diff options
Diffstat (limited to 'gl/lib/gl_anyrbtree_list2.h')
| -rw-r--r-- | gl/lib/gl_anyrbtree_list2.h | 1028 |
1 files changed, 1028 insertions, 0 deletions
diff --git a/gl/lib/gl_anyrbtree_list2.h b/gl/lib/gl_anyrbtree_list2.h new file mode 100644 index 0000000..95d193c --- /dev/null +++ b/gl/lib/gl_anyrbtree_list2.h @@ -0,0 +1,1028 @@ +/* Sequential list data type implemented by a binary tree. + Copyright (C) 2006-2007, 2009-2022 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2006. + + This file is free software: you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. + + This file is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +/* Common code of gl_rbtree_list.c and gl_rbtreehash_list.c. */ + +/* -------------------------- gl_list_t Data Type -------------------------- */ + +/* Creates a subtree for count >= 1 elements. + Its black-height bh is passed as argument, with + 2^bh - 1 <= count <= 2^(bh+1) - 1. bh == 0 implies count == 1. + Its height is h where 2^(h-1) <= count <= 2^h - 1. + Return NULL upon out-of-memory. */ +static gl_list_node_t +create_subtree_with_contents (unsigned int bh, + size_t count, const void **contents) +{ + size_t half1 = (count - 1) / 2; + size_t half2 = count / 2; + /* Note: half1 + half2 = count - 1. */ + gl_list_node_t node = + (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl)); + if (node == NULL) + return NULL; + + if (half1 > 0) + { + /* half1 > 0 implies count > 1, implies bh >= 1, implies + 2^(bh-1) - 1 <= half1 <= 2^bh - 1. */ + node->left = + create_subtree_with_contents (bh - 1, half1, contents); + if (node->left == NULL) + goto fail1; + node->left->parent = node; + } + else + node->left = NULL; + + node->value = contents[half1]; + + if (half2 > 0) + { + /* half2 > 0 implies count > 1, implies bh >= 1, implies + 2^(bh-1) - 1 <= half2 <= 2^bh - 1. */ + node->right = + create_subtree_with_contents (bh - 1, half2, contents + half1 + 1); + if (node->right == NULL) + goto fail2; + node->right->parent = node; + } + else + node->right = NULL; + + node->color = (bh == 0 ? RED : BLACK); + + node->branch_size = count; + + return node; + + fail2: + if (node->left != NULL) + free_subtree (node->left); + fail1: + free (node); + return NULL; +} + +static gl_list_t +gl_tree_nx_create (gl_list_implementation_t implementation, + gl_listelement_equals_fn equals_fn, + gl_listelement_hashcode_fn hashcode_fn, + gl_listelement_dispose_fn dispose_fn, + bool allow_duplicates, + size_t count, const void **contents) +{ + struct gl_list_impl *list = + (struct gl_list_impl *) malloc (sizeof (struct gl_list_impl)); + + if (list == NULL) + return NULL; + + list->base.vtable = implementation; + list->base.equals_fn = equals_fn; + list->base.hashcode_fn = hashcode_fn; + list->base.dispose_fn = dispose_fn; + list->base.allow_duplicates = allow_duplicates; +#if WITH_HASHTABLE + { + size_t estimate = xsum (count, count / 2); /* 1.5 * count */ + if (estimate < 10) + estimate = 10; + list->table_size = next_prime (estimate); + if (size_overflow_p (xtimes (list->table_size, sizeof (gl_hash_entry_t)))) + goto fail1; + list->table = + (gl_hash_entry_t *) calloc (list->table_size, sizeof (gl_hash_entry_t)); + if (list->table == NULL) + goto fail1; + } +#endif + if (count > 0) + { + /* Assuming 2^bh - 1 <= count <= 2^(bh+1) - 2, we create a tree whose + upper bh levels are black, and only the partially present lowest + level is red. */ + unsigned int bh; + { + size_t n; + for (n = count + 1, bh = 0; n > 1; n = n >> 1) + bh++; + } + + list->root = create_subtree_with_contents (bh, count, contents); + if (list->root == NULL) + goto fail2; + list->root->parent = NULL; + +#if WITH_HASHTABLE + /* Now that the tree is built, node_position() works. Now we can + add the nodes to the hash table. */ + if (add_nodes_to_buckets (list) < 0) + goto fail3; +#endif + } + else + list->root = NULL; + + return list; + +#if WITH_HASHTABLE + fail3: + free_subtree (list->root); +#endif + fail2: +#if WITH_HASHTABLE + free (list->table); + fail1: +#endif + free (list); + return NULL; +} + +/* Rotates left a subtree. + + B D + / \ / \ + A D --> B E + / \ / \ + C E A C + + Changes the tree structure, updates the branch sizes. + The caller must update the colors and register D as child of its parent. */ +static gl_list_node_t +rotate_left (gl_list_node_t b_node, gl_list_node_t d_node) +{ + gl_list_node_t a_node = b_node->left; + gl_list_node_t c_node = d_node->left; + gl_list_node_t e_node = d_node->right; + + b_node->right = c_node; + d_node->left = b_node; + + d_node->parent = b_node->parent; + b_node->parent = d_node; + if (c_node != NULL) + c_node->parent = b_node; + + b_node->branch_size = + (a_node != NULL ? a_node->branch_size : 0) + + 1 + (c_node != NULL ? c_node->branch_size : 0); + d_node->branch_size = + b_node->branch_size + 1 + (e_node != NULL ? e_node->branch_size : 0); + + return d_node; +} + +/* Rotates right a subtree. + + D B + / \ / \ + B E --> A D + / \ / \ + A C C E + + Changes the tree structure, updates the branch sizes. + The caller must update the colors and register B as child of its parent. */ +static gl_list_node_t +rotate_right (gl_list_node_t b_node, gl_list_node_t d_node) +{ + gl_list_node_t a_node = b_node->left; + gl_list_node_t c_node = b_node->right; + gl_list_node_t e_node = d_node->right; + + d_node->left = c_node; + b_node->right = d_node; + + b_node->parent = d_node->parent; + d_node->parent = b_node; + if (c_node != NULL) + c_node->parent = d_node; + + d_node->branch_size = + (c_node != NULL ? c_node->branch_size : 0) + + 1 + (e_node != NULL ? e_node->branch_size : 0); + b_node->branch_size = + (a_node != NULL ? a_node->branch_size : 0) + 1 + d_node->branch_size; + + return b_node; +} + +/* Ensures the tree is balanced, after an insertion operation. + Also assigns node->color. + parent is the given node's parent, known to be non-NULL. */ +static void +rebalance_after_add (gl_list_t list, gl_list_node_t node, gl_list_node_t parent) +{ + for (;;) + { + /* At this point, parent = node->parent != NULL. + Think of node->color being RED (although node->color is not yet + assigned.) */ + gl_list_node_t grandparent; + gl_list_node_t uncle; + + if (parent->color == BLACK) + { + /* A RED color for node is acceptable. */ + node->color = RED; + return; + } + + grandparent = parent->parent; + /* Since parent is RED, we know that + grandparent is != NULL and colored BLACK. */ + + if (grandparent->left == parent) + uncle = grandparent->right; + else if (grandparent->right == parent) + uncle = grandparent->left; + else + abort (); + + if (uncle != NULL && uncle->color == RED) + { + /* Change grandparent from BLACK to RED, and + change parent and uncle from RED to BLACK. + This makes it acceptable for node to be RED. */ + node->color = RED; + parent->color = uncle->color = BLACK; + node = grandparent; + } + else + { + /* grandparent and uncle are BLACK. parent is RED. node wants + to be RED too. + In this case, recoloring is not sufficient. Need to perform + one or two rotations. */ + gl_list_node_t *grandparentp; + + if (grandparent->parent == NULL) + grandparentp = &list->root; + else if (grandparent->parent->left == grandparent) + grandparentp = &grandparent->parent->left; + else if (grandparent->parent->right == grandparent) + grandparentp = &grandparent->parent->right; + else + abort (); + + if (grandparent->left == parent) + { + if (parent->right == node) + { + /* Rotation between node and parent. */ + grandparent->left = rotate_left (parent, node); + node = parent; + parent = grandparent->left; + } + /* grandparent and uncle are BLACK. parent and node want to be + RED. parent = grandparent->left. node = parent->left. + + grandparent parent + bh+1 bh+1 + / \ / \ + parent uncle --> node grandparent + bh bh bh bh + / \ / \ + node C C uncle + bh bh bh bh + */ + *grandparentp = rotate_right (parent, grandparent); + parent->color = BLACK; + node->color = grandparent->color = RED; + } + else /* grandparent->right == parent */ + { + if (parent->left == node) + { + /* Rotation between node and parent. */ + grandparent->right = rotate_right (node, parent); + node = parent; + parent = grandparent->right; + } + /* grandparent and uncle are BLACK. parent and node want to be + RED. parent = grandparent->right. node = parent->right. + + grandparent parent + bh+1 bh+1 + / \ / \ + uncle parent --> grandparent node + bh bh bh bh + / \ / \ + C node uncle C + bh bh bh bh + */ + *grandparentp = rotate_left (grandparent, parent); + parent->color = BLACK; + node->color = grandparent->color = RED; + } + return; + } + + /* Start again with a new (node, parent) pair. */ + parent = node->parent; + + if (parent == NULL) + { + /* Change node's color from RED to BLACK. This increases the + tree's black-height. */ + node->color = BLACK; + return; + } + } +} + +/* Ensures the tree is balanced, after a deletion operation. + CHILD was a grandchild of PARENT and is now its child. Between them, + a black node was removed. CHILD is also black, or NULL. + (CHILD can also be NULL. But PARENT is non-NULL.) */ +static void +rebalance_after_remove (gl_list_t list, gl_list_node_t child, gl_list_node_t parent) +{ + for (;;) + { + /* At this point, we reduced the black-height of the CHILD subtree by 1. + To make up, either look for a possibility to turn a RED to a BLACK + node, or try to reduce the black-height tree of CHILD's sibling + subtree as well. */ + gl_list_node_t *parentp; + + if (parent->parent == NULL) + parentp = &list->root; + else if (parent->parent->left == parent) + parentp = &parent->parent->left; + else if (parent->parent->right == parent) + parentp = &parent->parent->right; + else + abort (); + + if (parent->left == child) + { + gl_list_node_t sibling = parent->right; + /* sibling's black-height is >= 1. In particular, + sibling != NULL. + + parent + / \ + child sibling + bh bh+1 + */ + + if (sibling->color == RED) + { + /* sibling is RED, hence parent is BLACK and sibling's children + are non-NULL and BLACK. + + parent sibling + bh+2 bh+2 + / \ / \ + child sibling --> parent SR + bh bh+1 bh+1 bh+1 + / \ / \ + SL SR child SL + bh+1 bh+1 bh bh+1 + */ + *parentp = rotate_left (parent, sibling); + parent->color = RED; + sibling->color = BLACK; + + /* Concentrate on the subtree of parent. The new sibling is + one of the old sibling's children, and known to be BLACK. */ + parentp = &sibling->left; + sibling = parent->right; + } + /* Now we know that sibling is BLACK. + + parent + / \ + child sibling + bh bh+1 + */ + if (sibling->right != NULL && sibling->right->color == RED) + { + /* + parent sibling + bh+1|bh+2 bh+1|bh+2 + / \ / \ + child sibling --> parent SR + bh bh+1 bh+1 bh+1 + / \ / \ + SL SR child SL + bh bh bh bh + */ + *parentp = rotate_left (parent, sibling); + sibling->color = parent->color; + parent->color = BLACK; + sibling->right->color = BLACK; + return; + } + else if (sibling->left != NULL && sibling->left->color == RED) + { + /* + parent parent + bh+1|bh+2 bh+1|bh+2 + / \ / \ + child sibling --> child SL + bh bh+1 bh bh+1 + / \ / \ + SL SR SLL sibling + bh bh bh bh + / \ / \ + SLL SLR SLR SR + bh bh bh bh + + where SLL, SLR, SR are all black. + */ + parent->right = rotate_right (sibling->left, sibling); + /* Change sibling from BLACK to RED and SL from RED to BLACK. */ + sibling->color = RED; + sibling = parent->right; + sibling->color = BLACK; + + /* Now do as in the previous case. */ + *parentp = rotate_left (parent, sibling); + sibling->color = parent->color; + parent->color = BLACK; + sibling->right->color = BLACK; + return; + } + else + { + if (parent->color == BLACK) + { + /* Change sibling from BLACK to RED. Then the entire + subtree at parent has decreased its black-height. + parent parent + bh+2 bh+1 + / \ / \ + child sibling --> child sibling + bh bh+1 bh bh + */ + sibling->color = RED; + + child = parent; + } + else + { + /* Change parent from RED to BLACK, but compensate by + changing sibling from BLACK to RED. + parent parent + bh+1 bh+1 + / \ / \ + child sibling --> child sibling + bh bh+1 bh bh + */ + parent->color = BLACK; + sibling->color = RED; + return; + } + } + } + else if (parent->right == child) + { + gl_list_node_t sibling = parent->left; + /* sibling's black-height is >= 1. In particular, + sibling != NULL. + + parent + / \ + sibling child + bh+1 bh + */ + + if (sibling->color == RED) + { + /* sibling is RED, hence parent is BLACK and sibling's children + are non-NULL and BLACK. + + parent sibling + bh+2 bh+2 + / \ / \ + sibling child --> SR parent + bh+1 ch bh+1 bh+1 + / \ / \ + SL SR SL child + bh+1 bh+1 bh+1 bh + */ + *parentp = rotate_right (sibling, parent); + parent->color = RED; + sibling->color = BLACK; + + /* Concentrate on the subtree of parent. The new sibling is + one of the old sibling's children, and known to be BLACK. */ + parentp = &sibling->right; + sibling = parent->left; + } + /* Now we know that sibling is BLACK. + + parent + / \ + sibling child + bh+1 bh + */ + if (sibling->left != NULL && sibling->left->color == RED) + { + /* + parent sibling + bh+1|bh+2 bh+1|bh+2 + / \ / \ + sibling child --> SL parent + bh+1 bh bh+1 bh+1 + / \ / \ + SL SR SR child + bh bh bh bh + */ + *parentp = rotate_right (sibling, parent); + sibling->color = parent->color; + parent->color = BLACK; + sibling->left->color = BLACK; + return; + } + else if (sibling->right != NULL && sibling->right->color == RED) + { + /* + parent parent + bh+1|bh+2 bh+1|bh+2 + / \ / \ + sibling child --> SR child + bh+1 bh bh+1 bh + / \ / \ + SL SR sibling SRR + bh bh bh bh + / \ / \ + SRL SRR SL SRL + bh bh bh bh + + where SL, SRL, SRR are all black. + */ + parent->left = rotate_left (sibling, sibling->right); + /* Change sibling from BLACK to RED and SL from RED to BLACK. */ + sibling->color = RED; + sibling = parent->left; + sibling->color = BLACK; + + /* Now do as in the previous case. */ + *parentp = rotate_right (sibling, parent); + sibling->color = parent->color; + parent->color = BLACK; + sibling->left->color = BLACK; + return; + } + else + { + if (parent->color == BLACK) + { + /* Change sibling from BLACK to RED. Then the entire + subtree at parent has decreased its black-height. + parent parent + bh+2 bh+1 + / \ / \ + sibling child --> sibling child + bh+1 bh bh bh + */ + sibling->color = RED; + + child = parent; + } + else + { + /* Change parent from RED to BLACK, but compensate by + changing sibling from BLACK to RED. + parent parent + bh+1 bh+1 + / \ / \ + sibling child --> sibling child + bh+1 bh bh bh + */ + parent->color = BLACK; + sibling->color = RED; + return; + } + } + } + else + abort (); + + /* Start again with a new (child, parent) pair. */ + parent = child->parent; + +#if 0 /* Already handled. */ + if (child != NULL && child->color == RED) + { + child->color = BLACK; + return; + } +#endif + + if (parent == NULL) + return; + } +} + +static void +gl_tree_remove_node_from_tree (gl_list_t list, gl_list_node_t node) +{ + gl_list_node_t parent = node->parent; + + if (node->left == NULL) + { + /* Replace node with node->right. */ + gl_list_node_t child = node->right; + + if (child != NULL) + { + child->parent = parent; + /* Since node->left == NULL, child must be RED and of height 1, + hence node must have been BLACK. Recolor the child. */ + child->color = BLACK; + } + if (parent == NULL) + list->root = child; + else + { + if (parent->left == node) + parent->left = child; + else /* parent->right == node */ + parent->right = child; + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = parent; p != NULL; p = p->parent) + p->branch_size--; + } + + if (child == NULL && node->color == BLACK) + rebalance_after_remove (list, child, parent); + } + } + else if (node->right == NULL) + { + /* It is not absolutely necessary to treat this case. But the more + general case below is more complicated, hence slower. */ + /* Replace node with node->left. */ + gl_list_node_t child = node->left; + + child->parent = parent; + /* Since node->right == NULL, child must be RED and of