1 files changed, 158 insertions, 146 deletions

diff --git a/database/rrdvar.c b/database/rrdvar.c
index d4dda1079..28be4f6a1 100644
--- a/database/rrdvar.c
+++ b/database/rrdvar.c
@@ -1,8 +1,19 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-#define NETDATA_HEALTH_INTERNALS
 #include "rrd.h"
 
+// the variables as stored in the variables indexes
+// there are 3 indexes:
+// 1. at each chart   (RRDSET.rrdvar_root_index)
+// 2. at each context (RRDFAMILY.rrdvar_root_index)
+// 3. at each host    (RRDHOST.rrdvar_root_index)
+typedef struct rrdvar {
+    STRING *name;
+    void *value;
+    RRDVAR_FLAGS flags:24;
+    RRDVAR_TYPE type:8;
+} RRDVAR;
+
 // ----------------------------------------------------------------------------
 // RRDVAR management
 
@@ -20,168 +31,153 @@ inline int rrdvar_fix_name(char *variable) {
     return fixed;
 }
 
-int rrdvar_compare(void* a, void* b) {
-    if(((RRDVAR *)a)->hash < ((RRDVAR *)b)->hash) return -1;
-    else if(((RRDVAR *)a)->hash > ((RRDVAR *)b)->hash) return 1;
-    else return strcmp(((RRDVAR *)a)->name, ((RRDVAR *)b)->name);
+inline STRING *rrdvar_name_to_string(const char *name) {
+    char *variable = strdupz(name);
+    rrdvar_fix_name(variable);
+    STRING *name_string = string_strdupz(variable);
+    freez(variable);
+    return name_string;
 }
 
-static inline RRDVAR *rrdvar_index_add(avl_tree_lock *tree, RRDVAR *rv) {
-    RRDVAR *ret = (RRDVAR *)avl_insert_lock(tree, (avl_t *)(rv));
-    if(ret != rv)
-        debug(D_VARIABLES, "Request to insert RRDVAR '%s' into index failed. Already exists.", rv->name);
+struct rrdvar_constructor {
+    STRING *name;
+    void *value;
+    RRDVAR_FLAGS options:16;
+    RRDVAR_TYPE type:8;
 
-    return ret;
-}
+    enum {
+        RRDVAR_REACT_NONE    = 0,
+        RRDVAR_REACT_NEW     = (1 << 0),
+    } react_action;
+};
+
+static void rrdvar_insert_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdvar, void *constructor_data) {
+    RRDVAR *rv = rrdvar;
+    struct rrdvar_constructor *ctr = constructor_data;
 
-static inline RRDVAR *rrdvar_index_del(avl_tree_lock *tree, RRDVAR *rv) {
-    RRDVAR *ret = (RRDVAR *)avl_remove_lock(tree, (avl_t *)(rv));
-    if(!ret)
-        error("Request to remove RRDVAR '%s' from index failed. Not Found.", rv->name);
+    ctr->options &= ~RRDVAR_OPTIONS_REMOVED_ON_NEW_OBJECTS;
 
-    return ret;
+    rv->name = string_dup(ctr->name);
+    rv->type = ctr->type;
+    rv->flags = ctr->options;
+
+    if(!ctr->value) {
+        NETDATA_DOUBLE *v = mallocz(sizeof(NETDATA_DOUBLE));
+        *v = NAN;
+        rv->value = v;
+        rv->flags |= RRDVAR_FLAG_ALLOCATED;
+    }
+    else
+        rv->value = ctr->value;
+
+    ctr->react_action = RRDVAR_REACT_NEW;
 }
 
-static inline RRDVAR *rrdvar_index_find(avl_tree_lock *tree, const char *name, uint32_t hash) {
-    RRDVAR tmp;
-    tmp.name = (char *)name;
-    tmp.hash = (hash)?hash:simple_hash(tmp.name);
+static void rrdvar_delete_callback(const DICTIONARY_ITEM *item __maybe_unused, void *rrdvar, void *nothing __maybe_unused) {
+    RRDVAR *rv = rrdvar;
 
-    return (RRDVAR *)avl_search_lock(tree, (avl_t *)&tmp);
+    if(rv->flags & RRDVAR_FLAG_ALLOCATED)
+        freez(rv->value);
+
+    string_freez(rv->name);
+    rv->name = NULL;
 }
 
-inline void rrdvar_free(RRDHOST *host, avl_tree_lock *tree, RRDVAR *rv) {
-    (void)host;
+DICTIONARY *rrdvariables_create(void) {
+    DICTIONARY *dict = dictionary_create(DICT_OPTION_DONT_OVERWRITE_VALUE);
 
