Rename struct avl to avl_element and the typedef to avl_t (#10735)

Before:

```
struct foobar {
    avl avl;
    ...
}
```

After:

```
struct foobar {
    avl_t avl;
    ...
};
```

Which makes figuring out the type from field name easier.

6 files changed, 52 insertions, 52 deletions

diff --git a/libnetdata/avl/avl.c b/libnetdata/avl/avl.c
index 5219851896..b05b97acb5 100644
--- a/libnetdata/avl/avl.c
+++ b/libnetdata/avl/avl.c
@@ -17,8 +17,8 @@
 
 /* Search |tree| for an item matching |item|, and return it if found.
      Otherwise return |NULL|. */
-avl *avl_search(avl_tree_type *tree, avl *item) {
-    avl *p;
+avl_t *avl_search(avl_tree_type *tree, avl_t *item) {
+    avl_t *p;
 
     // assert (tree != NULL && item != NULL);
 
@@ -40,11 +40,11 @@ avl *avl_search(avl_tree_type *tree, avl *item) {
      If a duplicate item is found in the tree,
      returns a pointer to the duplicate without inserting |item|.
  */
-avl *avl_insert(avl_tree_type *tree, avl *item) {
-    avl *y, *z; /* Top node to update balance factor, and parent. */
-    avl *p, *q; /* Iterator, and parent. */
-    avl *n;     /* Newly inserted node. */
-    avl *w;     /* New root of rebalanced subtree. */
+avl_t *avl_insert(avl_tree_type *tree, avl_t *item) {
+    avl_t *y, *z; /* Top node to update balance factor, and parent. */
+    avl_t *p, *q; /* Iterator, and parent. */
+    avl_t *n;     /* Newly inserted node. */
+    avl_t *w;     /* New root of rebalanced subtree. */
     unsigned char dir; /* Direction to descend. */
 
     unsigned char da[AVL_MAX_HEIGHT]; /* Cached comparison results. */
@@ -52,7 +52,7 @@ avl *avl_insert(avl_tree_type *tree, avl *item) {
 
     // assert(tree != NULL && item != NULL);
 
-    z = (avl *) &tree->root;
+    z = (avl_t *) &tree->root;
     y = tree->root;
     dir = 0;
     for (q = z, p = y; p != NULL; q = p, p = p->avl_link[dir]) {
@@ -79,7 +79,7 @@ avl *avl_insert(avl_tree_type *tree, avl *item) {
             p->avl_balance++;
 
     if (y->avl_balance == -2) {
-        avl *x = y->avl_link[0];
+        avl_t *x = y->avl_link[0];
         if (x->avl_balance == -1) {
             w = x;
             y->avl_link[0] = x->avl_link[1];
@@ -103,7 +103,7 @@ avl *avl_insert(avl_tree_type *tree, avl *item) {
         }
     }
     else if (y->avl_balance == +2) {
-        avl *x = y->avl_link[1];
+        avl_t *x = y->avl_link[1];
         if (x->avl_balance == +1) {
             w = x;
             y->avl_link[1] = x->avl_link[0];
@@ -136,19 +136,19 @@ avl *avl_insert(avl_tree_type *tree, avl *item) {
 
 /* Deletes from |tree| and returns an item matching |item|.
      Returns a null pointer if no matching item found. */
-avl *avl_remove(avl_tree_type *tree, avl *item) {
+avl_t *avl_remove(avl_tree_type *tree, avl_t *item) {
     /* Stack of nodes. */
-    avl *pa[AVL_MAX_HEIGHT]; /* Nodes. */
+    avl_t *pa[AVL_MAX_HEIGHT]; /* Nodes. */
     unsigned char da[AVL_MAX_HEIGHT];    /* |avl_link[]| indexes. */
     int k;                               /* Stack pointer. */
 
-    avl *p;   /* Traverses tree to find node to delete. */
+    avl_t *p;   /* Traverses tree to find node to delete. */
     int cmp;              /* Result of comparison between |item| and |p|. */
 
     // assert (tree != NULL && item != NULL);
 
     k = 0;
-    p = (avl *) &tree->root;
+    p = (avl_t *) &tree->root;
     for(cmp = -1; cmp != 0; cmp = tree->compar(item, p)) {
         unsigned char dir = (unsigned char)(cmp > 0);
 
