| /* |
| * Copyright (c) 1989 The Regents of the University of California. |
| * All rights reserved. |
| * |
| * This code is derived from software contributed to Berkeley by |
| * Michael Rendell of Memorial University of Newfoundland. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. All advertising materials mentioning features or use of this software |
| * must display the following acknowledgement: |
| * This product includes software developed by the University of |
| * California, Berkeley and its contributors. |
| * 4. Neither the name of the University nor the names of its contributors |
| * may be used to endorse or promote products derived from this software |
| * without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| /* 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@misiek.eu.org> |
| * - added Native Language Support |
| */ |
| |
| #include <sys/types.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <ctype.h> |
| #include <string.h> |
| #include "nls.h" |
| |
| /* |
| * Topological sort. Input is a list of pairs of strings seperated by |
| * white space (spaces, tabs, and/or newlines); strings are written to |
| * standard output in sorted order, one per line. |
| * |
| * usage: |
| * tsort [inputfile] |
| * If no input file is specified, standard input is read. |
| * |
| * Should be compatable with AT&T tsort HOWEVER the output is not identical |
| * (i.e. for most graphs there is more than one sorted order, and this tsort |
| * usually generates a different one then the AT&T tsort). Also, cycle |
| * reporting seems to be more accurate in this version (the AT&T tsort |
| * sometimes says a node is in a cycle when it isn't). |
| * |
| * Michael Rendell, michael@stretch.cs.mun.ca - Feb 26, '90 |
| */ |
| #define HASHSIZE 53 /* doesn't need to be big */ |
| #define NF_MARK 0x1 /* marker for cycle detection */ |
| #define NF_ACYCLIC 0x2 /* this node is cycle free */ |
| |
| typedef struct node_str NODE; |
| |
| struct node_str { |
| char *n_name; /* name of this node */ |
| NODE **n_prevp; /* pointer to previous node's n_next */ |
| NODE *n_next; /* next node in graph */ |
| NODE *n_hash; /* next node in hash table */ |
| int n_narcs; /* number of arcs in n_arcs[] */ |
| int n_arcsize; /* size of n_arcs[] array */ |
| NODE **n_arcs; /* array of arcs to other nodes */ |
| int n_refcnt; /* # of arcs pointing to this node */ |
| int n_flags; /* NF_* */ |
| }; |
| |
| typedef struct _buf { |
| char *b_buf; |
| int b_bsize; |
| } BUF; |
| |
| NODE *add_node(char *), *find_node(char *); |
| void add_arc(char *, char *), no_memory(void); |
| void remove_node(NODE *), tsort(void); |
| char *grow_buf(char *, int); |
| int find_cycle(NODE *, NODE *, int, int); |
| |
| NODE *graph; |
| NODE *hashtable[HASHSIZE]; |
| NODE **cycle_buf; |
| NODE **longest_cycle; |
| |
| int |
| main(int argc, char **argv) { |
| BUF *b; |
| int c, n; |
| FILE *fp; |
| int bsize, nused; |
| BUF bufs[2]; |
| |
| setlocale(LC_ALL, ""); |
| bindtextdomain(PACKAGE, LOCALEDIR); |
| textdomain(PACKAGE); |
| |
| if (argc < 2) |