-    if(!rv) return;
+    dictionary_register_insert_callback(dict, rrdvar_insert_callback, NULL);
+    dictionary_register_delete_callback(dict, rrdvar_delete_callback, NULL);
 
-    if(tree) {
-        debug(D_VARIABLES, "Deleting variable '%s'", rv->name);
-        if(unlikely(!rrdvar_index_del(tree, rv)))
-            error("RRDVAR: Attempted to delete variable '%s' from host '%s', but it is not found.", rv->name, host->hostname);
-    }
+    return dict;
+}
 
-    if(rv->options & RRDVAR_OPTION_ALLOCATED)
-        freez(rv->value);
+void rrdvariables_destroy(DICTIONARY *dict) {
+    dictionary_destroy(dict);
+}
 
-    freez(rv->name);
-    freez(rv);
+static inline const RRDVAR_ACQUIRED *rrdvar_get_and_acquire(DICTIONARY *dict, STRING *name) {
+    return (const RRDVAR_ACQUIRED *)dictionary_get_and_acquire_item_advanced(dict, string2str(name), (ssize_t)string_strlen(name) + 1);
 }
 
-inline RRDVAR *rrdvar_create_and_index(const char *scope __maybe_unused, avl_tree_lock *tree, const char *name,
-                                       RRDVAR_TYPE type, RRDVAR_OPTIONS options, void *value) {
-    char *variable = strdupz(name);
-    rrdvar_fix_name(variable);
-    uint32_t hash = simple_hash(variable);
-
-    RRDVAR *rv = rrdvar_index_find(tree, variable, hash);
-    if(unlikely(!rv)) {
-        debug(D_VARIABLES, "Variable '%s' not found in scope '%s'. Creating a new one.", variable, scope);
-
-        rv = callocz(1, sizeof(RRDVAR));
-        rv->name = variable;
-        rv->hash = hash;
-        rv->type = type;
-        rv->options = options;
-        rv->value = value;
-        rv->last_updated = now_realtime_sec();
-
-        RRDVAR *ret = rrdvar_index_add(tree, rv);
-        if(unlikely(ret != rv)) {
-            debug(D_VARIABLES, "Variable '%s' in scope '%s' already exists", variable, scope);
-            freez(rv);
-            freez(variable);
-            rv = NULL;
-        }
-        else
-            debug(D_VARIABLES, "Variable '%s' created in scope '%s'", variable, scope);
-    }
-    else {
-        debug(D_VARIABLES, "Variable '%s' is already found in scope '%s'.", variable, scope);
+inline void rrdvar_release_and_del(DICTIONARY *dict, const RRDVAR_ACQUIRED *rva) {
+    if(unlikely(!dict || !rva)) return;
 
-        // already exists
-        freez(variable);
+    RRDVAR *rv = dictionary_acquired_item_value((const DICTIONARY_ITEM *)rva);
 
-        // this is important
-        // it must return NULL - not the existing variable - or double-free will happen
-        rv = NULL;
-    }
+    dictionary_del_advanced(dict, string2str(rv->name), (ssize_t)string_strlen(rv->name) + 1);
 
-    return rv;
+    dictionary_acquired_item_release(dict, (const DICTIONARY_ITEM *)rva);
 }
 
-void rrdvar_free_remaining_variables(RRDHOST *host, avl_tree_lock *tree_lock) {
-    // This is not bullet proof - avl should support some means to destroy it
-    // with a callback for each item already in the index
+inline const RRDVAR_ACQUIRED *rrdvar_add_and_acquire(const char *scope __maybe_unused, DICTIONARY *dict, STRING *name, RRDVAR_TYPE type, RRDVAR_FLAGS options, void *value) {
+    if(unlikely(!dict || !name)) return NULL;
 
-    RRDVAR *rv, *last = NULL;
-    while((rv = (RRDVAR *)tree_lock->avl_tree.root)) {
-        if(unlikely(rv == last)) {
-            error("RRDVAR: INTERNAL ERROR: Cannot cleanup tree of RRDVARs");
-            break;
-        }
-        last = rv;
-        rrdvar_free(host, tree_lock, rv);
-    }
+    struct rrdvar_constructor tmp = {
+        .name = name,
+        .value = value,
+        .type = type,
+        .options = options,
+        .react_action = RRDVAR_REACT_NONE,
+    };
+    return (const RRDVAR_ACQUIRED *)dictionary_set_and_acquire_item_advanced(dict, string2str(name), (ssize_t)string_strlen(name) + 1, NULL, sizeof(RRDVAR), &tmp);
+}
+
+void rrdvar_delete_all(DICTIONARY *dict) {
+    dictionary_flush(dict);
 }
 
