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03c5e4ffe7
- jrb.h, jrb.c (jrb_find_or_insert): new function to look for a node and to insert a new one if not found - id.c (make_id): use jrb_find_or_insert to avoid looking up new nodes twice - TODO: report the improvement
127 lines
3.9 KiB
C
127 lines
3.9 KiB
C
/*
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Libraries for fields, doubly-linked lists and red-black trees.
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Copyright (C) 2001 James S. Plank
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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---------------------------------------------------------------------------
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Please see http://www.cs.utk.edu/~plank/plank/classes/cs360/360/notes/Libfdr/
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for instruction on how to use this library.
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Jim Plank
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plank@cs.utk.edu
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http://www.cs.utk.edu/~plank
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Associate Professor
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Department of Computer Science
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University of Tennessee
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203 Claxton Complex
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1122 Volunteer Blvd.
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Knoxville, TN 37996-3450
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865-974-4397
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Fax: 865-974-4404
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*/
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/* Heavily edited and reformatted to K&R style 2010 by Werner Almesberger */
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#ifndef _JRB_H_
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#define _JRB_H_
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/* Main jrb_node. You only ever use the fields
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flink
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blink
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k.key or k.ikey
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v.val
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*/
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struct jrb {
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unsigned char red;
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unsigned char internal;
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unsigned char left;
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unsigned char roothead; /* (bit 1 is root, bit 2 is head) */
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struct jrb *flink;
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struct jrb *blink;
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struct jrb *parent;
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void *key;
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void *val;
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};
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struct jrb *make_jrb(void); /* Creates a new rb-tree */
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/* Creates a node with key key and val val and inserts it into the tree.
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jrb_insert uses strcmp() as comparison funcion. jrb_inserti uses <>=,
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jrb_insertg uses func() */
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struct jrb *jrb_insert(struct jrb *tree, void *key, void *val,
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int (*func)(const void *a, const void *b));
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/* If the key already exists, return the node (without altering it).
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Otherwise, insert a new node. */
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struct jrb *jrb_find_or_insert(struct jrb *tree, void *key, void *val,
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int (*func)(const void *a, const void *b));
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/* returns an external node in t whose value is equal k. Returns NULL if
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there is no such node in the tree */
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struct jrb *jrb_find(struct jrb *root, const void *key,
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int (*func)(const void *a, const void *b));
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/* returns an external node in t whose value is equal
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k or whose value is the smallest value greater than k. Sets found to
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1 if the key was found, and 0 otherwise. */
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struct jrb *jrb_find_gte(struct jrb *root, const void *key,
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int (*func)(const void *a, const void *b), int *found);
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/* Creates a node with key key and val val and inserts it into the
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tree before/after node nd. Does not check to ensure that you are
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keeping the correct order */
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void jrb_delete_node(struct jrb *node); /* Deletes and frees a node (but
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not the key or val) */
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void jrb_free_tree(struct jrb *root); /* Deletes and frees an entire tree */
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void *jrb_val(struct jrb *node); /* Returns node->v.val -- this is to shut
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lint up */
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int jrb_nblack(struct jrb *n); /* returns # of black nodes in path from
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n to the root */
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int jrb_plength(struct jrb *n); /* returns the # of nodes in path from
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n to the root */
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#define jrb_first(n) ((n)->flink)
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#define jrb_last(n) ((n)->blink)
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#define jrb_next(n) ((n)->flink)
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#define jrb_prev(n) ((n)->blink)
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#define jrb_empty(t) ((t)->flink == (t))
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#ifndef jrb_nil
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#define jrb_nil(t) (t)
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#endif
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#define jrb_traverse(ptr, lst) \
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for (ptr = jrb_first(lst); ptr != jrb_nil(lst); ptr = jrb_next(ptr))
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#define jrb_rtraverse(ptr, lst) \
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for (ptr = jrb_last(lst); ptr != jrb_nil(lst); ptr = jrb_prev(ptr))
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#endif
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