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-rw-r--r--src/avl.c403
1 files changed, 0 insertions, 403 deletions
diff --git a/src/avl.c b/src/avl.c
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index a2c6911e7..000000000
--- a/src/avl.c
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@@ -1,403 +0,0 @@
-#include "common.h"
-
-/* ------------------------------------------------------------------------- */
-/*
- * avl_insert(), avl_remove() and avl_search()
- * are adaptations (by Costa Tsaousis) of the AVL algorithm found in libavl
- * v2.0.3, so that they do not use any memory allocations and their memory
- * footprint is optimized (by eliminating non-necessary data members).
- *
- * libavl - library for manipulation of binary trees.
- * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software
- * Foundation, Inc.
- * GNU Lesser General Public License
-*/
-
-
-/* Search |tree| for an item matching |item|, and return it if found.
- Otherwise return |NULL|. */
-avl *avl_search(avl_tree *tree, avl *item) {
- avl *p;
-
- // assert (tree != NULL && item != NULL);
-
- for (p = tree->root; p != NULL; ) {
- int cmp = tree->compar(item, p);
-
- if (cmp < 0)
- p = p->avl_link[0];
- else if (cmp > 0)
- p = p->avl_link[1];
- else /* |cmp == 0| */
- return p;
- }
-
- return NULL;
-}
-
-/* Inserts |item| into |tree| and returns a pointer to |item|'s address.
- If a duplicate item is found in the tree,
- returns a pointer to the duplicate without inserting |item|.
- */
-avl *avl_insert(avl_tree *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. */
- int dir; /* Direction to descend. */
-
- unsigned char da[AVL_MAX_HEIGHT]; /* Cached comparison results. */
- int k = 0; /* Number of cached results. */
-
- // assert(tree != NULL && item != NULL);
-
- z = (avl *) &tree->root;
- y = tree->root;
- dir = 0;
- for (q = z, p = y; p != NULL; q = p, p = p->avl_link[dir]) {
- int cmp = tree->compar(item, p);
- if (cmp == 0)
- return p;
-
- if (p->avl_balance != 0)
- z = q, y = p, k = 0;
- da[k++] = dir = (cmp > 0);
- }
-
- n = q->avl_link[dir] = item;
-
- // tree->avl_count++;
- n->avl_link[0] = n->avl_link[1] = NULL;
- n->avl_balance = 0;
- if (y == NULL) return n;
-
- for (p = y, k = 0; p != n; p = p->avl_link[da[k]], k++)
- if (da[k] == 0)
- p->avl_balance--;
- else
- p->avl_balance++;
-
- if (y->avl_balance == -2) {
- avl *x = y->avl_link[0];
- if (x->avl_balance == -1) {
- w = x;
- y->avl_link[0] = x->avl_link[1];
- x->avl_link[1] = y;
- x->avl_balance = y->avl_balance = 0;
- }
- else {
- // assert (x->avl_balance == +1);
- w = x->avl_link[1];
- x->avl_link[1] = w->avl_link[0];
- w->avl_link[0] = x;
- y->avl_link[0] = w->avl_link[1];
- w->avl_link[1] = y;
- if (w->avl_balance == -1)
- x->avl_balance = 0, y->avl_balance = +1;
- else if (w->avl_balance == 0)
- x->avl_balance = y->avl_balance = 0;
- else /* |w->avl_balance == +1| */
- x->avl_balance = -1, y->avl_balance = 0;
- w->avl_balance = 0;
- }
- }
- else if (y->avl_balance == +2) {
- avl *x = y->avl_link[1];
- if (x->avl_balance == +1) {
- w = x;
- y->avl_link[1] = x->avl_link[0];
- x->avl_link[0] = y;
- x->avl_balance = y->avl_balance = 0;
- }
- else {
- // assert (x->avl_balance == -1);
- w = x->avl_link[0];
- x->avl_link[0] = w->avl_link[1];
- w->avl_link[1] = x;
- y->avl_link[1] = w->avl_link[0];
- w->avl_link[0] = y;
- if (w->avl_balance == +1)
- x->avl_balance = 0, y->avl_balance = -1;
- else if (w->avl_balance == 0)
- x->avl_balance = y->avl_balance = 0;
- else /* |w->avl_balance == -1| */
- x->avl_balance = +1, y->avl_balance = 0;
- w->avl_balance = 0;
- }
- }
- else return n;
-
- z->avl_link[y != z->avl_link[0]] = w;
-
- // tree->avl_generation++;
- return n;
-}
-
-/* Deletes from |tree| and returns an item matching |item|.
