         if(value_is_null) *value_is_null = 1;
 
-        return HTTP_RESP_BAD_REQUEST;
+        ret = HTTP_RESP_BAD_REQUEST;
+        goto cleanup;
     }
 
     if(wb) {
@@ -199,13 +200,17 @@ int rrdset2value_api_v1(
 
     long i = (!(options & RRDR_OPTION_REVERSED))?rrdr_rows(r) - 1:0;
     *n = rrdr2value(r, i, options, value_is_null, NULL);
+    ret = HTTP_RESP_OK;
 
-    rrdr_free(r);
-    return HTTP_RESP_OK;
+cleanup:
+    if(r) rrdr_free(owa, r);
+    onewayalloc_destroy(owa);
+    return ret;
 }
 
 int rrdset2anything_api_v1(
-          RRDSET *st
+          ONEWAYALLOC *owa
+        , RRDSET *st
         , BUFFER *wb
         , BUFFER *dimensions
         , uint32_t format
@@ -225,14 +230,14 @@ int rrdset2anything_api_v1(
     if (context_param_list && !(context_param_list->flags & CONTEXT_FLAGS_ARCHIVE))
         st->last_accessed_time = now_realtime_sec();
 
-    RRDR *r = rrd2rrdr(st, points, after, before, group_method, group_time, options, dimensions?buffer_tostring(dimensions):NULL, context_param_list, timeout);
+    RRDR *r = rrd2rrdr(owa, st, points, after, before, group_method, group_time, options, dimensions?buffer_tostring(dimensions):NULL, context_param_list, timeout);
     if(!r) {
         buffer_strcat(wb, "Cannot generate output with these parameters on this chart.");
         return HTTP_RESP_INTERNAL_SERVER_ERROR;
     }
 
     if (r->result_options & RRDR_RESULT_OPTION_CANCEL) {
-        rrdr_free(r);
+        rrdr_free(owa, r);
         return HTTP_RESP_BACKEND_FETCH_FAILED;
     }
 
@@ -411,6 +416,6 @@ int rrdset2anything_api_v1(
         break;
     }
 
-    rrdr_free(r);
+    rrdr_free(owa, r);
     return HTTP_RESP_OK;
 }
diff --git a/web/api/formatters/rrd2json.h b/web/api/formatters/rrd2json.h
index af809c54f9..a3fe50cbbb 100644
--- a/web/api/formatters/rrd2json.h
+++ b/web/api/formatters/rrd2json.h
@@ -54,7 +54,8 @@ extern void rrd_stats_api_v1_chart(RRDSET *st, BUFFER *wb);
 extern void rrdr_buffer_print_format(BUFFER *wb, uint32_t format);
 
 extern int rrdset2anything_api_v1(
-          RRDSET *st
+          ONEWAYALLOC *owa
+        , RRDSET *st
         , BUFFER *wb
         , BUFFER *dimensions
         , uint32_t format
@@ -88,8 +89,8 @@ extern int rrdset2value_api_v1(
         , int timeout
 );
 
-extern void build_context_param_list(struct context_param **param_list, RRDSET *st);
-extern void rebuild_context_param_list(struct context_param *context_param_list, time_t after_requested);
-extern void free_context_param_list(struct context_param **param_list);
+extern void build_context_param_list(ONEWAYALLOC *owa, struct context_param **param_list, RRDSET *st);
+extern void rebuild_context_param_list(ONEWAYALLOC *owa, struct context_param *context_param_list, time_t after_requested);
+extern void free_context_param_list(ONEWAYALLOC *owa, struct context_param **param_list);
 
 #endif /* NETDATA_RRD2JSON_H */
diff --git a/web/api/queries/query.c b/web/api/queries/query.c
index c55a970609..9308d10bf5 100644
--- a/web/api/queries/query.c
+++ b/web/api/queries/query.c
@@ -831,7 +831,8 @@ static int rrdr_convert_before_after_to_absolute(
 }
 
 static RRDR *rrd2rrdr_fixedstep(
-        RRDSET *st
+          ONEWAYALLOC *owa
+        , RRDSET *st
         , long points_requested
         , long long after_requested
         , long long before_requested
@@ -855,7 +856,7 @@ static RRDR *rrd2rrdr_fixedstep(
     RRDDIM *temp_rd = context_param_list ? context_param_list->rd : NULL;
 
     if(duration <= 0 || available_points <= 0)
-        return rrdr_create(st, 1, context_param_list);
+        return rrdr_create(owa, st, 1, context_param_list);
 