+
 // ----------------------------------------------------------------------------
 // CUSTOM HOST VARIABLES
 
-inline int rrdvar_callback_for_all_host_variables(RRDHOST *host, int (*callback)(void * /*rrdvar*/, void * /*data*/), void *data) {
-    return avl_traverse_lock(&host->rrdvar_root_index, callback, data);
+inline int rrdvar_walkthrough_read(DICTIONARY *dict, int (*callback)(const DICTIONARY_ITEM *item, void *rrdvar, void *data), void *data) {
+    if(unlikely(!dict)) return 0;  // when health is not enabled
+    return dictionary_walkthrough_read(dict, callback, data);
 }
 
-static RRDVAR *rrdvar_custom_variable_create(const char *scope, avl_tree_lock *tree_lock, const char *name) {
-    NETDATA_DOUBLE *v = callocz(1, sizeof(NETDATA_DOUBLE));
-    *v = NAN;
-
-    RRDVAR *rv = rrdvar_create_and_index(scope, tree_lock, name, RRDVAR_TYPE_CALCULATED, RRDVAR_OPTION_CUSTOM_HOST_VAR|RRDVAR_OPTION_ALLOCATED, v);
-    if(unlikely(!rv)) {
-        freez(v);
-        debug(D_VARIABLES, "Requested variable '%s' already exists - possibly 2 plugins are updating it at the same time.", name);
+const RRDVAR_ACQUIRED *rrdvar_custom_host_variable_add_and_acquire(RRDHOST *host, const char *name) {
+    DICTIONARY *dict = host->rrdvars;
+    if(unlikely(!dict)) return NULL; // when health is not enabled
 
-        char *variable = strdupz(name);
-        rrdvar_fix_name(variable);
-        uint32_t hash = simple_hash(variable);
+    STRING *name_string = rrdvar_name_to_string(name);
 
-        // find the existing one to return it
-        rv = rrdvar_index_find(tree_lock, variable, hash);
+    const RRDVAR_ACQUIRED *rva = rrdvar_add_and_acquire("host", dict, name_string, RRDVAR_TYPE_CALCULATED, RRDVAR_FLAG_CUSTOM_HOST_VAR, NULL);
 
-        freez(variable);
-    }
-
-    return rv;
+    string_freez(name_string);
+    return rva;
 }
 
-RRDVAR *rrdvar_custom_host_variable_create(RRDHOST *host, const char *name) {
-    return rrdvar_custom_variable_create("host", &host->rrdvar_root_index, name);
-}
+void rrdvar_custom_host_variable_set(RRDHOST *host, const RRDVAR_ACQUIRED *rva, NETDATA_DOUBLE value) {
+    if(unlikely(!host->rrdvars || !rva)) return; // when health is not enabled
 
-void rrdvar_custom_host_variable_set(RRDHOST *host, RRDVAR *rv, NETDATA_DOUBLE value) {
-    if(rv->type != RRDVAR_TYPE_CALCULATED || !(rv->options & RRDVAR_OPTION_CUSTOM_HOST_VAR) || !(rv->options & RRDVAR_OPTION_ALLOCATED))
-        error("requested to set variable '%s' to value " NETDATA_DOUBLE_FORMAT " but the variable is not a custom one.", rv->name, value);
+    if(rrdvar_type(rva) != RRDVAR_TYPE_CALCULATED || !(rrdvar_flags(rva) & (RRDVAR_FLAG_CUSTOM_HOST_VAR | RRDVAR_FLAG_ALLOCATED)))
+        error("requested to set variable '%s' to value " NETDATA_DOUBLE_FORMAT " but the variable is not a custom one.", rrdvar_name(rva), value);
     else {
+        RRDVAR *rv = dictionary_acquired_item_value((const DICTIONARY_ITEM *)rva);
         NETDATA_DOUBLE *v = rv->value;
         if(*v != value) {
             *v = value;
 
-            rv->last_updated = now_realtime_sec();
-
             // if the host is streaming, send this variable upstream immediately
-            rrdpush_sender_send_this_host_variable_now(host, rv);
+            rrdpush_sender_send_this_host_variable_now(host, rva);
         }
     }
 }
 
-int foreach_host_variable_callback(RRDHOST *host, int (*callback)(RRDVAR * /*rv*/, void * /*data*/), void *data) {
-    return avl_traverse_lock(&host->rrdvar_root_index, (int (*)(void *, void *))callback, data);
+void rrdvar_release(DICTIONARY *dict, const RRDVAR_ACQUIRED *rva) {
+    if(unlikely(!dict || !rva)) return;  // when health is not enabled
+    dictionary_acquired_item_release(dict, (const DICTIONARY_ITEM *)rva);
 }
 
