From: Lionel Sambuc Date: Tue, 4 Dec 2012 13:02:11 +0000 (+0100) Subject: Importing NetBSD tsort X-Git-Tag: v3.2.1~163 X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/rndc.conf.html?a=commitdiff_plain;h=8e5df35e84e62bb6fe3ec211e177c205ccdbfe00;p=minix.git Importing NetBSD tsort Change-Id: I110de8037b9253f4fe53cbe13dc8fc281aeea2ec --- diff --git a/commands/Makefile b/commands/Makefile index 73e104dd4..ffd193b64 100644 --- a/commands/Makefile +++ b/commands/Makefile @@ -27,7 +27,7 @@ SUBDIR= add_route arp ash at backup banner basename btrace cal \ stty svclog svrctl swifi sync synctree sysenv \ syslogd tail tcpd tcpdp tcpstat tee telnet \ telnetd term termcap tget time touch tr \ - truncate tsort tty udpstat umount uname unexpand \ + truncate tty udpstat umount uname unexpand \ unstack update uud uue version vol wc \ whereis which who write writeisofs fetch \ xargs yes zdump zmodem pkgin_cd \ diff --git a/commands/tsort/Makefile b/commands/tsort/Makefile deleted file mode 100644 index 4a438ab72..000000000 --- a/commands/tsort/Makefile +++ /dev/null @@ -1,4 +0,0 @@ -PROG= tsort -MAN= - -.include diff --git a/commands/tsort/tsort.c b/commands/tsort/tsort.c deleted file mode 100644 index 4c9ee2452..000000000 --- a/commands/tsort/tsort.c +++ /dev/null @@ -1,356 +0,0 @@ -/* topo - topological sort Author: Kent Williams */ - -/* -** topo - perform a topological sort of the output of lorder. -** -** Usage : topo [infile] [outfile] -** -** Author: Kent Williams (williams@umaxc.weeg.uiowa.edu) -*/ - -#include -#include -#include -#include - -typedef struct __v { - struct __v *next; /* link list node */ - int indegree, /* number of edges into this vertex */ - visited, /* depth-first search visited flag */ - on_the_path, /* used to find cycles */ - has_a_cycle; /* true if a cycle at this vertex */ - struct __e *out; /* outgoing edges from this vertex */ - char key[1]; /* name of this vertex */ -} vertex; - -typedef struct __e { - struct __e *next; /* link list node */ - vertex *v; /* vertex to which this edge goes */ -} edge; - -int main(int argc, char **argv); -void *xmalloc(size_t siz); -edge *new_edge(vertex *v); -char *copyupto(char *name, char *buf, int stop); -int child_of(vertex *parent, vertex *child); -vertex *add_v(char *s); -void readin(void); -void pushname(char *s); -char *popname(void); -void topo(void); -void print_cycle(vertex *parent, vertex *child); -void dfs(vertex *v); -void check_cycles(void); - -/* -** xmalloc -- standard do or die malloc front end. -*/ -void * -xmalloc(siz) -size_t siz; -{ - void *rval = (void *)malloc(siz); - if(rval == NULL) { - fputs("Out of memory.\n",stderr); - exit(1); - } - return rval; -} - -/* -** edge allocater. -*/ -edge * -new_edge(v) -vertex *v; -{ - edge *rval; - rval = (edge *)xmalloc(sizeof(edge)); - rval->v = v; return rval; -} - -/* -** copyupto - copy until you see the stop character. -*/ -char * -copyupto(name,buf,stop) -char *name,*buf,stop; -{ - while(*buf != '\0' && *buf != stop) - *name++ = *buf++; - *name = '\0'; - while(*buf != '\0' && isspace(*buf)) - buf++; - return buf; -} - -/* -** find out if the vertex child is a child of the vertex parent. -*/ -int -child_of(parent,child) -vertex *parent,*child; -{ - edge *e; - for(e = parent->out; e != NULL && e->v != child; e = e->next) - ; - return e == NULL ? 