     // check the number of wanted points in the result
     if(unlikely(points_requested < 0)) points_requested = -points_requested;
@@ -1013,7 +1014,7 @@ static RRDR *rrd2rrdr_fixedstep(
     // initialize our result set
     // this also locks the chart for us
 
-    RRDR *r = rrdr_create(st, points_wanted, context_param_list);
+    RRDR *r = rrdr_create(owa, st, points_wanted, context_param_list);
     if(unlikely(!r)) {
         #ifdef NETDATA_INTERNAL_CHECKS
         error("INTERNAL CHECK: Cannot create RRDR for %s, after=%u, before=%u, duration=%u, points=%ld", st->id, (uint32_t)after_wanted, (uint32_t)before_wanted, (uint32_t)duration, points_wanted);
@@ -1216,7 +1217,8 @@ static RRDR *rrd2rrdr_fixedstep(
 
 #ifdef ENABLE_DBENGINE
 static RRDR *rrd2rrdr_variablestep(
-        RRDSET *st
+        ONEWAYALLOC *owa
+        , RRDSET *st
         , long points_requested
         , long long after_requested
         , long long before_requested
@@ -1242,7 +1244,7 @@ static RRDR *rrd2rrdr_variablestep(
 
     if(duration <= 0 || available_points <= 0) {
         freez(region_info_array);
-        return rrdr_create(st, 1, context_param_list);
+        return rrdr_create(owa, st, 1, context_param_list);
     }
 
     // check the number of wanted points in the result
@@ -1401,7 +1403,7 @@ static RRDR *rrd2rrdr_variablestep(
     // initialize our result set
     // this also locks the chart for us
 
-    RRDR *r = rrdr_create(st, points_wanted, context_param_list);
+    RRDR *r = rrdr_create(owa, st, points_wanted, context_param_list);
     if(unlikely(!r)) {
         #ifdef NETDATA_INTERNAL_CHECKS
         error("INTERNAL CHECK: Cannot create RRDR for %s, after=%u, before=%u, duration=%u, points=%ld", st->id, (uint32_t)after_wanted, (uint32_t)before_wanted, (uint32_t)duration, points_wanted);
@@ -1608,7 +1610,8 @@ static RRDR *rrd2rrdr_variablestep(
 #endif //#ifdef ENABLE_DBENGINE
 
 RRDR *rrd2rrdr(
-        RRDSET *st
+          ONEWAYALLOC *owa
+        , RRDSET *st
         , long points_requested
         , long long after_requested
         , long long before_requested
@@ -1644,7 +1647,7 @@ RRDR *rrd2rrdr(
             first_entry_t = after_requested;
 
     if (context_param_list && !(context_param_list->flags & CONTEXT_FLAGS_ARCHIVE)) {
-        rebuild_context_param_list(context_param_list, after_requested);
+        rebuild_context_param_list(owa, context_param_list, after_requested);
         st = context_param_list->rd ? context_param_list->rd->rrdset : NULL;
         if (unlikely(!st))
             return NULL;
@@ -1669,7 +1672,7 @@ RRDR *rrd2rrdr(
                 }
                 freez(region_info_array);
             }
-            return rrd2rrdr_fixedstep(st, points_requested, after_requested, before_requested, group_method,
+            return rrd2rrdr_fixedstep(owa, st, points_requested, after_requested, before_requested, group_method,
                                       resampling_time_requested, options, dimensions, rrd_update_every,
                                       first_entry_t, last_entry_t, absolute_period_requested, context_param_list, timeout);
         } else {
@@ -1680,13 +1683,13 @@ RRDR *rrd2rrdr(
                                                                                   rrd_update_every, first_entry_t,
                                                                                   last_entry_t, options);
             }
-            return rrd2rrdr_variablestep(st, points_requested, after_requested, before_requested, group_method,
+            return rrd2rrdr_variablestep(owa, st, points_requested, after_requested, before_requested, group_method,
                                          resampling_time_requested, options, dimensions, rrd_update_every,
                                          first_entry_t, last_entry_t, absolute_period_requested, region_info_array, context_param_list, timeout);
         }
     }
 #endif
-    return rrd2rrdr_fixedstep(st, points_requested, after_requested, before_requested, group_method,
+    return rrd2rrdr_fixedstep(owa, st, points_requested, after_requested, before_requested, group_method,
                               resampling_time_requested, options, dimensions,
                               rrd_update_every, first_entry_t, last_entry_t, absolute_period_requested, context_param_list, timeout);
 }
diff --git a/web/api/queries/rrdr.c b/web/api/queries/rrdr.c
index b64868222d..03b71db558 100644
--- a/web/api/queries/rrdr.c
+++ b/web/api/queries/rrdr.c
@@ -83,7 +83,7 @@ inline static void rrdr_unlock_rrdset(RRDR *r) {
     }
 }
 