- Returns a null pointer if no matching item found. */
-avl *avl_remove(avl_tree *tree, avl *item) {
- /* Stack of nodes. */
- avl *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. */
- int cmp; /* Result of comparison between |item| and |p|. */
-
- // assert (tree != NULL && item != NULL);
-
- k = 0;
- p = (avl *) &tree->root;
- for(cmp = -1; cmp != 0; cmp = tree->compar(item, p)) {
- int dir = (cmp > 0);
-
- pa[k] = p;
- da[k++] = dir;
-
- p = p->avl_link[dir];
- if(p == NULL) return NULL;
- }
-
- item = p;
-
- 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];
- if (r->avl_link[0] == NULL) {
- r->avl_link[0] = p->avl_link[0];
- r->avl_balance = p->avl_balance;
- pa[k - 1]->avl_link[da[k - 1]] = r;
- da[k] = 1;
- pa[k++] = r;
- }
- else {
- avl *s;
- int j = k++;
-
- for (;;) {
- da[k] = 0;
- pa[k++] = r;
- s = r->avl_link[0];
- if (s->avl_link[0] == NULL) break;
-
- r = s;
- }
-
- s->avl_link[0] = p->avl_link[0];
- r->avl_link[0] = s->avl_link[1];
- s->avl_link[1] = p->avl_link[1];
- s->avl_balance = p->avl_balance;
-
- pa[j - 1]->avl_link[da[j - 1]] = s;
- da[j] = 1;
- pa[j] = s;
- }
- }
-
- // assert (k > 0);
- while (--k > 0) {
- avl *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];
- if (x->avl_balance == -1) {
- avl *w;
- // assert (x->avl_balance == -1);
- w = x->avl_link[0];
- x->avl_link[0] = w->avl_link[1];
- w->avl_link[1] = x;
- y->avl_link[1] = w->avl_link[0];
- w->avl_link[0] = y;
- if (w->avl_balance == +1)
- x->avl_balance = 0, y->avl_balance = -1;
- else if (w->avl_balance == 0)
- x->avl_balance = y->avl_balance = 0;
- else /* |w->avl_balance == -1| */
- x->avl_balance = +1, y->avl_balance = 0;
- w->avl_balance = 0;
- pa[k - 1]->avl_link[da[k - 1]] = w;
- }
- else {
- y->avl_link[1] = x->avl_link[0];
- x->avl_link[0] = y;
- pa[k - 1]->avl_link[da[k - 1]] = x;
- if (x->avl_balance == 0) {
- x->avl_balance = -1;
- y->avl_balance = +1;
- break;
- }
- else x->avl_balance = y->avl_balance = 0;
- }
- }
- }
- else
- {
- y->avl_balance--;
- if (y->avl_balance == -1) break;
- else if (y->avl_balance == -2) {
- avl *x = y->avl_link[0];
- if (x->avl_balance == +1) {
- avl *w;
- // assert (x->avl_balance == +1);
- w = x->avl_link[1];
- x->avl_link[1] = w->avl_link[0];
- w->avl_link[0] = x;
- y->avl_link[0] = w->avl_link[1];
- w->avl_link[1] = y;
- if (w->avl_balance == -1)
- x->avl_balance = 0, y->avl_balance = +1;
- else if (w->avl_balance == 0)
- x->avl_balance = y->avl_balance = 0;
- else /* |w->avl_balance == +1| */
- x->avl_balance = -1, y->avl_balance = 0;
- w->avl_balance = 0;
- pa[k - 1]->avl_link[da[k - 1]] = w;
- }
- else {
- y->avl_link[0] = x->avl_link[1];
- x->avl_link[1] = y;
- pa[k - 1]->avl_link[da[k - 1]] = x;
- if (x->avl_balance == 0) {
- x->avl_balance = +1;
- y->avl_balance = -1;
- break;
- }
- else x->avl_balance = y->avl_balance = 0;
- }
- }
- }
- }
-
- // tree->avl_count--;
- // tree->avl_generation++;