0 : 1; -} - -/* -** the vertex set. -** -** add_v adds a vertex to the set if it's not already there. -*/ -vertex *vset = NULL; - -vertex * -add_v(s) -char *s; -{ - vertex *v,*last; - /* - ** go looking for this key in the vertex set. - */ - for(last = v = vset; v != NULL && strcmp(v->key,s) != 0; - last = v, v = v->next) - ; - if(v != NULL) { - /* - ** use the move-to-front heuristic to keep this from being - ** an O(N^2) algorithm. - */ - if(last != vset) { - last->next = v->next; - v->next = vset; - vset = v; - } - return v; - } - - v = (vertex *)xmalloc(sizeof(vertex) + strlen(s)); - - v->out = NULL; - strcpy(v->key,s); - v->indegree = - v->on_the_path = - v->has_a_cycle = - v->visited = 0; - v->next = vset; - vset = v; - return v; -} - -/* -** readin -- read in the dependency pairs. -*/ -void -readin() -{ - static char buf[128]; - static char name[64]; - char *bp; - vertex *child,*parent; - edge *e; - while(fgets(buf,sizeof(buf),stdin) != NULL) { - bp = buf + strlen(buf); - if (bp > buf && bp[-1] == '\n') *--bp = 0; - bp = copyupto(name,buf,' '); - child = add_v(name); - parent = add_v(bp); - if(child != parent && !child_of(parent,child)) { - e = new_edge(child); - e->next = parent->out; - parent->out = e; - child->indegree++; - } - } -} - -/* -** the topological sort produces names of modules in reverse of -** the order we want them in, so use a stack to hold the names -** until we get them all, then pop them off to print them. -*/ -struct name { struct name *next; char *s; } -*namelist = NULL; - -void -pushname(s) -char *s; -{ - struct name *x = (struct name *)xmalloc(sizeof(struct name)); - x->s = s; - x->next = namelist; - namelist = x; -} - -char * -popname() { - char *rval; - struct name *tmp; - if(namelist == NULL) - return NULL; - tmp = namelist; - rval = namelist->s; - namelist = namelist->next; - free(tmp); - return rval; -} - -/* -** topo - do a topological sort of the dependency graph. -*/ -void topo() { - vertex *x = vset,*n; - edge *e; - vertex *outq = NULL,*tmp; -#define insq(x) ((x->next = outq),(outq = x)) -#define deq() ((tmp = outq),(outq = outq->next),tmp) - - /* - ** find all vertices that don't depend on any other vertices - ** Since it breaks the "next" links to insert x into the queue, - ** x->next is saved before insq, to resume the list traversal. - */ - while (x != NULL) { - n = x->next; - if(x->indegree == 0) { - insq(x); - pushname(x->key); - } - x = n; - } - - /* - ** for each vertex V with indegree of zero, - ** for each edge E from vertex V - ** subtract one from the indegree of the vertex V' - ** pointed to by E. If V' now has an indegree of zero, - ** add it to the set of vertices with indegree zero, and - ** push its name on the output stack. - */ - while(outq != NULL) { - x = deq(); - e = x->out; - while(e != NULL) { - if(--(e->v->indegree) == 0) { - insq(e->v); - pushname(e->v->key); - } - e = e->next; - } - } - - /* - ** print the vertex names in opposite of the order they were - ** encountered. - */ - while(namelist != NULL) - puts(popname()); -} - -/* -** print_cycle -- -** A cycle has been detected between parent and child. -** Start with the child, and look at each of its edges for -** the parent. -** -** We know a vertex is on the path from the child to the parent -** because the depth-first search sets on_the_path true for each -** vertex it visits. -*/ -void -print_cycle(parent,child) -vertex *parent, *child; -{ - char *s; - vertex *x; - edge *e; - for(x = child; x != parent; ) { - pushname(x->key); - for(e = x->out; e != NULL; e = e->next) { - /* - ** stop looking for the path at the first node found - ** that's on the path. Watch out for cycles already - ** detected, because if you follow an edge into a cycle, - ** you're stuck in an infinite