-inline void rrdr_free(RRDR *r)
+inline void rrdr_free(ONEWAYALLOC *owa, RRDR *r)
 {
     if(unlikely(!r)) {
         error("NULL value given!");
@@ -91,21 +91,21 @@ inline void rrdr_free(RRDR *r)
     }
 
     rrdr_unlock_rrdset(r);
-    freez(r->t);
-    freez(r->v);
-    freez(r->o);
-    freez(r->od);
-    freez(r);
+    onewayalloc_freez(owa, r->t);
+    onewayalloc_freez(owa, r->v);
+    onewayalloc_freez(owa, r->o);
+    onewayalloc_freez(owa, r->od);
+    onewayalloc_freez(owa, r);
 }
 
-RRDR *rrdr_create(struct rrdset *st, long n, struct context_param *context_param_list)
+RRDR *rrdr_create(ONEWAYALLOC *owa, struct rrdset *st, long n, struct context_param *context_param_list)
 {
     if (unlikely(!st)) {
         error("NULL value given!");
         return NULL;
     }
 
-    RRDR *r = callocz(1, sizeof(RRDR));
+    RRDR *r = onewayalloc_callocz(owa, 1, sizeof(RRDR));
     r->st = st;
 
     if (!context_param_list || !(context_param_list->flags & CONTEXT_FLAGS_ARCHIVE)) {
@@ -126,10 +126,10 @@ RRDR *rrdr_create(struct rrdset *st, long n, struct context_param *context_param
 
     r->n = n;
 
-    r->t = callocz((size_t)n, sizeof(time_t));
-    r->v = mallocz(n * r->d * sizeof(calculated_number));
-    r->o = mallocz(n * r->d * sizeof(RRDR_VALUE_FLAGS));
-    r->od = mallocz(r->d * sizeof(RRDR_DIMENSION_FLAGS));
+    r->t = onewayalloc_callocz(owa, (size_t)n, sizeof(time_t));
+    r->v = onewayalloc_mallocz(owa, n * r->d * sizeof(calculated_number));
+    r->o = onewayalloc_mallocz(owa, n * r->d * sizeof(RRDR_VALUE_FLAGS));
+    r->od = onewayalloc_mallocz(owa, r->d * sizeof(RRDR_DIMENSION_FLAGS));
 
     // set the hidden flag on hidden dimensions
     int c;
diff --git a/web/api/queries/rrdr.h b/web/api/queries/rrdr.h
index bd94e56e2b..00125ddf57 100644
--- a/web/api/queries/rrdr.h
+++ b/web/api/queries/rrdr.h
@@ -102,13 +102,14 @@ typedef struct rrdresult {
 #define rrdr_rows(r) ((r)->rows)
 
 #include "database/rrd.h"
-extern void rrdr_free(RRDR *r);
-extern RRDR *rrdr_create(struct rrdset *st, long n, struct context_param *context_param_list);
+extern void rrdr_free(ONEWAYALLOC *owa, RRDR *r);
+extern RRDR *rrdr_create(ONEWAYALLOC *owa, struct rrdset *st, long n, struct context_param *context_param_list);
 