@@ -164,7 +164,7 @@ avl *avl_remove(avl_tree_type *tree, avl *item) {
     if (p->avl_link[1] == NULL)
         pa[k - 1]->avl_link[da[k - 1]] = p->avl_link[0];
     else {
-        avl *r = p->avl_link[1];
+        avl_t *r = p->avl_link[1];
         if (r->avl_link[0] == NULL) {
             r->avl_link[0] = p->avl_link[0];
             r->avl_balance = p->avl_balance;
@@ -173,7 +173,7 @@ avl *avl_remove(avl_tree_type *tree, avl *item) {
             pa[k++] = r;
         }
         else {
-            avl *s;
+            avl_t *s;
             int j = k++;
 
             for (;;) {
@@ -198,15 +198,15 @@ avl *avl_remove(avl_tree_type *tree, avl *item) {
 
     // assert (k > 0);
     while (--k > 0) {
-        avl *y = pa[k];
+        avl_t *y = pa[k];
 
         if (da[k] == 0) {
             y->avl_balance++;
             if (y->avl_balance == +1) break;
             else if (y->avl_balance == +2) {
-                avl *x = y->avl_link[1];
+                avl_t *x = y->avl_link[1];
                 if (x->avl_balance == -1) {
-                    avl *w;
+                    avl_t *w;
                     // assert (x->avl_balance == -1);
                     w = x->avl_link[0];
                     x->avl_link[0] = w->avl_link[1];
@@ -240,9 +240,9 @@ avl *avl_remove(avl_tree_type *tree, avl *item) {
             y->avl_balance--;
             if (y->avl_balance == -1) break;
             else if (y->avl_balance == -2) {
-                avl *x = y->avl_link[0];
+                avl_t *x = y->avl_link[0];
                 if (x->avl_balance == +1) {
-                    avl *w;
+                    avl_t *w;
                     // assert (x->avl_balance == +1);
                     w = x->avl_link[1];
                     x->avl_link[1] = w->avl_link[0];
@@ -284,7 +284,7 @@ avl *avl_remove(avl_tree_type *tree, avl *item) {
 // ---------------------------
 // traversing
 
-int avl_walker(avl *node, int (*callback)(void * /*entry*/, void * /*data*/), void *data) {
+int avl_walker(avl_t *node, int (*callback)(void * /*entry*/, void * /*data*/), void *data) {
     int total = 0, ret = 0;
 
     if(node->avl_link[0]) {
@@ -383,23 +383,23 @@ void avl_destroy_lock(avl_tree_lock *tree) {
 #endif /* AVL_WITHOUT_PTHREADS */
 }
 
-avl *avl_search_lock(avl_tree_lock *tree, avl *item) {
+avl_t *avl_search_lock(avl_tree_lock *tree, avl_t *item) {
     avl_read_lock(tree);
-    avl *ret = avl_search(&tree->avl_tree, item);
+    avl_t *ret = avl_search(&tree->avl_tree, item);
     avl_unlock(tree);
     return ret;
 }
 
-avl * avl_remove_lock(avl_tree_lock *tree, avl *item) {
+avl_t * avl_remove_lock(avl_tree_lock *tree, avl_t *item) {
     avl_write_lock(tree);
-    avl *ret = avl_remove(&tree->avl_tree, item);
+    avl_t *ret = avl_remove(&tree->avl_tree, item);
     avl_unlock(tree);
     return ret;
 }
 
-avl *avl_insert_lock(avl_tree_lock *tree, avl *item) {
+avl_t *avl_insert_lock(avl_tree_lock *tree, avl_t *item) {
     avl_write_lock(tree);
-    avl * ret = avl_insert(&tree->avl_tree, item);
+    avl_t * ret = avl_insert(&tree->avl_tree, item);
     avl_unlock(tree);
     return ret;
 }
diff --git a/libnetdata/avl/avl.h b/libnetdata/avl/avl.h
index 32e3f27a8b..eba967fd0e 100644
--- a/libnetdata/avl/avl.h
+++ b/libnetdata/avl/avl.h
@@ -28,14 +28,14 @@
 /* Data structures */
 
 /* One element of the AVL tree */
-typedef struct avl {
-    struct avl *avl_link[2];  /* Subtrees. */
+typedef struct avl_element {
+    struct avl_element *avl_link[2];  /* Subtrees. */
     signed char avl_balance;       /* Balance factor. */
-} avl;
+} avl_t;
 
 /* An AVL tree */
 typedef struct avl_tree_type {
-    avl *root;
+    avl_t *root;
     int (*compar)(void *a, void *b);
 } avl_tree_type;
 
