1 files changed, 285 insertions, 0 deletions

diff --git a/database/rrdvar.c b/database/rrdvar.c
new file mode 100644
index 00000000..951a38ca
--- /dev/null
+++ b/database/rrdvar.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#define NETDATA_HEALTH_INTERNALS
+#include "rrd.h"
+
+// ----------------------------------------------------------------------------
+// RRDVAR management
+
+inline int rrdvar_fix_name(char *variable) {
+    int fixed = 0;
+    while(*variable) {
+        if (!isalnum(*variable) && *variable != '.' && *variable != '_') {
+            *variable++ = '_';
+            fixed++;
+        }
+        else
+            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);
+}
+
+static inline RRDVAR *rrdvar_index_add(avl_tree_lock *tree, RRDVAR *rv) {
+    RRDVAR *ret = (RRDVAR *)avl_insert_lock(tree, (avl *)(rv));
+    if(ret != rv)
+        debug(D_VARIABLES, "Request to insert RRDVAR '%s' into index failed. Already exists.", rv->name);
+
+    return ret;
+}
+
+static inline RRDVAR *rrdvar_index_del(avl_tree_lock *tree, RRDVAR *rv) {
+    RRDVAR *ret = (RRDVAR *)avl_remove_lock(tree, (avl *)(rv));
+    if(!ret)
+        error("Request to remove RRDVAR '%s' from index failed. Not Found.", rv->name);
+
+    return ret;
+}
+
+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);
+
+    return (RRDVAR *)avl_search_lock(tree, (avl *)&tmp);
+}
+
+inline void rrdvar_free(RRDHOST *host, avl_tree_lock *tree, RRDVAR *rv) {
+    (void)host;
+
+    if(!rv) return;
+
+    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);
+    }
+
+    if(rv->options & RRDVAR_OPTION_ALLOCATED)
+        freez(rv->value);
+
+    freez(rv->name);
+    freez(rv);
+}
+
+inline RRDVAR *rrdvar_create_and_index(const char *scope, 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);
+
+        // already exists
+        freez(variable);
+
+        // this is important
+        // it must return NULL - not the existing variable - or double-free will happen
+        rv = NULL;
+    }
+
+    return rv;
+}
+
+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
+
+    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);
+    }
+}
+
+// ----------------------------------------------------------------------------
+// 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);
+}
+
+static RRDVAR *rrdvar_custom_variable_create(const char *scope, avl_tree_lock *tree_lock, const char *name) {
+    calculated_number *v = callocz(1, sizeof(calculated_number));
+    *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)) {
+        free(v);
+        debug(D_VARIABLES, "Requested variable '%s' already exists - possibly 2 plugins are updating it at the same time.", name);
+
+        char *variable = strdupz(name);
+        rrdvar_fix_name(variable);
+        uint32_t hash = simple_hash(variable);
+
+        // find the existing one to return it
+        rv = rrdvar_index_find(tree_lock, variable, hash);
+
+        freez(variable);
+    }
+
+    return rv;
+}
+
+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, RRDVAR *rv, calculated_number 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 " CALCULATED_NUMBER_FORMAT " but the variable is not a custom one.", rv->name, value);
+    else {
+        calculated_number *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);
+        }
+    }
+}
+
+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);
+}
+
+// ----------------------------------------------------------------------------
+// RRDVAR lookup
+
+calculated_number rrdvar2number(RRDVAR *rv) {
+    switch(rv->type) {
+        case RRDVAR_TYPE_CALCULATED: {
+            calculated_number *n = (calculated_number *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_TIME_T: {
+            time_t *n = (time_t *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_COLLECTED: {
+            collected_number *n = (collected_number *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_TOTAL: {
+            total_number *n = (total_number *)rv->value;
+            return *n;
+        }
+
+        case RRDVAR_TYPE_INT: {
+            int *n = (int *)rv->value;
+            return *n;
+        }
+
+        default:
+            error("I don't know how to convert RRDVAR type %u to calculated_number", rv->type);
+            return NAN;
+    }
+}
+
+int health_variable_lookup(const char *variable, uint32_t hash, RRDCALC *rc, calculated_number *result) {
+    RRDSET *st = rc->rrdset;
+    if(!st) return 0;
+
+    RRDHOST *host = st->rrdhost;
+    RRDVAR *rv;
+
+    rv = rrdvar_index_find(&st->rrdvar_root_index, variable, hash);
+    if(rv) {
+        *result = rrdvar2number(rv);
+        return 1;
+    }
+
+    rv = rrdvar_index_find(&st->rrdfamily->rrdvar_root_index, variable, hash);
+    if(rv) {
+        *result = rrdvar2number(rv);
+        return 1;
+    }
+
+    rv = rrdvar_index_find(&host->rrdvar_root_index, variable, hash);
+    if(rv) {
+        *result = rrdvar2number(rv);
+        return 1;
+    }
+
+    return 0;
+}
+
+// ----------------------------------------------------------------------------
+// RRDVAR to JSON
+
+struct variable2json_helper {
+    BUFFER *buf;
+    size_t counter;
+};
+
+static int single_variable2json(void *entry, void *data) {
+    struct variable2json_helper *helper = (struct variable2json_helper *)data;
+    RRDVAR *rv = (RRDVAR *)entry;
+    calculated_number value = rrdvar2number(rv);
+
+    if(unlikely(isnan(value) || isinf(value)))
+        buffer_sprintf(helper->buf, "%s\n\t\t\"%s\": null", helper->counter?",":"", rv->name);
+    else
+        buffer_sprintf(helper->buf, "%s\n\t\t\"%s\": %0.5" LONG_DOUBLE_MODIFIER, helper->counter?",":"", rv->name, (LONG_DOUBLE)value);
+
+    helper->counter++;
+
+    return 0;
+}
+
+void health_api_v1_chart_variables2json(RRDSET *st, BUFFER *buf) {
+    RRDHOST *host = st->rrdhost;
+
+    struct variable2json_helper helper = {
+            .buf = buf,
+            .counter = 0
+    };
+
+    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},\n\t\"family\": \"%s\",\n\t\"family_variables\": {", st->family);
+    helper.counter = 0;
+    avl_traverse_lock(&st->rrdfamily->rrdvar_root_index, single_variable2json, (void *)&helper);
+    buffer_sprintf(buf, "\n\t},\n\t\"host\": \"%s\",\n\t\"host_variables\": {", host->hostname);
+    helper.counter = 0;
+    avl_traverse_lock(&host->rrdvar_root_index, single_variable2json, (void *)&helper);
+    buffer_strcat(buf, "\n\t}\n}\n");
+}
+