 // ----------------------------------------------------------------------------
 // RRDVAR lookup
 
-NETDATA_DOUBLE rrdvar2number(RRDVAR *rv) {
+NETDATA_DOUBLE rrdvar2number(const RRDVAR_ACQUIRED *rva) {
+    if(unlikely(!rva)) return NAN;
+
+    RRDVAR *rv = dictionary_acquired_item_value((const DICTIONARY_ITEM *)rva);
+
     switch(rv->type) {
         case RRDVAR_TYPE_CALCULATED: {
             NETDATA_DOUBLE *n = (NETDATA_DOUBLE *)rv->value;
@@ -190,17 +186,17 @@ NETDATA_DOUBLE rrdvar2number(RRDVAR *rv) {
 
         case RRDVAR_TYPE_TIME_T: {
             time_t *n = (time_t *)rv->value;
-            return *n;
+            return (NETDATA_DOUBLE)*n;
         }
 
         case RRDVAR_TYPE_COLLECTED: {
             collected_number *n = (collected_number *)rv->value;
-            return *n;
+            return (NETDATA_DOUBLE)*n;
         }
 
         case RRDVAR_TYPE_TOTAL: {
             total_number *n = (total_number *)rv->value;
-            return *n;
+            return (NETDATA_DOUBLE)*n;
         }
 
         case RRDVAR_TYPE_INT: {
@@ -214,28 +210,31 @@ NETDATA_DOUBLE rrdvar2number(RRDVAR *rv) {
     }
 }
 
-int health_variable_lookup(const char *variable, uint32_t hash, RRDCALC *rc, NETDATA_DOUBLE *result) {
+int health_variable_lookup(STRING *variable, RRDCALC *rc, NETDATA_DOUBLE *result) {
     RRDSET *st = rc->rrdset;
     if(!st) return 0;
 
     RRDHOST *host = st->rrdhost;
-    RRDVAR *rv;
+    const RRDVAR_ACQUIRED *rva;
 
-    rv = rrdvar_index_find(&st->rrdvar_root_index, variable, hash);
-    if(rv) {
-        *result = rrdvar2number(rv);
+    rva = rrdvar_get_and_acquire(st->rrdvars, variable);
+    if(rva) {
+        *result = rrdvar2number(rva);
+        dictionary_acquired_item_release(st->rrdvars, (const DICTIONARY_ITEM *)rva);
         return 1;
     }
 
-    rv = rrdvar_index_find(&st->rrdfamily->rrdvar_root_index, variable, hash);
-    if(rv) {
-        *result = rrdvar2number(rv);
+    rva = rrdvar_get_and_acquire(rrdfamily_rrdvars_dict(st->rrdfamily), variable);
+    if(rva) {
+        *result = rrdvar2number(rva);
+        dictionary_acquired_item_release(rrdfamily_rrdvars_dict(st->rrdfamily), (const DICTIONARY_ITEM *)rva);
         return 1;
     }
 
-    rv = rrdvar_index_find(&host->rrdvar_root_index, variable, hash);
-    if(rv) {
-        *result = rrdvar2number(rv);
+    rva = rrdvar_get_and_acquire(host->rrdvars, variable);
+    if(rva) {
+        *result = rrdvar2number(rva);
+        dictionary_acquired_item_release(host->rrdvars, (const DICTIONARY_ITEM *)rva);
         return 1;
     }
 
@@ -248,19 +247,19 @@ int health_variable_lookup(const char *variable, uint32_t hash, RRDCALC *rc, NET
 struct variable2json_helper {
     BUFFER *buf;
     size_t counter;
-    RRDVAR_OPTIONS options;
+    RRDVAR_FLAGS options;
 };
 
-static int single_variable2json(void *entry, void *data) {
-    struct variable2json_helper *helper = (struct variable2json_helper *)data;
-    RRDVAR *rv = (RRDVAR *)entry;
-    NETDATA_DOUBLE value = rrdvar2number(rv);
+static int single_variable2json_callback(const DICTIONARY_ITEM *item __maybe_unused, void *entry __maybe_unused, void *helper_data) {
+    struct variable2json_helper *helper = (struct variable2json_helper *)helper_data;
+    const RRDVAR_ACQUIRED *rva = (const RRDVAR_ACQUIRED *)item;
+    NETDATA_DOUBLE value = rrdvar2number(rva);
 