loop! - */ - if(e->v->on_the_path && !e->v->has_a_cycle) { - x = e->v; - break; - } - } - } - /* - ** print the name of the parent, and then names of each of the - ** vertices on the path from the child to the parent. - */ - fprintf(stderr,"%s\n",x->key); - while((s = popname()) != NULL) - fprintf(stderr,"%s\n",s); -} - -/* -** depth first search for cycles in the dependency graph. -** See "Introduction to Algorithms" by Udi Manber Addison-Wesley 1989 -*/ -void -dfs(v) -vertex *v; -{ - edge *e; - - if(v->visited) /* If you've been here before, don't go again! */ - return; - v->visited++; - v->on_the_path++; /* this node is on the path from the root. */ - - /* - ** depth-first search all outgoing edges. - */ - for(e = v->out; e != NULL; e = e->next) { - if(!e->v->visited) - dfs(e->v); - if(e->v->on_the_path) { - fprintf(stderr,"cycle found between %s and %s\n", - v->key,e->v->key); - print_cycle(v,e->v); - v->has_a_cycle++; - } - } - v->on_the_path = 0; -} - -/* -** check cycles starts the recursive depth-first search from -** each vertex in vset. -*/ -void -check_cycles() -{ - vertex *v; - for(v = vset; v != NULL; v = v->next) - dfs(v); -} - -/* -** main program. -*/ -int main(argc,argv) -int argc; -char **argv; -{ - if(argc > 1 && freopen(argv[1],"r",stdin) == NULL) { - perror(argv[1]); - exit(0); - } - if(argc > 2 && freopen(argv[2],"w",stdout) == NULL) { - perror(argv[2]); - exit(0); - } - readin(); - check_cycles(); - topo(); - return(0); -} diff --git a/docs/UPDATING b/docs/UPDATING index 841663ed5..a49924c45 100644 --- a/docs/UPDATING +++ b/docs/UPDATING @@ -1,3 +1,9 @@ +20121205: + The tsort tool has been also upgraded and is now also used during + the build: + # make -C usr.bin/tsort all install + # cp share/mk/* /usr/share/mk + 20121205: lorder requires a newer version of sort, so to ensure it is present do the following: diff --git a/man/man1/Makefile b/man/man1/Makefile index 0abec304e..c3df9e45e 100644 --- a/man/man1/Makefile +++ b/man/man1/Makefile @@ -19,7 +19,7 @@ MAN= ash.1 at.1 banner.1 basename.1 \ split.1 stty.1 svc.1 svrctl.1 \ synctree.1 sysenv.1 sz.1 tail.1 tee.1 telnet.1 template.1 \ term.1 termcap.1 tget.1 time.1 tr.1 true.1 \ - truncate.1 tsort.1 tty.1 umount.1 uname.1 unexpand.1 \ + truncate.1 tty.1 umount.1 uname.1 unexpand.1 \ uud.1 uue.1 vol.1 wc.1 whereis.1 which.1 \ who.1 write.1 xargs.1 yap.1 yes.1 linkfarm.1 pkg_view.1 diff --git a/man/man1/tsort.1 b/man/man1/tsort.1 deleted file mode 100644 index 19fa6da43..000000000 --- a/man/man1/tsort.1 +++ /dev/null @@ -1,27 +0,0 @@ -.TH TSORT 1 -.SH NAME -tsort \- topological sort [IBM] -.SH SYNOPSIS -\fBtsort \fIfile\fR -.br -.de FL -.TP -\\fB\\$1\\fR -\\$2 -.. -.de EX -.TP 20 -\\fB\\$1\\fR -# \\$2 -.. -.SH EXAMPLES -.TP 20 -.B lorder *.s | tsort -# Give library ordering -.TP 20 -.B ar cr libc.a \`lorder *.s | tsort\` -# Build library -.SH DESCRIPTION -.PP -\fITsort\fR accepts a file of lines containing ordered pairs and builds a -total ordering from the partial orderings. diff --git a/releasetools/nbsd_ports b/releasetools/nbsd_ports index 661bdc036..a87a49f51 100644 --- a/releasetools/nbsd_ports +++ b/releasetools/nbsd_ports @@ -67,6 +67,7 @@ 2012/10/17 12:00:00,tools/nbperf 2012/10/17 12:00:00,tools/sed 2012/10/17 12:00:00,tools/tic +2012/10/17 12:00:00,tools/tsort 2012/10/17 12:00:00,usr.bin/gzip/Makefile 2012/10/17 12:00:00,usr.bin/indent 2012/10/17 12:00:00,usr.bin/join @@ -76,6 +77,7 @@ 2012/10/17 12:00:00,usr.bin/nbperf 2012/10/17 12:00:00,usr.bin/passwd/Makefile 2012/10/17 12:00:00,usr.bin/sort +2012/10/17 12:00:00,usr.bin/tsort 2012/10/17 12:00:00,usr.bin/xinstall 2012/10/17 12:00:00,usr.sbin/Makefile 2012/10/17 12:00:00,usr.sbin/Makefile.inc diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk index 1db0a8275..622b7a916 100644 --- a/share/mk/bsd.lib.mk +++ b/share/mk/bsd.lib.mk @@ -510,12 +510,7 @@ _INSTRANLIB=${empty(PRESERVE):?