@@ -59,23 +59,23 @@ typedef struct avl_tree_lock {
  * a is linked directly to the tree, so it has to
  * be properly allocated by the caller.
  */
-avl *avl_insert_lock(avl_tree_lock *tree, avl *item) NEVERNULL WARNUNUSED;
-avl *avl_insert(avl_tree_type *tree, avl *item) NEVERNULL WARNUNUSED;
+avl_t *avl_insert_lock(avl_tree_lock *tree, avl_t *item) NEVERNULL WARNUNUSED;
+avl_t *avl_insert(avl_tree_type *tree, avl_t *item) NEVERNULL WARNUNUSED;
 
 /* Remove an element a from the AVL tree t
  * returns a pointer to the removed element
  * or NULL if an element equal to a is not found
  * (equal as returned by t->compar())
  */
-avl *avl_remove_lock(avl_tree_lock *tree, avl *item) WARNUNUSED;
-avl *avl_remove(avl_tree_type *tree, avl *item) WARNUNUSED;
+avl_t *avl_remove_lock(avl_tree_lock *tree, avl_t *item) WARNUNUSED;
+avl_t *avl_remove(avl_tree_type *tree, avl_t *item) WARNUNUSED;
 
 /* Find the element into the tree that equal to a
  * (equal as returned by t->compar())
  * returns NULL is no element is equal to a
  */
-avl *avl_search_lock(avl_tree_lock *tree, avl *item);
-avl *avl_search(avl_tree_type *tree, avl *item);
+avl_t *avl_search_lock(avl_tree_lock *tree, avl_t *item);
+avl_t *avl_search(avl_tree_type *tree, avl_t *item);
 
 /* Initialize the avl_tree_lock
  */
diff --git a/libnetdata/config/appconfig.c b/libnetdata/config/appconfig.c
index d9dcde71a5..f570f32d7c 100644
--- a/libnetdata/config/appconfig.c
+++ b/libnetdata/config/appconfig.c
@@ -123,15 +123,15 @@ static int appconfig_option_compare(void *a, void *b) {
     else return strcmp(((struct config_option *)a)->name, ((struct config_option *)b)->name);
 }
 
-#define appconfig_option_index_add(co, cv) (struct config_option *)avl_insert_lock(&((co)->values_index), (avl *)(cv))
-#define appconfig_option_index_del(co, cv) (struct config_option *)avl_remove_lock(&((co)->values_index), (avl *)(cv))
+#define appconfig_option_index_add(co, cv) (struct config_option *)avl_insert_lock(&((co)->values_index), (avl_t *)(cv))
+#define appconfig_option_index_del(co, cv) (struct config_option *)avl_remove_lock(&((co)->values_index), (avl_t *)(cv))
 
 static struct config_option *appconfig_option_index_find(struct section *co, const char *name, uint32_t hash) {
     struct config_option tmp;
     tmp.hash = (hash)?hash:simple_hash(name);
     tmp.name = (char *)name;
 
-    return (struct config_option *)avl_search_lock(&(co->values_index), (avl *) &tmp);
+    return (struct config_option *)avl_search_lock(&(co->values_index), (avl_t *) &tmp);
 }
 
 
@@ -144,15 +144,15 @@ int appconfig_section_compare(void *a, void *b) {
     else return strcmp(((struct section *)a)->name, ((struct section *)b)->name);
 }
 
-#define appconfig_index_add(root, cfg) (struct section *)avl_insert_lock(&(root)->index, (avl *)(cfg))
-#define appconfig_index_del(root, cfg) (struct section *)avl_remove_lock(&(root)->index, (avl *)(cfg))
+#define appconfig_index_add(root, cfg) (struct section *)avl_insert_lock(&(root)->index, (avl_t *)(cfg))
+#define appconfig_index_del(root, cfg) (struct section *)avl_remove_lock(&(root)->index, (avl_t *)(cfg))
 
 static struct section *appconfig_index_find(struct config *root, const char *name, uint32_t hash) {
     struct section tmp;
     tmp.hash = (hash)?hash:simple_hash(name);
     tmp.name = (char *)name;
 
-    return (struct section *)avl_search_lock(&root->index, (avl *) &tmp);
+    return (struct section *)avl_search_lock(&root->index, (avl_t *) &tmp);
 }
 
 
diff --git a/libnetdata/config/appconfig.h b/libnetdata/config/appconfig.h
index 9d02e4ada6..f405eeb09b 100644
--- a/libnetdata/config/appconfig.h
+++ b/libnetdata/config/appconfig.h
@@ -111,7 +111,7 @@
 #define CONFIG_VALUE_CHECKED 0x08 // has been checked if the value is different from the default
 
 struct config_option {
-    avl avl_node;           // the index entry of this entry - this has to be first!
+    avl_t avl_node;         // the index entry of this entry - this has to be first!
 