 #include "../web_api_v1.h"
 #include "web/api/queries/query.h"
 
 extern RRDR *rrd2rrdr(
+    ONEWAYALLOC *owa,
     RRDSET *st, long points_requested, long long after_requested, long long before_requested,
     RRDR_GROUPING group_method, long resampling_time_requested, RRDR_OPTIONS options, const char *dimensions,
     struct context_param *context_param_list, int timeout);
diff --git a/web/api/web_api_v1.c b/web/api/web_api_v1.c
index 8cf89d38d5..54c5e52808 100644
--- a/web/api/web_api_v1.c
+++ b/web/api/web_api_v1.c
@@ -512,6 +512,7 @@ inline int web_client_api_request_v1_data(RRDHOST *host, struct web_client *w, c
     fix_google_param(outFileName);
 
     RRDSET *st = NULL;
+    ONEWAYALLOC *owa = onewayalloc_create(0);
 
     if((!chart || !*chart) && (!context)) {
         buffer_sprintf(w->response.data, "No chart id is given at the request.");
@@ -519,8 +520,10 @@ inline int web_client_api_request_v1_data(RRDHOST *host, struct web_client *w, c
     }
 
     struct context_param  *context_param_list = NULL;
+
     if (context && !chart) {
         RRDSET *st1;
+
         uint32_t context_hash = simple_hash(context);
 
         rrdhost_rdlock(host);
@@ -532,14 +535,14 @@ inline int web_client_api_request_v1_data(RRDHOST *host, struct web_client *w, c
                 (!chart_label_key || rrdset_contains_label_keylist(st1, chart_label_key)) &&
                 (!chart_labels_filter ||
                  rrdset_matches_label_keys(st1, chart_labels_filter, words, hash_key_list, &word_count, MAX_CHART_LABELS_FILTER)))
-                    build_context_param_list(&context_param_list, st1);
+                    build_context_param_list(owa, &context_param_list, st1);
         }
         rrdhost_unlock(host);
         if (likely(context_param_list && context_param_list->rd))  // Just set the first one
             st = context_param_list->rd->rrdset;
         else {
             if (!chart_label_key && !chart_labels_filter)
-                sql_build_context_param_list(&context_param_list, host, context, NULL);
+                sql_build_context_param_list(owa, &context_param_list, host, context, NULL);
         }
     }
     else {
@@ -549,14 +552,14 @@ inline int web_client_api_request_v1_data(RRDHOST *host, struct web_client *w, c
         if (likely(st))
             st->last_accessed_time = now_realtime_sec();
         else
-            sql_build_context_param_list(&context_param_list, host, NULL, chart);
+            sql_build_context_param_list(owa, &context_param_list, host, NULL, chart);
     }
 
     if (!st) {
         if (likely(context_param_list && context_param_list->rd && context_param_list->rd->rrdset))
             st = context_param_list->rd->rrdset;
         else {
-            free_context_param_list(&context_param_list);
+            free_context_param_list(owa, &context_param_list);
             context_param_list = NULL;
         }
     }
@@ -630,12 +633,12 @@ inline int web_client_api_request_v1_data(RRDHOST *host, struct web_client *w, c
         buffer_strcat(w->response.data, "(");
     }
 
-    ret = rrdset2anything_api_v1(st, w->response.data, dimensions, format,
+    ret = rrdset2anything_api_v1(owa, st, w->response.data, dimensions, format,
                                  points, after, before, group, group_time,
                                  options, &last_timestamp_in_data, context_param_list,
                                  chart_label_key, max_anomaly_rates, timeout);
 
-    free_context_param_list(&context_param_list);
+    free_context_param_list(owa, &context_param_list);
 
     if(format == DATASOURCE_DATATABLE_JSONP) {
         if(google_timestamp < last_timestamp_in_data)
@@ -652,7 +655,8 @@ inline int web_client_api_request_v1_data(RRDHOST *host, struct web_client *w, c
     else if(format == DATASOURCE_JSONP)
         buffer_strcat(w->response.data, ");");
 
-    cleanup:
+cleanup:
+    onewayalloc_destroy(owa);
     buffer_free(dimensions);
     return ret;
 }