-a "${RANLIB} -t":} __archivebuild: .USE ${_MKTARGET_BUILD} rm -f ${.TARGET} -.if defined(__MINIX) - # LSC FIXME MINIX: We do not have yet imported tsort nor lorder - ${AR} ${_ARFL} ${.TARGET} ${.ALLSRC:M*o} -.else ${AR} ${_ARFL} ${.TARGET} `NM=${NM} ${LORDER} ${.ALLSRC:M*o} | ${TSORT}` -.endif # defined(__MINIX) .endif .if !target(__archiveinstall) diff --git a/tools/Makefile b/tools/Makefile index e4b8d71d8..36bd77028 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -61,7 +61,7 @@ LINT_BITS= lint lint2 SUBDIR= host-mkdep .WAIT compat .WAIT \ binstall .WAIT mktemp .WAIT sed .WAIT \ genassym join \ - lorder makewhatis mkdep mtree nbperf .WAIT \ + lorder makewhatis mkdep mtree nbperf .WAIT tsort \ m4 \ .WAIT mkfs.mfs \ .WAIT yacc \ diff --git a/tools/tsort/Makefile b/tools/tsort/Makefile new file mode 100644 index 000000000..bb516a70f --- /dev/null +++ b/tools/tsort/Makefile @@ -0,0 +1,6 @@ +# $NetBSD: Makefile,v 1.4 2002/12/08 20:20:06 thorpej Exp $ + +HOSTPROGNAME= ${_TOOL_PREFIX}tsort +HOST_SRCDIR= usr.bin/tsort + +.include "${.CURDIR}/../Makefile.host" diff --git a/usr.bin/Makefile b/usr.bin/Makefile index 92f1ea20e..53984bb4c 100644 --- a/usr.bin/Makefile +++ b/usr.bin/Makefile @@ -20,7 +20,8 @@ SUBDIR= \ sed seq \ sort stat su \ tic \ - uniq \ + tsort \ + uniq \ xinstall .if !defined(__MINIX) diff --git a/usr.bin/tsort/Makefile b/usr.bin/tsort/Makefile new file mode 100644 index 000000000..06e78c7bb --- /dev/null +++ b/usr.bin/tsort/Makefile @@ -0,0 +1,6 @@ +# $NetBSD: Makefile,v 1.7 2009/04/14 22:15:27 lukem Exp $ +# @(#)Makefile 8.1 (Berkeley) 6/9/93 + +PROG= tsort + +.include diff --git a/usr.bin/tsort/tsort.1 b/usr.bin/tsort/tsort.1 new file mode 100644 index 000000000..061824b7b --- /dev/null +++ b/usr.bin/tsort/tsort.1 @@ -0,0 +1,87 @@ +.\" $NetBSD: tsort.1,v 1.10 2003/08/07 11:16:50 agc Exp $ +.\" +.\" Copyright (c) 1990, 1993, 1994 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" This manual is derived from one 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. 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. +.\" +.\" @(#)tsort.1 8.3 (Berkeley) 4/1/94 +.\" +.Dd April 1, 1994 +.Dt TSORT 1 +.Os +.Sh NAME +.Nm tsort +.Nd topological sort of a directed graph +.Sh SYNOPSIS +.Nm +.Op Fl l +.Op Fl q +.Op Ar file +.Sh DESCRIPTION +.Nm +takes a list of pairs of node names representing directed arcs in +a graph and prints the nodes in topological order on standard output. +Input is taken from the named +.Ar file , +or from standard input if no file +is given. +.Pp +Node names in the input are separated by white space and there must +be an even number of node names. +.Pp +Presence of a node in a graph can be represented by an arc from the node +to itself. +This is useful when a node is not connected to any other nodes. +.Pp +If the graph contains a cycle (and therefore cannot be properly sorted), +one of the arcs in the cycle is ignored and the sort continues. +Cycles are reported on standard error. +.Pp +The options are as follows: +.Bl -tag -width Ds +.It Fl l +Search for and display the longest cycle. +Can take a very long time. +.It Fl q +Do not display informational messages about cycles. +This is primarily +intended