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Diffstat (limited to 'Build/source/texk/web2c/luatexdir/utils/avl.c')
-rw-r--r-- | Build/source/texk/web2c/luatexdir/utils/avl.c | 794 |
1 files changed, 794 insertions, 0 deletions
diff --git a/Build/source/texk/web2c/luatexdir/utils/avl.c b/Build/source/texk/web2c/luatexdir/utils/avl.c new file mode 100644 index 00000000000..79c746cd10d --- /dev/null +++ b/Build/source/texk/web2c/luatexdir/utils/avl.c @@ -0,0 +1,794 @@ +/* Produced by texiweb from libavl.w. */ + +/* libavl - library for manipulation of binary trees. + Copyright (C) 1998-2002, 2004 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + 02111-1307, USA. + + The author may be contacted at <blp@gnu.org> on the Internet, or + write to Ben Pfaff, Stanford University, Computer Science Dept., 353 + Serra Mall, Stanford CA 94305, USA. +*/ + +#include <assert.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "avl.h" + +/* Creates and returns a new table + with comparison function |compare| using parameter |param| + and memory allocator |allocator|. + Returns |NULL| if memory allocation failed. */ +struct avl_table *avl_create(avl_comparison_func * compare, void *param, + struct libavl_allocator *allocator) +{ + struct avl_table *tree; + + assert(compare != NULL); + + if (allocator == NULL) + allocator = &avl_allocator_default; + + tree = allocator->libavl_malloc(allocator, sizeof *tree); + if (tree == NULL) + return NULL; + + tree->avl_root = NULL; + tree->avl_compare = compare; + tree->avl_param = param; + tree->avl_alloc = allocator; + tree->avl_count = 0; + tree->avl_generation = 0; + + return tree; +} + +/* Search |tree| for an item matching |item|, and return it if found. + Otherwise return |NULL|. */ +void *avl_find(const struct avl_table *tree, const void *item) +{ + const struct avl_node *p; + + assert(tree != NULL && item != NULL); + for (p = tree->avl_root; p != NULL;) { + int cmp = tree->avl_compare(item, p->avl_data, tree->avl_param); + + if (cmp < 0) + p = p->avl_link[0]; + else if (cmp > 0) + p = p->avl_link[1]; + else /* |cmp == 0| */ + return p->avl_data; + } + + 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|. + Returns |NULL| in case of memory allocation failure. */ +void **avl_probe(struct avl_table *tree, void *item) +{ + struct avl_node *y, *z; /* Top node to update balance factor, and parent. */ + struct avl_node *p, *q; /* Iterator, and parent. */ + struct avl_node *n; /* Newly inserted node. */ + struct avl_node *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 = (struct avl_node *) &tree->avl_root; + y = tree->avl_root; + dir = 0; + for (q = z, p = y; p != NULL; q = p, p = p->avl_link[dir]) { + int cmp = tree->avl_compare(item, p->avl_data, tree->avl_param); + if (cmp == 0) + return &p->avl_data; + + if (p->avl_balance != 0) + z = q, y = p, k = 0; + da[k++] = dir = cmp > 0; + } + + n = q->avl_link[dir] = + tree->avl_alloc->libavl_malloc(tree->avl_alloc, sizeof *n); + if (n == NULL) + return NULL; + + tree->avl_count++; + n->avl_data = item; + n->avl_link[0] = n->avl_link[1] = NULL; + n->avl_balance = 0; + if (y == NULL) + return &n->avl_data; + + 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) { + struct avl_node *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) { + struct avl_node *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->avl_data; + z->avl_link[y != z->avl_link[0]] = w; + + tree->avl_generation++; + return &n->avl_data; +} + +/* Inserts |item| into |table|. + Returns |NULL| if |item| was successfully inserted + or if a memory allocation error occurred. + Otherwise, returns the duplicate item. */ +void *avl_insert(struct avl_table *table, void *item) +{ + void **p = avl_probe(table, item); + return p == NULL || *p == item ? NULL : *p; +} + +/* Inserts |item| into |table|, replacing any duplicate item. + Returns |NULL| if |item| was inserted without replacing a duplicate, + or if a memory allocation error occurred. + Otherwise, returns the item that was replaced. */ +void *avl_replace(struct avl_table *table, void *item) +{ + void **p = avl_probe(table, item); + if (p == NULL || *p == item) + return NULL; + else { + void *r = *p; + *p = item; + return r; + } +} + +/* Deletes from |tree| and returns an item matching |item|. + Returns a null pointer