| fp = stdin; |
| /* == becomes > in next line per Volker Meyer_zu_Bexten |
| <vmzb@ims.fhg.de> -- faith@cs.unc.edu, Sat Feb 4 21:25:09 1995 */ |
| else if (argc > 2) { |
| (void)fprintf(stderr, _("usage: tsort [ inputfile ]\n")); |
| exit(1); |
| } else if (!(fp = fopen(argv[1], "r"))) { |
| (void)fprintf(stderr, "tsort: %s.\n", strerror(errno)); |
| exit(1); |
| } |
| |
| for (b = bufs, n = 2; --n >= 0; b++) |
| b->b_buf = grow_buf((char *)NULL, b->b_bsize = 1024); |
| |
| /* parse input and build the graph */ |
| for (n = 0, c = getc(fp);;) { |
| while (c != EOF && isspace(c)) |
| c = getc(fp); |
| if (c == EOF) |
| break; |
| |
| nused = 0; |
| b = &bufs[n]; |
| bsize = b->b_bsize; |
| do { |
| b->b_buf[nused++] = c; |
| if (nused == bsize) { |
| bsize *= 2; |
| b->b_buf = grow_buf(b->b_buf, bsize); |
| } |
| c = getc(fp); |
| } while (c != EOF && !isspace(c)); |
| |
| b->b_buf[nused] = '\0'; |
| b->b_bsize = bsize; |
| if (n) |
| add_arc(bufs[0].b_buf, bufs[1].b_buf); |
| n = !n; |
| } |
| (void)fclose(fp); |
| if (n) { |
| (void)fprintf(stderr, _("tsort: odd data count.\n")); |
| exit(1); |
| } |
| |
| /* do the sort */ |
| tsort(); |
| return 0; |
| } |
| |
| /* double the size of oldbuf and return a pointer to the new buffer. */ |
| char * |
| grow_buf(char *bp, int size) { |
| if (!(bp = realloc(bp, (u_int)size))) |
| no_memory(); |
| return(bp); |
| } |
| |
| /* |
| * add an arc from node s1 to node s2 in the graph. If s1 or s2 are not in |
| * the graph, then add them. |
| */ |
| void |
| add_arc(char *s1, char *s2) { |
| NODE *n1; |
| NODE *n2; |
| int bsize; |
| |
| n1 = find_node(s1); |
| if (!n1) |
| n1 = add_node(s1); |
| |
| if (!strcmp(s1, s2)) |
| return; |
| |
| n2 = find_node(s2); |
| if (!n2) |
| n2 = add_node(s2); |
| |
| /* |
| * could check to see if this arc is here already, but it isn't |
| * worth the bother -- there usually isn't and it doesn't hurt if |
| * there is (I think :-). |
| */ |
| if (n1->n_narcs == n1->n_arcsize) { |
| if (!n1->n_arcsize) |
| n1->n_arcsize = 10; |
| bsize = n1->n_arcsize * sizeof(*n1->n_arcs) * 2; |
| n1->n_arcs = (NODE **)grow_buf((char *)n1->n_arcs, bsize); |
| n1->n_arcsize = bsize / sizeof(*n1->n_arcs); |
| } |
| n1->n_arcs[n1->n_narcs++] = n2; |
| ++n2->n_refcnt; |
| } |
| |
| static int |
| hash_string(char *s) { |
| int hash, i; |
| |
| for (hash = 0, i = 1; *s; s++, i++) |
| hash += *s * i; |
| return(hash % HASHSIZE); |
| } |
| |
| /* |
| * find a node in the graph and return a pointer to it - returns null if not |
| * found. |
| */ |
| NODE * |
| find_node(char *name) { |
| NODE *n; |
| |
| for (n = hashtable[hash_string(name)]; n; n = n->n_hash) |
| if (!strcmp(n->n_name, name)) |
| return(n); |
| return((NODE *)NULL); |
| } |
| |
| /* Add a node to the graph and return a pointer to it. */ |
| NODE * |
| add_node(char *name) { |
| NODE *n; |
| int hash; |
| |
| if (!(n = (NODE *)malloc(sizeof(NODE))) || !(n->n_name = strdup(name))) |
| no_memory(); |
| |
| n->n_narcs = 0; |
| n->n_arcsize = 0; |
| n->n_arcs = (NODE **)NULL; |
| n->n_refcnt = 0; |
| n->n_flags = 0; |