for building libraries, where optimal ordering is not critical, +and cycles occur often. +.El +.Sh SEE ALSO +.Xr ar 1 +.Sh HISTORY +A +.Nm +command appeared in +.At v7 . +This +.Nm +command and manual page are derived from sources contributed to Berkeley by +Michael Rendell of Memorial University of Newfoundland. diff --git a/usr.bin/tsort/tsort.c b/usr.bin/tsort/tsort.c new file mode 100644 index 000000000..3e8d5692f --- /dev/null +++ b/usr.bin/tsort/tsort.c @@ -0,0 +1,433 @@ +/* $NetBSD: tsort.c,v 1.23 2011/09/06 18:34:37 joerg Exp $ */ + +/* + * Copyright (c) 1989, 1993, 1994 + * 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. 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. + */ + +#if HAVE_NBTOOL_CONFIG_H +#include "nbtool_config.h" +#endif + +#include +#if !defined(lint) +__COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\ + The Regents of the University of California. All rights reserved."); +#if 0 +static char sccsid[] = "@(#)tsort.c 8.3 (Berkeley) 5/4/95"; +#endif +__RCSID("$NetBSD: tsort.c,v 1.23 2011/09/06 18:34:37 joerg Exp $"); +#endif /* not lint */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Topological sort. Input is a list of pairs of strings separated by + * white space (spaces, tabs, and/or newlines); strings are written to + * standard output in sorted order, one per line. + * + * usage: + * tsort [-l] [inputfile] + * If no input file is specified, standard input is read. + * + * Should be compatible 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 */ +#define NF_NODEST 0x4 /* Unreachable */ + +typedef struct node_str NODE; + +struct node_str { + NODE **n_prevp; /* pointer to previous node's n_next */ + NODE *n_next; /* next node in graph */ + NODE **n_arcs; /* array of arcs to other nodes */ + int n_narcs; /* number of arcs in n_arcs[] */ + int n_arcsize; /* size of n_arcs[] array */ + int n_refcnt; /* # of arcs pointing to this node */ + int n_flags; /* NF_* */ + char n_name[1]; /* name of this node */ +}; + +typedef struct _buf { + char *b_buf; + int b_bsize; +} BUF; + +static DB *db; +static NODE *graph, **cycle_buf, **longest_cycle; +static int debug, longest, quiet; + +static void add_arc(char *, char *); +static void clear_cycle(void); +static int find_cycle(NODE *, NODE *, int, int); +static NODE *get_node(char *); +static void *grow_buf(void *, int); +static void remove_node(NODE *); +static void tsort(void); +__dead static void usage(void); + +int +main(int argc, char *argv[]) +{ + BUF *b; + int c, n; + FILE *fp; + int bsize, ch, nused; + BUF bufs[2]; + + setprogname(argv[0]); + + fp = NULL; + while ((ch = getopt(argc, argv, "dlq")) != -1) + switch (ch) { + case 'd': + debug = 1; + break; + case 'l': + longest = 1; + break; + case 'q': + quiet = 1; + break; + case '?': + default: + usage(); + } + argc -= optind; + argv += optind; + + switch (argc) { + case 0: + fp = stdin; + break; + case 1: + if ((fp = fopen(*argv, "r")) == NULL) + err(1, "%s", *argv); + break; + default: + usage(); + } + + for (b = bufs, n = 2; --n >= 0; b++) + b->b_buf = grow_buf(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) + b->b_buf = grow_buf(b->b_buf, bsize *= 2); + 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) + errx(1, "odd data count"); + + /* do the sort */ + tsort(); + return(0); +} + +/* double the size of oldbuf and return a pointer to the new buffer. */ +static void * +grow_buf(void *bp, int size) +{ + void *n; + + if ((n = realloc(bp, (u_int)size)) == NULL) + err(1, "realloc"); + bp = n; + 