height 1, + hence node must have been BLACK. Recolor the child. */ + child->color = BLACK; + if (parent == NULL) + list->root = child; + else + { + if (parent->left == node) + parent->left = child; + else /* parent->right == node */ + parent->right = child; + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = parent; p != NULL; p = p->parent) + p->branch_size--; + } + } + } + else + { + /* Replace node with the rightmost element of the node->left subtree. */ + gl_list_node_t subst; + gl_list_node_t subst_parent; + gl_list_node_t child; + color_t removed_color; + + for (subst = node->left; subst->right != NULL; ) + subst = subst->right; + + subst_parent = subst->parent; + + child = subst->left; + + removed_color = subst->color; + + /* The case subst_parent == node is special: If we do nothing special, + we get confusion about node->left, subst->left and child->parent. + subst_parent == node + <==> The 'for' loop above terminated immediately. + <==> subst == subst_parent->left + [otherwise subst == subst_parent->right] + In this case, we would need to first set + child->parent = node; node->left = child; + and later - when we copy subst into node's position - again + child->parent = subst; subst->left = child; + Altogether a no-op. */ + if (subst_parent != node) + { + if (child != NULL) + child->parent = subst_parent; + subst_parent->right = child; + } + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = subst_parent; p != NULL; p = p->parent) + p->branch_size--; + } + + /* Copy subst into node's position. + (This is safer than to copy subst's value into node, keep node in + place, and free subst.) */ + if (subst_parent != node) + { + subst->left = node->left; + subst->left->parent = subst; + } + subst->right = node->right; + subst->right->parent = subst; + subst->color = node->color; + subst->branch_size = node->branch_size; + subst->parent = parent; + if (parent == NULL) + list->root = subst; + else if (parent->left == node) + parent->left = subst; + else /* parent->right == node */ + parent->right = subst; + + if (removed_color == BLACK) + { + if (child != NULL && child->color == RED) + /* Recolor the child. */ + child->color = BLACK; + else + /* Rebalancing starts at child's parent, that is subst_parent - + except when subst_parent == node. In this case, we need to use + its replacement, subst. */ + rebalance_after_remove (list, child, + subst_parent != node ? subst_parent : subst); + } + } +} + +static gl_list_node_t +gl_tree_nx_add_first (gl_list_t list, const void *elt) +{ + /* Create new node. */ + gl_list_node_t new_node = + (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl)); + + if (new_node == NULL) + return NULL; + + new_node->left = NULL; + new_node->right = NULL; + new_node->branch_size = 1; + new_node->value = elt; +#if WITH_HASHTABLE + new_node->h.hashcode = + (list->base.hashcode_fn != NULL + ? list->base.hashcode_fn (new_node->value) + : (size_t)(uintptr_t) new_node->value); +#endif + + /* Add it to the tree. */ + if (list->root == NULL) + { + new_node->color = BLACK; + list->root = new_node; + new_node->parent = NULL; + } + else + { + gl_list_node_t node; + + for (node = list->root; node->left != NULL; ) + node = node->left; + + node->left = new_node; + new_node->parent = node; + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = node; p != NULL; p = p->parent) + p->branch_size++; + } + + /* Color and rebalance. */ + rebalance_after_add (list, new_node, node); + } + +#if WITH_HASHTABLE + /* Add node to the hash table. + Note that this is only possible _after_ the node has been added to the + tree structure, because add_to_bucket() uses node_position(). */ + if (add_to_bucket (list, new_node) < 0) + { + gl_tree_remove_node_from_tree (list, new_node); + free (new_node); + return NULL; + } + hash_resize_after_add (list); +#endif + + return new_node; +} + +static gl_list_node_t +gl_tree_nx_add_last (gl_list_t list, const void *elt) +{ + /* Create new node. */ + gl_list_node_t new_node = + (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl)); + + if (new_node == NULL) + return NULL; + + new_node->left = NULL; + new_node->right = NULL; + new_node->branch_size = 1; + new_node->value = elt; +#if WITH_HASHTABLE + new_node->h.hashcode = + (list->base.hashcode_fn != NULL + ? list->base.hashcode_fn (new_node->value) + : (size_t)(uintptr_t) new_node->value); +#endif + + /* Add it to the tree. */ + if (list->root == NULL) + { + new_node->color = BLACK; + list->root = new_node; + new_node->parent = NULL; + } + else + { + gl_list_node_t node; + + for (node = list->root; node->right != NULL; ) + node = node->right; + + node->right = new_node; + new_node->parent = node; + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = node; p != NULL; p = p->parent) + p->branch_size++; + } + + /* Color and rebalance. */ + rebalance_after_add (list, new_node, node); + } + +#if WITH_HASHTABLE + /* Add node to the hash table. + Note that this is only possible _after_ the node has been added to the + tree structure, because add_to_bucket() uses node_position(). */ + if (add_to_bucket (list, new_node) < 0) + { + gl_tree_remove_node_from_tree (list, new_node); + free (new_node); + return NULL; + } + hash_resize_after_add (list); +#endif + + return new_node; +} + +static gl_list_node_t +gl_tree_nx_add_before (gl_list_t list, gl_list_node_t node, const void *elt) +{ + /* Create new node. */ + gl_list_node_t new_node = + (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl)); + + if (new_node == NULL) + return NULL; + + new_node->left = NULL; + new_node->right = NULL; + new_node->branch_size = 1; + new_node->value = elt; +#if WITH_HASHTABLE + new_node->h.hashcode = + (list->base.hashcode_fn != NULL + ? list->base.hashcode_fn (new_node->value) + : (size_t)(uintptr_t) new_node->value); +#endif + + /* Add it to the tree. */ + if (node->left == NULL) + node->left = new_node; + else + { + for (node = node->left; node->right != NULL; ) + node = node->right; + node->right = new_node; + } + new_node->parent = node; + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = node; p != NULL; p = p->parent) + p->branch_size++; + } + + /* Color and rebalance. */ + rebalance_after_add (list, new_node, node); + +#if WITH_HASHTABLE + /* Add node to the hash table. + Note that this is only possible _after_ the node has been added to the + tree structure, because add_to_bucket() uses node_position(). */ + if (add_to_bucket (list, new_node) < 0) + { + gl_tree_remove_node_from_tree (list, new_node); + free (new_node); + return NULL; + } + hash_resize_after_add (list); +#endif + + return new_node; +} + +static gl_list_node_t +gl_tree_nx_add_after (gl_list_t list, gl_list_node_t node, const void *elt) +{ + /* Create new node. */ + gl_list_node_t new_node = + (struct gl_list_node_impl *) malloc (sizeof (struct gl_list_node_impl)); + + if (new_node == NULL) + return NULL; + + new_node->left = NULL; + new_node->right = NULL; + new_node->branch_size = 1; + new_node->value = elt; +#if WITH_HASHTABLE + new_node->h.hashcode = + (list->base.hashcode_fn != NULL + ? list->base.hashcode_fn (new_node->value) + : (size_t)(uintptr_t) new_node->value); +#endif + + /* Add it to the tree. */ + if (node->right == NULL) + node->right = new_node; + else + { + for (node = node->right; node->left != NULL; ) + node = node->left; + node->left = new_node; + } + new_node->parent = node; + + /* Update branch_size fields of the parent nodes. */ + { + gl_list_node_t p; + + for (p = node; p != NULL; p = p->parent) + p->branch_size++; + } + + /* Color and rebalance. */ + rebalance_after_add (list, new_node, node); + +#if WITH_HASHTABLE + /* Add node to the hash table. + Note that this is only possible _after_ the node has been added to the + tree structure, because add_to_bucket() uses node_position(). */ + if (add_to_bucket (list, new_node) < 0) + { + gl_tree_remove_node_from_tree (list, new_node); + free (new_node); + return NULL; + } + hash_resize_after_add (list); +#endif + + return new_node; +} |