| |
| /* add to linked list */ |
| if ((n->n_next = graph) != NULL) |
| graph->n_prevp = &n->n_next; |
| n->n_prevp = &graph; |
| graph = n; |
| |
| /* add to hash table */ |
| hash = hash_string(name); |
| n->n_hash = hashtable[hash]; |
| hashtable[hash] = n; |
| return(n); |
| } |
| |
| /* do topological sort on graph */ |
| void |
| tsort(void) { |
| NODE *n, *next; |
| int cnt; |
| |
| while (graph) { |
| /* |
| * keep getting rid of simple cases until there are none left, |
| * if there are any nodes still in the graph, then there is |
| * a cycle in it. |
| */ |
| do { |
| for (cnt = 0, n = graph; n; n = next) { |
| next = n->n_next; |
| if (n->n_refcnt == 0) { |
| remove_node(n); |
| ++cnt; |
| } |
| } |
| } while (graph && cnt); |
| |
| if (!graph) |
| break; |
| |
| if (!cycle_buf) { |
| /* |
| * allocate space for two cycle logs - one to be used |
| * as scratch space, the other to save the longest |
| * cycle. |
| */ |
| for (cnt = 0, n = graph; n; n = n->n_next) |
| ++cnt; |
| cycle_buf = |
| (NODE **)malloc((u_int)sizeof(NODE *) * cnt); |
| longest_cycle = |
| (NODE **)malloc((u_int)sizeof(NODE *) * cnt); |
| if (!cycle_buf || !longest_cycle) |
| no_memory(); |
| } |
| for (n = graph; n; n = n->n_next) |
| if (!(n->n_flags & NF_ACYCLIC)) { |
| if ((cnt = find_cycle(n, n, 0, 0)) != 0) { |
| int i; |
| |
| (void)fprintf(stderr, |
| _("tsort: cycle in data.\n")); |
| for (i = 0; i < cnt; i++) |
| (void)fprintf(stderr, |
| "tsort: %s.\n", longest_cycle[i]->n_name); |
| remove_node(n); |
| break; |
| } else |
| /* to avoid further checks */ |
| n->n_flags = NF_ACYCLIC; |
| } |
| |
| if (!n) { |
| (void)fprintf(stderr, |
| _("tsort: internal error -- could not find cycle.\n")); |
| exit(1); |
| } |
| } |
| } |
| |
| /* print node and remove from graph (does not actually free node) */ |
| void |
| remove_node(NODE *n) { |
| NODE **np; |
| int i; |
| |
| (void)printf("%s\n", n->n_name); |
| for (np = n->n_arcs, i = n->n_narcs; --i >= 0; np++) |
| --(*np)->n_refcnt; |
| n->n_narcs = 0; |
| *n->n_prevp = n->n_next; |
| if (n->n_next) |
| n->n_next->n_prevp = n->n_prevp; |
| } |
| |
| /* look for the longest cycle from node from to node to. */ |
| int |
| find_cycle(NODE *from, NODE *to, int longest_len, int depth) { |
| NODE **np; |
| int i, len; |
| |
| /* |
| * avoid infinite loops and ignore portions of the graph known |
| * to be acyclic |
| */ |
| if (from->n_flags & (NF_MARK|NF_ACYCLIC)) |
| return(0); |
| from->n_flags = NF_MARK; |
| |
| for (np = from->n_arcs, i = from->n_narcs; --i >= 0; np++) { |
| cycle_buf[depth] = *np; |
| if (*np == to) { |
| if (depth + 1 > longest_len) { |
| longest_len = depth + 1; |
| (void)memcpy((char *)longest_cycle, |
| (char *)cycle_buf, |
| longest_len * sizeof(NODE *)); |
| } |
| } else { |
| len = find_cycle(*np, to, longest_len, depth + 1); |
| if (len > longest_len) |
| longest_len = len; |
| } |
| } |
| from->n_flags &= ~NF_MARK; |
| return(longest_len); |
| } |
| |
| void |
| no_memory(void) { |
| (void)fprintf(stderr, "tsort: %s.\n", strerror(ENOMEM)); |
| exit(1); |
| } |