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. + */ +static void +add_arc(char *s1, char *s2) +{ + NODE *n1; + NODE *n2; + int bsize, i; + + n1 = get_node(s1); + + if (!strcmp(s1, s2)) + return; + + n2 = get_node(s2); + + /* + * Check if this arc is already here. + */ + for (i = 0; i < n1->n_narcs; i++) + if (n1->n_arcs[i] == n2) + return; + /* + * Add it. + */ + 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 = grow_buf(n1->n_arcs, bsize); + n1->n_arcsize = bsize / sizeof(*n1->n_arcs); + } + n1->n_arcs[n1->n_narcs++] = n2; + ++n2->n_refcnt; +} + +/* Find a node in the graph (insert if not found) and return a pointer to it. */ +static NODE * +get_node(char *name) +{ + DBT data, key; + NODE *n; + + if (db == NULL && + (db = dbopen(NULL, O_RDWR, 0, DB_HASH, NULL)) == NULL) + err(1, "db: %s", name); + + key.data = name; + key.size = strlen(name) + 1; + + switch ((*db->get)(db, &key, &data, 0)) { + case 0: + (void)memmove(&n, data.data, sizeof(n)); + return (n); + case 1: + break; + default: + case -1: + err(1, "db: %s", name); + } + + if ((n = malloc(sizeof(NODE) + key.size)) == NULL) + err(1, "malloc"); + + n->n_narcs = 0; + n->n_arcsize = 0; + n->n_arcs = NULL; + n->n_refcnt = 0; + n->n_flags = 0; + (void)memmove(n->n_name, name, key.size); + + /* 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. */ + data.data = &n; + data.size = sizeof(n); + if ((*db->put)(db, &key, &data, 0)) + err(1, "db: %s", name); + return (n); +} + + +/* + * Clear the NODEST flag from all nodes. + */ +static void +clear_cycle(void) +{ + NODE *n; + + for (n = graph; n != NULL; n = n->n_next) + n->n_flags &= ~NF_NODEST; +} + +/* do topological sort on graph */ +static void +tsort(void) +{ + NODE *n, *next; + int cnt, i; + + while (graph != NULL) { + /* + * 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 != NULL; n = next) { + next = n->n_next; + if (n->n_refcnt == 0) { + remove_node(n); + ++cnt; + } + } + } while (graph != NULL && cnt); + + if (graph == NULL) + 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 != NULL; n = n->n_next) + ++cnt; + cycle_buf = malloc((u_int)sizeof(NODE *) * cnt); + longest_cycle = malloc((u_int)sizeof(NODE *) * cnt); + if (cycle_buf == NULL || longest_cycle == NULL) + err(1, "malloc"); + } + for (n = graph; n != NULL; n = n->n_next) { + if (!(n->n_flags & NF_ACYCLIC)) { + if ((cnt = find_cycle(n, n, 0, 0)) != 0) { + if (!quiet) { + warnx("cycle in data"); + for (i = 0; i < cnt; i++) + warnx("%s", + longest_cycle[i]->n_name); + } + remove_node(n); + clear_cycle(); + break; + } else { + /* to avoid further checks */ + n->n_flags |= NF_ACYCLIC; + clear_cycle(); + } + } + } + if (n == NULL) + errx(1, "internal error -- could not find cycle"); + } +} + +/* print node and remove from graph (does not actually free node) */ +static 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. */ +static 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_NODEST|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(longest_cycle, cycle_buf, + longest_len * sizeof(NODE *)); + } + } else { + if ((*np)->n_flags & (NF_MARK|NF_ACYCLIC|NF_NODEST)) + continue; + len = find_cycle(*np, to, longest_len, depth + 1); + + if (debug) + (void)printf("%*s %s->%s %d\n", depth, "", + from->n_name, to->n_name, len); + + if (len == 0) + (*np)->n_flags |= NF_NODEST; + + if (len > longest_len) + longest_len = len; + + if (len > 0 && !longest) + break; + } + } + from->n_flags &= ~NF_MARK; + return (longest_len); +} + +static void +usage(void) +{ + (void)fprintf(stderr, "usage: tsort [-lq] [file]\n"); + exit(1); +}