if no matching item found. */ +void *avl_delete(struct avl_table *tree, const void *item) +{ + /* Stack of nodes. */ + struct avl_node *pa[AVL_MAX_HEIGHT]; /* Nodes. */ + unsigned char da[AVL_MAX_HEIGHT]; /* |avl_link[]| indexes. */ + int k; /* Stack pointer. */ + + struct avl_node *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 = (struct avl_node *) &tree->avl_root; + for (cmp = -1; cmp != 0; + cmp = tree->avl_compare(item, p->avl_data, tree->avl_param)) { + int dir = cmp > 0; + + pa[k] = p; + da[k++] = dir; + + p = p->avl_link[dir]; + if (p == NULL) + return NULL; + } + item = p->avl_data; + + if (p->avl_link[1] == NULL) + pa[k - 1]->avl_link[da[k - 1]] = p->avl_link[0]; + else { + struct avl_node *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 { + struct avl_node *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; + } + } + + tree->avl_alloc->libavl_free(tree->avl_alloc, p); + + assert(k > 0); + while (--k > 0) { + struct avl_node *y = pa[k]; + + if (da[k] == 0) { + y->avl_balance++; + if (y->avl_balance == +1) + break; + else if (y->avl_balance == +2) { + struct avl_node *x = y->avl_link[1]; + if (x->avl_balance == -1) { + struct avl_node *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) { + struct avl_node *x = y->avl_link[0]; + if (x->avl_balance == +1) { + struct avl_node *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 (void *) item; +} + +/* Refreshes the stack of parent pointers in |trav| + and updates its generation number. */ +static void trav_refresh(struct avl_traverser *trav) +{ + assert(trav != NULL); + + trav->avl_generation = trav->avl_table->avl_generation; + + if (trav->avl_node != NULL) { + avl_comparison_func *cmp = trav->avl_table->avl_compare; + void *param = trav->avl_table->avl_param; + struct avl_node *node = trav->avl_node; + struct avl_node *i; + + trav->avl_height = 0; + for (i = trav->avl_table->avl_root; i != node;) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + assert(i != NULL); + + trav->avl_stack[trav->avl_height++] = i; + i = i->avl_link[cmp(node->avl_data, i->avl_data, param) > 0]; + } + } +} + +/* Initializes |trav| for use with |tree| + and selects the null node. */ +void avl_t_init(struct avl_traverser *trav, struct avl_table *tree) +{ + trav->avl_table = tree; + trav->avl_node = NULL; + trav->avl_height = 0; + trav->avl_generation = tree->avl_generation; +} + +/* Initializes |trav| for |tree| + and selects and returns a pointer to its least-valued item. + Returns |NULL| if |tree| contains no nodes. */ +void *avl_t_first(struct avl_traverser *trav, struct avl_table *tree) +{ + struct avl_node *x; + + assert(tree != NULL && trav != NULL); + + trav->avl_table = tree; + trav->avl_height = 0; + trav->avl_generation = tree->avl_generation; + + x = tree->avl_root; + if (x != NULL) + while (x->avl_link[0] != NULL) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = x; + x = x->avl_link[0]; + } + trav->avl_node = x; + + return x != NULL ? x->avl_data : NULL; +} + +/* Initializes |trav| for |tree| + and selects and returns a pointer to its greatest-valued item. + Returns |NULL| if |tree| contains no nodes. */ +void *avl_t_last(struct avl_traverser *trav, struct avl_table *tree) +{ + struct avl_node *x; + + assert(tree != NULL && trav != NULL); + + trav->avl_table = tree; + trav->avl_height = 0; + trav->avl_generation = tree->avl_generation; + + x = tree->avl_root; + if (x != NULL) + while (x->avl_link[1] != NULL) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = x; + x = x->avl_link[1]; + } + trav->avl_node = x; + + return x != NULL ? x->avl_data : NULL; +} + +/* Searches for |item| in |tree|. + If found, initializes |trav| to the item found and returns the item + as well. + If there is no matching item, initializes |trav| to the null item + and returns |NULL|. */ +void *avl_t_find(struct avl_traverser *trav, struct avl_table *tree, void *item) +{ + struct avl_node *p, *q; + + assert(trav != NULL && tree != NULL && item != NULL); + trav->avl_table = tree; + trav->avl_height = 0; + trav->avl_generation = tree->avl_generation; + for (p = tree->avl_root; p != NULL; p = q) { + int cmp = tree->avl_compare(item, p->avl_data, tree->avl_param); + + if (cmp < 0) + q = p->avl_link[0]; + else if (cmp > 0) + q = p->avl_link[1]; + else { /* |cmp == 0| */ + + trav->avl_node = p; + return p->avl_data; + } + + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = p; + } + + trav->avl_height = 0; + trav->avl_node = NULL; + return NULL; +} + +/* Attempts to insert |item| into |tree|. + If |item| is inserted successfully, it is returned and |trav| is + initialized to its location. + If a duplicate is found, it is returned and |trav| is initialized to + its location. No replacement of the item occurs. + If a memory allocation failure occurs, |NULL| is returned and |trav| + is initialized to the null item. */ +void *avl_t_insert(struct avl_traverser *trav, struct avl_table *tree, + void *item) +{ + void **p; + + assert(trav != NULL && tree != NULL && item != NULL); + + p = avl_probe(tree, item); + if (p != NULL) { + trav->avl_table = tree; + trav->avl_node = ((struct avl_node *) + ((char *) p - offsetof(struct avl_node, avl_data))); + trav->avl_generation = tree->avl_generation - 1; + return *p; + } else { + avl_t_init(trav, tree); + return NULL; + } +} + +/* Initializes |trav| to have the same current node as |src|. */ +void *avl_t_copy(struct avl_traverser *trav, const struct avl_traverser *src) +{ + assert(trav != NULL && src != NULL); + + if (trav != src) { + trav->avl_table = src->avl_table; + trav->avl_node = src->avl_node; + trav->avl_generation = src->avl_generation; + if (trav->avl_generation == trav->avl_table->avl_generation) { + trav->avl_height = src->avl_height; + memcpy(trav->avl_stack, (const void *) src->avl_stack, + sizeof *trav->avl_stack * trav->avl_height); + } + } + + return trav->avl_node != NULL ? trav->avl_node->avl_data : NULL; +} + +/* Returns the next data item in inorder + within the tree being traversed with |trav|, + or if there are no more data items returns |NULL|. */ +void *avl_t_next(struct avl_traverser *trav) +{ + struct avl_node *x; + + assert(trav != NULL); + + if (trav->avl_generation != trav->avl_table->avl_generation) + trav_refresh(trav); + + x = trav->avl_node; + if (x == NULL) { + return avl_t_first(trav, trav->avl_table); + } else if (x->avl_link[1] != NULL) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = x; + x = x->avl_link[1]; + + while (x->avl_link[0] != NULL) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = x; + x = x->avl_link[0]; + } + } else { + struct avl_node *y; + + do { + if (trav->avl_height == 0) { + trav->avl_node = NULL; + return NULL; + } + + y = x; + x = trav->avl_stack[--trav->avl_height]; + } + while (y == x->avl_link[1]); + } + trav->avl_node = x; + + return x->avl_data; +} + +/* Returns the previous data item in inorder + within the tree being traversed with |trav|, + or if there are no more data items returns |NULL|. */ +void *avl_t_prev(struct avl_traverser *trav) +{ + struct avl_node *x; + + assert(trav != NULL); + + if (trav->avl_generation != trav->avl_table->avl_generation) + trav_refresh(trav); + + x = trav->avl_node; + if (x == NULL) { + return avl_t_last(trav, trav->avl_table); + } else if (x->avl_link[0] != NULL) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = x; + x = x->avl_link[0]; + + while (x->avl_link[1] != NULL) { + assert(trav->avl_height < AVL_MAX_HEIGHT); + trav->avl_stack[trav->avl_height++] = x; + x = x->avl_link[1]; + } + } else { + struct avl_node *y; + + do { + if (trav->avl_height == 0) { + trav->avl_node = NULL; + return NULL; + } + + y = x; + x = trav->avl_stack[--trav->avl_height]; + } + while (y == x->avl_link[0]); + } + trav->avl_node = x; + + return x->avl_data; +} + +/* Returns |trav|'s current item. */ +void *avl_t_cur(struct avl_traverser *trav) +{ + assert(trav != NULL); + + return trav->avl_node != NULL ? trav->avl_node->avl_data : NULL; +} + +/* Replaces the current item in |trav| by |new| and returns the item replaced. + |trav| must not have the null item selected. + The new item must not upset the ordering of the tree. */ +void *avl_t_replace(struct avl_traverser *trav, void *new) +{ + void *old; + + assert(trav != NULL && trav->avl_node != NULL && new != NULL); + old = trav->avl_node->avl_data; + trav->avl_node->avl_data = new; + return old; +} + +/* Destroys |new| with |avl_destroy (new, destroy)|, + first setting right links of nodes in |stack| within |new| + to null pointers to avoid touching uninitialized data. */ +static void +copy_error_recovery(struct avl_node **stack, int height, + struct avl_table *new, avl_item_func * destroy) +{ + assert(stack != NULL && height >= 0 && new != NULL); + + for (; height > 2; height -= 2) + stack[height - 1]->avl_link[1] = NULL; + avl_destroy(new, destroy); +} + +/* Copies |org| to a newly created tree, which is returned. + If |copy != NULL|, each data item in |org| is first passed to |copy|, + and the return values are inserted into the tree, + with |NULL| return values taken as indications of failure. + On failure, destroys the partially created new tree, + applying |destroy|, if non-null, to each item in the new tree so far, + and returns |NULL|. + If |allocator != NULL|, it is used for allocation in the new tree. + Otherwise, the same allocator used for |org| is used. */ +struct avl_table *avl_copy(const struct avl_table *org, avl_copy_func * copy, + avl_item_func * destroy, + struct libavl_allocator *allocator) +{ + struct avl_node *stack[2 * (AVL_MAX_HEIGHT + 1)]; + int height = 0; + + struct avl_table *new; + const struct avl_node *x; + struct avl_node *y; + + assert(org != NULL); + new = avl_create(org->avl_compare, org->avl_param, + allocator != NULL ? allocator : org->avl_alloc); + if (new == NULL) + return NULL; + new->avl_count = org->avl_count; + if (new->avl_count == 0) + return new; + + x = (const struct avl_node *) &org->avl_root; + y = (struct avl_node *) &new->avl_root; + for (;;) { + while (x->avl_link[0] != NULL) { + assert(height < 2 * (AVL_MAX_HEIGHT + 1)); + + y->avl_link[0] = + new->avl_alloc->libavl_malloc(new->avl_alloc, + sizeof *y->avl_link[0]); + if (y->avl_link[0] == NULL) { + if (y != (struct avl_node *) &new->avl_root) { + y->avl_data = NULL; + y->avl_link[1] = NULL; + } + + copy_error_recovery(stack, height, new, destroy); + return NULL; + } + + stack[height++] = (struct avl_node *) x; + stack[height++] = y; + x = x->avl_link[0]; + y = y->avl_link[0]; + } + y->avl_link[0] = NULL; + + for (;;) { + y->avl_balance = x->avl_balance; + if (copy == NULL) + y->avl_data = x->avl_data; + else { + y->avl_data = copy(x->avl_data, org->avl_param); + if (y->avl_data == NULL) { + y->avl_link[1] = NULL; + copy_error_recovery(stack, height, new, destroy); + return NULL; + } + } + + if (x->avl_link[1] != NULL) { + y->avl_link[1] = + new->avl_alloc->libavl_malloc(new->avl_alloc, + sizeof *y->avl_link[1]); + if (y->avl_link[1] == NULL) { + copy_error_recovery(stack, height, new, destroy); + return NULL; + } + + x = x->avl_link[1]; + y = y->avl_link[1]; + break; + } else + y->avl_link[1] = NULL; + + if (height <= 2) + return new; + + y = stack[--height]; + x = stack[--height]; + } + } +} + +/* Frees storage allocated for |tree|. + If |destroy != NULL|, applies it to each data item in inorder. */ +void avl_destroy(struct avl_table *tree, avl_item_func * destroy) +{ + struct avl_node *p, *q; + + assert(tree != NULL); + + for (p = tree->avl_root; p != NULL; p = q) + if (p->avl_link[0] == NULL) { + q = p->avl_link[1]; + if (destroy != NULL && p->avl_data != NULL) + destroy(p->avl_data, tree->avl_param); + tree->avl_alloc->libavl_free(tree->avl_alloc, p); + } else { + q = p->avl_link[0]; + p->avl_link[0] = q->avl_link[1]; + q->avl_link[1] = p; + } + + tree->avl_alloc->libavl_free(tree->avl_alloc, tree); +} + +/* Allocates |size| bytes of space using |malloc()|. + Returns a null pointer if allocation fails. */ +void *avl_malloc(struct libavl_allocator *allocator, size_t size) +{ + assert(allocator != NULL && size > 0); + return malloc(size); +} + +/* Frees |block|. */ +void avl_free(struct libavl_allocator *allocator, void *block) +{ + assert(allocator != NULL && block != NULL); + free(block); +} + +/* Default memory allocator that uses |malloc()| and |free()|. */ +struct libavl_allocator avl_allocator_default = { + avl_malloc, + avl_free +}; + +#undef NDEBUG +#include <assert.h> + +/* Asserts that |avl_insert()| succeeds at inserting |item| into |table|. */ +void + (avl_assert_insert) (struct avl_table * table, void *item) { + void **p = avl_probe(table, item); + assert(p != NULL && *p == item); +} + +/* Asserts that |avl_delete()| really removes |item| from |table|, + and returns the removed item. */ +void *(avl_assert_delete) (struct avl_table * table, void *item) { + void *p = avl_delete(table, item); + assert(p != NULL); + return p; +} |