- return item;
-}
-
-/* ------------------------------------------------------------------------- */
-// below are functions by (C) Costa Tsaousis
-
-// ---------------------------
-// traversing
-
-int avl_walker(avl *node, int (*callback)(void *entry, void *data), void *data) {
- int total = 0, ret = 0;
-
- if(node->avl_link[0]) {
- ret = avl_walker(node->avl_link[0], callback, data);
- if(ret < 0) return ret;
- total += ret;
- }
-
- ret = callback(node, data);
- if(ret < 0) return ret;
- total += ret;
-
- if(node->avl_link[1]) {
- ret = avl_walker(node->avl_link[1], callback, data);
- if (ret < 0) return ret;
- total += ret;
- }
-
- return total;
-}
-
-int avl_traverse(avl_tree *t, int (*callback)(void *entry, void *data), void *data) {
- if(t->root)
- return avl_walker(t->root, callback, data);
- else
- return 0;
-}
-
-// ---------------------------
-// locks
-
-void avl_read_lock(avl_tree_lock *t) {
-#ifndef AVL_WITHOUT_PTHREADS
-#ifdef AVL_LOCK_WITH_MUTEX
- netdata_mutex_lock(&t->mutex);
-#else
- netdata_rwlock_rdlock(&t->rwlock);
-#endif
-#endif /* AVL_WITHOUT_PTHREADS */
-}
-
-void avl_write_lock(avl_tree_lock *t) {
-#ifndef AVL_WITHOUT_PTHREADS
-#ifdef AVL_LOCK_WITH_MUTEX
- netdata_mutex_lock(&t->mutex);
-#else
- netdata_rwlock_wrlock(&t->rwlock);
-#endif
-#endif /* AVL_WITHOUT_PTHREADS */
-}
-
-void avl_unlock(avl_tree_lock *t) {
-#ifndef AVL_WITHOUT_PTHREADS
-#ifdef AVL_LOCK_WITH_MUTEX
- netdata_mutex_unlock(&t->mutex);
-#else
- netdata_rwlock_unlock(&t->rwlock);
-#endif
-#endif /* AVL_WITHOUT_PTHREADS */
-}
-
-// ---------------------------
-// operations with locking
-
-void avl_init_lock(avl_tree_lock *t, int (*compar)(void *a, void *b)) {
- avl_init(&t->avl_tree, compar);
-
-#ifndef AVL_WITHOUT_PTHREADS
- int lock;
-
-#ifdef AVL_LOCK_WITH_MUTEX
- lock = netdata_mutex_init(&t->mutex, NULL);
-#else
- lock = netdata_rwlock_init(&t->rwlock);
-#endif
-
- if(lock != 0)
- fatal("Failed to initialize AVL mutex/rwlock, error: %d", lock);
-
-#endif /* AVL_WITHOUT_PTHREADS */
-}
-
-avl *avl_search_lock(avl_tree_lock *t, avl *a) {
- avl_read_lock(t);
- avl *ret = avl_search(&t->avl_tree, a);
- avl_unlock(t);
- return ret;
-}
-
-avl * avl_remove_lock(avl_tree_lock *t, avl *a) {
- avl_write_lock(t);
- avl *ret = avl_remove(&t->avl_tree, a);
- avl_unlock(t);
- return ret;
-}
-
-avl *avl_insert_lock(avl_tree_lock *t, avl *a) {
- avl_write_lock(t);
- avl * ret = avl_insert(&t->avl_tree, a);
- avl_unlock(t);
- return ret;
-}
-
-int avl_traverse_lock(avl_tree_lock *t, int (*callback)(void *entry, void *data), void *data) {
- int ret;
- avl_read_lock(t);
- ret = avl_traverse(&t->avl_tree, callback, data);
- avl_unlock(t);
- return ret;
-}
-
-void avl_init(avl_tree *t, int (*compar)(void *a, void *b)) {
- t->root = NULL;
- t->compar = compar;
-}
-
-// ------------------ \ No newline at end of file
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