     uint8_t flags;
     uint32_t hash;          // a simple hash to speed up searching
@@ -124,7 +124,7 @@ struct config_option {
 };
 
 struct section {
-    avl avl_node;           // the index entry of this section - this has to be first!
+    avl_t avl_node;         // the index entry of this section - this has to be first!
 
     uint32_t hash;          // a simple hash to speed up searching
                             // we first compare hashes, and only if the hashes are equal we do string comparisons
diff --git a/libnetdata/dictionary/dictionary.c b/libnetdata/dictionary/dictionary.c
index cfcf1fbab1..b3dc3f371c 100644
--- a/libnetdata/dictionary/dictionary.c
+++ b/libnetdata/dictionary/dictionary.c
@@ -67,7 +67,7 @@ static inline NAME_VALUE *dictionary_name_value_index_find_nolock(DICTIONARY *di
     tmp.name = (char *)name;
 
     NETDATA_DICTIONARY_STATS_SEARCHES_PLUS1(dict);
-    return (NAME_VALUE *)avl_search(&(dict->values_index), (avl *) &tmp);
+    return (NAME_VALUE *)avl_search(&(dict->values_index), (avl_t *) &tmp);
 }
 
 // ----------------------------------------------------------------------------
@@ -95,7 +95,7 @@ static NAME_VALUE *dictionary_name_value_create_nolock(DICTIONARY *dict, const c
 
     // index it
     NETDATA_DICTIONARY_STATS_INSERTS_PLUS1(dict);
-    if(unlikely(avl_insert(&((dict)->values_index), (avl *)(nv)) != (avl *)nv))
+    if(unlikely(avl_insert(&((dict)->values_index), (avl_t *)(nv)) != (avl_t *)nv))
         error("dictionary: INTERNAL ERROR: duplicate insertion to dictionary.");
 
     NETDATA_DICTIONARY_STATS_ENTRIES_PLUS1(dict);
@@ -107,7 +107,7 @@ static void dictionary_name_value_destroy_nolock(DICTIONARY *dict, NAME_VALUE *n
     debug(D_DICTIONARY, "Destroying name value entry for name '%s'.", nv->name);
 
     NETDATA_DICTIONARY_STATS_DELETES_PLUS1(dict);
-    if(unlikely(avl_remove(&(dict->values_index), (avl *)(nv)) != (avl *)nv))
+    if(unlikely(avl_remove(&(dict->values_index), (avl_t *)(nv)) != (avl_t *)nv))
         error("dictionary: INTERNAL ERROR: dictionary invalid removal of node.");
 
     NETDATA_DICTIONARY_STATS_ENTRIES_MINUS1(dict);
@@ -258,7 +258,7 @@ int dictionary_del(DICTIONARY *dict, const char *name) {
 // the dictionary is locked for reading while this happens
 // do not user other dictionary calls while walking the dictionary - deadlock!
 
-static int dictionary_walker(avl *a, int (*callback)(void *entry, void *data), void *data) {
+static int dictionary_walker(avl_t *a, int (*callback)(void *entry, void *data), void *data) {
     int total = 0, ret = 0;
 
     if(a->avl_link[0]) {
@@ -293,7 +293,7 @@ int dictionary_get_all(DICTIONARY *dict, int (*callback)(void *entry, void *data
     return ret;
 }
 
-static int dictionary_walker_name_value(avl *a, int (*callback)(char *name, void *entry, void *data), void *data) {
+static int dictionary_walker_name_value(avl_t *a, int (*callback)(char *name, void *entry, void *data), void *data) {
     int total = 0, ret = 0;
 
     if(a->avl_link[0]) {
diff --git a/libnetdata/dictionary/dictionary.h b/libnetdata/dictionary/dictionary.h
index fc24ec2ecf..76213887e6 100644
--- a/libnetdata/dictionary/dictionary.h
+++ b/libnetdata/dictionary/dictionary.h
@@ -13,7 +13,7 @@ struct dictionary_stats {
 };
 
 typedef struct name_value {
-    avl avl_node;           // the index - this has to be first!
+    avl_t avl_node;         // the index - this has to be first!
 
     uint32_t hash;          // a simple hash to speed up searching
                             // we first compare hashes, and only if the hashes are equal we do string comparisons