-    if (helper->options == RRDVAR_OPTION_DEFAULT || rv->options & helper->options) {
+    if (helper->options == RRDVAR_FLAG_NONE || rrdvar_flags(rva) & helper->options) {
         if(unlikely(isnan(value) || isinf(value)))
-            buffer_sprintf(helper->buf, "%s\n\t\t\"%s\": null", helper->counter?",":"", rv->name);
+            buffer_sprintf(helper->buf, "%s\n\t\t\"%s\": null", helper->counter?",":"", rrdvar_name(rva));
         else
-            buffer_sprintf(helper->buf, "%s\n\t\t\"%s\": %0.5" NETDATA_DOUBLE_MODIFIER, helper->counter?",":"", rv->name, (NETDATA_DOUBLE)value);
+            buffer_sprintf(helper->buf, "%s\n\t\t\"%s\": %0.5" NETDATA_DOUBLE_MODIFIER, helper->counter?",":"", rrdvar_name(rva), (NETDATA_DOUBLE)value);
 
         helper->counter++;
     }
@@ -272,11 +271,10 @@ void health_api_v1_chart_custom_variables2json(RRDSET *st, BUFFER *buf) {
     struct variable2json_helper helper = {
             .buf = buf,
             .counter = 0,
-            .options = RRDVAR_OPTION_CUSTOM_CHART_VAR
-    };
+            .options = RRDVAR_FLAG_CUSTOM_CHART_VAR};
 
     buffer_sprintf(buf, "{");
-    avl_traverse_lock(&st->rrdvar_root_index, single_variable2json, (void *)&helper);
+    rrdvar_walkthrough_read(st->rrdvars, single_variable2json_callback, &helper);
     buffer_strcat(buf, "\n\t\t\t}");
 }
 
@@ -286,20 +284,34 @@ void health_api_v1_chart_variables2json(RRDSET *st, BUFFER *buf) {
     struct variable2json_helper helper = {
             .buf = buf,
             .counter = 0,
-            .options = RRDVAR_OPTION_DEFAULT
-    };
+            .options = RRDVAR_FLAG_NONE};
 
-    buffer_sprintf(buf, "{\n\t\"chart\": \"%s\",\n\t\"chart_name\": \"%s\",\n\t\"chart_context\": \"%s\",\n\t\"chart_variables\": {", st->id, st->name, st->context);
-    avl_traverse_lock(&st->rrdvar_root_index, single_variable2json, (void *)&helper);
+    buffer_sprintf(buf, "{\n\t\"chart\": \"%s\",\n\t\"chart_name\": \"%s\",\n\t\"chart_context\": \"%s\",\n\t\"chart_variables\": {", rrdset_id(st), rrdset_name(st), rrdset_context(st));
+    rrdvar_walkthrough_read(st->rrdvars, single_variable2json_callback, &helper);
 
-    buffer_sprintf(buf, "\n\t},\n\t\"family\": \"%s\",\n\t\"family_variables\": {", st->family);
+    buffer_sprintf(buf, "\n\t},\n\t\"family\": \"%s\",\n\t\"family_variables\": {", rrdset_family(st));
     helper.counter = 0;
-    avl_traverse_lock(&st->rrdfamily->rrdvar_root_index, single_variable2json, (void *)&helper);
+    rrdvar_walkthrough_read(rrdfamily_rrdvars_dict(st->rrdfamily), single_variable2json_callback, &helper);
 
-    buffer_sprintf(buf, "\n\t},\n\t\"host\": \"%s\",\n\t\"host_variables\": {", host->hostname);
+    buffer_sprintf(buf, "\n\t},\n\t\"host\": \"%s\",\n\t\"host_variables\": {", rrdhost_hostname(host));
     helper.counter = 0;
-    avl_traverse_lock(&host->rrdvar_root_index, single_variable2json, (void *)&helper);
+    rrdvar_walkthrough_read(host->rrdvars, single_variable2json_callback, &helper);
 
     buffer_strcat(buf, "\n\t}\n}\n");
 }
 
+// ----------------------------------------------------------------------------
+// RRDVAR private members examination
+
+const char *rrdvar_name(const RRDVAR_ACQUIRED *rva) {
+    return dictionary_acquired_item_name((const DICTIONARY_ITEM *)rva);
+}
+
+RRDVAR_FLAGS rrdvar_flags(const RRDVAR_ACQUIRED *rva) {
+    RRDVAR *rv = dictionary_acquired_item_value((const DICTIONARY_ITEM *)rva);
+    return rv->flags;
+}
+RRDVAR_TYPE rrdvar_type(const RRDVAR_ACQUIRED *rva) {
+    RRDVAR *rv = dictionary_acquired_item_value((const DICTIONARY_ITEM *)rva);
+    return rv->type;
+}